~IRC. 1046

U.S. GEOLOGICAL SURVEY CIRCULAR 1046

The Alaska Mineral Resource 

Assessment Program: Background 

Information to Accompany Folio of 

Geologic and Resource Maps of the 

Ugashik, Bristol Bay, and Western 

Part of Karluk Quadrangles, Alaska
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The Alaska Mineral Resource 

Assessment Program: Background 

Information to Accompany Folio of 

Geologic and Resource Maps of the 

Ugashik, Bristol Bay, and Western 

Part of Karluk Quadrangles, Alaska

By R.L. DETTERMAN, J.E. CASE, S.E. CHURCH, 

J.G. FRISKEN, F.H. WILSON, and M.E. YOUNT

U.S. GEOLOGICAL SURVEY CIRCULAR 1046
DEPARTMENT OF THE INTERIOR 

MANUEL LUJAN, JR., Secretary

U.S. GEOLOGICAL SURVEY 

Dallas L Peck, Director

Any use of trade, product, or firm names in this publication 

is for descriptive purposes only and does not imply 

endorsement by the U.S. Government

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1990

Library of Congress Cataloging-in-Publication Data

The Alaska Mineral Resource Assessment Program.

(U.S. Geological Survey circular; 1046)

Includes bibliographical references (p. ).

Supt. of Docs, no.: I 19.4/2:1046

1. Geology Alaska Alaska Peninsula. 2. Mines and mineral resourcesAlaska Alaska Peninsula. 3. Alaska Mineral Resource Assessment Program. 

I. Detterman, Robert L II. Series. 

QE84.A34A43 1990 553'.09798 90-3121
CONTENTS

Abstract 1 

Introduction 1

Purpose and scope 1 

Geography and access 1

Summary of mineral and petroleum investigations 3 

Acknowledgments 4 

Geologic investigations 5

Previous investigations 5 

Present investigation 5 

Description of component folio maps 6 

Geology (MF-1539-A) 6 

Megafossil data (MF-1539-B) 7 

Bedrock geochemistry (MF-1539-C) 7 

Aeromagnetic map and interpretation (MF-1539-D) 8

Regional gravity anomalies 8

Geochronology and major-element geochemistry (MF-1539-E) 8 

Geochemistry (MF-1539-F, -G, -H) 9 

Stream sediments 9 

Pan concentrates 9 

Mineralogy 9

Mineral and energy resource assessment (MF-1539-I) 9 

Bulletins 10

Stratigraphic clarification of the Shelikof Formation, Alaska Peninsula

(1537-A) 10 

Petrography, chemistry, and geologic history of Yantarni volcano, Aleutian

volcanic arc, Alaska (1761) 10 

Interpretation of exploration geochemical data from the Ugashik, Bristol Bay,

and western Karluk quadrangles, Alaska (1858) 11 

References 11

FIGURES

1. Location map showing study area on the Alaska Peninsula 2

2. Map of study area showing geographic features and physiographic 

provinces 3

3. Map of study area showing claims, prospects, exploratory wells, and areas of 

potential mineralization 4

TABLES

1. Component maps of the Ugashik, Bristol Bay, and western part of Karluk 

quadrangles, Alaska 2

2. Data on exploratory wells drilled for petroleum in the Ugashik and western part 

of Karluk quadrangles 5

Contents III
The Alaska Mineral Resource Assessment Prograpn: 

Background Information to Accompany Folio of 

Geologic and Resource Maps of the Ugashik, 

Bristol Bay, and Western Part of Karluk Quadrangles, 

Alaska

ayR.L Detterman, J.E. Case, S.E. Church, J.G. Frisken, F.H. Wilson, andM.E. Yount

Abstract

The Ugashik, Bristol Bay, and western part of Karluk 

quadrangles (1:250,000) are a part of the Alaska Peninsula in 

southwestern Alaska. This circular, in conjunction with a 

companion folio of MF-series maps, two l-series geologic 

maps, and three bulletins, represents the results of integrated 

field and laboratory studies on the geology, geophysics, 

geochemistry, paleontology, geochronology, and mineral 

resources of the quadrangles. These studies were undertaken to provide a modern assessment of the mineral and 

energy resources of the quadrangles. Each map contains 

descriptive text, explanatory material, tables, diagrams, and 

pertinent references. This circular provides background information for the mineral resource assessment map 

(MF-1539-l) and integrates the component MF-and l-series 

maps. A comprehensive bibliography cites both specific and 

general references relevant to the geology and resources of 

the quadrangles.

INTRODUCTION 

Purpose and Scope

This circular and the companion folio of related 

maps are a part of a series of U.S. Geological Survey 

reports designed to provide an inventory of Alaska's 

mineral resources. The reports furnish information for 

mineral and energy policy-making decisions by Federal 

and State governments, native corporations, and industry 

concerning the future use of Alaskan land and resources. 

This report and the folio of maps were prepared under 

the auspices of the Alaska Mineral Resource Assessment

Manuscript approved for publication, November 21, 1989.

Program (AMRAP) by a multidisciplinary team of earth 

scientists. Field and laboratory studies were conducted 

between 1979 and 1982.

