**U.S. DEPARTMENT OF THE INTERIOR**

**U.S. GEOLOGICAL SURVEY**

**DOCUMENTATION FOR GEOGRAPHIC INFORMATION SYSTEMS (GIS) COMPILATION OF
GEOPHYSICAL, GEOLOGIC, AND TECTONIC DATA**

**FOR THE CIRCUM-NORTH PACIFIC**

***By* Mark L. Greninger\* and Simon L. Klemperer**

**(Department of Geophysics, Stanford University, Stanford, California
94305-2215), *and***

**Warren J. Nokleberg (U.S. Geological Survey, Menlo Park, California
94025)**

\*Now at: Anteon Corporation, PMD-10, 75 Hawthorne Street, San
Francisco, CA 94105

######## Warren J. Nokleberg *and* Michael F. Diggles, Editors

###### Open-File Report 99-422

###### Version 1.0

With Contributions From (listed alphabetically):

+-----------------------------------+-----------------------------------+
| Douglas S. Aitken (U.S.           | Boris Khlebnikov (Research        |
| Geological Survey, Menlo Park,    | Information Center, GlavNIC,      |
| California, USA)                  | Russian Ministry of Natural       |
|                                   | Resources, Moscow, Russia)        |
| Brian S. Bennett (U.S. Geological |                                   |
| Survey, Menlo Park, California,   | D. Paul Mathieux (U.S. Geological |
| USA)                              | Survey, Reston, Virginia, USA)    |
|                                   |                                   |
| Keri L. Brennan (Chapleau,        | James W. H. Monger (Geological    |
| Ontario, Canada)                  | Survey of Canada, Vancouver,      |
|                                   | Canada)                           |
| Ronald W. Buhmann (National       |                                   |
| Geophysical Data Center, NOAA,    | Boris A. Natalin (Russian Academy |
| Boulder, Colorado, USA)           | of Sciences, Khabarovsk, Russia)  |
|                                   |                                   |
| Stanislav G. Byalobzhesky         | Leonid M. Parfenov (Russian       |
| (Russian Academy of Sciences,     | Academy of Sciences, Yakutsk,     |
| Magadan, Russia)                  | Russia)                           |
|                                   |                                   |
| Steven P. Gordey (Geological      | Richard W. Saltus (U.S.           |
| Survey of Canada, Vancouver,      | Geological Survey, Denver,        |
| Canada)                           | Colorado, USA)                    |
|                                   |                                   |
| Roger A. Hansen (University of    | D.T. Sandwell (University of      |
| Alaska, Fairbanks)                | California San Diego, San Diego,  |
|                                   | California, USA)                  |
| Paul P. Hearn, Jr. (U.S.          |                                   |
| Geological Survey, Reston,        | Thomas Simkin (Smithsonian        |
| Virginia, USA)                    | Institution, Washington, DC       |
|                                   | 20560)                            |
| Thomas G. Hildenbrand (U.S.       |                                   |
| Geological Survey, Menlo Park,    | Gregory Ulmishek (U.S. Geological |
| California, USA)                  | Survey, Reston, Virginia, USA)    |
|                                   |                                   |
| Allen M. Hittelman (National      | Frederic H. Wilson (U.S.          |
| Geophysical Data Center, NOAA,    | Geological Survey, Anchorage,     |
| Boulder, Colorado, USA)           | Alaska, USA)                      |
|                                   |                                   |
| J. Murray Journeay (Geological    |                                   |
| Survey of Canada, Vancouver,      |                                   |
| Canada)                           |                                   |
|                                   |                                   |
| Alexander I. Khanchuk (Russian    |                                   |
| Academy of Sciences, Vladivostok, |                                   |
| Russia)                           |                                   |
+-----------------------------------+-----------------------------------+

# 

With Data Made Available By (listed alphabetically):

+-----------------------------------+-----------------------------------+
| Alaska Biological Science Center  | > National Ocean Service          |
|                                   | >                                 |
| Alaska Division of Oil and Gas    | > National Oceanic and            |
|                                   | > Atmospheric Administration      |
| Defense Mapping Agency            | > (NOAA)                          |
|                                   | >                                 |
| Eros Data Center                  | > Naval Research Laboratory (NRL) |
|                                   | >                                 |
| European Space Agency             | > Research Information Center     |
|                                   | > (GlavNIVC), Russian Ministry of |
| Exxon Production Research Company | > Natural Resources (RMNR)        |
|                                   | >                                 |
| Geological Society of America     | > Russian Academy of Sciences     |
| (GSA)                             | >                                 |
|                                   | > Scripps Institution of          |
| Geological Survey of Canada (GSC) | > Oceanography                    |
|                                   | >                                 |
| Geological Survey of Japan        | > Smithsonian Institution, Global |
|                                   | > Volcanism Program               |
| International Seismological       | >                                 |
| Centre (ISC)                      | > Society of Exploration          |
|                                   | > Geophysicists                   |
| Japan Oceanographic Data Center   | >                                 |
|                                   | > Stanford University             |
| Lamont-Doherty Earth Observatory  | >                                 |
|                                   | > United Nations Environment      |
| Ministry of Geology, U.S.S.R.     | > Programme/Global Resource       |
|                                   | > Information Database            |
| National Aeronautics and Space    | > (UNEP/GRID)                     |
| Administration (NASA)             | >                                 |
|                                   | > U.S. Agency for International   |
| National Earthquake Information   | > Development (USAID)             |
| Center (NEIC)                     | >                                 |
|                                   | > United States Geological Survey |
| National Geophysical Data Center  | > (USGS)                          |
| (NGDC)                            | >                                 |
|                                   | > University of Alaska, Fairbanks |
+-----------------------------------+-----------------------------------+

This report is preliminary and has not been reviewed for conformity with
U.S. Geological Survey

editorial standards or with the North American Stratigraphic Code. Any
use of trade, firm, or product names

is for descriptive purposes only and does not imply endorsement by the
U.S. Government.

**1999**

**ABSTRACT**

The accompanying CD-ROM contains a Geographic Information Systems (GIS)
compilation of geophysical, geological, and tectonic data for the
Circum-North Pacific. This area includes the Russian Far East, Alaska,
the Canadian Cordillera, linking continental shelves, and adjacent
oceans. This GIS compilation extends from 120°E to 115°W, and from 40°N
to 80°N. This area encompasses: (1) to the south, the modern Pacific
plate boundary of the Japan-Kuril and Aleutian subduction zones, the
Queen Charlotte transform fault, and the Cascadia subduction zone; (2)
to the north, the continent-ocean transition from the Eurasian and North
American continents to the Arctic Ocean; (3) to the west, the diffuse
Eurasian-North American plate boundary, including the probable Okhotsk
plate; and (4) to the east, the Alaskan-Canadian Cordilleran fold belt.
This compilation should be useful for: (1) studying the Mesozoic and
Cenozoic collisional and accretionary tectonics that assembled this
continental crust of this region; (2) studying the neotectonics of
active and passive plate margins in this region; and (3) constructing
and interpreting geophysical, geologic, and tectonic models of the
region.

Geographic Information Systems (GIS) programs provide powerful tools for
managing and analyzing spatial databases. Geological applications
include regional tectonics, geophysics, mineral and petroleum
exploration, resource management, and land-use planning. This CD-ROM
contains thematic layers of spatial data-sets for geology, gravity
field, magnetic field, oceanic plates, overlap assemblages, seismology
(earthquakes), tectonostratigraphic terranes, topography, and volcanoes.
The GIS compilation can be viewed, manipulated, and plotted with
commercial software (ArcView and ARC/INFO) or through a freeware program
(ArcExplorer) that is included on this CD-ROM, or can be downloaded from
the internet/Web at http://www.esri.com for both Unix and Windows
computers. This report is for sale by U.S. Geological Survey,
Information Services, ESIC Open-File Reports, PO Box 25286, Denver, CO
80225 (Telephone: 303-202-4210).

**INTRODUCTION**

In order to facilitate geological understanding of a tectonically
complex region this Geographical Information Systems (GIS) compilation
of the Circum-North Pacific is presented on the companion CD-ROM.
Geologically and politically, the Circum-North Pacific is a complex
region that is partially marine, straddles the Russia/U.S.A./Canada
political boundaries, crosses the International Dateline and 180°
longitude, and includes a major part of the Arctic. This GIS compilation
contains thematic layers of spatial data-sets for geology, gravity
field, magnetic field, oceanic plates, overlap assemblages, seismology
(earthquakes), tectonostratigraphic terranes, topography, and volcanoes.

Several problems exist in studying the earth science of this region. (1)
The political boundaries of many geologic maps disguises the fact that a
large part of the North American plate is in Russia. As examples, the
current geological map of Alaska shows Russia as a white outline; the
converse occurs for the geological map of Russia. (2) Traditional
geological tools permits mapping land areas but not marine areas. As a
result, the geology of the vast area of the submerged Bering and Chukchi
continental shelves, extending over 500 km offshore between mainland
Alaska and Chukotka (Russian Northeast), is even less well known than
Siberia, even though the coastline over much of this region is an
accidental manifestation of modern-day sea-level rather than a
fundamental geological boundary. (3) For high latitudes, the most common
map projection (Mercator) introduces large distortion. To solve this
problem, Polar and Lambert projections are often used, creating the
necessary but difficult task of transforming data between projections.
And (4) many digital data-sets are stored from 180°W (-180°) to 180°E
(+180°) and many querying routines do not allow access of data-sets
straddling the 180° longitude. To address these four difficulties -
political boundaries, coastlines, variable projections, and an arbitrary
longitude reference system - a GIS compilation (initially presented by
Greninger and others, 1996, 1999) is herein presented to advance crustal
studies of the Bering and Chukchi Seas, and adjacent onshore areas of
Alaska and Chukotka. The centerpiece of these studies was two month-long
geophysical cruises in 1994 that collected the first deep seismic
reflection transects across this region. In offshore areas,
interpretation of reflection data requires considerable input from
onshore geology and regional potential field data which are not always
readily available. To assist the studies of adjacent regions, the GIS
compilation is extended to include the entire Circum-North Pacific area
from 120°E to 115°W and from 40°N to 80°N. This area coincides with that
of a previously published terrane and overlap assemblage map of the
Circum-North Pacific (Nokleberg and others, 1994b).

This GIS compilation includes digital datasets which will assist
geological and geophysical research in the fields of: geology, gravity
field, magnetic field, oceanic plates, overlap assemblages, seismology
(earthquakes), tectonics, tectonostratigraphic terranes, topography,
volcanoes, environmental studies, resource management, and land-use
planning. A huge amount of GIS data exists for the Circum-North Pacific.
As a result, important data was chosen for publication on this single
CD-ROM. Although this GIS study is a compilation and not a synthesis,
three sample views are included of the datasets in order to illustrate
the type and quality of data available, and some different ways in which
data may be combined by utilizing the ability of GIS software to permit
spatial queries. The data can be interactively analyzed, viewed, and
printed using ArcView, ARC/INFO, ArcExplorer, or other GIS programs. The
explanations for the digital cartographic data and companion datasets
are provided in several formats. The many individuals and organizations
who have contributed data and assistance in preparing that data at
listed as contributors.

**METHOD OF GIS COMPILATION**

The digital data consist of vector, raster, and point data. (1) Vector
data (e.g. the geographic base map) have a location precision that
depends upon the scale of the original map and the density of the
digitization points. Because of the large area covered, no datasets or
maps originally compiled at scales greater than 1:250,000, and some
datasets compiled at scales as small as 1:10,000,000, are included. (2)
Raster data (gridded data) have a resolution that depends upon the grid
spacing and cell size. Our raster datasets range from less than 1 km to
greater than 5  km spacing. And (3) point data (e.g. trackline shot
locations or earthquake epicenter locations) are only limited by their
location precision. All datasets are recorded in the Lambert azimuthal
projection with a center of projection at 165°W, 70°N as originally
utilized for the terrane and overlap assemblage map of the Circum-North
Pacific (Nokleberg and others, 1994b) that forms the principal geologic
base this GIS compilation. It is common for digital data releases to be
prepared as unprojected data, i.e., as data referenced to a geographic
(latitude/longitude) co-ordinate system, with no assigned map
projection. In contrast, all datasets in this GIS compilation are
projected to a single chosen map projection in order to avoid problems
associated with datasets that straddle the longitude of 180°E/180°W.

This GIS compilation is also designed to be accessible to customers who
lack proprietary GIS software and who will be using the freeware
ArcExplorer GIS program provided on this CD-ROM. If unprojected,
ArcExplorer would display the spatial datasets centered on the
Greenwich, or zero meridian, split into separate far western and far
eastern sections. Advanced users, i.e. those using programs such ArcView
or ARC/INFO, have the option and ability to unproject and reproject the
spatial data to a chosen projection. This procedure may lead to some
loss of precision (due to a data conversion within ESRI software from
double-precision to single-precision coordinates) but this loss of
precision is not significant for datasets at scales of 1 million and
smaller. The geological or geophysical potential-field datasets on this
CD-ROM are not intended for use at scales larger than 1:1 million.

All cartographic datasets for this GIS compilation are in ARC/INFO
coverage or GRID format. Various text files, including explanatory
README files, this detailed explanation and reference list, and detailed
explanations to the terrane and overlap assemblage map of the
Circum-North Pacific, are available in text (\*\*\*.txt), Word 6
(\*\*\*.doc), and Adobe Acrobat PDF formats. In addition, a suite of 178
stratigraphic columns for the terrane and overlap assemblage map of
Circum-North Pacific are included in Adobe Acrobat format. The digital
cartographic data for this compilation were compiled with ARC/INFO 7.0.3
on a Sun Microsystems SPARC Station 20 computer running with Solaris
OpenWindows version 5.4 (Sun OS 2.4).

The map-making software most commonly used by academic geophysicists is
probably Generic Mapping Tools (GMT) (Wessel and Smith, 1995) and the
newer Interactive Generic Mapping Tools (iGMT) (Becker and Braun, 1998).
Both programs are free software packages for Unix computers. GMT is
widely used to create images of superimposed point datasets (e.g.
hypocenters) and raster datasets (e.g. topography). GMT has been used to
create many of the datasets compiled for this study (e.g., ETOPO5,
GTOPO30, satellite-derived free-air gravity). Despite the widespread use
of GMT and iGMT, the ESRI ARC/INFO and ArcView programs are used for
this GIS compilation for three reasons. (1) These programs permit
database queries that are not available in GMT and iGMT. (2) Use of
ARC/INFO and ArcView will hopefully encourage new, innovative ways of
working with multiple geophysical and geological datasets such as
geologic maps of the Russian Far East, Alaska, and the Canadian
Cordillera. And (3) because ESRI software is available for both Windows
and Unix computers, a greater opportunity exists for scientists in the
former Soviet Union to have access to this GIS compilation.

Users of this publication should note that this CD-ROM consists of two
separate products: (1) a compilation of datasets in ARC/INFO format; and
(2) two collection of displays (views) of combinations of these datasets
in ArcView and ArcExplorer projects. The datasets in the ARC/INFO format
are available to any GIS user for further manipulation and analysis. The
ArcView or ArcExplorer projects can be used as displays for
interpretation without any additional GIS manipulation of
interpretation. Users of this publication should also note that it is
beyond the scope of this publication to provide a GIS tutorial. Training
is available online, for example through ESRI at the internet address of
http://campus.esri.com/campus/catalog/courses.cfm, or in readily
available textbooks (e.g. ESRI, 1997; Hutchinson and Daniel, 1997).

# ARC/INFO

ARC/INFO is a full-featured GIS software program sold by Environmental
Systems Research Institute, Inc. (ESRI), and is generally used on
Unix-based servers and workstations and for Windows NT. A separate
software package, PC ARC/INFO, is available for Windows (3.x, 95, 98,
and NT), as well as DOS. For this GIS compilation, the data are in
ARC/INFO 7.1.2, utilizing both coverage and GRID formats. ARC/INFO can
be utilized to view and manipulate the data sets on the CD-ROM exactly
as compiled.

# ArcView

ArcView (version 3.1) is a desktop GIS software program sold by
Environmental Systems Research Institute, Inc. (ESRI). Although ArcView
does not have all the features of ARC/INFO, it is easier to learn; and
some recent ArcView extensions (e.g. 3D Analyst) are not available in
ARC/INFO 7.1.2. ArcView 3.1 runs on Unix- computers and on Windows
computers (3.x, 95, 98, or NT).

# ArcExplorer

ArcExplorer is a freeware GIS-viewing program created by and available
from Environmental Systems Research Institute, Inc. (ESRI). The
directory */norpac/setup/arcexplo* contains installers for ArcExplorer
1.1 for Windows 95/98/NT. NT machines must have Service Pack 3
installed. In addition to viewing GIS data in ARC/INFO, ArcView, and
other digital formats, ArcExplorer permits GIS data queries. ArcExplorer
is currently only available for Windows computers (95, 98, or NT 4.0).
ArcExplorer can access the GIS data contained in ARC/INFO 7.1.2
coverages on this CD-ROM. But because ArcExplorer can not display
gridded datasets, images of these datasets are created as *\*\*\*.bil*
files which are displayed for the following datasets: (1) three raster
topographic datasets (*/norpac/data/topogrfy/raster/etopo5*, */gtopo2*
and */gtopo30);* (2) three gravity datasets
(*/norpac/data/gravity/dgrav*, */geosat* and */sea-surf*); and (3) five
magnetic datasets (*/norpac/data/magnetic/ak_mag*, */arct_mag*,
*/asia_mag*, */dnag_mag* and */russ_mag*). Please refer to the section
below on "Contents and Description of /norpac/data".

SYSTEM REQUIREMENTS

The data and text on this CD-ROM require a computer and software able to
read ESRI (Environmental Systems Research Institute) data formats.
Appropriate software packages include ARC/INFO version 7.1.2 or higher,
ArcView 3.1 or higher, and ArcExplorer. Full system requirements for
each software package can be found at the internet (Web) homepage for
ESRI, http://www.esri.com. In order to run ArcView 3.1, a Windows
computer is required with a Pentium processor with 24 Mb of RAM (32 Mb
recommended). A Pentium-II processor with a speed ≥ 200 MHz is
recommended for handling the large data files. All systems require a
color monitor that can display 256 colors. This CD-ROM was produced in
accordance with the ISO 9660 and Macintosh HFS standards. All ASCII text
on this CD-ROM file can be accessed from DOS, Windows, Macintosh, and
Unix computers.

USE OF GIS COMPILATION ON UNIX, MACINTOSH, AND DOS/WINDOWS COMPUTERS

Depending on system configuration and user needs, the data can be viewed
directly from the CD-ROM, or the data can be downloaded onto a computer
hard drive for viewing, manipulation, and plotting.

**Unix**

To mount this CD-ROM on a Unix-based computer, become the root user,
then: *% su* - (not necessary for a Silicon Graphics workstation).

If a */cdrom* directory does not exist, create one:

*\# cd/*

*#mkdir cdrom*

Use the command appropriate to the UnixTM host:

DG AViiON: *mount -o noversion,ro -t cdrom /\<dev\> /cdrom*

DEC ALPHA: *mount -t cdfs -r -o nodefperm,noversion /\<dev\> /cdrom*

DECstation: *mount -t cdfs -r -o nodefperfm /\<dev\> /cdrom*

HP 700/8x7: *mount -rt cdfs /\<dev\> /cdrom* (or use *sam*)

IBM RS/6000: *mount -v \'cdrfs\' -p\' \' -r\' \' /\<dev\> /cdrom* (or
use *smit*)

Silicon Graphics: *mount -o setx -t iso9660 /dev/ssi/\<dev\> /cdrom*

Sun Solaris 1.x: *mount -rt hsfs /\<dev\> /cdrom*

Sun Solaris 2.3: Use volume management software to mount and access the
CD-ROM. Sun Workstations running the Common Desktop Environment will
auto-mount the CD-ROM.

Macintosh

ArcView 3.1 and ArcExplorer are not available for the Macintosh
computer. The document, Adobe Acrobat PDF, and readme files can be view,
manipulated, and printed with a Macintosh computer. ArcView 3.0 for
Macintosh can be used to create new ArcView project files. ArcView 3.0
for Macintosh can be used to create new ArcView project files.

DOS/Windows

To mount this CD-ROM on a DOS/Windows-based computer, insert the CD-ROM
into a drive, and open the CD-ROM window. Follow the below instructions
in the next section.

OPENING THE DATA SETS AND EXAMPLES OF GIS COMPILATION

In the directory /*norpac/setup*, two ArcView projects (*norpac1.apr*,
*norpac2.apr*) and one ArcExplorer project (*norpac.aep*) are provided
to give users easy access to data on the CD-ROM. *norpac1.apr* requires
that Spatial Analyst, an ArcView Extension which allows advanced
manipulation and analysis of raster or point data (such as aeromagnetic,
gravity, and earthquake data) compiled in ARC/INFO GRID format, be
installed as well as ArcView 3.1. Use of *norpac2.apr* is designed for
ArcView users who do not also have Spatial Analyst. Use of the
ArcExplorer 1.1 file, norpac.aep, requires installation of the
ArcExplorer program that is provided on the CD-ROM.

Use of GIS Compilation with ArcView 3.1

If ArcView 3.1 or higher is installed on your computer:

1\. Place the CD-ROM in the CD Drive. Open the CD-ROM window.

2\. Find the ArcView project *setup.apr* located in the directory
*/norpac/setup*.

3\. Open the ArcView project by clicking on *setup.apr*, either from a
file manager or from within ArcView.

4\. ArcView should start with a small window with the title, "Cannot
find the NorPac Data" followed by the sentence, "Enter the location of
the NorPac Data". In the white box, replace "Drive Name" with the drive
name and directory, "N:/norpac/" where "N" is the letter or name of the
CD or hard drive. Next click "OK". A new window will appear with the
title, "Found Spatial Analyst!" followed by the sentence, "Select a
Project to load:" In the white box, select either "Norpac1.apr (Spatial
Analyst)", if your computer has both ArcView 3.1 and Spatial Analyst
installed, or select "Norpac2.apr (non-Spatial Analyst)", if your
computer has only ArcView 3.1 installed. The selected ArcView project
should load automatically. (Please note that if Spatial Analyst is not
installed, Norpac2.apr will automatically load.) A window will appear
with the title norpac1.apr or norpac2.apr, depending on the preceding
selection. In the white box on the left side of the window will be a
list of views that can be opened, viewed, manipulated, or printed within
ArcView. Each view is a digital map of part of the GIS compilation. Each
view has one or more themes (layers) that can be selected (made visible)
or deselected (made invisible).

The views are:

Active Earth Example

Magnetic -- Lithologic Correlation Example

Topographic Example

Cultural Features

Geology - Alaska

Geology -- Russia

Gravity -- DGRAV

Gravity -- Geosat

Gravity -- Seasurface

Magnetics -- Alaska

Magnetics -- Arctic

Magnetics - DNAG

Magnetics -- East Asia

Magnetics -- Russia

Reflection Profile Tracklines

Seismicity

Terranes -- Alaska

Terranes -- Canadian Cordillera

Terranes -- Circum-North Pacific

Topography -- Raster

Topography -- Vector

Volcanoes -- Active

A more detailed description of the views in given in the below section
on Description of Views. Please note that if new themes and views are
added to either *norpac1.apr* or to *norpac2.apr* and the ArcView
project is saved, the ArcView project file needs to be edited before
subsequent use of *setup.a*pr. Using a text editor such as WordPad, the
path name *N:/norpac*/ (where N is the designator of the CD drive) in
either *norpac1.apr* or *norpac2.apr* (as appropriate) will need to be
replaced by *\$norpac/.*

Use of GIS Compilation with ArcExplorer 1.1

If ArcExplorer 1.1 is installed on your computer:

1\. Place the CD-ROM in the CD Drive. Open the CD-ROM window.

2\. Find the ArcView project "*norpac.aep"* located in the directory
*/norpac/setup*.

3\. Copy the ArcExplorer project, "*norpac.aep"* into a directory on
your hard drive. Deselect the Read-only box for the properties of this
file. In order to accomplish this on a Windows computer, right-click on
the file name and select "Properties".

4\. Open the *norpac.aep* file in a word processor program, such as
WordPad. Substitute the text string, *D:\\norpac\\* with *N:\\norpac\\*
where "N" is the letter or name of the CD drive. Save the file as a text
file with a new file name. Please note that a back slash ("\\") is used
in the substitution**.**

5\. Start the ArcExplorer project by clicking on the new file name. The
ArcExplorer project will start. In the gray box on the left side will be
a list of pre-selected themes that can be opened (by selecting), viewed,
and printed. Each theme is one part of the GIS compilation. Other themes
can be added from the GIS compilation by referring to the below data
descriptions. The themes consist of the basic ARC/INFO files contained
in the GIS compilation. The theme names and their "translated" names
are:

  --------------------- -------------------------------------------------
  **THEME NAME**        **"TRANSLATED NAME"**

  **Circum-North        
  Pacific Terrane and   
  Overlap Assemblage    
  Map**                 

  basins.aat            Mesozoic and Cenozoic basins for Circum-North
                        Pacific terrane and overlap assemblage map

  coast.aat             Coastline for Circum-North Pacific terrane and
                        overlap assemblage map

  flts_lnd.aat          Onshore (land) faults for Circum-North Pacific
                        terrane and overlap assemblage map

  flts_ocn.aat          Offshore faults for Circum-North Pacific terrane
                        and overlap assemblage map

  flts_pos.aat          Post-accretionary faults, onshore and offshore,
                        for Circum-North Pacific terrane and overlap
                        assemblage map

  mag_lins.aat          Magnetic lineaments for Circum-North Pacific
                        terrane and overlap assemblage map

  nor_pac.pat           Topography for Circum-North Pacific terrane and
                        overlap assemblage map

  ocn_geol.aat          Oceanic geology for Circum-North Pacific terrane
                        and overlap assemblage map

  rivers.aat            River drainages from Circum-North Pacific terrane
                        and overlap assemblage map

  terr_lnd.pat1         Onshore terranes for Circum-North Pacific terrane
                        and overlap assemblage map

  terr_ocn.pat          Offshore terranes for Circum-North Pacific
                        terrane and overlap assemblage map

  sea_mnts.pat          Seamounts for Circum-North Pacific terrane and
                        overlap assemblage map

  **Geologic Map of     
  Russian Far East**    

  rus_flts.aat          Faults for geologic map of Russia

  rus_geol.pat          Geologic units of Russian Far East

  rus_geol.patimpac     Impactite areas for geologic map of Russia

  **Terrane and         
  Geologic Maps of      
  Alaska and Canadian   
  Cordillera**          

  ak_geol.pat           Geologic map of Alaska

  assemblg.pat          Terrane and tectonic-assemblage maps of the
                        Canadian Cordillera

  terr_lnd.pat          Detailed terrane map of Alaska at 1:2.5 M scale

  **Gravity and         
  Magnetic Maps**       

  ak_mag (image)        Magnetic map of Alaska (mainly onshore)

  arct_mag (image)      Magnetic map of the Arctic (mainly offshore).

  asia_mag (image)      Magnetic map of Far East Asia

  dgrav (image)         Onshore Bouguer gravity anomalies and offshore
                        free-air gravity anomalies for Alaska and
                        adjacent offshore area

  dnag_mag (image)      Magnetic map of North America, onshore and
                        offshore

  geosat (image)        Satellite-derived free-air gravity for offshore
                        areas only.

  russ_mag (image)      Magnetic map of Russia

  sea_surf (image)      Satellite-derived sea-surface heights

  **Seismicity**        

  ak_seis.pat           Seismicity for Alaska, 1888-1998

  isc_cat.pat           Global seismicity, 1964-1991
  --------------------- -------------------------------------------------

  --------------------- -------------------------------------------------
  **Topography and      
  Bathymetry**          

  ak_shelf.pat          Bathymetry for US waters shallower than 200 m,
                        Beaufort Sea to the Aleutians

  ber_chuk.pat          Bathymetry for Chukchi Sea and Bering Straits, US
                        and Russian waters

  chukchi.pat           Bathymetry for Chukchi Sea

  etopo5 (image)        5'-sampled land topography and marine bathymetry.

  gtopo2 (image)        2'-sampled land topography and marine bathymetry
                        (only available to 70°N)

  gtopo30 (image)       30"-sampled topography (land only)

  **Cultural Features** 

  boundary.pat          International boundaries for Circum-North Pacific

  cities.pat            Major cities for Circum-North Pacific

  features.pat          Cultural features for Circum-North Pacific

  latlong5.aat          Latitude and longitude grid at 5 degree spacing
                        for Circum-North Pacific

  latlon12.pat          Latitude and longitude grid at 12° spacing for
                        Circum-North Pacific

  **Tracklines**        

  ew94_09.pat           Ship trackline for geophysical cruise EW94-09

  ew94_10.pat           Ship trackline for geophysical cruise EW94-10
  --------------------- -------------------------------------------------

Please note that for the geologic and terrane maps, unique colors can be
added to polygons (units) and lines (faults or contacts), and map unit
abbreviations can be displayed. (Please refer to the ArcExplorer
documentation included on the CD.)

PORTABLE DOCUMENT FORMAT (PDF) FILES

This publication makes use of Adobe Acrobat PDF files that are viewed
with Adobe Acrobat Reader (versions 3.01 and 4.0 provided on this CD-ROM
in the */norpac/setup/Acrobat* folder). To make best use of this CD-ROM,
you will need to develop some familiarity with Acrobat Reader; an
on-line guide is available within Acrobat Reader under \"Help.\" The
Acrobat directory contains installers for Adobe Acrobat Reader 3.01
(ACROBAT3 subdirectory) and 4.0 (ACROBAT4 subdirectory) for both 32-bit
Windows (PC directories) and Macintosh (MAC directories). Acrobat 3.01
will run on the minimum system requirements for this disc given above.
To use Acrobat Reader 4.0 under Windows, you need an 80486 or Pentium
processor-based personal computer, Microsoft Windows 95, Windows 98, or
Windows NT 4.0 with Service Pack 3 or later, 8 MB of RAM on Windows 95
and Windows 98 (16 MB recommended), or 16 MB of RAM on Windows NT (24 MB
recommended). To use Acrobat Reader 4.0 on a Macintosh, you need a Power
Macintosh computer. This CD-ROM contains a full-text index (index.pdx
and associated files in the \"index\" directory) that is for use in
searching the PDF files for words or sets of words, using the search
tool in Acrobat Reader. You can use the installers provided on this disc
or download the latest version of Adobe Acrobat Reader free via the
World Wide Web from the Adobe homepage at http://www.adobe.com/.

DIRECTORY ORGANIZATION

The */norpac* directory of this CD-ROM contains four directories,
*/data*, */readme*, and */setup* plus the */index* directory used for
Acrobat Search. In all tables, directories, sub-directories and
filenames are listed alphabetically. Please note, however, that the
ArcView windows with the available views for the projects *norpac#.apr*
are listed alphabetically by "theme name", as listed in the contents of
*/data*.

+-------+--------------------------------------------------------------+
| **D   | **Description of Files**                                     |
| irect |                                                              |
| ory** |                                                              |
+-------+--------------------------------------------------------------+
| data  | GIS data in ARC/INFO 7.1.2 coverage and GRID formats.        |
|       |                                                              |
|       | Data directories are organized by data type in the following |
|       | sub-directories: cultural; geology; gravity; magnetic;       |
|       | seismcty; shiptrax; terranes; topogrfy; and volcano. Each of |
|       | these contains a sub-directory for each dataset which in     |
|       | turn contains all necessary files for use of the data with   |
|       | ESRI Arc software. All the vector datasets are presented as  |
|       | ARC/INFO coverages accessible by ArcView and ARC/INFO.       |
|       | Because ARC/INFO GRID format files are not accessible by     |
|       | ArcExplorer, these datasets are represented as \*\*\*.bil    |
|       | images which can be opened in ArcExplorer. Sub-directories   |
|       | within geology and terranes also contain explanatory texts   |
|       | and figures, in \*\*\*.txt, \*\*\*.doc, and \*\*\*.pdf       |
|       | formats, within sub-sub-directories called /explanat. All    |
|       | data directories act as ARC/INFO work spaces and include an  |
|       | ARC/INFO files.                                              |
|       |                                                              |
|       | Two additional sub-directories exist. The directory          |
|       | /norpac/data/examples contains shape files for new coverages |
|       | created from this CD-ROM that are used to produce example    |
|       | views of data compilations. The directory                    |
|       | /norpac/data/legends contains suggested color tables and     |
|       | legends for different data-sets. The directories /examples   |
|       | and /legends are not ARC/INFO work-spaces and have no        |
|       | ARC/INFO files.                                              |
+-------+--------------------------------------------------------------+
| *re   | Information files for this CD-ROM in multiple file formats,  |
| adme* | text (*\*\*\*.txt*), Word (*\*\*\*.doc*), Rich-Text Format   |
|       | *(\*\*\*.rtf*), and portable document format (*\*\*\*.pdf*). |
|       | (*\*\*\*.pdf* files can be read with Adobe Acrobat Reader    |
|       | 4.0, freeware contained in */norpac/setup/Acrobat*)          |
|       |                                                              |
|       | *readme.\*\*\** contains brief ASCII information about this  |
|       | CD-ROM.                                                      |
|       |                                                              |
|       | *document.\*\*\** (this file) contains full documentation    |
|       | for all data-sets on this CD-ROM.                            |
|       |                                                              |
|       | Subdirectory *cpyright* contains copyright notices           |
|       | associated with multiple-generation data.                    |
+-------+--------------------------------------------------------------+
| setup | Installation files for ArcExplorer, the freeware software    |
|       | for users of this CD-ROM who lack access to the proprietary  |
|       | ArcView and ARC/INFO GIS software. The files are contained   |
|       | in the sub-directory /norpac/setup/explorer. Files for       |
|       | Acrobat, freeware text-viewing software for PDF files are    |
|       | contained in the sub-directory /norpac/setup/Acrobat.        |
|       |                                                              |
|       | Project files for use with ArcView (norpac1.apr for users    |
|       | with the extension Spatial Analyst installed; and            |
|       | norpac2.apr for those without and for use with ArcExplorer   |
|       | (norpac.aep).                                                |
+-------+--------------------------------------------------------------+

CONTENTS AND DESCRIPTION OF */norpac/setup*

The directory */norpac/setup* contains sub-directories /*explorer* and
/*Acrobat*, which hold the freeware programs ArcExplorer and Adobe
Acrobat, respectively.

The directory */norpac/setup/Acrobat* contains installers for Adobe
Acrobat Reader 3.01 and 4.0 for both Windows 95/98/NT and Macintosh. The
latest version of Adobe Acrobat Reader can also be downloaded free via
the Internet from the Adobe homepage on the World Wide Web at
http://www.adobe.com.

The directory */norpac/setup* also contains the files *norpac.aep*,
*norpac1.apr* and *norpac2.apr*. The *\*\*\*.aep* and *\*\*\*.apr* files
are project files for ArcExplorer and ArcView, respectively. If either
ArcView and/or ArcExplorer are installed, the *\*\*\*.apr* and
*\*\*\*.aep* files can be loaded from within these programs, using the
instructions given in the above section on "OPENING THE DATASETS..." to
display preset examples of the data. In general, users need not modify
these files, but will rather wish to create new project files for
individual needs.

SUMMARY CONTENTS OF */norpac/data*

+------+------+-------+---------------+-----------------------+-----+
| **   | **   | **Fil | **Theme name  | **Brief description   | **L |
| Data | Sub- | ename | used in views | of data**             | aye |
| dir  | dire | (dat  | presented in  |                       | r** |
| ecto | c-to | a-set | projects      |                       |     |
| ry** | ry** | name) | *norpac1.apr* |                       | **  |
|      |      | in    | &             |                       | siz |
|      |      | GIS** | *n            |                       | e** |
|      |      |       | orpac2.apr*** |                       |     |
|      |      |       |               |                       | **  |
|      |      |       |               |                       | (Mb |
|      |      |       |               |                       | )** |
+------+------+-------+---------------+-----------------------+-----+
| *c   |      | *boun | Intern        | International,        | 1   |
| ultu |      | dary* | ational/state | provincial and state  |     |
| ral* |      |       | boundaries    | boundaries            |     |
+------+------+-------+---------------+-----------------------+-----+
|      |      | *ci   | Cities        | Significant           | 0.6 |
|      |      | ties* |               | population centers    |     |
+------+------+-------+---------------+-----------------------+-----+
|      |      | *feat | Manmade       | Other socio-cultural  | 1.6 |
|      |      | ures* | features      | features, such as     |     |
|      |      |       |               | airports amd          |     |
|      |      |       |               | golf-courses          |     |
+------+------+-------+---------------+-----------------------+-----+
|      |      | *latl | Latit         | Latitude and          | \<  |
|      |      | ong5* | ude/longitude | longitude grid at 5°  | 0.1 |
|      |      |       | grid (5°)     | spacing               |     |
+------+------+-------+---------------+-----------------------+-----+
|      |      | *latl | Latit         | Latitude and          | \<  |
|      |      | on12* | ude/longitude | longitude grid at 12° | 0.3 |
|      |      |       | grid (12°)    | spacing               |     |
+------+------+-------+---------------+-----------------------+-----+
| *e   |      |       |               | Shape files used in   | 37  |
| xamp |      |       |               | constructing the      |     |
| les* |      |       |               | example views.        |     |
|      |      |       |               | "Active Earth and     |     |
|      |      |       |               | Magnetic-Lithologic   |     |
|      |      |       |               | correlation,          |     |
|      |      |       |               | examples" discussed   |     |
|      |      |       |               | in text               |     |
+------+------+-------+---------------+-----------------------+-----+
| *    |      | *ak_  | Geologic map  | Geologic map of       | 8   |
| geol |      | geol* | of Alaska     | Alaska                |     |
| ogy* |      |       |               |                       |     |
+------+------+-------+---------------+-----------------------+-----+
|      |      | *rus_ | Fault map of  | Fault map of Russia   | 1   |
|      |      | flts* | Russia        |                       |     |
+------+------+-------+---------------+-----------------------+-----+
|      |      | *rus_ | Geologic map  | Geologic map of       | 26  |
|      |      | geol* | of Russia     | Russia                |     |
+------+------+-------+---------------+-----------------------+-----+
| *    |      | *d    | Onshore       | Onshore Bouguer       | \<  |
| grav |      | grav* | Bouguer and   | gravity anomalies and | 0.3 |
| ity* |      |       | offshore      | offshore free-air     |     |
|      |      |       | free-air      | gravity anomalies.    |     |
|      |      |       | gravity       | Blank areas in        |     |
|      |      |       | (mGal)        | regions offshore      |     |
|      |      |       |               | Southwestern Alaska,  |     |
|      |      |       |               | in interior Alaska,   |     |
|      |      |       |               | and in Canadian       |     |
|      |      |       |               | Cordillera have not   |     |
|      |      |       |               | data.  Note that      |     |
|      |      |       |               | *dgrav.bil* has been  |     |
|      |      |       |               | created               |     |
+------+------+-------+---------------+-----------------------+-----+
|      |      | *ge   | Satellite     | Satellite-derived     | 6   |
|      |      | osat* | free-air      | free-air gravity,     |     |
|      |      |       | gravity       | offshore areas only.  |     |
|      |      |       | (mGal)        |  Note that            |     |
|      |      |       |               | *geosat.bil* has been |     |
|      |      |       |               | created.              |     |
+------+------+-------+---------------+-----------------------+-----+
|      |      | sea   | Satellite     | Satellite-derived     | 1   |
|      |      | _surf | sea-surface   | sea-surface heights.  |     |
|      |      |       | height (m)    |  Note that            |     |
|      |      |       |               | *sea_surf.bil* has    |     |
|      |      |       |               | been created.         |     |
+------+------+-------+---------------+-----------------------+-----+
| leg  |      |       |               | Contains suggested    | 1   |
| ends |      |       |               | color-bars and        |     |
|      |      |       |               | contour information   |     |
|      |      |       |               | for each data-set as  |     |
|      |      |       |               | \*\*\*.avl files;     |     |
|      |      |       |               | automatically         |     |
|      |      |       |               | accessed by ArcView   |     |
|      |      |       |               | as needed; contains   |     |
|      |      |       |               | sub-directories for   |     |
|      |      |       |               | each of the other     |     |
|      |      |       |               | sub-directories to    |     |
|      |      |       |               | /norpac/data \[i.e.   |     |
|      |      |       |               | cultural, geology,    |     |
|      |      |       |               | gravity, etc.\]       |     |
+------+------+-------+---------------+-----------------------+-----+

+------+------+-------+---------------+-----------------------+-----+
| magn |      | a     | Magnetic map  | Magnetic map of       | 2   |
| etic |      | k_mag | of Alaska     | Alaska (mainly        |     |
|      |      |       | (nT)          | onshore)  Note that   |     |
|      |      |       |               | ak_mag.bil has been   |     |
|      |      |       |               | created               |     |
+------+------+-------+---------------+-----------------------+-----+
|      |      | *arct | Magnetic map  | Magnetic map of the   | \<  |
|      |      | _mag* | of the Arctic | Arctic (largely       | 0.2 |
|      |      |       | (nT)          | offshore).  Note that |     |
|      |      |       |               | *arct_mag.bil* has    |     |
|      |      |       |               | been created          |     |
+------+------+-------+---------------+-----------------------+-----+
|      |      | *asia | Magnetic map  | Magnetic map of Far   | 2   |
|      |      | _mag* | of Far East   | East Asia.  Note that |     |
|      |      |       | Asia (nT)     | *asia_mag* has been   |     |
|      |      |       |               | created               |     |
+------+------+-------+---------------+-----------------------+-----+
|      |      | *dnag | Magnetic map  | Magnetic map of North | 44  |
|      |      | _mag* | of North      | America, onshore and  |     |
|      |      |       | America (nT)  | offshore.  Note that  |     |
|      |      |       |               | *dnag_mag.bil* has    |     |
|      |      |       |               | been created          |     |
+------+------+-------+---------------+-----------------------+-----+
|      |      | *russ | Magnetic map  | Magnetic map of       | 1   |
|      |      | _mag* | of Russia     | Russia.  Note that    |     |
|      |      |       | (nT)          | *russ_mag.bil* has    |     |
|      |      |       |               | been created          |     |
+------+------+-------+---------------+-----------------------+-----+
| *s   |      | *isc  | Global        | Catalog of global     | 5   |
| eism |      | _cat* | seismicity,   | seismicity, 1964-1991 |     |
| cty* |      |       | 1964-1991     |                       | 7   |
|      |      | *ak_  |               | Alaska State          |     |
|      |      | seis* | Alaskan       | Seismicity, 1898-1998 |     |
|      |      |       | seismicity,   |                       |     |
|      |      |       | 1898-1998     |                       |     |
+------+------+-------+---------------+-----------------------+-----+
| ship |      | ew    | Ship          | Ship trackline for    | \<  |
| trax |      | 94_09 | trackline,    | geophysical cruise    | 0.5 |
|      |      |       | EW94-09       | EW94-09               |     |
+------+------+-------+---------------+-----------------------+-----+
|      |      | ew    | Ship          | Ship trackline for    | \<  |
|      |      | 94_10 | trackline,    | geophysical cruise    | 0.5 |
|      |      |       | EW94-10       | EW94-10               |     |
+------+------+-------+---------------+-----------------------+-----+
| *t   | *ala | exp   |               | *mapexpln.\*\*\**     | \<  |
| erra | ska* | lanat |               | (map explanations)    | 0.6 |
| nes* |      |       |               |                       |     |
+------+------+-------+---------------+-----------------------+-----+
|      |      | *terr | Alaska        | Tectonostratigraphic  | 2   |
|      |      | _lnd* | terrane map,  | terrane and overlap   |     |
|      |      |       | 1:2.5M        | map of Alaska (scale, |     |
|      |      |       |               | 1:2.5 M)              |     |
+------+------+-------+---------------+-----------------------+-----+
|      | *can | *asse | Canadian      | Terrane and           | 22  |
|      | ada* | mblg* | Cordillera -  | tectonic-assemblage   |     |
|      |      |       | terranes /    | maps of the Canadian  |     |
|      |      |       | tectonic      | Cordillera. Note that |     |
|      |      |       | assemblages   | useful hotlinks       |     |
|      |      |       |               | exist.                |     |
+------+------+-------+---------------+-----------------------+-----+
|      | *    |       | Circum-North  | Circum-North Pacific  | n/a |
|      | nor_ |       | Pacific       | Tectonostratigraphic  |     |
|      | pac* |       | Terrane Map   | Terrane Map. Note     |     |
|      |      |       |               | that useful hotlinks  |     |
|      |      |       |               | exist.                |     |
+------+------+-------+---------------+-----------------------+-----+
|      |      | *ba   | Circum-North  | Outlines of Mesozoic  | \<  |
|      |      | sins* | Pacific       | and Cenozoic basins   | 0.2 |
|      |      |       | basins        |                       |     |
+------+------+-------+---------------+-----------------------+-----+
|      |      | coast | Circum-North  | Coastline; same as    | 2   |
|      |      |       | Pacific       | topo                  |     |
|      |      |       | coastline     | grfy/vector/contours, |     |
|      |      |       |               | but presented as      |     |
|      |      |       |               | sea-level contour     |     |
|      |      |       |               | only                  |     |
+------+------+-------+---------------+-----------------------+-----+
|      |      | *expl |               | *assemb* (text files  | 10  |
|      |      | anat* |               | for assemblage        |     |
|      |      |       |               | descriptions;         |     |
|      |      |       |               | *columns*             |     |
|      |      |       |               | (stratigraphic        |     |
|      |      |       |               | columns); *terranes*  |     |
|      |      |       |               | (text files for       |     |
|      |      |       |               | terrane               |     |
|      |      |       |               | descriptions);        |     |
|      |      |       |               | *mapexpln.\*\*\**     |     |
|      |      |       |               | (map explanation)     |     |
+------+------+-------+---------------+-----------------------+-----+
|      |      | *flts | Circum-North  | Onshore faults        | 1   |
|      |      | _lnd* | Pacific       |                       |     |
|      |      |       | onshore       |                       |     |
|      |      |       | faults        |                       |     |
+------+------+-------+---------------+-----------------------+-----+
|      |      | *flts | Circum-North  | Offshore faults       | \<  |
|      |      | _ocn* | Pacific       |                       | 0.5 |
|      |      |       | offshore      |                       |     |
|      |      |       | faults        |                       |     |
+------+------+-------+---------------+-----------------------+-----+

  ------------ ---------- ------------ ------------------------ ------------------------ ------
                          *flts_pos*   Circum-North Pacific     Post-accretionary        \< 0.3
                                       post-accretionary faults faults, onshore and      
                                                                offshore                 

                          *mag_lins*   Circum-North Pacific     Magnetic lineaments      \< 0.3
                                       magnetic lineaments                               

                          *ocn_geol*   Circum-North Pacific     Oceanic geology          \< 0.2
                                       oceanic geology                                   

                          *sea_mnts*   Circum-North Pacific     Seamounts                \< 0.2
                                       seamounts                                         

                          *terr_lnd*   Circum-North Pacific     Onshore terranes         9
                                       onshore terranes -                                
                                       terranes / overlap                                
                                       abbreviations / overlap                           
                                       assemblages                                       

                          *terr_ocn*   Circum-North Pacific     Offshore terranes        3
                                       offshore terranes                                 

  *topogrfy*   *raster*                                         *raster* contains        n/a
                                                                gridded topographic data 

                          etopo5       5'                       5'-sampled land          \< 0.3
                                       topography/bathy-metry   topography and marine    
                                       (m)                      bathymetry.  Note that   
                                                                etopo5.bil has been      
                                                                created                  

                          gtopo2       2'                       2'-sampled land          15
                                       topography/bathy-metry   topography and marine    
                                       (m)                      bathymetry (only         
                                                                available to 70°N).      
                                                                 Note that gtopo2.bil    
                                                                has been created         

                          *gtopo30*    30" land topography (m)  30"-sampled topography   23
                                                                (land only).  Note that  
                                                                *gtopo30.bil* has been   
                                                                created                  

                          hillshad     hillshade of 30" land    30"-sampled topography   12
                                       topography               illuminated by sun from  
                                                                315° at 45° elevation    

               vector                                           vector contains contours n/a
                                                                (elevation or            
                                                                bathymetry) and hence    
                                                                polygons lying between   
                                                                fixed contour values     

                          ak_shelf     US shelf bathymetry (m)  Bathymetry for US waters 17
                                       (1:0.25M)                shallower than 200m,     
                                                                Beaufort Sea to the      
                                                                Aleutians (most          
                                                                detailed, 1:0.25M)       

                          ber_chuk     Bering/Chukchi Seas      Bathymetry for Bering    4
                                       bathymetry (m) (1:2.5M)  and Chukchi Seas, US and 
                                                                Russian waters           
                                                                (intermediate detail,    
                                                                1:2.5M)                  

                          chukchi      Chukchi Sea/Bering       Bathymetry for Chukchi   1
                                       Straits bathymetry (m)   Sea and Bering Straits,  
                                       (1:1M)                   US and Russian waters    
                                                                (more detailed, 1:1M)    

                          nor_pac      1:10M                    Circum-North Pacific     4
                                       topography/bathymetry    topography and           
                                       (m)                      bathymetry (least        
                                                                detailed, 1:10M)         

                          rivers       Rivers                   Major drainages,         \< 0.3
                                                                circum-North Pacific     
  ------------ ---------- ------------ ------------------------ ------------------------ ------

  --------- ------- ---------- ---------------- ------------------------ ------
                    shorline   World Vector     World Vector Shoreline,  4
                               Shoreline        designed for use at      
                               (1:0.25M)        scales of up to          
                                                1:250,000                

  volcano           volcano    Volcanoes        Historically active      \< 0.1
                                                volcanoes                
  --------- ------- ---------- ---------------- ------------------------ ------

 Note: For some gridded datasets, an image file,
*/data/data-directory/data-subdirectory/filename.bil,* is created to for
viewing of these datasets in the freeware ArcExplorer program which
otherwise cannot display these data-sets.

 Note: For some datasets, hotlinks are created to link features in views
to other data sources, typically text descriptions of geologic units.
When the linked feature is clicked with the Hot Link tool, ArcView opens
the linked data source. Hotlinks are created for the map explanations
for the Circum-North Pacific tectonostratigraphic terrane map and for
the terrane and tectonic assemblage maps of the Canadian Cordilleran.
Refer to ArcView manuals for use of the hotlink tool.

DETAILED DESCRIPTION OF */norpac/data*

General Form of Metadata

For each of the datasets, the relevant metadata are presented in tabular
form. The first table is generic and lists the various type of metadata.

+------------------+---------------------------------------------------+
| **Filename:**    | **Summary title / Brief description of data**     |
| (in the format   |                                                   |
| sub-dir          |                                                   |
| ectory/filename) |                                                   |
+------------------+---------------------------------------------------+
| **(Additional    | **Additional title(s) in bold imply all these     |
| filename)**      | data share the same source and similar metadata** |
+------------------+---------------------------------------------------+
| Data type:       | Information contained in the dataset \[e.g.,      |
|                  | "Bouguer gravity anomalies"\]                     |
+------------------+---------------------------------------------------+
| Geographic       | The north, west, south and east limits of the     |
| extent:          | dataset; if the dataset extends to the full area  |
|                  | of coverage (120°E, 80°N, 115°W, 40°N) the        |
|                  | annotation *full coverage* is used                |
+------------------+---------------------------------------------------+
| Projection:      | The projection of the original map or data        |
|                  | source. This projection may affect the spacing of |
|                  | grid-points or accuracy of arcs and polygons. The |
|                  | accuracy is usually a function of latitude; and   |
|                  | is not normally relevant for point data.          |
+------------------+---------------------------------------------------+
| Source scale:    | Scale of original map or scale of compilation of  |
|                  | original data source. This section provides a     |
| *or*             | measure of spatial accuracy of the data. Where    |
|                  | data are digitized from paper maps, this section  |
| Source grid      | provides, when known, the spacing of digitizing   |
| interval:        | vertices. Such information is not normally        |
|                  | applicable to point data.                         |
+------------------+---------------------------------------------------+
| Data             | Documentation files are included on this CD-ROM,  |
| documentation:   | are described herein. These files are usually     |
|                  | presented in three formats, ASCII (\*\*\*.*txt*), |
|                  | Word (\*\*\*.*doc*), and Adobe Acrobat Reader     |
|                  | (\*\*\*.*pdf*).                                   |
+------------------+---------------------------------------------------+
| Arc attributes,  | For vector data, a list of the attributes (data   |
| polygon          | types) stored for the data-set for each arc and   |
| attributes, or   | each polygon \[e.g. "Lithology"\] \[in arc        |
| point            | attribute tables, *\*\*\*.aat*, and in polygon    |
| attributes:      | attribute tables, *\*\*\*.pat*, respectively\]    |
|                  | are stated. Also stated are region attributes for |
|                  | datasets where regions (subsets of a single       |
|                  | coverage) are defined. The names of attribute     |
|                  | fields are listed as \[name\], and for attribute  |
|                  | names that are not immediately obvious, a         |
|                  | definition is listed, As an example, for the      |
|                  | field value, all possible values are listed.      |
|                  |                                                   |
|                  | For raster (gridded) data and point data are      |
|                  | listed the attributes (data values) stored for    |
|                  | the data-set for each point \[in point attribute  |
|                  | tables, *\*\*\*.pat*\], and the units of          |
|                  | measurement \[e.g. "Bouguer anomaly, units of     |
|                  | mGal"\].                                          |
+------------------+---------------------------------------------------+
| Range:           | Where appropriate, the maximum and minimum values |
|                  | contained in the dataset are listed. Knowledge of |
|                  | the full range can assist in choosing display     |
|                  | scales. Note that some datasets are truncated     |
|                  | (e.g. topographic datasets that only extend to    |
|                  | the shelf edge) other datasets include specially  |
|                  | coded values to indicate missing data.            |
+------------------+---------------------------------------------------+

+------------------+---------------------------------------------------+
| Resolution:      | Where appropriate data on resolution are          |
|                  | included, for example "Contour interval 200 m",   |
| *&/or* Error     | or "±3 mGal". This type of data may not be        |
| estimates:       | applicable to vector coverages, e.g. Geology.     |
+------------------+---------------------------------------------------+
| Legends:         | For customized legends available within the       |
|                  | projects *norpac#.apr*, the name (*\*\*\*.avl*)   |
|                  | and the relevant details are provided herein.     |
+------------------+---------------------------------------------------+
| Primary          | Source of dataset, to which reference should be   |
| reference:       | made when any derivative maps or products are     |
|                  | presented or published. Original sources that     |
|                  | contain significant additional datasets are noted |
|                  | herein.                                           |
+------------------+---------------------------------------------------+
| Further          | Publisher or developer of the dataset; included   |
| information:     | to provide further credit to the providers of the |
|                  | datasets, and as a source for further information |
+------------------+---------------------------------------------------+

Note that additional notes are provided for some datasets.

Cultural Datasets

+------------------+---------------------------------------------------+
| **cul            | **International, provincial and state             |
| tural/boundary** | boundaries**                                      |
+------------------+---------------------------------------------------+
| **c              | **Significant population centers**                |
| ultural/cities** |                                                   |
+------------------+---------------------------------------------------+
| **cul            | **Other socio-cultural features, such as airports |
| tural/features** | amd golf-courses**                                |
+------------------+---------------------------------------------------+
| **cul            | **Latitude and longitude grid at 5° spacing**     |
| tural/latlong5** |                                                   |
+------------------+---------------------------------------------------+
| **cul            | **Latitude and longitude grid at 12° spacing**    |
| tural/latlon12** |                                                   |
+------------------+---------------------------------------------------+
| Data type:       | Various, see above                                |
+------------------+---------------------------------------------------+
| Geographic       | Full coverage                                     |
| extent:          |                                                   |
+------------------+---------------------------------------------------+
| Projection:      | Decimal Degrees                                   |
+------------------+---------------------------------------------------+
| Source scale:    | Boundary: 1:5 million                             |
|                  |                                                   |
|                  | Cities: n/a                                       |
|                  |                                                   |
|                  | Features: 1:1 million                             |
+------------------+---------------------------------------------------+
| Point            | **cultural/cities**                               |
| attributes:      | /norpac/data/cultural/info/cities.pat contains    |
|                  | attributes:                                       |
|                  |                                                   |
|                  | \[Name\] = city name; spellings are based on      |
|                  | Board of Geographic Names standards and           |
|                  | commercial atlases                                |
|                  |                                                   |
|                  | \[Country\] = abbreviated country name            |
|                  |                                                   |
|                  | \[Population\] = total population for the entire  |
|                  | metropolitan area; values are from recent census  |
|                  | or estimates; attributes of -99 are null values   |
|                  | (data not available)                              |
|                  |                                                   |
|                  | \[Capital\] = indicates whether a city is a       |
|                  | national capital (possible values are Y and N)    |
|                  |                                                   |
|                  | **cultural/features**                             |
|                  | /norpac/data/cultural/info/features.pat contains  |
|                  | attributes:                                       |
|                  |                                                   |
|                  | \[Text\] = feature name, e.g. Laptev Sea, Denali; |
|                  | spellings based on DMA Operational Navigation     |
|                  | Charts                                            |
|                  |                                                   |
|                  | \[Type\] = the type of feature to which the name  |
|                  | pertains (possible values: Administrative name,   |
|                  | Airport, Country name, Cultural landmark, Desert  |
|                  | name, Drainage feature, Island name, Land place   |
|                  | name, Mountain name, Ocean name, Populated place) |
+------------------+---------------------------------------------------+
| Arc attributes:  | **cultural/latlong5**                             |
|                  | */norpac/data/cultural/info/latlong5.aat*         |
|                  | contains attributes:                              |
|                  |                                                   |
|                  | \[Value\] = degree value and the latitude or      |
|                  | longitude directional reference of the grid line  |
|                  |                                                   |
|                  | \[Degree10\] = indicates whether a grid line is   |
|                  | part of the 10 by 10 degree grid (Y/N)            |
|                  |                                                   |
|                  | \[Degree15\] = indicates whether a grid line is   |
|                  | part of the 15 by 15 degree grid (Y/N)            |
|                  |                                                   |
|                  | \[Degree20\] = indicates whether a grid line is   |
|                  | part of the 20 by 20 degree grid (Y/N)            |
|                  |                                                   |
|                  | \[Degree30\] = indicates whether a grid line is   |
|                  | part of the 30 by 30 degree grid (Y/N)            |
+------------------+---------------------------------------------------+

+------------------+---------------------------------------------------+
| Polygon          | **cultural/boundary**                             |
| attributes:      | */norpac/data/cultural/info/boundary.pat*         |
|                  | contains attributes:                              |
|                  |                                                   |
|                  | \[Fips_admin\] = two-letter, two-number United    |
|                  | States Federal Information Processing Standards   |
|                  | (FIPS) code for a first-level administrative      |
|                  | unit; for countries without administrative units, |
|                  | this field contains only the two-letter country   |
|                  | code                                              |
|                  |                                                   |
|                  | \[Gmi_admin\] = three -letter country code        |
|                  | combined with a three-letter code for a           |
|                  | first-level administrative unit created by Global |
|                  | Mapping International                             |
|                  |                                                   |
|                  | \[Admin_Name\] = name of a first-level            |
|                  | administrative unit                               |
|                  |                                                   |
|                  | \[Fips_cntry\] = two-letter country code from the |
|                  | United States Federal Information Processing      |
|                  | Standards (FIPS) coding scheme                    |
|                  |                                                   |
|                  | \[Gmi_cntry\] = three-letter country code from    |
|                  | Global Mapping International                      |
|                  |                                                   |
|                  | \[Cntry_Name\] = country name; shortened and not  |
|                  | necessarily official                              |
|                  |                                                   |
|                  | \[Region\] = name of the world region; data is    |
|                  | grouped into 25 commonly recognized regions to    |
|                  | permit selection of a small multicountry area for |
|                  | display or study                                  |
|                  |                                                   |
|                  | \[Continent\] = continent name                    |
|                  |                                                   |
|                  | \[Pop_admin\] = population of a first level       |
|                  | administrative unit (from NCGIA: The Global       |
|                  | Demography Project; 1994 estimated population);   |
|                  | --99999 indicates population figures unavailable  |
|                  |                                                   |
|                  | \[Sqkm_admin\] = total area of a first level      |
|                  | administrative unit in square km                  |
|                  |                                                   |
|                  | \[Sqmi_admin\] = total area of a first level      |
|                  | administrative unit in square mi                  |
|                  |                                                   |
|                  | \[Type_eng\] = English name for the type of       |
|                  | administrative unit                               |
|                  |                                                   |
|                  | \[Type_loc\] = local name for the type of         |
|                  | administrative unit                               |
+------------------+---------------------------------------------------+
| Primary          | **cultural/boundary** ESRI\'s ArcWorld database   |
| reference:       |                                                   |
|                  | **cultural/cities** ESRI\'s ArcWorld database     |
|                  | supplemented with other data from the Rand        |
|                  | McNally New International Atlas, 1991             |
|                  |                                                   |
|                  | **cultural/features** Digital Chart of the World  |
|                  | (DCW), from the United States Defense Mapping     |
|                  | Agency (DMA) Operational Navigation Charts (ONC)  |
|                  |                                                   |
|                  | **cultural/latlong5** mathematically generated by |
|                  | ESRI using ARC/INFO software and converted to an  |
|                  | ESRI shapefile                                    |
+------------------+---------------------------------------------------+
| Further          | Environmental Systems Research Institute, Inc.,   |
| information:     | http://www.esri.com                               |
+------------------+---------------------------------------------------+

Geology Datasets

+------------------+---------------------------------------------------+
| **g              | **Geologic map of Alaska**                        |
| eology/ak_geol** |                                                   |
+------------------+---------------------------------------------------+
| Data type:       | Geologic data separated by lithology and age.     |
|                  | \[Faults present in the source map are not        |
|                  | contained in our database.\]                      |
+------------------+---------------------------------------------------+
| Geographic       | State of Alaska                                   |
| extent:          |                                                   |
+------------------+---------------------------------------------------+
| Projection:      | The original map (Beikman, 1980) is based upon    |
|                  | two base maps of different unknown projections    |
|                  | which have been combined at unknown locations to  |
|                  | create the final product.                         |
+------------------+---------------------------------------------------+
| Source scale:    | 1:2,500,000; digitized with 500 m vertices        |
+------------------+---------------------------------------------------+
| Data             | A description of the map units is contained in    |
| documentation:   | files /*explanat/mapexpln.\*\*\**                 |
+------------------+---------------------------------------------------+
| Arc attributes:  | # *ak_geol.aat* contains:                         |
|                  |                                                   |
|                  | \[Type\] = Contact information (Visible,          |
|                  | Non-visible, Ice)                                 |
+------------------+---------------------------------------------------+
| Polygon          | #########                                         |
| attributes:      | */norpac/data/geology/info/ak_geol.pat* contains: |
|                  |                                                   |
|                  | \[Code\] = Lookup code for the geologic unit; the |
|                  | unit description is also appended                 |
|                  |                                                   |
|                  | \[Mapunit_ab\] = Geologic Unit, e.g. DVM for      |
|                  | Devonian mafic volcanics, after Beikman (1980)    |
+------------------+---------------------------------------------------+
| **Legends:**     | *ak_geol.avl* is modelled as closely as possible  |
|                  | on the colors and patterns of the Beikman (1980)  |
|                  | map. Due to limitations in available ArcView      |
|                  | color palettes and patterns, the matching is not  |
|                  | exact, and some distinct units are mapped by      |
|                  | identical colors and patterns. Note also that,    |
|                  | typically, screen colors are not faithfully       |
|                  | reproduced by plotters.                           |
+------------------+---------------------------------------------------+

  ------------------ ----------------------------------------------------
  Primary reference: Geologic Map of Alaska, Beikman (1980); digital
                     version prepared by F.R. Wilson (USGS).

  Further            F.R. Wilson, U.S. Geological Survey, Anchorage,
  information:       Alaska 99508
  ------------------ ----------------------------------------------------

+------------------+---------------------------------------------------+
| **ge             | **Fault map of Russia**                           |
| ology/rus_flts** |                                                   |
+------------------+---------------------------------------------------+
| **ge             | **Geologic map of Russia**                        |
| ology/rus_geol** |                                                   |
+------------------+---------------------------------------------------+
| Data type:       | Geologic data separated by lithology and age      |
+------------------+---------------------------------------------------+
| Geographic       | Eastern Former Soviet Union and adjacent marine   |
| extent:          | areas                                             |
+------------------+---------------------------------------------------+
| Projection:      | Geographic (decimal degrees); original coverage   |
|                  | was split across 180° longitude; the regions west |
|                  | and east of 180° have been merged but not         |
|                  | formally joined so affected polygons are split    |
|                  | into two parts by a line along 180°               |
+------------------+---------------------------------------------------+
| Source scale:    | 1:2,500,000                                       |
+------------------+---------------------------------------------------+
| Data             | A description of the map is contained in files    |
| documentation:   | /*explanat/mapexpln.doc* and                      |
|                  | *explanat/mapexpln.pdf;* and look-up tables for   |
|                  | the numeric attributes are contained in           |
|                  | *explanat/attribut.doc* and                       |
|                  | *explanat/attribut.pdf*                           |
+------------------+---------------------------------------------------+
| Arc attributes:  | ######### *                                       |
|                  | /norpac/data/geology/info/rus_geol.aat* contains: |
|                  |                                                   |
|                  | \[Numleg\] = lookup code for geoleg, the geologic |
|                  | legend (see /*explanat/attribut.doc*)             |
|                  |                                                   |
|                  | \[Line-type\] = all line work, including e.g.     |
|                  | 'Proved faults', 'Shoreline', 'Boundaries between |
|                  | facies varieties of rocks'                        |
+------------------+---------------------------------------------------+
| Polygon          | ######### *                                       |
| attributes:      | /norpac/data/geology/info/rus_geol.pat* contains: |
|                  |                                                   |
|                  | \[Numleg\] = legend number for plotting           |
|                  |                                                   |
|                  | \[Numl\] = legend number for plotting             |
|                  |                                                   |
|                  | \[Err\] = errors in the printed map (see          |
|                  | /*explanat/mapexpln.doc*)                         |
|                  |                                                   |
|                  | \[Priz\] = special features (see                  |
|                  | *explanat/mapexpln.doc*)                          |
|                  |                                                   |
|                  | \[Agecod\] = lookup code for agesleg, the age     |
|                  | legend (see /*explanat/attribut.doc*)             |
|                  |                                                   |
|                  | \[GeoCod\] = lookup code for geoleg, the geologic |
|                  | legend (see /*explanat/attribut.doc*)             |
|                  |                                                   |
|                  | \[Geo_unit\] = rock type, e.g. 'Continental       |
|                  | deposits' \[*sic*\], 'Granite'                    |
|                  |                                                   |
|                  | \[AgeIndex\] = abbreviated geologic age, e.g.     |
|                  | 'AR' for Archean, J1 for Lower Jurassic           |
|                  |                                                   |
|                  | \[Age\] = geologic age, e.g. 'Archean', 'Lower    |
|                  | Jurassic'                                         |
+------------------+---------------------------------------------------+
| Region           | *Acoust* No values; "Acoustic Basement" includes  |
| attributes:      | basement uplifts determined geophysically in      |
|                  | offshore areas                                    |
|                  |                                                   |
|                  | *Impac* No values; "Impactite" includes rocks     |
|                  | with characteristics of metamorphism but chemical |
|                  | characteristics of primary rocks                  |
|                  |                                                   |
|                  | *Diaph* No values; "Diaphthorite Rocks" includes  |
|                  | rocks changed by retrogressive metamorphism       |
+------------------+---------------------------------------------------+
| Legends:         | *rus_age.avl* is derived from the polygon         |
|                  | attribute \[Numleg\] and contains a distinct      |
|                  | color/pattern for each geologic age \[Age\]       |
|                  |                                                   |
|                  | *rus_arcs.avl* contains a separate line symbol    |
|                  | for every value of the arc attribute              |
|                  | \[Line-type\], including various types of         |
|                  | tectonic boundaries as well as coastlines, state  |
|                  | boundaries, etc.                                  |
|                  |                                                   |
|                  | *rus_flts.avl* contains line symbols for tectonic |
|                  | contacts                                          |
|                  |                                                   |
|                  | *rus_geol.avl* contains distinct color/pattern    |
|                  | combinations for each value of the polygon        |
|                  | attribute \[Geo_unit\], i.e. for separate rock    |
|                  | types                                             |
+------------------+---------------------------------------------------+
| Primary          | Nalivkin (1994); GlavNIVC (1998). GlavNIVC team:  |
| references:      | Boris L. Khlebnikov, Paul P. Hearn, Jr., Gregory  |
|                  | Ulmishek, Michael P.Nemynov, Elena M. Nuzhdenova, |
|                  | Svetlana A. Goryushina, Galina I.Bogolyubova,     |
|                  | Andrew P. Gilbershteyn, Valeriy A. Medvedev,      |
|                  | Aleksey A. Polishchu, Paul G. Schruben, Walter    |
|                  | Bawiec, Nina Y. Lebedeva, and Andrew V. Korotkov. |
|                  | Original data compilation also includes           |
|                  | topographic base maps, mineral deposits map and   |
|                  | petroleum basins/gas fields map.                  |
+------------------+---------------------------------------------------+
| Further          | Boris Khlebnikov (GlavNIVC, RMNR,                 |
| information:     | boris@glavnivc.msk.su); and Paul P. Hearn (USGS,  |
|                  | phearn@usgs.gov). Russian Far East part of        |
|                  | geologic map of Russia compiled herein with       |
|                  | permission of Boris Khlebnikov and Paul P. Hearn. |
+------------------+---------------------------------------------------+

**Gravity Datasets**

+------------------+---------------------------------------------------+
| *                | **Onshore Bouguer gravity anomalies and offshore  |
| *gravity/dgrav** | free-air gravity anomalies**                      |
+------------------+---------------------------------------------------+
| Data type:       | Bouguer gravity on land; free-air gravity over    |
|                  | oceans.                                           |
|                  |                                                   |
|                  | Computation of gravity anomalies based on the     |
|                  | International Gravity Standardization Net 1971    |
|                  | and the Geodetic Reference System 1967. Bouguer   |
|                  | anomalies calculated using a crustal density of   |
|                  | 2670 kg.m^-3^. Data for "high-relief areas of     |
|                  | Canada and the United States" have been terrain   |
|                  | corrected; elsewhere data are generally not       |
|                  | terrain corrected.                                |
|                  |                                                   |
|                  | Data were originally compiled from surface,       |
|                  | airborne, and satellite measurements. For Alaska, |
|                  | Chukchi Sea, Western Beaufort Sea, and Norton     |
|                  | Sound, where surface data could not be readily    |
|                  | obtained in digital form, synthetic point gravity |
|                  | values were created from contour maps: Childs and |
|                  | others (1985) for the Bering Sea, Fisher and      |
|                  | others (1982) for the Norton Basin, Barnes (1977) |
|                  | for Alaska, May (1985) for the Chukchi and        |
|                  | Beaufort Seas and Arctic Ocean. Over the oceans,  |
|                  | up to about 70°N, satellite-derived free-air      |
|                  | values filled in areas where surface data were    |
|                  | unavailable or sparse. Satellite data provided on |
|                  | a 15-minute geographic grid were gridded at a     |
|                  | 24-km interval to remove the short-wavelength     |
|                  | components at higher latitudes and then combined  |
|                  | with the surface data. The resultant data set was |
|                  | then interpolated to a 6-km grid.                 |
+------------------+---------------------------------------------------+
| Geographic       | full coverage east of 170°E                       |
| extent:          |                                                   |
+------------------+---------------------------------------------------+
| Projection:      | Regridded into latitude and longitude from an     |
|                  | original spherical transverse Mercator            |
|                  | projection.                                       |
|                  |                                                   |
|                  | Decade of North American (DNAG) 6-km gravity grid |
|                  | was regridded by NGDC using a grid cell dimension |
|                  | of 2.5' of longitude and latitude and a Brigg\'s  |
|                  | minimum curvature algorithm which allowed         |
|                  | generation of grids from randomly distributed     |
|                  | data. The 2.5' grid cell dimension leads to a     |
|                  | high degree of spatial distortion at very high    |
|                  | latitudes, so the latitude-longitude grids have   |
|                  | been truncated above 80°N. \[Because regridding   |
|                  | the potential field data from km on a map         |
|                  | projection into latitude and longitude introduced |
|                  | some gradient distortions at all latitudes it is  |
|                  | recommended that anyone attempting to do          |
|                  | quantitative work with the potential field grids  |
|                  | use the original 6-km gravity grids.\]            |
+------------------+---------------------------------------------------+
| Source grid      | 2.5 minute (from original 6-km spacing)           |
| interval:        |                                                   |
+------------------+---------------------------------------------------+
| Point            | values are milligals                              |
| attributes:      |                                                   |
+------------------+---------------------------------------------------+
| Range:           | -284 to +204 mGal                                 |
+------------------+---------------------------------------------------+
| Spatial          | field data were often sampled along a traverse or |
| resolution:      | along a ship track; the grids produced often      |
|                  | generate solutions several grid cells wide, and   |
|                  | so will appear on color raster images as narrow   |
|                  | bands of color-coded information rather than as   |
|                  | lines                                             |
+------------------+---------------------------------------------------+
| Error estimates: | estimated rms error for land, surface marine, and |
|                  | airborne data ranges from +/- 1 to +/- 5 mGal;    |
|                  | satellite data have an estimated rms error of +/- |
|                  | 8 mGal                                            |
+------------------+---------------------------------------------------+
| Primary          | NGDC Gravity CD-ROM: Hittelman (1994); Committee  |
| reference:       | for the Gravity Anomaly Map of North America      |
|                  | (1987)                                            |
+------------------+---------------------------------------------------+

+------------------+---------------------------------------------------+
| **               | **Satellite-derived free-air gravity, offshore    |
| gravity/geosat** | areas only**                                      |
+------------------+---------------------------------------------------+
| Data type:       | Satellite-derived free-air gravity over oceans;   |
|                  | low-pass filtered with 0.5 gain at a wavelength   |
|                  | of 20 km, gridded on a Mercator projection        |
|                  | (method of Sandwell, 1992); derived from the      |
|                  | following sources:                                |
|                  |                                                   |
|                  | Geosat/ERM - average of 62 Geosat Exact Repeat    |
|                  | Mission profiles; Geosat/GM -- declassified       |
|                  | Geosat Geodetic mission data for all ocean areas; |
|                  | ERS-1 -ERS-1 OPR GDR\'s from the first 16 repeat  |
|                  | cycles of the 35-day repeat orbit were averaged   |
|                  | to improve their accuracy and resolution;         |
|                  | ERS-1/GM - ERS-1 OPR GDR\'s from the first 200    |
|                  | days of the ERS-1 Geodetic mission                |
+------------------+---------------------------------------------------+
| Geographic       | full coverage below 72°N (marine areas only)      |
| extent:          |                                                   |
+------------------+---------------------------------------------------+

+------------------+---------------------------------------------------+
| Projection:      | latitude and longitude grid                       |
+------------------+---------------------------------------------------+
| Source grid      | 2 minute; but effective resolution is only about  |
| interval:        | 10 km (ERS-1 provided 8-km-spaced profiles, and   |
|                  | Geosat 6-km-spaced profiles).                     |
|                  |                                                   |
|                  | Source data includes values over land areas,      |
|                  | presumably an artifact of the contouring or       |
|                  | extrapolation method, so we used the coastline    |
|                  | from the Circum-North Pacific Terrane map,        |
|                  | /*topogrfy/vector/nor_pac*, to mask out all land  |
|                  | areas                                             |
+------------------+---------------------------------------------------+
| Point            | values are milligals                              |
| attributes:      |                                                   |
+------------------+---------------------------------------------------+
| Range:           | -3329 to +3211 mGal                               |
+------------------+---------------------------------------------------+
| Error estimates: | \> 3 mGal                                         |
+------------------+---------------------------------------------------+
| Primary          | Smith and Sandwell (1997)                         |
| reference:       |                                                   |
+------------------+---------------------------------------------------+
| Further          | http://topex.ucsd.edu/marine_grav/mar_grav.html   |
| information:     |                                                   |
+------------------+---------------------------------------------------+

A similarly gridded data-set that extends to 80° N over the polar
ice-cap (Laxon and McAdoo, 1998) is available from
http://msslsp.mssl.ucl.ac.uk:80/people/swl/polar-gravity.html.

  ---------------------- ----------------------------------------------------
  **gravity/sea_surf**   **Satellite-derived sea-surface heights**

  Data type:             Sea-surface height computed on a 0.125-degree grid
                         in the ocean areas from a combined
                         GEOS3/SEASAT/GEOSAT altimeter data set to provide
                         the long-wavelength component of the gravity field.

  Geographic extent:     Full coverage below 72°N (marine areas only)

  Projection:            latitude and longitude grid

  Source grid interval:  0.125°

  Point attributes:      Values are meters

  Range:                 -36 to +41

  Primary reference:     NGDC Gravity CD-ROM: Hittelman (1994)
  ---------------------- ----------------------------------------------------

**Magnetic Datasets**

+------------------+---------------------------------------------------+
| **m              | **Magnetic map of Alaska (largely onshore)**      |
| agnetic/ak_mag** |                                                   |
+------------------+---------------------------------------------------+
| Data type:       | Aeromagnetic, compilation of 85 previous surveys  |
|                  | conducted between 1945 and 1982 with varying      |
|                  | attributes (note that large regions of Alaska are |
|                  | covered only by very coarse surveys); upward or   |
|                  | downward continued and converted from level to    |
|                  | drape as necessary to produce a consistent survey |
|                  | specification of 1000 ft above ground;            |
|                  |                                                   |
|                  | the Definitive Geomagnetic Reference Field (DGRF) |
|                  | has been applied for the date of each original    |
|                  | survey                                            |
+------------------+---------------------------------------------------+
| Geographic       | Alaska and immediate offshore areas only          |
| extent:          |                                                   |
+------------------+---------------------------------------------------+
| Projection:      | Latitude and longitude grid                       |
+------------------+---------------------------------------------------+
| Source grid      | 1 km, regridded from original surveys             |
| interval:        |                                                   |
+------------------+---------------------------------------------------+
| Data             | An index map stored as a gif image showing data   |
| documentation:   | sources is contained in the file *ak_mag.gif.*    |
|                  | Click on the ? ikon in the view to display a gif  |
|                  | image of the data.                                |
+------------------+---------------------------------------------------+
| Point            | Values are nanoteslas                             |
| attributes:      |                                                   |
+------------------+---------------------------------------------------+
| Range:           | -1867 to +4640 nT                                 |
+------------------+---------------------------------------------------+
| Primary          | Saltus and Simmons (1997), Saltus et al. (1999)   |
| reference:       |                                                   |
+------------------+---------------------------------------------------+
| Further          | http://minerals.c                                 |
| information:     | r.usgs.gov/publications/ofr/97-520/alaskamag.html |
+------------------+---------------------------------------------------+

+------------------+---------------------------------------------------+
| **mag            | **Magnetic map of the Arctic (largely offshore)** |
| netic/arct_mag** |                                                   |
+------------------+---------------------------------------------------+
| Data type:       | Short and medium-wavelength (\< 400 km) magnetic  |
|                  | anomaly over the Arctic and adjacent land areas;  |
|                  | numerous datasets merged to develop a digital     |
|                  | data base of coherent magnetic observations       |
|                  | suitable for quantitative tectonic                |
|                  | interpretations                                   |
+------------------+---------------------------------------------------+
| Geographic       | Full coverage above 60°N                          |
| extent:          |                                                   |
|                  | (but only patchy coverage of the Bering Straits   |
|                  | region)                                           |
+------------------+---------------------------------------------------+

+------------------+---------------------------------------------------+
| Projection:      | Original dataset was Transverse Mercator, a       |
|                  | projection not supported by ARC/INFO. Therefore   |
|                  | the source grid was converted to an ARC/INFO      |
|                  | point coverage with entries of type latitude,     |
|                  | longitude, data value; and the ARC/INFO command   |
|                  | POINTGRID was then used to create the final GRID  |
|                  | coverage in our standard Lambert-Azimuthal        |
|                  | projection. Because the equi-spaced sampling of   |
|                  | the grid points in orthogonal co-ordinates does   |
|                  | not translate to equi-spaced sampling in          |
|                  | latitude-longitude co-ordinates, although the     |
|                  | data coverage appears continuous at lower         |
|                  | latitudes, increasing numbers of data-points near |
|                  | the poles contain no data value and appear as     |
|                  | "holes" in the coverage at high latitudes.        |
+------------------+---------------------------------------------------+
| Source grid      | 5 km, reduced to 12 km in creating this coverage  |
| interval:        |                                                   |
+------------------+---------------------------------------------------+
| Point            | Values are nanoteslas                             |
| attributes:      |                                                   |
+------------------+---------------------------------------------------+
| Spatial          | Isolated data profiles, e.g. In the Bering Sea,   |
| resolution:      | appear as swaths 15 km wide                       |
+------------------+---------------------------------------------------+
| Range:           | -2573 to +1748 nT                                 |
+------------------+---------------------------------------------------+
| Primary          | GAMMAA5 ([G]{.underline}ridded                    |
| reference:       | [A]{.underline}eromagnetic and                    |
|                  | [M]{.underline}arine [M]{.underline}agnetics of   |
|                  | the north [A]{.underline}tlantic and              |
|                  | [A]{.underline}rctic, [5]{.underline} km)         |
|                  | Magnetic Anomalies of the Arctic and North        |
|                  | Atlantic Oceans and Adjacent Land Areas CD-ROM:   |
|                  | Verhoef and others (1996); Macnab and others      |
|                  | (1995)                                            |
|                  |                                                   |
|                  | \[original data compilation also includes a       |
|                  | separate grid defining the long-wavelength (\>    |
|                  | 400 km) anomalies, and ancillary grids containing |
|                  | a quantitative indication of the quality and      |
|                  | accuracy of the final data set\]                  |
+------------------+---------------------------------------------------+
| Further          | Jacob Verhoef, verhoef@agc.bio.ns.ca; Ron Macnab, |
| information:     | macnab@agc.bio.ns.ca;                             |
|                  | http://agcwww.bio.ns.ca/index.html.               |
+------------------+---------------------------------------------------+

+------------------+---------------------------------------------------+
| **mag            | **Magnetic map of Far East Asia**                 |
| netic/asia_mag** |                                                   |
+------------------+---------------------------------------------------+
| Data type:       | Aeromagnetic and marine magnetic data for East    |
|                  | Asia                                              |
+------------------+---------------------------------------------------+
| Geographic       | West = 120°E                                      |
| extent:          |                                                   |
|                  | North = 50°N                                      |
|                  |                                                   |
|                  | East = 150°E                                      |
|                  |                                                   |
|                  | South = 40°N                                      |
+------------------+---------------------------------------------------+
| Projection:      | XY values of geographic co-ordinates are          |
|                  | calculated using Lambert azimuthal equal-area     |
|                  | projection with central point 15°N, 120°E; a      |
|                  | spherical earth with radius 6377 km has been      |
|                  | assumed. Locations in Latitude and longitude in   |
|                  | units of 10^-4^° inversely projected from the X   |
|                  | and Y co-ordinates.                               |
+------------------+---------------------------------------------------+
| Source grid      | 2 km; original map scale was 1:4,000,000          |
| interval:        |                                                   |
+------------------+---------------------------------------------------+
| Point            | values are nanoteslas                             |
| attributes:      |                                                   |
+------------------+---------------------------------------------------+
| Range:           | -770.6 to +1278.4 nT                              |
+------------------+---------------------------------------------------+
| Primary          | Magnetic Anomaly Map of East Asia, 1:4,000,000,   |
| reference:       | CD-ROM: Geological Survey of Japan and CCOP       |
|                  | (1996).                                           |
+------------------+---------------------------------------------------+
| Further          | Information and Publication Office, Geological    |
| information:     | Survey of Japan fukyu@gsjnet.gsj.go.jp            |
|                  |                                                   |
|                  | CCOP Technical Secretariat, Thailand              |
|                  | ccop@external.ait.ac.th                           |
+------------------+---------------------------------------------------+

  ----------------------- ----------------------------------------------------
  **magnetic/dnag_mag**   **Magnetic map of North America, onshore and
                          offshore**

  Data type:              Merged land and marine magnetic anomalies gravity
                          for the western hemisphere part of our area, created
                          from the Magnetic Anomaly Map of North America with
                          x and y step intervals of 2.0 km in a Spherical
                          Transverse Mercator projection, with reference
                          meridian 100°W and earth radius 6371.204 km, using
                          the Definitive Geomagnetic Reference Field (DGRF)

  Geographic extent:      Full coverage east of 170°E

  Projection:             Geographic (decimal degrees)
  ----------------------- ----------------------------------------------------

  ------------------ ----------------------------------------------------
  Source grid        2 km; data were originally compiled at an interval
  interval:          appropriate for contour intervals of 100 nT (gamma);
                     attempts to produce contour intervals less than 100
                     nT may reveal discontinuities between some data sets
                     used in compiling the map

  Point attributes:  Values are nanoteslas

  Spatial            field data were often sampled along a traverse or
  resolution:        along a ship track; the grids produced often
                     generate solutions several grid cells wide, and so
                     will appear on color raster images as narrow bands
                     of color-coded information rather than as lines

  Error estimates:   Joins between the data sets were largely free of
                     major discrepancies, though adjustment was necessary
                     in the panhandle of Alaska where the data were
                     lowered approximately 150 nT (Hittelman and others,
                     1989)

  Range:             -3580 to + 4278 nT

  Primary reference: Committee for the Magnetic Anomaly Map of North
                     America, (1987); Hittelman and others (1989);
                     unpublished contributions by Tom Hildenbrand (USGS).

  Further            Tom Hildenbrand (USGS), thildenbrand@usgs.gov
  information:       
  ------------------ ----------------------------------------------------

+------------------+---------------------------------------------------+
| **mag            | **Magnetic map of Russia**                        |
| netic/russ_mag** |                                                   |
+------------------+---------------------------------------------------+
| Data type:       | Magnetic data for the Russian Far East; magnetic  |
|                  | maps of the land and offshore areas of China and  |
|                  | Former Soviet Union originally published (1974)   |
|                  | at 1:2.5 million scale, from which digitized      |
|                  | contours were extracted and a 1 arc-minute grid   |
|                  | prepared (1980) by U.S. Naval Oceanographic       |
|                  | Office; some data spikes, data errors, and data   |
|                  | omissions corrected by Conoco, Inc., and the      |
|                  | entire dataset reduced to IGRF 1980 and merged to |
|                  | produce a composite grid with a spacing of 5 km   |
|                  | for publication by GSC.                           |
|                  |                                                   |
|                  | The data set has been high-pass filtered to       |
|                  | remove long-wavelength components greater than    |
|                  | 400 km.                                           |
+------------------+---------------------------------------------------+
| Geographic       | Full coverage west of 170°W                       |
| extent:          |                                                   |
+------------------+---------------------------------------------------+
| Projection:      | Geographic (decimal degrees); the data were       |
|                  | warped to match the geographic boundaries of      |
|                  | Russia present in our topography datasets. The    |
|                  | warping process results in a resampling of the    |
|                  | original data, so the warp we performed on        |
|                  | russ_mag (second-order using bilinear             |
|                  | interpolation) attempted to minimize the change   |
|                  | in the data while maximizing the spatial          |
|                  | correlation between the dataset and the rest of   |
|                  | this GIS compilation. Warping the data in the     |
|                  | opposite direction will give users the original   |
|                  | data. The links (start and end points) used in    |
|                  | the polynomial transformation follow, measured in |
|                  | meters from the zero point of our Lambert         |
|                  | Azimuthal projection at 165°W, 70°N:              |
|                  |                                                   |
|                  | FromX, FromY, ToX, ToY                            |
|                  |                                                   |
|                  | -216917.74665, -557259.82339, -262657.03815,      |
|                  | -467793.08008                                     |
|                  |                                                   |
|                  | -351321.53412, -649351.26631, -362506.63694,      |
|                  | -596866.94939                                     |
|                  |                                                   |
|                  | -891425.24825, -709086.26153, -903155.52350,      |
|                  | -691845.80497                                     |
|                  |                                                   |
|                  | -1318354.49763, -843782.70439, -1348161.08791,    |
|                  | -839295.42439                                     |
|                  |                                                   |
|                  | -1268575.33967, 348428.11170, -1272665.05031,     |
|                  | 356464.22264                                      |
|                  |                                                   |
|                  | -3690477.54461, -965302.33514, -3710012.77456,    |
|                  | -994272.58564                                     |
|                  |                                                   |
|                  | -3563540.77141, -1358557.69744, -3585809.70113,   |
|                  | -1366881.90032                                    |
|                  |                                                   |
|                  | -1773248.38155, 1212828.44935, -1787853.37859,    |
|                  | 1219243.57022                                     |
|                  |                                                   |
|                  | -1696090.66104, 1416923.10222, -1714792.71517,    |
|                  | 1426248.63379                                     |
|                  |                                                   |
|                  | -1815560.66822, 1663329.96941, -1834125.11242,    |
|                  | 1647866.06602                                     |
|                  |                                                   |
|                  | -1235633.40954, 493519.50358, -1254510.70082,     |
|                  | 491072.49600                                      |
|                  |                                                   |
|                  | -3071605.57077, -496939.04713, -3106487.58154,    |
|                  | -509194.14353                                     |
|                  |                                                   |
|                  | -3400148.00418, -698544.66635, -3423083.69172,    |
|                  | -716199.31972                                     |
|                  |                                                   |
|                  | -3123873.77287, -365024.33190, -3143017.94007,    |
|                  | -367943.59381                                     |
|                  |                                                   |
|                  | -2118920.66639, -501477.84139, -2132566.99217,    |
|                  | -485061.94724                                     |
|                  |                                                   |
|                  | -2539554.48655, -145556.91664, -2546577.33383,    |
|                  | -146547.55909                                     |
|                  |                                                   |
|                  | -1735838.89182, -1287415.70477, -1746339.61803,   |
|                  | -1283420.28833                                    |
|                  |                                                   |
|                  | -2261874.12690, -1214115.69280, -2271713.18177,   |
|                  | -1201182.97012                                    |
|                  |                                                   |
|                  | -1377962.56550, 803790.20963, -1412303.98862,     |
|                  | 789149.13093                                      |
|                  |                                                   |
|                  | -1511627.12488, 1058184.32338, -1540739.78304,    |
|                  | 1046584.95009                                     |
|                  |                                                   |
|                  | -3266515.28444, 75101.88353, -3284529.34896,      |
|                  | 52187.30721                                       |
+------------------+---------------------------------------------------+
| Source grid      | 5 km                                              |
| interval:        |                                                   |
+------------------+---------------------------------------------------+
| Point            | Values are nanoteslas                             |
| attributes:      |                                                   |
+------------------+---------------------------------------------------+
| Range:           | -1059 to + 1380 nT                                |
+------------------+---------------------------------------------------+
| Primary          | Racey and others (1996)                           |
| reference:       |                                                   |
+------------------+---------------------------------------------------+
| Further          | The dataset included on this CD-ROM was           |
| information:     | transformed by the National Geophysical Data      |
|                  | Center (NGDC) into a 3 arc-minute dataset that is |
|                  | available from R.W. Buhmann, rwb@ngdc.noaa.gov,   |
|                  | National Geophysical Data Center (E/GC1), 325     |
|                  | Broadway, Boulder Colorado, 80303, U.S.A.         |
+------------------+---------------------------------------------------+

**Seismic Datasets**

+------------------+---------------------------------------------------+
| **se             | **Catalog of global seismicity, 1964-1991**       |
| ismcty/isc_cat** |                                                   |
+------------------+---------------------------------------------------+
| Data type:       | Earthquake hypocenters for 1964-1991, probably    |
|                  | complete for teleseismic events with body-wave    |
|                  | magnitude m~b~ \> 5.0                             |
+------------------+---------------------------------------------------+
| Geographic       | Full coverage                                     |
| extent:          |                                                   |
+------------------+---------------------------------------------------+
| Projection:      | Geographic (decimal degrees)                      |
+------------------+---------------------------------------------------+
| Point            | */norpac/data/seismcty/info/isc_cat.pat* contains |
| attributes:      | attributes:                                       |
|                  |                                                   |
|                  | \[Isc_cat-id\], \[Year\], \[Month\], \[Day\],     |
|                  | \[Hour\], \[Minute\], \[Second\], \[Depth\],      |
|                  | \[Magnitude\]                                     |
+------------------+---------------------------------------------------+
| **Legends:**     | Two separate legends are available,               |
|                  | *isc_cat.avl*, and *mag##.avl*. *isc_cat.avl*     |
|                  | displays earthquakes color-coded by depth, not by |
|                  | magnitude (since many earthquakes in the ISC      |
|                  | catalog have no assigned magnitude). *mag##.avl*  |
|                  | is a series of eight legends designed             |
|                  | respectively for use with earthquakes of          |
|                  | magnitudes in the range (## to ##+5)/10 (for      |
|                  | example, *mag40.avl* refers to earthquakes with   |
|                  | 4.0 [\<]{.underline} magnitude \< 4.5), in which  |
|                  | symbol size increases with increasing magnitude   |
|                  | range but earthquakes are also color-coded by     |
|                  | depth as in *isc_cat.avl*. The eight *mag##.avl*  |
|                  | legends together provide a bivariate legend,      |
|                  | simultaneously coding for size and depth, when    |
|                  | applied to the shape files                        |
|                  | */norpac/data/examples/mag##.shp* which contain   |
|                  | all earthquakes for which magnitudes are          |
|                  | assigned.                                         |
+------------------+---------------------------------------------------+
| Primary          | Whiteside and others (1996)                       |
| reference:       |                                                   |
+------------------+---------------------------------------------------+
| Further          | R.J. Willemann, International Seismological       |
| information:     | Centre, United Kingdom, RG 19 4NS                 |
|                  |                                                   |
|                  | http://www.isc.ac.uk/                             |
+------------------+---------------------------------------------------+

*Notes for seismcty/isc_cat*

Earthquake focal-plane solutions ("beach-ball" diagrams) are available
for individual earthquakes from
http://www.seismology.harvard.edu/CMTsearch.html We lack software to
plot focal mechanisms within ESRI software packages.

  ---------------------- ----------------------------------------------------
  **seismcty/ak_seis**   **Alaska state seismicity, 1898-1998**

  Data type:             Earthquake hypocenters for 1898-1998

  Geographic extent:     Alaska

  Projection:            Geographic (decimal degrees)
  ---------------------- ----------------------------------------------------

+------------------+---------------------------------------------------+
| Point            | */norpac/data/seismcty/info/ak_seis.pat* contains |
| attributes:      | attributes:                                       |
|                  |                                                   |
|                  | \[Lat\] = Latitude of hypocenter                  |
|                  |                                                   |
|                  | \[Lon\] = Longitude of hypocenter                 |
|                  |                                                   |
|                  | \[Depth\] = Depth of hypocenter                   |
|                  |                                                   |
|                  | \[Date\] = Date of Earthquake                     |
|                  |                                                   |
|                  | \[Doy\] = Julian day of a year                    |
|                  |                                                   |
|                  | \[Time_utc\] = UTC time of earthquake origin      |
|                  |                                                   |
|                  | \[ML\] = Local (or Richter)magnitude, or the best |
|                  | etimate magnitude for events prior to 1988        |
|                  |                                                   |
|                  | \[Mb\] = Body wave magnitude (1 second period)    |
|                  |                                                   |
|                  | \[Ms\] = Surface wave magnitude (20 second        |
|                  | period)                                           |
|                  |                                                   |
|                  | \[Mw} = Moment magnitude (more robust energy at   |
|                  | high magnitude)                                   |
+------------------+---------------------------------------------------+
| Legends:         | The ISC legend, *isc_cat.avl*, can be applied to  |
|                  | this dataset. *isc_cat.avl* displays earthquakes  |
|                  | color-coded by depth, not by magnitude.           |
+------------------+---------------------------------------------------+
| Primary          | Hansen and others (1999)                          |
| reference:       |                                                   |
+------------------+---------------------------------------------------+
| Further          | Roger Hansen, State Seismologist, State           |
| information:     | Seismologists Office, Alaska Earthquake           |
|                  | Information Center, University of Alaska          |
|                  | Geophysical Institute, Fairbanks, Alaska.         |
+------------------+---------------------------------------------------+

**Ship Trackline Datasets**

+------------------+---------------------------------------------------+
| **sh             | **Ship trackline for geophysical cruises          |
| iptrax/ew94_09** | EW94-09**                                         |
+------------------+---------------------------------------------------+
| **sh             | **Ship trackline for geophysical cruises          |
| iptrax/ew94_10** | EW94-10**                                         |
+------------------+---------------------------------------------------+
| Data type:       | Tracklines for marine non-proprietary             |
|                  | deep-crustal seismic reflection profiles recorded |
|                  | in July and August 1994 by the UNOLS vessel R/V   |
|                  | Ewing in the Bering and Chukchi seas and around   |
|                  | the Aleutians; latitude and longitude             |
|                  | co-ordinates for every 10th seismic source        |
|                  | position (variously every 500 m or 750 m along    |
|                  | the track-line)                                   |
+------------------+---------------------------------------------------+
| Geographic       | Full coverage                                     |
| extent:          |                                                   |
+------------------+---------------------------------------------------+
| Projection:      | Point data                                        |
+------------------+---------------------------------------------------+
| Error estimates: | Dataset contains every 10th source-point;         |
|                  | original dataset contains every datapoint,        |
|                  | measured with single-station GPS                  |
+------------------+---------------------------------------------------+
| Primary          | Bering-Chukchi Working Group (1999); Brocher and  |
| reference:       | others (1995); Fliedner and Klemperer (1999);     |
|                  | Holbrook and others (1999)                        |
|                  |                                                   |
|                  | \[original datasets also include underway deep    |
|                  | seismic reflection profiling; gravity; magnetic;  |
|                  | 3.5 kHz profiler; occasional sonobuoy recordings; |
|                  | and recordings by on-land refraction seismographs |
|                  | and by ocean-bottom seismographs (OBS)\]          |
+------------------+---------------------------------------------------+
| Further          | Simon Klemperer, sklemp@geo.stanford.edu;         |
| information:     |                                                   |
|                  | http://geo.stanford.                              |
|                  | edu/\~sklemp/bering_chukchi/alaska.overview.html; |
|                  |                                                   |
|                  | http://                                           |
|                  | www.gg.uwyo.edu/faculty/holbrook/aleut/aleut.html |
+------------------+---------------------------------------------------+

Terrane and Tectonic Assemblage Datasets

  ------------------------------ ----------------------------------------------------
  **terranes/alaska/terr_lnd**   **Terrane map of Alaska**

  Data type:                     Terrane and overlap assemblage map derived from
                                 extensive geologic mapping and associated tectonic
                                 studies suggesting that most of the region can be
                                 interpreted as a collage of fault-bounded
                                 tectonostratigraphic terranes accreted onto
                                 continental margins around the Circum-North Pacific
                                 mainly during the Mesozoic and Cenozoic

  Geographic extent:             Alaska onshore only

  Projection:                    Lambert Azimuthal; center of projection at 165°W,
                                 70°N

  Source scale:                  1:2,500,000 (i.e. the same scale as
                                 *geology/ak_geol* but properly projected)

  Data documentation:            A description of the terranes is contained in files
                                 *terranes/alaska/explanat/mapexpln.\*\*\**
  ------------------------------ ----------------------------------------------------

+------------------+---------------------------------------------------+
| Polygon          | \[Unit\] = Map Unit Abbreviation                  |
| attributes:      |                                                   |
|                  | \[Age\] = Geologic Age                            |
+------------------+---------------------------------------------------+
| Legend:          | The legend, contained in the file                 |
|                  | *data/legends/terranes/alaska/terrane.avl*, is    |
|                  | colored according to tectonic environment for     |
|                  | terranes and according to age for overlap         |
|                  | assemblages.                                      |
+------------------+---------------------------------------------------+
| Primary          | Nokleberg and others (1994b)                      |
| reference:       |                                                   |
+------------------+---------------------------------------------------+
| Further          | Compiled in ARC/INFO format by Keri L. Brennan    |
| information:     |                                                   |
+------------------+---------------------------------------------------+

+------------------+---------------------------------------------------+
| **terranes/c     | **Tectonic assemblage map of the Canadian         |
| anada/assemblg** | Cordillera**                                      |
+------------------+---------------------------------------------------+
| Data type:       | Tectonic assemblages, plutonic suites, and        |
|                  | terranes for the western part of Canada,          |
|                  | originally compiled at 1:1,000,000 scale by       |
|                  | Wheeler and McFeeley (1991) from published        |
|                  | geologic maps, reports, university theses, and    |
|                  | unpublished data of the GSC, the British Columbia |
|                  | Geological Survey, the Department of Indian and   |
|                  | Northern Affairs, and the U.S. Geological Survey  |
+------------------+---------------------------------------------------+
| Geographic       | West = 145°W; North = 72°N; East = 108°W; South = |
| extent:          | 48°N                                              |
+------------------+---------------------------------------------------+
| Projection:      | ## Lambert, standard parallels 49° a              |
|                  | nd 77°N, central meridian 95°W, Y-shift 6,585,000 |
+------------------+---------------------------------------------------+
| Source scale:    | 1:1,000,000                                       |
+------------------+---------------------------------------------------+
| Data             | A description of each terrane or tectonic         |
| documentation:   | assemblage is contained in multiple ASCII files   |
|                  | /*terranes/canada/explana/tectonic/\*\*\*.txt*    |
|                  | and */terranes/canada/explana/                    |
|                  | terrane/\*\*\*.txt*, where \*\*\* corresponds to  |
|                  | the map-unit identifying abbreviation; an         |
|                  | overview of data on the source CD-ROM is          |
|                  | contained in /*terranes/canada/explanat/          |
|                  | cdexpln.doc*                                      |
+------------------+---------------------------------------------------+
| Polygon          | */norpac/data/terranes/canada/info/assemblg.pat*  |
| attributes:      | contains attributes:                              |
|                  |                                                   |
|                  | \[Tecunit\] A tectonic unit apart from terrane    |
|                  |                                                   |
|                  | \[Terunit\] e.g. KTN.                             |
|                  |                                                   |
|                  | \[Name\] e.g. Nanaimo                             |
|                  |                                                   |
|                  | \[Rock_clas\] e.g. sedimentary                    |
|                  |                                                   |
|                  | \[Rock_type\] e.g. sandstone/conglomerate/shale   |
|                  |                                                   |
|                  | \[Descript\] e.g. non-marine calc-alkaline arc    |
|                  | volcanics                                         |
|                  |                                                   |
|                  | \[Belt\] e.g. Insular/Coast                       |
|                  |                                                   |
|                  | \[Terrane\] e.g. Admiralty                        |
|                  |                                                   |
|                  | \[Era_epoch\] e.g. Neogene                        |
|                  |                                                   |
|                  | \[Age_max\]                                       |
|                  |                                                   |
|                  | \[Age_min\]                                       |
|                  |                                                   |
|                  | \[Textfile\] e.g. ntp.txt (text for Neogene       |
|                  | Pemberton volcanics)                              |
|                  |                                                   |
|                  | \[Vmunit\] e.g. CAV                               |
|                  |                                                   |
|                  | \[Superterr\] e.g. Insular                        |
|                  |                                                   |
|                  | \[Subterr\] e.g. Okanagan                         |
|                  |                                                   |
|                  | \[Tertype\] e.g. Oceanic island arc               |
|                  |                                                   |
|                  | \[Description\] e.g. Amalgamated by latest        |
|                  | Triassic time and accreted to Ancestral North     |
|                  | America in the Jurassic                           |
|                  |                                                   |
|                  | \[Assemblage\] e.g. lPmv (undifferentiated, lower |
|                  | Paleozoic, craton-related metavolcanic rocks)     |
|                  |                                                   |
|                  | \[Plutons\] e.g. Epnt (Early Paleozoic Tochieka   |
|                  | orthogneiss)                                      |
+------------------+---------------------------------------------------+
| Primary          | GIS Map Library: A Window on Cordillera Geology   |
| reference:       | CD-ROM: Journeay and Williams (1995)              |
+------------------+---------------------------------------------------+
| Further          |                                                   |
| information:     |                                                   |
+------------------+---------------------------------------------------+

*Notes for /terranes/canada/assemblg*

Each terrane of the Canadian Cordillera is an assemblage or assemblages
of rocks whose paleogeographic setting with respect to adjacent terranes
is known or suspected to be a major fault. Terranes are categorized
according to their relationship to the ancestral North American craton
and flanking miogeoclinal strata present along the continental margin in
early Paleozoic time. Displaced continental margin terranes have a
stratigraphic record similar to that of Ancestral North America.
Pericratonic terranes represent rocks that were originally contiguous
with, but distal to, the North American Continental Margin. Accreted
terranes represent oceanic and/or island arc assemblages of unknown or
uncertain paleogeographic origin, which are clearly allochthonous with
respect to Ancestral North America. Pre-accretionary plutonic
assemblages are included in the terranes, whereas post-accretionary
plutons are shown separately. Plutonic suites are subdivided on the
basis of age and composition and are grouped into magmatic episodes.

  ------------------------------- ----------------------------------------------------
  **terranes/nor_pac**            **Terrane and Overlap Assemblage Map of the
                                  Circum-North Pacific**

  **terranes/nor_pac/basins**     **Outlines of Mesozoic and Cenozoic basins**

  **terranes/nor_pac/coast**      **Coastline**

  **terranes/nor_pac/flts_lnd**   **Onshore faults**

  **terranes/nor_pac/flts_ocn**   **Offshore faults**

  **terranes/nor_pac/flts_pos**   **Post-accretionary faults, onshore and offshore**

  **terranes/nor_pac/mag_lins**   **Magnetic lineaments**

  **terranes/nor_pac/ocn_geol**   **Oceanic geology**

  **terranes/nor_pac/sea_mnts**   **Seamounts**

  **terranes/nor_pac/terr_lnd**   **Onshore terranes**

  **terranes/nor_pac/terr_ocn**   **Offshore terranes**

  Data type:                      Terrane and overlap assemblage map, and major
                                  offshore geologic features, along with map
                                  explanation and stratigraphic columns; derived from
                                  extensive geologic mapping and associated tectonic
                                  studies suggesting that most of the region can be
                                  interpreted as a collage of fault-bounded
                                  tectonostratigraphic terranes accreted onto
                                  continental margins around the Circum-North Pacific
                                  mainly during the Mesozoic and Cenozoic

  Geographic extent:              Full coverage

  Projection:                     Lambert Azimuthal; center of projection at 165°W,
                                  70°N

  Source scale:                   1:10,000,000 with vertices at about 1 km

  Data documentation:             A lengthy text explanation for the entire terrane
                                  map, including cited references, is provided in the
                                  files
                                  /*terranes/nor_pac**/**explanat/mapexpln.\*\*\*;* a
                                  brief description of each terrane or overlap
                                  assemblage is contained in files
                                  /*terranes/nor_pac/explanat/assemblg/\*\*\*.txt* or
                                  */terranes/nor_pac/explanat/terranes/\*\*\*.txt*;
                                  and a summary characteristic stratigraphic column
                                  for each terrane or overlap assemblage in files
                                  /*terranes/nor_pac/explanat/columns/\*\*\*.pdf*,
                                  where *\*\*\** corresponds to the map-unit
                                  identifying abbreviation, *\*\*\*.doc* are Word
                                  documents, *\*\*\*.pdf* are Adobe Acrobat files, and
                                  *\*\*\*.txt* are ASCII text files

  Arc attributes:                 **terranes/nor_pac/flts_lnd** *-
                                  /norpac/data/terranes/nor_pac/flts_lad* contains the
                                  attribute: \[Ltype\] = Fault Name and Type, e.g.
                                  "Thrust fault, certain"
  ------------------------------- ----------------------------------------------------

+------------------+---------------------------------------------------+
| Polygon          | **terranes/nor_pac/flts_lnd** -                   |
| attributes:      | */norpac/data/terranes/nor_pac/info/terr_lnd.pat* |
|                  | contains the attributes*:*                        |
|                  |                                                   |
|                  | \[terrane_abbrev\] = map abbreviation (typically  |
|                  | three letters) for each tectonostratigraphic      |
|                  | terrane (individual polygons can be either a      |
|                  | terrane or an overlap assemblage, but not both)   |
|                  |                                                   |
|                  | \[overlap_abbrev\] = map abbreviation (typically  |
|                  | three letters) for each overlap assemblage        |
|                  |                                                   |
|                  | \[overlap_name\] = geologic abbreviation          |
|                  | summarizing age and lithology of each overlap     |
|                  | assemblage, e.g. Czs for Cenozoic sedimentary     |
|                  | rocks                                             |
|                  |                                                   |
|                  | \[terrane_igneous\] = geologic abbreviation       |
|                  | summarizing age and lithology of pre-accretionary |
|                  | plutonic units, e.g. Kpfi for a Cretaceous        |
|                  | plutonic felsic intrusive                         |
|                  |                                                   |
|                  | \[terrane_name\] = terrane name spelled out in    |
|                  | full, e.g. Endicott Mountains terrane, Arctic     |
|                  | Alaska Superterrane"                              |
|                  |                                                   |
|                  | \[tectonic_environ\] = tectonic environment of    |
|                  | formation of each terrane, e.g. "island arc"      |
|                  |                                                   |
|                  | terranes/nor_pac/flts_ocn -                       |
|                  | */norpac/data/terranes/nor_pac/info/terr_ocn.pat* |
|                  | contains the attributes*:*                        |
|                  |                                                   |
|                  | \[Tectonicterranes\] = map abbreviation for each  |
|                  | tectonostratigraphic terrane                      |
|                  |                                                   |
|                  | \[Mapunits\] = geologic abbreviation summarizing  |
|                  | age and lithology of each overlap assemblage,     |
|                  | e.g. Czs for Cenozoic sedimentary rocks           |
|                  |                                                   |
|                  | \[Assemblages\] e.g. Kw for Kuskokwim Group       |
|                  |                                                   |
|                  | \[Land/ocean\] is set as OCEAN                    |
+------------------+---------------------------------------------------+
| Legends:         | The complete legend (explanation) is contained in |
|                  | the directory                                     |
|                  | /norpac/data/terranes/nor_pac/explanat in the     |
|                  | files mapexpln.doc and mapexplan.pdf.             |
+------------------+---------------------------------------------------+
| Primary          | Nokleberg and others (1994b)                      |
| reference:       |                                                   |
+------------------+---------------------------------------------------+
| Further          | Warren J. Nokleberg (USGS), wnokleberg@usgs.gov   |
| information:     |                                                   |
+------------------+---------------------------------------------------+

*Notes for terranes /nor_pac*

A key definition for the map is *tectonostratigraphic terrane.* A
tectonostratigraphic terrane (hereafter referred to as *terrane*) is a
fault-bounded, stratigraphically coherent assemblage that formed before
accretion, i.e. tectonic juxtaposition, to adjacent units. A few
terranes are fault-bounded structural complexes, mainly subduction zone
or accretionary-wedge complexes. The terranes are bounded by various
types of major faults or fault zones, termed sutures.

Terranes are interpreted according to inferred tectonic environments:
(1) cratonal; (2) passive continental margin; (3) metamorphosed
continental margin; (4) continental-margin arc; (5) island arc; (6)
oceanic crust, seamount, and ophiolite; (7) accretionary wedge and
subduction zone; (8) turbidite basin; and (9) metamorphic for terranes
that are too highly-deformed and metamorphosed to determine the original
tectonic environment. For terranes with complex geologic histories, the
assignation indicates the tectonic environment most prevalent during
this history of the terrane.

Tectonic environments inferred for igneous rocks are both temporal
(pre-accretion and post-accretion) and genetic (subduction-related,
rift-related, and collision (anatectic)-related).

Post-accretion units that include: (1) Cenozoic and Mesozoic overlap
assemblages of sedimentary and volcanic rocks that are deposited across
two or more terranes that formed generally after accretion of most
terranes in the region; (2) Cenozoic and Mesozoic basinal deposits that
occur within a terrane or on the craton; and (3) plutonic rocks.
Post-accretion igneous units are identified by age-lithologic
abbreviations and by name. Some Cenozoic and Mesozoic overlap
assemblages and basinal deposits, as well as fragments of terranes, are
extensively offset by movement along post-accretion faults.

Onshore, the map depicts major pre-accretion plutonic rocks that are
limited to individual terranes. Offshore, the map depicts major oceanic
plates, ocean-floor magnetic lineations, oceanic spreading ridges, and
seamounts. Significant differences exist between the representation of
onshore and offshore geology: (1) the offshore part is depicted in a
more schematic fashion because of more limited data and because the
offshore terranes and early Cenozoic and older overlap assemblages
generally are obscured by extensive late Cenozoic sedimentary cover that
is not shown unless thicker than about 2 km; (2) marginal contacts of
offshore Cenozoic and Cretaceous sedimentary basins do not match
contacts of onshore Cenozoic and Cretaceous sedimentary units because
offshore basins are limited to those regions with sediment thicknesses
greater than two km; (3) stratigraphic columns are provided only for
onshore terranes because the geology of offshore terranes is generally
less well-known; and (4) for simplicity, the major onshore Cenozoic
sedimentary basins are generally not defined and described separately.

**Topographic Datasets (Raster)**

+------------------+---------------------------------------------------+
| **topogrfy       | **5'-sampled land topography and marine           |
| /raster/etopo5** | bathymetry**                                      |
+------------------+---------------------------------------------------+
| Data type:       | Raster land topography and marine bathymetry from |
|                  | ETOPO5, a global digital elevation model (DEM)    |
|                  | with a horizontal grid spacing of 5 arc minutes;  |
|                  |                                                   |
|                  | data sources include: ocean Areas: U.S. Naval     |
|                  | Oceanographic Office; U.S.A. and Japan: U.S.      |
|                  | Defense Mapping Agency; other land masses: U.S.   |
|                  | Navy Fleet Numerical Oceanographic Center.        |
+------------------+---------------------------------------------------+
| Geographic       | Full coverage                                     |
| extent:          |                                                   |
+------------------+---------------------------------------------------+
| Projection:      | Latitude and longitude grid                       |
+------------------+---------------------------------------------------+
| Source grid      | 5 arc-minutes (c. 9 km); in some areas true       |
| interval:        | resolution may be lower                           |
+------------------+---------------------------------------------------+
| Point            | Elevations in meters representing the elevation   |
| attributes:      | of the center of each cell                        |
+------------------+---------------------------------------------------+
| Range:           | -9067 to +3657 m                                  |
+------------------+---------------------------------------------------+
| Spatial          | Resolution of the gridded data varies from true   |
| resolution:      | 5-minute for the ocean floors, the U.S.A. and     |
|                  | Japan, to 1 degree in data-deficient parts of     |
|                  | Asia and northern Canada                          |
+------------------+---------------------------------------------------+
| Error estimates: | In general, the dataset for the USA is most       |
|                  | precise, having a vertical resolution of 1 m.     |
|                  | Data for Asia vary in resolution from +/- a few   |
|                  | meters to only representing every 150m, depending |
|                  | on the available source data. Very little detail  |
|                  | is contained in the oceanic data shallower than   |
|                  | 200m; the interpolation algorithm used by the US  |
|                  | Navy to create the oceanic grid from contour      |
|                  | charts was set to an arbitrary cutoff of -10m     |
|                  | wherever the algorithm would have \"overshot\"    |
|                  | and marked points as above sea level.             |
|                  |                                                   |
|                  | Because the pixel size in ETOPO5 is about 9 km,   |
|                  | one should anticipate discrepancies of this       |
|                  | magnitude when comparing ETOPO5 to                |
|                  | higher-resolution products, e.g. GTOPO30.         |
+------------------+---------------------------------------------------+
| Primary          | Hittelman and others (1994); NOAA (1988)          |
| reference:       |                                                   |
+------------------+---------------------------------------------------+
| Further          | http://web.ngdc.noaa.gov/mgg/global/etopo5.HTML;  |
| information:     | psloss@ngdc.noaa.gov                              |
+------------------+---------------------------------------------------+

+------------------+---------------------------------------------------+
| **topogrfy       | **2'-sampled land topography and marine           |
| /raster/gtopo2** | bathymetry**                                      |
+------------------+---------------------------------------------------+
| Data type:       | Raster topography (land areas only) from GTOPO30. |
|                  | See below description. Bathymetry has been        |
|                  | resampled from ship tracks                        |
+------------------+---------------------------------------------------+
| Geographic       | Full coverage to 70°N                             |
| extent:          |                                                   |
+------------------+---------------------------------------------------+
| Projection:      | Mercator                                          |
+------------------+---------------------------------------------------+
| Source grid      | 2 arc-minutes (c. 4 km)                           |
| interval:        |                                                   |
+------------------+---------------------------------------------------+
| Point            | Decimal degrees of latitude and longitude         |
| attributes:      | referenced to WGS84;                              |
|                  |                                                   |
|                  | vertical units are meters.                        |
+------------------+---------------------------------------------------+
| Range:           | -9561 to +5625 m                                  |
+------------------+---------------------------------------------------+
| Primary          | Smith and Sandwell (1997)                         |
| reference:       |                                                   |
+------------------+---------------------------------------------------+
| Further          | http://topex.ucsd.edu/marine_grav/mar_grav.html   |
| information:     |                                                   |
+------------------+---------------------------------------------------+

  ----------------------------- ----------------------------------------------------
  **topogrfy/raster/gtopo30**   **30"-sampled topography (land only)**

  ----------------------------- ----------------------------------------------------

+------------------+---------------------------------------------------+
| **topogrfy/r     | **30"-sampled topography illuminated by sun from  |
| aster/hillshad** | 315° at 45° elevation**                           |
+------------------+---------------------------------------------------+
| Data type:       | Raster topography (land areas only) from GTOPO30, |
|                  | a global digital elevation model (DEM) with a     |
|                  | horizontal grid spacing of 30 arc seconds; the    |
|                  | major data source for Asia and Canada is Digital  |
|                  | Terrain Elevation Data, a raster topographic base |
|                  | with a horizontal grid spacing of 3 arc-seconds,  |
|                  | produced by National Imagery and Mapping Agency   |
|                  | (formerly DMA); the major data source for the USA |
|                  | is USGS "1-degree DEMs" (Digital Elevation Models |
|                  | distributed in 1° blocks), also with a horizontal |
|                  | grid spacing of 3 arc-seconds; one representative |
|                  | elevation value was selected (by median value for |
|                  | Asia and by systematic subsampling for North      |
|                  | America) to represent the area covered by 100     |
|                  | full-resolution cells (10 by 10 matrix).          |
|                  |                                                   |
|                  | The effect of illumination with a sun angle of    |
|                  | 45° from the northwest (315°) was computed using  |
|                  | the ESRI Spatial Analyst module, and this derived |
|                  | dataset saved as /*raster/hillshad.*              |
+------------------+---------------------------------------------------+
| Geographic       | Full coverage                                     |
| extent:          |                                                   |
+------------------+---------------------------------------------------+
| Projection:      | Latitude and longitude grid                       |
+------------------+---------------------------------------------------+
| Source grid      | 30 arc-seconds (c. 1 km)                          |
| interval:        |                                                   |
+------------------+---------------------------------------------------+
| Point            | Decimal degrees of latitude and longitude         |
| attributes:      | referenced to WGS84;                              |
|                  |                                                   |
|                  | vertical units are elevation above sea-level in   |
|                  | meters;                                           |
|                  |                                                   |
|                  | ocean values are masked as "no data" and have     |
|                  | been assigned a value of -9999                    |
+------------------+---------------------------------------------------+
| Range:           | +1 to +6009 m                                     |
+------------------+---------------------------------------------------+
| Error estimates: | ±18 m root mean square error, with higher         |
|                  | relative accuracy                                 |
+------------------+---------------------------------------------------+
| Primary          | GTOPO30: U.S. Geological Survey (1997)            |
| reference:       |                                                   |
+------------------+---------------------------------------------------+
| Further          | http:/                                            |
| information:     | /edcwww.cr.usgs.gov/landdaac/gtopo30/gtopo30.html |
+------------------+---------------------------------------------------+

**Topographic Datasets (Vector)**

+------------------+---------------------------------------------------+
| **topogrfy/v     | **Bathymetry for US waters shallower than 200 m,  |
| ector/ak_shelf** | Beaufort Sea to the Aleutians (1:0.25M)**         |
+------------------+---------------------------------------------------+
| Data type:       | Bathymetric contours for offshore Alaska (from    |
|                  | the Alaska-Yukon border to Unimak Island in the   |
|                  | Aleutian Chain) to 200 m water depth;             |
|                  |                                                   |
|                  | derived from over 90 digitized NOAA-NOS maps      |
|                  | (90%) and point soundings from the NOS            |
|                  | Hydrographic CD-ROM (10%).                        |
+------------------+---------------------------------------------------+
| Geographic       | West = 178°W North = 74°N East = 138°W South =    |
| extent:          | 53°N                                              |
+------------------+---------------------------------------------------+
| Projection:      | geographic units, -180°/0°/+180°, NAD 1927        |
+------------------+---------------------------------------------------+
| Source scale:    | 1:250,000                                         |
+------------------+---------------------------------------------------+
| Arc attributes:  | \[Elevation\] = depth below sea level, in         |
|                  | negative meters                                   |
|                  |                                                   |
|                  | +999 = arc defining boundary, holiday area, or    |
|                  | used to clip dangling contours to next shallowest |
|                  | contour                                           |
|                  |                                                   |
|                  | \[Methods\] = method used to develop contours     |
|                  |                                                   |
|                  | DIGITIZE = digitized from paper NOS maps          |
|                  |                                                   |
|                  | GENERATE = generated from NOS digital survey      |
|                  | point data                                        |
+------------------+---------------------------------------------------+
| Polygon          | */norpac/data/topogrfy/vector/info/ak_shelf.pat*  |
| attributes:      | contains the attribute:                           |
|                  |                                                   |
|                  | \[Elevation\] = mid-value between arc values (-5m |
|                  | to -195m)                                         |
|                  |                                                   |
|                  | +999 = \"holiday areas\" where no data were       |
|                  | collected                                         |
|                  |                                                   |
|                  | -999 = polygons deeper than 200m                  |
|                  |                                                   |
|                  | +998 = enclosed polygons outside map area         |
|                  |                                                   |
|                  | +5 = land polygons                                |
+------------------+---------------------------------------------------+
| Range:           | 0m to -200m                                       |
+------------------+---------------------------------------------------+
| Depth            | 10 m                                              |
| resolution:      |                                                   |
+------------------+---------------------------------------------------+
| Primary          | Alaska Biological Science Center (1998)           |
| reference:       |                                                   |
+------------------+---------------------------------------------------+
| Further          | http://                                           |
| information:     | www.absc.usgs.gov/research/bering/bathy/index.htm |
+------------------+---------------------------------------------------+

+------------------+---------------------------------------------------+
| **topogrfy/v     | **Bathymetry for Bering and Chukchi Seas, US and  |
| ector/ber_chuk** | Russian waters (1:2.5M)**                         |
+------------------+---------------------------------------------------+
| Data type:       | Bathymetric contours for Chukchi Sea and Bering   |
|                  | Straits;                                          |
|                  |                                                   |
|                  | a single Bering/Chukchi Sea coverage was created  |
|                  | by joining two USGS Open File Report maps: The    |
|                  | Bathymetric Map of the Chukchi Sea and Arctic     |
|                  | Ocean (USGS OFR 76-823) and The Bathymetric Map   |
|                  | of the Aleutian Trench and Bering Sea (USGS OFR   |
|                  | 76-821)                                           |
+------------------+---------------------------------------------------+
| Geographic       | West = 206°W North = 76°N East = 130°W South =    |
| extent:          | 48°N                                              |
+------------------+---------------------------------------------------+
| Projection:      | Geographic units, 0°/-360°, NAD 1927              |
|                  |                                                   |
|                  | The USGS Bering and Chukchi Sea coverage crosses  |
|                  | the 180th meridian - a situation ARC/INFO does    |
|                  | not cope with well. To avoid this problem, it is  |
|                  | stored with longitudes in 0°/-360° format instead |
|                  | of the usual -180°/0°/+180° format. This allows   |
|                  | the coverage to be reprojected normally using the |
|                  | PROJECT command and standard projection files.    |
|                  |                                                   |
|                  | Note that reprojection may split arcs along the   |
|                  | 180th meridian; inspect the coverage before use   |
|                  | (note: ArcView may not be able to reproject from  |
|                  | this format into certain projections.)            |
+------------------+---------------------------------------------------+
| Source scale:    | 1: 2,500,000                                      |
+------------------+---------------------------------------------------+
| Arc attributes:  | \[Depth\] = depth below sea level, in positive    |
|                  | meters                                            |
|                  |                                                   |
|                  | \[Class\] = function of arc                       |
|                  |                                                   |
|                  | 0 = digitized bathymetric contours                |
|                  |                                                   |
|                  | 8 = arcs added to close polygons                  |
|                  |                                                   |
|                  | 9 = coastlines                                    |
+------------------+---------------------------------------------------+
| Polygon          | */norpac/data/topogrfy/vector/info/ber_chuk.pat*  |
| attributes:      | contains the attributes:                          |
|                  |                                                   |
|                  | \[Mid-depth\] = mid-value between arc values (25  |
|                  | m to 8,000 m)                                     |
|                  |                                                   |
|                  | \[Mid-elevation\] = mid-value between arc values, |
|                  | as a negative number (-25 m to --8,000 m)         |
+------------------+---------------------------------------------------+
| Range:           | 0 to 8,000 m                                      |
+------------------+---------------------------------------------------+
| Depth            | varies, 10-400 m                                  |
| resolution:      |                                                   |
+------------------+---------------------------------------------------+
| Primary          | Schumacher (1976a & b); Alaska Biological Science |
| reference:       | Center (1998)                                     |
+------------------+---------------------------------------------------+
| Further          | http://                                           |
| information:     | www.absc.usgs.gov/research/bering/bathy/index.htm |
+------------------+---------------------------------------------------+

+------------------+---------------------------------------------------+
| **topogrfy/      | **Bathymetry for Chukchi Sea and Bering Straits,  |
| vector/chukchi** | US and Russian waters (1:1M)**                    |
+------------------+---------------------------------------------------+
| Data type:       | Bathymetric contours for Chukchi Sea and Bering   |
|                  | Straits                                           |
+------------------+---------------------------------------------------+
| Geographic       | West = 176°W North = 74.5°N East = 153°W South =  |
| extent:          | 65.5°N;                                           |
|                  |                                                   |
|                  | Chukchi Sea from Smith Bay, Alaska (east of Point |
|                  | Barrow) to Herald Island, Russia (east of Wrangel |
|                  | Island) and south to the Bering Strait            |
+------------------+---------------------------------------------------+
| Projection:      | geographic units, -180°/0°/+180°, NAD 1927        |
+------------------+---------------------------------------------------+
| Source scale:    | 1:1,000,000                                       |
+------------------+---------------------------------------------------+
| Arc attributes:  | \[Depth\] = depth below sea level, in positive    |
|                  | meters                                            |
|                  |                                                   |
|                  | -999 = arc defining boundary, holiday area, or    |
|                  | used to clip dangling contours to next shallowest |
|                  | contour                                           |
|                  |                                                   |
|                  | \[Class\] = method used to develop contours       |
|                  |                                                   |
|                  | 0 = digitized bathymetric contours                |
|                  |                                                   |
|                  | 8 = arcs added to close polygons                  |
|                  |                                                   |
|                  | 9 = coastlines                                    |
+------------------+---------------------------------------------------+
| Polygon          | */norpac/data/topogrfy/vector/info/chukchi.pat*   |
| attributes:      | contains the attributes:                          |
|                  |                                                   |
|                  | \[Mid-depth\] = mid-value between arc values (5m  |
|                  | to 3500m)                                         |
|                  |                                                   |
|                  | \[Mid-elevation\] = mid-value between arc values, |
|                  | as a negative number (-5m to -3500m)              |
+------------------+---------------------------------------------------+
| Range:           | 0 m to 3000 m                                     |
+------------------+---------------------------------------------------+
| Depth            | Varies with depth: 10 m (10-100 m); 100 m         |
| resolution:      | (100-1000 m); 1000 m (\>1000 m)                   |
+------------------+---------------------------------------------------+

  ------------------ ----------------------------------------------------------
  Primary reference: Hill and others (1984); Alaska Biological Science Center
                     (1998)

  Further            http://www.absc.usgs.gov/research/bering/bathy/index.htm
  information:       
  ------------------ ----------------------------------------------------------

+------------------+---------------------------------------------------+
| **topogrfy/      | **Circum-North Pacific topography and bathymetry  |
| vector/nor_pac** | (1:10M)**                                         |
+------------------+---------------------------------------------------+
| **topogrfy       | **Major drainages, circum-North Pacific**         |
| /vector/rivers** |                                                   |
+------------------+---------------------------------------------------+
| Data type:       | Contour areas as polygons for the circum-North    |
|                  | Pacific Region                                    |
+------------------+---------------------------------------------------+
| Geographic       | Full coverage                                     |
| extent:          |                                                   |
+------------------+---------------------------------------------------+
| Projection:      | Lambert azimuthal; center of projection at 165°W, |
|                  | 70°N                                              |
+------------------+---------------------------------------------------+
| Source scale:    | 1: 10,000,000 with 10 km digitizing vertices;     |
|                  | coastline from printed map was hand-inked on      |
|                  | mylar and scanned                                 |
+------------------+---------------------------------------------------+
| Polygon          | topogrfy/vector/nor_pac                           |
| attributes:      | */norpac/data/topogrfy/vector/info/nor_pac.pat*   |
|                  | contains the attribute:                           |
|                  |                                                   |
|                  | ## \[Meters\] =                                   |
|                  |  height of the lower contour line of the polygon. |
+------------------+---------------------------------------------------+
| Range:           | -9000 to +4000 m                                  |
+------------------+---------------------------------------------------+
| Depth            | Topography, from --9000 to +4000 m, at 1000 m     |
| resolution:      | increments, with additional contours at ±200 m    |
+------------------+---------------------------------------------------+
| Errors:          | These contours, coastline and drainages are       |
|                  | internally consistent, and were used as a base    |
|                  | for the Circum_North Pacific Terrane map (see     |
|                  | /*terranes/nor_pac*); however, they are           |
|                  | collectively offset from the coastlines in        |
|                  | GTOPO30 (see /*topogrfy/raster/gtopo30*) and the  |
|                  | World Vector Shoreline (see                       |
|                  | /*topogrfy/vector/shorline*) by up to several km, |
|                  | with magnitude and direction of the discrepancy   |
|                  | varying systematically across the coverage. The   |
|                  | magnitude of the discrepancy, about 5 km, is      |
|                  | equivalent to a 0.5 mm error in drafting and      |
|                  | digitizing the source 1:10M map. Note also        |
|                  | several islands are missing from this coverage    |
|                  | (including Nunivak, about 50,000 km^2^!) and at   |
|                  | least a few polygons are miscoded (see e.g.       |
|                  | apparent landmass east of the Shumagin Islands).  |
+------------------+---------------------------------------------------+
| Primary          | Moore (1990); digitized and compiled by D.S.      |
| reference:       | Aitken, B.S. Bennett, and W.J. Nokleberg (USGS,   |
|                  | Menlo Park); in Nokleberg and others (1994a).     |
+------------------+---------------------------------------------------+

+------------------+---------------------------------------------------+
| **topogrfy/v     | **World Vector Shoreline (WVS), designed for use  |
| ector/shorline** | at scales of up to 1:250,000**                    |
+------------------+---------------------------------------------------+
| Data type:       | Coastline for our entire Circum-North Pacific     |
|                  | area as arcs; originally created by Defense       |
|                  | Mapping Agency (now NIMA).                        |
|                  |                                                   |
|                  | The source material for WVS was DMA's Digital     |
|                  | Landmass Blanking (DLMB) data 3 arc-second raster |
|                  | grid, which in turn was derived primarily from    |
|                  | the Joint Operations Graphics and coastal         |
|                  | nautical charts produced by DMA                   |
+------------------+---------------------------------------------------+
| Geographic       | Full coverage                                     |
| extent:          |                                                   |
+------------------+---------------------------------------------------+
| Projection:      | Latitude and longitude (decimal degrees);         |
|                  | horizontal datum is WGS84; for vertical datum,    |
|                  | shoreline is based on Mean High Water             |
+------------------+---------------------------------------------------+
| Source grid      | WVS consists of vectors derived from a 3          |
| interval:        | arc-second raster grid                            |
+------------------+---------------------------------------------------+
| Horizontal       | 500 m: 90% of all identifiable shoreline features |
| accuracy:        | are located within 500 m (2.0 mm at 1:250,000)    |
|                  | circular error of their true geographic positions |
|                  | with respect to the                               |
|                  |                                                   |
|                  | preferred datum (WGS 84).                         |
+------------------+---------------------------------------------------+
| Primary          | Soluri and Woodson (1990)                         |
| reference:       |                                                   |
+------------------+---------------------------------------------------+
| Further          | http://www.tmpo.nima.mil/guides/dtf/wvs_vpf.html  |
| information:     |                                                   |
+------------------+---------------------------------------------------+

**Volcano Datasets**

  ------------------ ----------------------------------------------------
  **volcano**        **Historically active volcanoes**

  Data type:         Basic geographic and geologic information for
                     volcanoes thought to have been active in the last
                     10,000 years (Holocene)

  Geographic extent: Full coverage

  Projection:        Point data
  ------------------ ----------------------------------------------------

+------------------+---------------------------------------------------+
| Point            | */norpac/data/volcano/info/volcano.pat* contains  |
| attributes:      | the attributees:                                  |
|                  |                                                   |
|                  | \[Number\]= Unique identification number based on |
|                  | the scheme established for the \"Catalog of       |
|                  | Active Volcanoes of the World\" (CAVW)            |
|                  |                                                   |
|                  | \[Name\]                                          |
|                  |                                                   |
|                  | \[Location\] Geographical and/or political area,  |
|                  | e.g. Russia-NE                                    |
|                  |                                                   |
|                  | \[Elevation\] = Summit elevation in m             |
|                  |                                                   |
|                  | \[Type\] = Volcano morphology e.g.                |
|                  | "Stratovolcano" or "Calderas" LOCATION:           |
|                  |                                                   |
|                  | \[Status\] = Type of evidence for Holocene        |
|                  | activity                                          |
|                  |                                                   |
|                  | \[Time frame\] = Code indicating whether dated    |
|                  | eruptions have been recorded, and the time period |
|                  | of the volcano\'s last known eruption             |
+------------------+---------------------------------------------------+
| Primary          | Simkin and others (1994b) and unpublished         |
| reference:       | contributions by Thomas Simkin and Paul Mathieux, |
|                  | Smithsonian Institution, Global Volcanism Program |
+------------------+---------------------------------------------------+
| Further          | Simkin and others (1994a);                        |
| information:     | http://www.volcano.si.edu/gvp/                    |
+------------------+---------------------------------------------------+

DESCRIPTION OF VIEWS

Views Contained in */norpac/setup/norpac#.apr*

The following "views" have been created in the ArcView "projects"
*norpac1.apr* and *norpac2.apr*. Each view contains one or more
superimposed datasets, with the higher-numbered layers above and partly
concealing the lower-numbered layers. Most of these views contain, as
their top two layers, a latitude-longitude grid
(*/norpac/data/cultural/latlon12*), and the World Vector Shoreline
(*/norpac/data/topogrfy/vector/shorline*). Because these fiducial layers
are often repeated, their details are only shown in the summary table.
All these views have map units and distance units set to kilometers.

  ----------------------------- ------------ ---------------- -------------------------------------
  **View name as appearing in                                 
  the project                                                 
  /norpac/setup/norpac#.apr**                                 

  layer \#                      Theme name   Dataset location Legend location in
                                as it appear in               */norpac/data/legends*
                                on-screen    */norpac/data*   
  ----------------------------- ------------ ---------------- -------------------------------------

  -----------------------------------------------------------------------
  **Active Earth Example** - discussed below, see "Active Earth Example"

  -----------------------------------------------------------------------

  -----------------------------------------------------------------------
  **Magnetic - Lithologic Correlation Example** - discussed below, see
  "Magnetic - Lithologic Correlation Example"

  -----------------------------------------------------------------------

  -----------------------------------------------------------------------
  **Topography Example** - discussed below, see "Topography Example"

  -----------------------------------------------------------------------

  ------------ --------------------- --------------------- -------------------------------------
  **Cultural                                               
  Features**                                               

  5            Latitude/longitude    *cultural/latlong5*   Latitude and longitude grid at 5°
               grid (5°)                                   spacing

  4            Latitude/longitude    *cultural/latlon12*   Latitude and longitude grid at 12°
               grid (12°)                                  spacing

  3            Manmade features      *cultural/features*   Other socio-cultural features, such
                                                           as airports and golf-courses

  2            Cities                *cultural/cities*     Significant population centers

  1            International/state   *cultural/boundary*   International, provincial and state
               boundaries                                  boundaries
  ------------ --------------------- --------------------- -------------------------------------

  ------------- --------------- ------------------- -------------------------------------
  **Geology -                                       
  Alaska**                                          

  1             Geologic map of *geology/ak_geol*   Geologic map of Alaska
                Alaska                              
  ------------- --------------- ------------------- -------------------------------------

  ------------- --------------- -------------------- -------------------------------------
  **Geology -                                        
  Russia**                                           

  5             Impactites      *geology/rus_geol*   "Impactite" includes rocks with
                                                     characteristics of metamorphism but
                                                     chemical characteristics of primary
                                                     rocks

  4             Diaphthoritic   *geology/rus_geol*   "Diaphthorite Rocks" includes rocks
                rocks                                changed by retrogressive metamorphism

  3             Acoustic        *geology/rus_geol*   "Acoustic Basement" includes basement
                basement                             uplifts determined geophysically in
                                                     offshore areas

  2             Fault map of    *geology/rus_flts*   Fault map of Russia
                Russia                               

  1             Geologic map of *geology/rus_geol*   Geologic map of Russia
                Russia                               
  ------------- --------------- -------------------- -------------------------------------

  ------------- --------------- ----------------- -------------------------------------
  **Gravity -                                     
  DGRAV**                                         

  1             Onshore Bouguer *gravity/dgrav*   Onshore Bouguer gravity anomalies and
                and offshore                      offshore free-air gravity anomalies
                free-air                          
                gravity (mGal)                    
  ------------- --------------- ----------------- -------------------------------------

  ------------- --------------- ------------------ -------------------------------------
  **Gravity -                                      
  Geosat**                                         

  1             Satellite       *gravity/geosat*   Satellite-derived free-air gravity,
                free-air                           offshore areas only
                gravity (mGal)                     
  ------------- --------------- ------------------ -------------------------------------

  -------------- --------------- -------------------- -------------------------------------
  **Gravity -                                         
  Seasurface**                                        

  1              Satellite       *gravity/sea_surf*   Satellite-derived sea-surface heights
                 sea-surface                          
                 height (m)                           
  -------------- --------------- -------------------- -------------------------------------

  --------------- --------------- ------------------- -------------------------------------
  **Magnetics -                                       
  Alaska**                                            

  1               Magnetic map of *magnetic/ak_mag*   Magnetic map of Alaska (largely
                  Alaska (nT)                         onshore)
  --------------- --------------- ------------------- -------------------------------------

  --------------- --------------- --------------------- -------------------------------------
  **Magnetics -                                         
  Arctic**                                              

  1               Magnetic map of *magnetic/arct_mag*   magnetic map of the Arctic (largely
                  the Arctic (nT)                       offshore)
  --------------- --------------- --------------------- -------------------------------------

  --------------- --------------- ------------------- -------------------------------------
  **Magnetics -                                       
  DNAG**                                              

  **1**           **Magnetic map  magnetic/dnag_mag   **Magnetic map of North America,
                  of North                            onshore and offshore**
                  America (nT)**                      
  --------------- --------------- ------------------- -------------------------------------

  --------------- --------------- --------------------- -------------------------------------
  **Magnetics -                                         
  East Asia**                                           

  1               Magnetic map of *magnetic/asia_mag*   Magnetic map of Far East Asia
                  Far East Asia                         
                  (nT)                                  
  --------------- --------------- --------------------- -------------------------------------

  --------------- --------------- --------------------- -------------------------------------
  **Magnetics -                                         
  Russia**                                              

  1               Magnetic map of *magnetic/russ_mag*   Magnetic map of Russia
                  Russia (nT)                           
  --------------- --------------- --------------------- -------------------------------------

  -------------- --------------- -------------------- -------------------------------------
  **Reflection                                        
  Profile                                             
  Tracklines**                                        

  2              Ship trackline, *shiptrax/ew94_10*   Ship trackline for geophysical cruise
                 EW94-10                              EW94-10

  1              Ship trackline, *shiptrax/ew94_09*   Ship trackline for geophysical cruise
                 EW94-09                              EW94-09
  -------------- --------------- -------------------- -------------------------------------

  ---------------- --------------- -------------------- -------------------------------------
  **Seismicity**                                        

  1                Alaska state    *seismcty/ak_seis*   Alaska state seismicity, 1898-1998
                   seismicity                           
                   1898-1998                            

  2                Global          *seismcty/isc_cat*   Catalog of global seismicity,
                   seismicity,                          1964-1991
                   1964-1991                            
  ---------------- --------------- -------------------- -------------------------------------

  -------------- --------------- ---------------------------- ----------------------------------
  **Terranes -                                                
  Canadian                                                    
  Cordillera**                                                

  2              Canadian        *terranes/canada/assemblg*   Terrane maps of the Canadian
                 Cordillera -                                 Cordillera
                 terranes                                     

  1              Canadian        *terranes/canada/assemblg*   Tectonic-assemblage maps of the
                 Cordillera -                                 Canadian Cordillera
                 tectonic                                     
                 assemblages                                  
  -------------- --------------- ---------------------------- ----------------------------------

  -------------- ------------------- ----------------------------- ----------------------------------
  **Terranes -                                                     
  Circum-North                                                     
  Pacific**                                                        

  12             Circum-North        *terranes/nor_pac/ocn_geol*   Oceanic geology from the
                 Pacific oceanic                                   Circum-North Pacific Terrane Map
                 geology                                           

  11             Circum-North        *terranes/nor_pac/terr_ocn*   Offshore terranes from the
                 Pacific offshore                                  Circum-North Pacific Terrane Map
                 terranes                                          

  10             Circum-North        *terranes/nor_pac/terr_lnd*   Onshore terrane names from the
                 Pacific onshore                                   Circum-North Pacific Terrane Map
                 terranes                                          

  9              Circum-North        *terranes/nor_pac/terr_lnd*   Map abbreviations from the
                 Pacific onshore                                   Circum-North Pacific Terrane Map
                 terranes                                          

  8              Circum-North        *terranes/nor_pac/terr_lnd*   Age and lithology for onshore
                 Pacific onshore                                   geology from the Circum-North
                 terranes                                          Pacific Terrane Map

  7              Circum-North        *terranes/nor_pac/sea_mnts*   Seamounts from the Circum-North
                 Pacific seamounts                                 Pacific Terrane Map

  6              Circum-North        *terranes/nor_pac/mag_lins*   Magnetic lineaments from the
                 Pacific magnetic                                  Circum-North Pacific Terrane Map
                 lineaments                                        

  5              Circum-North        *terranes/nor_pac/flts_pos*   Post-accretionary faults, onshore
                 Pacific                                           and offshore from the Circum-North
                 post-accretionary                                 Pacific Terrane Map
                 faults                                            

  4              Circum-North        *terranes/nor_pac/flts\_ ocn* Offshore faults from the
                 Pacific offshore                                  Circum-North Pacific Terrane Map
                 faults                                            

  3              Circum-North        *terranes/nor_pac/flts\_ lnd* Onshore faults from the
                 Pacific onshore                                   Circum-North Pacific Terrane Map
                 faults                                            

  2              Circum-North        *terranes/nor_pac/coast*      Coastline from the Circum-North
                 Pacific coastline                                 Pacific Terrane Map

  1              Circum-North        *terranes/nor_pac/basins*     Outlines of Mesozoic and Cenozoic
                 Pacific basins                                    basins from the Circum-North
                                                                   Pacific Terrane Map
  -------------- ------------------- ----------------------------- ----------------------------------

  ---------------- ----------------------- --------------------------- ----------------------------------
  **Topography -                                                       
  Raster**                                                             

  2                30" land topography (m) *topogrfy/raster/gtopo30*   30"-sampled topography (land only)

  1                2'                      *topogrfy/raster/gtopo2*    2'-sampled land topography and
                   topography/bathymetry                               marine bathymetry (only available
                   (m)                                                 to 70° N)
  ---------------- ----------------------- --------------------------- ----------------------------------

  ---------------- ----------------------- ---------------------------- ----------------------------------
  **Topography -                                                        
  Vector**                                                              

  5                US shelf bathymetry (m) *topogrfy/vector/ak_shelf*   Bathymetry for US waters shallower
                   (1:0.25M)                                            than 200 m, Beaufort Sea to the
                                                                        Aleutians (most detailed, 1:0.25
                                                                        M)

  4                Bering/Chukchi Seas     *topogrfy/vector/ber_chuk*   Bathymetry for Bering and Chukchi
                   bathymetry (m) (1:2.5M)                              Seas, US and Russian waters
                                                                        (intermediate detail, 1:2.5 M)

  3                Chukchi Sea/Bering      *topogrfy/vector/chukchi*    Bathymetry for Chukchi Sea and
                   Straits bathymetry (m)                               Bering Straits, US and Russian
                   (1:1 M)                                              waters (more detailed, 1:1 M)

  2                1:10 M                  *topogrfy/vector/nor_pac*    Circum-North Pacific topography
                   topography/bathymetry                                and bathymetry (least detailed,
                   (m)                                                  1:10 M)

  1                Rivers                  *topogrfy/vector/rivers*     Major drainages, circum-North
                                                                        Pacific
  ---------------- ----------------------- ---------------------------- ----------------------------------

  --------------- ---------------- ---------------- ----------------------------------
  **Volcanoes -                                     
  Active**                                          

  1               Volcanoes        *volcano*        Historically active volcanoes
  --------------- ---------------- ---------------- ----------------------------------

Example Compilations (Coverages) of Individual Datasets (Themes)

In order to display some features (and limitations) of the available
data-sets, and to illustrate some ways in which this GIS compilation
might stimulate data analysis, the following three example 'views' of
various combinations of datasets are created using ArcView or
ArcExplorer projects. (1) The Topography example shows the different
resolution raster and vector data available for different sub-areas, and
high-lights both the range of data availability and also data problems
for a single data type. (2) The Active Earth example combines tectonic
information (faults, volcanoes, earthquake locations) with topographic
and gravity data in order to show the relationship between these
features and to synthesize the neo-tectonic activity of our region. And
(3) the 'Magnetic-Lithologic Correlation' example shows overlays of
lithologic data on onshore aeromagnetic data, suggesting a correlation
between high-frequency magnetic signature and igneous rocks that may
then allow recognition of different geologic provinces offshore.

These three views are only a few examples of other possible
visualizations of various combinations of the spatial data in this GIS
compilation. For all three examples, the CD-ROM contains specific views
and color-scales that highlight features of interest. Users are
encouraged to experiment with their own views, to zoom into different
areas, and to select different display styles, in order to emphasize
different features and to portray different and new geological
relationships.

**Topography Example**

The following datasets are superimposed in the Topography example, with
the higher-numbered layers above and partly concealing the
lower-numbered layers.

+---+---------------+--------------+------------------------------------+
|   | **Dataset     | **Legend     | **Data description**               |
|   | location**    | location in  |                                    |
|   |               | */norpa      |                                    |
|   |               | c/data/legen |                                    |
|   |               | ds/topog_ex* |                                    |
|   |               | (locations   |                                    |
|   |               | of the form  |                                    |
|   |               | *            |                                    |
|   |               | \*\*\*2.avl* |                                    |
|   |               | are for use  |                                    |
|   |               | with         |                                    |
|   |               | *nor         |                                    |
|   |               | pac2.apr*)** |                                    |
+---+---------------+--------------+------------------------------------+
| 9 | *ship         | *            | Ship trackline for geophysical     |
|   | trax/ew94_09* | ew94_09.avl* | cruise EW94-09                     |
+---+---------------+--------------+------------------------------------+
| 8 | *ship         | *            | Ship trackline for geophysical     |
|   | trax/ew94_10* | ew94_10.avl* | cruise EW94-10                     |
+---+---------------+--------------+------------------------------------+
| 7 | *topogrfy/vec | *a           | Bathymetry for US waters shallower |
|   | tor/ak_shelf* | k_shelf.avl* | than 200 m, Beaufort Sea to the    |
|   |               |              | Aleutians (1:250,000)              |
|   |               | *(ak_        |                                    |
|   |               | shelf2.avl)* |                                    |
+---+---------------+--------------+------------------------------------+
| 6 | *topogrfy/ve  | *t           | Bathymetry for Chukchi Sea and     |
|   | ctor/chukchi* | opovect.avl* | Bering Straits, US and Russian     |
|   |               |              | waters (1:1,000,000)               |
|   |               | *(top        |                                    |
|   |               | ovect2.avl)* |                                    |
+---+---------------+--------------+------------------------------------+
| 5 | *topogrfy/vec | *t           | Bathymetry for Bering and Chukchi  |
|   | tor/ber_chuk* | opovect.avl* | Seas, US and Russian waters        |
|   |               |              | (1:2,500,000)                      |
|   |               | *(top        |                                    |
|   |               | ovect2.avl)* |                                    |
+---+---------------+--------------+------------------------------------+
| 4 | *topogrfy/ve  | *n           | Circum-North Pacific region        |
|   | ctor/nor_pac* | _p_eror.avl* | (1:10,000,000), as topographic     |
|   |               |              | contours and a single polygon      |
|   |               | *(n_p        | coded in error (see text)          |
|   |               | _eror2.avl)* |                                    |
+---+---------------+--------------+------------------------------------+
| 3 | *topogrfy/v   | *rivers.avl* | Major drainages, circum-North      |
|   | ector/rivers* |              | Pacific region                     |
+---+---------------+--------------+------------------------------------+
| 2 | *topogrfy/ra  | *            | 30"-sampled land topography,       |
|   | ster/gtopo30* | gtopo30.avl* | color-shaded topography            |
+---+---------------+--------------+------------------------------------+
| 1 | *topogrfy/ve  | *t           | Circum-North Pacific region        |
|   | ctor/nor_pac* | opovect.avl* | (1:10,000,000), color-shaded       |
|   |               |              | bathymetry                         |
|   |               | *(top        |                                    |
|   |               | ovect2.avl)* |                                    |
+---+---------------+--------------+------------------------------------+

Topography, the departure of the land and sea-floor elevation from the
geoid, is the most basic geophysical dataset; however data availability
and quality vary widely. The coverages in the above examples are chosen
to show the range of various raster and vector topographic datasets that
are publicly available, for both land (onshore) and marine (offshore),
and also to display typical data quality and expose reliability issues.

In the Topography example, the base layer is low-resolution (1:10M)
vector bathymetry with contours at 1000 m intervals, plus the -200 m
isobath. The land areas for this layer are obscured by layer 2, the best
global raster topography available, GTOPO30. This nominal 30-arc-second
topography has points at about 900 m spacing, corresponding to a vector
map of scale about 1:1 M, which for this raster data-set provides a
data-point every 1 mm. Superimposed on GTOPO30 is low-resolution
drainages for geographic reference (layer 3), and more importantly
contour lines (layer 4) from the low-resolution basal layer. Layers 1
and 4 are the same dataset displayed with different legends, the former
with color-shaded bathymetry (using the same legend as layers 5, 6 and
7), and the latter with only line contours with no shading. Comparison
of these contour lines with the raster GTOPO30 shows how the
low-resolution contour data matches well, but generalizes the
more-detailed raster data. For example, the narrow drainages dissecting
the south flank of the Brooks Range are visible in the raster data (the
chosen color-scale emphasizes the change from 200 m contour, with a
change from green to very pale green), but not in the 200 m
contour-line.

Layers 5, 6 and 7 of the Topography example are successively more
detailed bathymetric coverages (1:2.5 M; 1:1 M; 1:0.25 M, respectively)
(compare layers 1 and 4, 1:10M), with each dataset encompassing a
successively smaller area (Bering and Chukchi Seas; Chukchi Sea and
Bering Straits; U.S. continental shelf (waters shallower than 200 m))
(compare layer 1 with full coverage). Depth resolution increases
correspondingly, from 1000 m throughout (layer 1), to 10 m in shallow
water to 1000 m in deep water (layer 5), to 10 m throughout (layer 7).
An identical color bar has been chosen to shade layers 1, 5, 6, and 7,
so that the boundaries between the datasets are only visible where dense
contours give way to sparse contours, due to a thin outline drawn for
each layer. The nesting of these four layers shows clearly how
topographic resolution increases in more intensively studied countries
(U.S. waters) and in shallow, near-shore waters. The uppermost of these
bathymetric layers is used to illustrate a typical problem with digital
data-sets used uncritically. Some coastal regions of shallow tidal
waters exist for which /*topogrfy/vector/ak_shelf* is lacking data
("holiday areas"). The polygons are attributed with the elevation value
+999 in contrast to the true but unknown negative value. When shaded
uncritically, these areas may appear as land in a display. See for
example the proximal regions of the Yukon Delta entering into Norton
Sound which in reality have depths -9 to -1 m but are coded as positive
values and shaded light green by the legend
/*legends/topog_ex/ak_shelf.avl*.

The relative agreement of different datasets is tested by comparing
their coastlines with excellent results with respect to the World Vector
Shoreline. The 0 m (sea level) contour derived from GTOPO30 is
consistent to within 1 pixel (900 m) at St. Lawrence Island in the
approximate center of our coverages. Note that although GTOPO30 is
sampled at a 30 arc-second interval, in some areas, this represents an
over-sampling of originally coarser data. This over-sampling is
interpreted as the cause of some artifacts, e.g. sharp boundaries in the
elevation samples, both north-south and east-west, bounding the northern
promontory of the Seward Peninsula. Athough barely visible in this
Topography example, these artifacts are clearly seen in the Active Earth
example. A complete 1-km-sampled digital elevation model of land areas
of the earth (NOAA's Global Land One-kilometer Base Elevation (GLOBE)
Project) is under development at internet site at
http://web.ngdc.noaa.gov/seg/topo/globe.html.

With respect to the World Vector Shoreline, the vector coverage
/*topogrfy/vector/nor_pac* (layers 1 and 4 in the Topography example)
is: (1) offset by between 0 and 4 km around St. Lawrence Island; (2)
appears consistent, around Kamchatka; (3) is displaced about. 8 km north
near Barrow; and (4) is displaced about 4 km SW near Anchorage. These
errors presumably arose during the process of hand-tracing the coastline
from the 1:10M paper map (Moore, 1990) onto mylar, followed by scanning:
a mere 1 mm error at the 1:10 M scale results in 10 km relative
displacement. Displacements of these magnitudes should also be
anticipated in the other coverages of the Circum-North Pacific Terrane
Map, and represent the limits of useful accuracy in our database. Other
errors present in /*topogrfy/vector/nor_pac* include several missing
islands (including both the Diomede Islands and Nunivak, about 50,000
km^2^. At least a few polygons are miscoded (e.g., the closed
contour/apparent landmass east of the Shumagin Islands, highlighted in
bright yellow by the legend /*legends/topog_ex/n_p_eror.avl* designed
for this purpose). The other, higher-resolution vector coverages
(/*topogrfy/vector/ak_shelf*, /*topogrfy/vector/chukchi* and
/*topogrfy/vector/ber_chuk*), all appear consistent with the World
Vector Shoreline. The Canadian terrane map /*terranes/canada/assemblg*
appears to be very well registered with the World Vector Shoreline, and
the Alaska terrane map /*terranes/alaska/terr_lnd* seems to be offset by
only about 3 km to the SW, an error probably acquired during
hand-digitization from a Decade-of-North-American-Geology (DNAG) map
with its center-of-projection at about 100° W, well outside the present
coverage.

Finally, layers 8 and 9, ship-tracks, are included in the Topography
example as a visual centerpiece and to remind users of the original
purpose of this GIS database, to support interpretations of seismic
profiles acquired along these tracklines.

Although this example is designed only to illustrate features of the GIS
database, many uses exist for such topographic data. One obvious example
is using the surface elevation model to study surface hydrology. For
instance, the HYDRO1k geographic database (not included here for lack of
space on this CD-ROM) includes a hydrologically correct digital
elevation model, a slope dataset, an aspect (or slope-direction)
dataset, a flow-direction dataset, a compound-topographic (or wetness)
index, and a flow-accumulation dataset as six raster grids directly
derived from the GTOPO30 grid (http://edcsnw3.cr.usgs.gov/topo/hydro/).

**Active Earth Example**

The following datasets are superimposed in Active Earth example, with
the higher-numbered layers above and partly concealing the
lower-numbered layers:

  ---- ----------------------------- ----------------------------------- ---------------------------------
       **Dataset location**          **Legend location in                **Data description**
                                     */norpac/data/legends/act_erth***   

  14   *terranes/nor_pac/flts_pos*   *flts.avl*                          Post-accretionary faults, onshore
                                                                         and offshore onshore faults

  13   *terranes/nor_pac/flts_lnd*   *flts.avl*                          Onshore faults

  12   *terranes/nor_pac/flts_ocn*   *flts.avl*                          Offshore faults

  11   *volcano*                     *volcano.avl*                       Volcanoes active during the
                                                                         Holocene

  10   *examples/mag35* derived from *mag35.avl*                         Earthquakes of 3.5
       *seismcty/isc_cat*                                                [\<]{.underline} magnitude
                                                                         [\<]{.underline} 4.0, extracted
                                                                         from Catalog of global
                                                                         seismicity, 1964-1991

  9    *examples/mag40* derived from *mag40.avl*                         Earthquakes of 4.0
       *seismcty/isc_cat*                                                [\<]{.underline} magnitude
                                                                         [\<]{.underline} 4.5, extracted
                                                                         from Catalog of global
                                                                         seismicity, 1964-1991

  8    *examples/mag45* derived from *mag45.avl*                         Earthquakes of 4.5
       *seismcty/isc_cat*                                                [\<]{.underline} magnitude
                                                                         [\<]{.underline} 5.0, extracted
                                                                         from Catalog of global
                                                                         seismicity, 1964-1991
  ---- ----------------------------- ----------------------------------- ---------------------------------

  --- ---------------------------- ---------------- ---------------------------------
  7   *examples/mag50* derived     *mag50.avl*      Earthquakes of 5.0
      from *seismcty/isc_cat*                       [\<]{.underline} magnitude
                                                    [\<]{.underline} 5.5, extracted
                                                    from Catalog of global
                                                    seismicity, 1964-1991

  6   *examples/mag55* derived     *mag55.avl*      Earthquakes of 5.5
      from *seismcty/isc_cat*                       [\<]{.underline} magnitude
                                                    [\<]{.underline} 6.0, extracted
                                                    from Catalog of global
                                                    seismicity, 1964-1991

  5   *examples/mag60* derived     *mag60.avl*      Earthquakes of 6.0
      from *seismcty/isc_cat*                       [\<]{.underline} magnitude
                                                    [\<]{.underline} 6.5, extracted
                                                    from Catalog of global
                                                    seismicity, 1964-1991

  4   *examples/mag65* derived     *mag65.avl*      Earthquakes of magnitude
      from *seismcty/isc_cat*                       [\>]{.underline} 6.5, extracted
                                                    from Catalog of global
                                                    seismicity, 1964-1991

  3   *topogrfy/raster/hillshad*   *hillshad.avl*   30"-sampled topography
                                                    illuminated by sun from 315° at
                                                    45° elevation

  2   *topogrfy/vector/nor_pac*    *nor_pac.avl*    Circum-North Pacific region
                                                    (1:10,000,000)

  1   *gravity/geosat*             *geosat.avl*     Satellite-derived free-air
                                                    gravity, offshore areas only
  --- ---------------------------- ---------------- ---------------------------------

The above datasets are chosen to show how a map can be created from the
GIS database to illustrate the relations between active seismicity,
mapped faults, volcanoes, and topography. This view illustrates the
neotectonic setting of the study area.

Although topography is the most basic dataset for studying tectonics,
because marine gravity is shown in the Topography Example, for the base
layer in this example we display the satellite-derived free-air gravity,
/*gravity/geosat* using a standard blue-to-red dichromatic color-bar
(blue represents gravity lows; red gravity highs). On land, the GTOPO30
dataset is used, as in the Topography example, and because the marine
gravity data-set (which had its land areas masked using the *nor_pac*
coastline) has "no data values" shaded black, the offset between
*nor_pac* and GTOPO30 appears as a black rim wherever the *nor_pac*
coastline is outside (seaward of) the GTOPO30 coastline. This black
margin, for example adjacent to northern Alaska, represents the
discrepancy between the *nor_pac* coastline and the *gtopo30* coastline,
rather than a discrepancy between *nor_pac* and *gravity/geosat*.

Subsurface density variations are important to the gravity field, but
the most significant features are the major changes in water depth at
the Aleutian trench, and across the Beringian margin and the Arctic
shelf edge, as made clear by the superimposition of the second layer,
bathymetric contours from /*topogrfy/vector/nor_pac*. Abrupt bathymetric
features correspond well with corresponding features of the gravity
field, for example, the topographic promontory of the Bering Shelf edge,
just west of Zemchug Canyon (location of a magnitude 6.5 earthquake;
southwest of St. Matthew Island), and the Kodiak Seamounts of the
northeast Pacific.

For layer 3, rather than simply repeat the color-scale bar used for the
GTOPO30 layer in the Topography example, a "hillshade" is applied to
provide a real sense of the topography. The hillshade was created using
the ESRI Spatial Analyst (ARC GRID has an equivalent program) with a
sun-angle of 45° elevation from the northwest. This sun-angle highlights
the data-errors in GTOPO30 on the northern Seward Peninsula (described
in the above Topography Example), but, of more geological interest,
highlights (as dark lineaments) the topographic lineaments and valleys
corresponding to the southwest-northeast family of faults that transect
southern and western Alaska.

Earthquake epicenters are overlaid as seven different themes from the
ISC catalog, *seismcty/isc_cat*. In order to capture both the depth and
magnitude information on a single view, seven subsets of the catalog are
derived corresponding to magnitude ranges of one-half unit, from 3.5
[\<]{.underline} magnitude \< 4.0 to magnitude [\>]{.underline} 6.5. The
earthquakes of each magnitude range are displayed with a different size
circle, and these symbols are color-coded by hypocentral depth
(dichromatic yellow-to-blue representing shallow to deep sources). This
color variation clearly shows the northward dip of the Benioff zone
beneath the Alaskan Peninsula and the Aleutian Islands. There is no easy
way to use the focal mechanism of individual earthquakes as an
individual symbol within ArcView. Therefore focal-plane solutions are
not included in the data-base. For further reference, the Harvard
centroid-moment tensor (CMT) catalog provides solutions for individual
earthquakes at the internet site at
*http://www.seismology.harvard.edu/CMTsearch.html*. Other catalogs are
also available.

Layers of volcano and fault locations complete this example. The
volcanoes (black spots on red circles) depict not only the Pacific "Ring
of Fire" but also the young centers of Bering Straits basaltic province,
in association with sparse crustal seismicity in the Seward Peninsula.
The locations of earthquakes can be compared with topography, for
example, the Denali fault that is visible as a deep valley. For
instance, the Kaltag Fault plots about 5 km southeast of the Unalakleet
River and associated topographic lineament where they and the fault
enter Norton Sound. The Togiak-Tikchik strand of the Denali Fault plots
about 5 km southeast of its associated topographic lineament and Togiak
Lake occurs close to its entry into Bristol Bay near Hagemeister Island.
These discrepancies are consistent with the aforementioned errors in the
digitized /*topogrfy/vector/nor_pac* contours.

**Magnetic-Lithologic Correlation Example**

The following datasets are superimposed in the Magnetic-Lithologic
Correlation example, with the higher-numbered layers above and partly
concealing the lower-numbered layers:

  --- ---------------------------- ----------------------------------- ----------------------------------
      **Dataset location**         **Legend location in                **Data description**
                                   */norpac/data/legends/mag_lith***   

  9   *cultural/latlong5*          *shorline.avl*                      Latitude and longitude grid

  8   *topogrfy/vector/shorline*   *shorline.avl*                      World Vector Shoreline

  7   *examples/rus_geol.shp*      *igneous.avl*                       Geologic map of Russia with
                                                                       igneous lithologies selected

  6   *examples/ak_geol.shp*       *igneous.avl*                       Geologic map of Alaska with
                                                                       igneous lithologies selected

  5   *magnetic/russ_mag*          *russ_mag.avl*                      Magnetic map of Russia

  4   *magnetic/ak_mag*            *ak_mag.avl*                        Magnetic map of Alaska (largely
                                                                       onshore)

  3   *topogrfy/vector/nor_pac*    *nor_pac.avl*                       Circum-North Pacific region
                                                                       (1:10,000,000)

  2   *magnetic/dnag_mag*          *dnag_mag.avl*                      Magnetic map of North America,
                                                                       onshore and offshore

  1   *magnetic/arct_mag*          *arct_mag.avl*                      Magnetic map of the Arctic
                                                                       (largely offshore)
  --- ---------------------------- ----------------------------------- ----------------------------------

These datasets are chosen as examples of the possible use of GIS
databases to correlate different datasets, and then to use these
correlations to interpret other areas. This example attempts to
correlate rocks with magnetic anomalies. Though not a ubiquitous
relation, igneous rocks, particularly mafic and ultramafic varieties,
generally contain more magnetite and other magnetic minerals than
sedimentary rocks, and are therefore associated with high magnetic
anomalies. Although more-magnetic lithologies may exist at depth beneath
sedimentary basins, their associated anomalies are attenuated by a
greater distance from the sensor. Mid-crustal rocks lose their magnetic
signature due to temperatures being above the Curie limit of
magnetization.

Layers 1, 2, 4 and 5 in this example are all magnetic coverages,
displayed with data of higher quality and higher resolution towards the
top of the list of views. As a result, the shallowest magnetic layers, 4
and 5, are the land coverages for Alaska and Russia, typically derived
from dense flight-line coverages. The deeper layers, 1 and 2, have their
lower-resolution land parts obscured by the upper layers, but provide
offshore coverage which is typically less well-sampled by sparse marine
geophysical tracklines. Placing topographic contours
(/*topogrfy/vector/nor_pac)* above the marine magnetic coverages, but
below the land magnetic coverages, provides bathymetric contours that
identify the location of the shelf edge, without obscuring or confusing
the land areas on which geology is overlain. Because both *russ_mag* and
*ak_mag* obscure the coastlines and some near-shore bathymetry, the
World Vector Shoreline is displayed as layer 7. Note that where offshore
data were sampled along a single ship track, even though the information
is strictly correct only along that line, the grids typically show data
that are several grid cells wide, and so appear on our image as narrow
bands of color-coded information rather than as lines. For instance, the
outer Bristol Bay and the northeast Pacific Ocean provide are areas
where the magnetic information comes from sparse ship tracks. For all
four magnetic coverages, a dichromatic red-blue color-scale is used, as
for the gravity coverage in Active Earth Example. In order to visually
match the different coverages where they abut, because each magnetic
coverage has a slightly different mean and range, four different legends
are defined in which identical colors correspond to identical ranges of
standard deviations away from the specific data mean.

In order to compare geology with magnetic data two areal coverages are
displayed that are both visible simultaneously. Hence the onland part of
the geological map of Russia (polygons in /*geology/rus_geol* with
attribute *agecod* [\<]{.underline} 256), and the entire geological map
of Alaska (/*geology/ak_geol*), are shown as transparent overlays over
the magnetic grids. Because it is not possible to label individual
geological units without further obscuring the magnetic display, igneous
lithologies were highlighted in yellow; other lithologies were not
highlighted and are shaded gray. This example does not present well in
*norpac2.apr* for which Spatial Analyst is not available to provide the
dichromatic red-blue color-scale for the magnetic field. The Russian
geology and Alaskan geology data-sets are exported as shape files, then
igneous units (intrusive, volcanic and ophiolitic) were selected by
Boolean query of the legends, and given the value "True" for the new
polygon attribute \[Igneous\] in attribute files *ak_geol.dbf* and
*rus_geol.dbf*. These igneous units are, on the Alaska map, any unit
identifier (attribute \[mapunit_ab\]) containing the letter "i", except
units identified as "Ice" (i.e. all intrusives), and any identifier
containing the letter "v" (i.e. volcanics), or ending in the letter "u"
(i.e., ultramafics, but avoiding abbreviations for time periods, "Upper
\*\*\*"), and on the Russia map, lithologic units that did not contain
the label "acoustic" (corresponding to undifferentiated offshore
acoustic basement) or the label "continential" (sic) (corresponding to
platform deposits); all other units are labeled "False".

When the igneous outcrop areas in the southern Brooks Ranges or in
Chukotka are examined, this example shows that igneous rocks in these
regions indeed correlate with high-spatial-frequency, high-intensity
magnetic anomalies. In contrast areas underlain by sedimentary rocks,
such as the North Slope of Alaska, show more quiet signatures. Can this
correlation be taken offshore, into regions that are poorly mapped
geologically? On the Bering Shelf, the style of magnetic anomalies
varies quite widely, and has been described both as showing a fairly
simple pattern, low-high-low from north to south (Marlow and others,
1976), with the high anomaly zone marking a submarine, Late
Cretaceous-early Tertiary volcanic belt (Worrall, 1991), and as a more
complex pattern of magnetic domains interpretable as a group of accreted
terranes (McGeary and Ben-Avraham, 1981). However, the degree of
sedimentary burial of the basement also contributes significantly to the
observed magnetic signature. Thus Worrall (1991) identifies as
"volcanics" the zone from the Anadyr Basin, including the St.
Matthew-Nunivak arch and broadening eastwards to include the Goodnews
Arch and much of Bristol Bay. McGeary and Ben-Avraham (1981) interpret
the same data in more detail, for example describing a small region of
lower anomalies within the high anomaly zone midway between Nunivak
Island and the Pribilof Islands. Marlow and others (1976) note that the
northern boundary of the region of high-amplitude, high-frequency
magnetic anomalies lies close to the southern boundary of the St.
Matthew Basin-Hall Basin, whereas the southern limit of the
high-intensity magnetic belt generally coincides with the northern
boundaries of the large outer-shelf basins such as St. George and
Navarin, raising the possibility that any simple magnetic-lithologic
correlation in this region is incorrect in detail. A GIS database and
display such as ours cannot of themselves resolve such uncertainties,
but they can make it easier to understand the limits of the available
data and to test the possibilities.

ASSOCIATED STUDIES

This GIS compilation on this CD-ROM is part of a project on the major
mineral deposits, metallogenesis, and tectonics of the Russian Far East,
Alaska, and the Canadian Cordillera. The project provides critical
information for collaborators and customers on bedrock geology and
geophysics, tectonics, major metalliferous mineral resources,
metallogenic patterns, and crustal origin and evolution of mineralizing
systems for the Russian Far East, Alaska, and the Canadian Cordillera.

The major scientific goals and benefits of the project are to: (1)
provide a comprehensive international data base on the mineral resources
of the region that is the first, extensive knowledge available in
English; (2) provide major new interpretations of the origin and crustal
evolution of mineralizing systems and their host rocks, thereby enabling
enhanced, broad-scale tectonic reconstructions and interpretations; and
(3) promote trade and scientific and technical exchanges between North
America and Eastern Asia. Products from the project are providing sound
scientific data and interpretations for commercial firms, governmental
agencies, universities, and individuals that are developing new ventures
and studies in the project area, and for land-use planning studies that
deal with mineral resource issues. The Russian Far East part of the
project (as well as Alaska and the Canadian Cordillera) has vast
potential for known and undiscovered mineral deposits.

Published major companion studies for the project are: (1) a report on
the metallogenesis of mainland Alaska and the Russian Northeast
(Nokleberg and others, 1993); (2) a tectono-stratigraphic terrane map of
the Circum-North Pacific at 1:5 million scale with a detailed
explanation of map units and stratigraphic columns (Nokleberg and
others, 1994b); (3) a tectono-stratigraphic terrane map of Alaska at
1:2.5 million scale (Nokleberg and others, 1994a); (4) a summary terrane
map of the Circum-North Pacific at 1:10 million scale (Nokleberg and
others, 1997a); (5) detailed tables of mineral deposits and placer
districts for the Russian Far East, Alaska, and the Canadian Cordillera
in paper format (Nokleberg and others, 1996) and in CD-ROM format
(Nokleberg and others, 1997b); (6) a GIS presentation of a summary
terrane map, mineral deposit maps, and metallogenic belt maps of the
Russian Far East, Alaska, and the Canadian Cordillera (Nokleberg and
others, 1998b); and (7) a study of the Phanerozoic tectonic evolution of
the Circum-North Pacific (Nokleberg and others, 1998a).

ACKNOWLEDGMENTS

We thank the many organizations which contributed data, directly or
indirectly, to this compilation. We particularly thank the contributors
for their providing data, assistance in compiling, and reviewing of the
GIS compilation. We thank V.J.S. Grauch (U.S. Geological Survey, Denver,
Colorado, USA) for assistance in obtaining the aeromagnetic data set of
the former Soviet Union from the National Geophysical Data Center.
Support for compilation of the digital data sets was obtained from
*Research Experience for Undergraduate Funds* from the National Science
Foundation (award EAR-93-17087 from the Continental Dynamics program).
We thank Jeffrey C. Wynn and Frances R. Mills for their constructive
scientific reviews.

DISCLAIMERS

This Compact Disc-Read Only Memory (CD-ROM) publication was prepared by
an agency of the United States Government. Neither the United States
Government nor any agency thereof, nor any of their employees, makes any
warranty, expressed or implied, or assumes any legal liability or
responsibility for the accuracy, completeness, or usefulness of any
information, apparatus, product, or process disclosed in this report, or
represents that its use would not infringe privately owned rights.
Reference therein to any specific commercial product, process, or
service by trade name, trademark, manufacturer, or otherwise does not
necessarily constitute or imply its endorsement, recommendation, or
favoring by the United States Government or any agency thereof.

Although all data and software published on this CD-ROM have been used
by the USGS, no warranty, expressed or implied, is made by the USGS as
to the accuracy of the data and related materials and (or) the
functioning of the software. The act of distribution shall not
constitute any such warranty, and no responsibility is assumed by the
USGS in the use of this data, software, or related materials.

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Nokleberg, W.J., Bundtzen, T.K., Dawson, K.M., Eremin, R.A., Goryachev,
N.A., Koch, R.D. Ratkin, V.V., Rozenblum, I.S., Shpikerman, V.I.,
Frolov, Y.F., Gorodinsky, M.E., Melnikov, V.D., Ognyanov, N.V.,
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Nokleberg, W.J., Bundtzen, T.K., Dawson, K.M., Eremin, R.A., Goryachev,
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R.A., Rozenblum, I.S., Sidorov, A.A., Byalobzhesky, S.G., Sosunov, G.M.,
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tables, metallogenic belt maps and interpretation, and references cited:
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1:4,000,000; 5 maps, scale 1:10,000,000.

Nokleberg, W.J., Moll-Stalcup, E.J., Miller, T.P., Brew, D.A., Grantz,
A., Reed, J.C., Jr., Plafker, G., Moore, T.E., Silva, S.R., Patton,
W.R., Jr., 1994a, Tectonostratigraphic terrane and overlap assemblage
map of Alaska. USGS Open-File Report 94-194, scale 1:2,500,000, 26 p.

Nokleberg, W.J., Parfenov, L.M., and Monger, J.W.H., and Baranov, B.V.,
Byalobzhesky, S.G., Bundtzen, T.K., Feeney, T.D., Fujita, Kazuya,
Gordey, S.P., Grantz, Arthur, Khanchuk, A.I., Natal\'in, B.A., Natapov,
L.M., Norton, I.O., Patton, W.W., Jr., Plafker, George, Scholl, D.W.,
Sokolov, S.D., Sosunov, G.M., Stone, D.B., Tabor, R.W., Tsukanov, N.V.,
Vallier, T.L. and Wakita, Koji, 1994b, Circum-North Pacific
tectono-stratigraphic terrane map: U.S. Geological Survey Open-File
Report 94-714, 2 sheets, scale 1:5,000,000; 2 sheets, scale
1:10,000,000, 211 p.

Nokleberg, W.J., Parfenov, L.M., and Monger, J.W.H., Baranov, B.V.,
Byalobzhesky, S.G., Bundtzen, T.K., Feeney, T.D., Fujita, Kazuya,
Gordey, S.P., Grantz, Arthur, Khanchuk, A.I., Natal\'in, B.A., Natapov,
L.M., Norton, I.O., Patton, W.W., Jr., Plafker, George, Scholl, D.W.,
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Tectonic Evolution of the Circum-North Pacific: U.S. Geological Survey
Open-File Report 98-574, 125 p.

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