The folio consists of nine maps that provide information on the geology, geochemistry, geophysics, geochronology, paleontology, and mineral resource^1 of the 

quadrangles (table 1). The primary intent of the folio and 

circular is to furnish mineral and energy resource data 

for land-use planning and long-term national resource 

policy decisions. Additional aims are to determine the 

time and type of mineral emplacement and to increase 

the geologic knowledge of an actively accreting continental margin and volcanic arc.

This circular contains references relevant to the 

Ugasik, Bristol Bay, and western part of Karluk quadrangles. Individual maps of the folio contain additional 

references applicable to their subject matter.

In addition to the folio maps, which are printed in 

black and white, two companion multicolor Miscellaneous Geologic Investigations Series Maps (Detterman 

and others, 1987a, b) have been published. Topical 

studies conducted during the investigations also resulted 

in three bulletins (Allaway and others, 1984; Riehle and 

others, 1987; Church and others, 1989b), one masters 

thesis (Allaway, 1982), two circular articles (Defra and 

others, 1981; Allaway and Miller, 1984), and five openfile reports (Detterman and others, 1980, 1981K 1982; 

Wilson, 1982; Wilson and O'Leary, 1986).

Geography and Access

The Ugashik, Bristol Bay, and western part of the 

Karluk quadrangles encompass about 12,670 km2 (4,892 

mi2 ) on the Alaska Peninsula (figs. 1 and 2).

The study area is bounded by 57° and 58° N. lat. 

and by 155° and 158°41' W. long. (fig. 2). The Pacific

Introducl'on 1
Table 1. Component maps of the Ugashik, Bristol Bay, and 

western part of Karluk quadrangles, Alaska

U.S. Geological Survey

Miscellaneous Field Studies

Map MF-1539

Subject

-A (Detterman and others, 

1983)

-B (Detterman and others,

1985)

-C (Wilson and O'Leary,

1986)

-D (Case and others, 1988)

-E (Wilson and Shew, 1988)

-F (Church and others, 1988)

-G (Frisken and others, 

1988a)

-H (Frisken and others, 

19885)

-I (Church and others, 1989a)

General geology

Fossil locality map, checklists, 

and stratigraphic sections

Bedrock geochemistry

Aeromagnetic map and interpretation

Geochronology and majorelement geochemistry

Geochemical distribution in 

stream sediments

Geochemical distribution in 

pan concentrates

Mineralogy of pan concentrates

Mineral and energy resource 

assessment map

Ocean side of the peninsula is dominated by the rugged 

mountains of the Aleutian Range, which rise abruptly 

from the sea and are cut by numerous fjords and bays. 

The highest peaks are in the southeastern part of the map 

area, where the Quaternary volcanoes Mount Kialagvik, 

Mount Chiginagak, and Mount Yantarni dominate the 

skyline. Mount Chiginagak (2,120 m) is the highest peak 

in the area. Small valley glaciers radiate from these 

volcanoes, and a small (50 km2 ) ice field lies east of 

Mount Kialagvik. From Wide Bay to Puale Bay the

Figure 1. Index map showing location of study area.

mountains gradually decrease in height. North of Puale 

Bay they merge with the Kejulik Mountains of the Mount 

Katmai quadrangle. Mount Peulik (1,475 m), a Holocene 

stratovolcano, dominates the west side of this northern 

segment of mountains.

A broad, low, coastal plain west of the Aleutian 

Range slopes gradually northwestward from the mountains to Bristol Bay. Most of the low, rolling hills that dot 

the plain are remnants of glacial moraines that rarely 

exceed 100 m in elevation. Ash-flow tuff fron Aniakchak 

Crater to the south covers the southwestern part of the 

map area, burying morainal ridges. The ash-flow-tuff 

plain, extending nearly 20 km into the area, was formed 

by a major eruption of Aniakchak Crater about 3,400 

years ago (Miller and Smith, 1977, 1987).

Becharof Lake (1,175 km2 ), the second largest lake 

in Alaska, is mostly within the study area. Other large 

lakes include Upper Ugashik, Lower Ugashik, and Mother Goose. Hundreds of small glacial lakes and ponds dot 

the Bristol Bay Lowland. The large lakes are all confined 

behind terminal moraines of Pleistocene glaciers and are 

remnants of formerly much larger lakes (Detterman and 

others, 1987b). Becharof Lake and the Ugashik Lakes 

are less than 5 m above modern sea level, and most of the 

numerous other lakes and ponds are within 30 m of sea 

level.

Three major river systems, the Ugashik, King 

Salmon, and Dog Salmon, drain the western part of the 

map area. All three empty into Ugashik Bay after following meandering courses across a nearly flat, former 

lakebed deposit (Detterman and others, 1987b). The 

three rivers combined drain about two-third ^ of the map 

area and, even though they are low-gradient streams, 

carry a large volume of water. Another major westflowing stream, the Kejulik River, flows in*o Becharof 

Lake and drains the northeastern part of th~. map area. 

The Egegik River, north of the map area- runs from 

Becharof Lake to Bristol Bay. Streams draining into the 

Pacific Ocean are all short with steep gradients.

Only two permanent villages exist in the map area: 

Pilot Point with a population of 66, and Ugashik with 13 

residents (year-round population from 1980 census). 

Populations of both towns increase markedly during the 

summer months owing to commercial fishing. Numerous 

hunting and fishing camps near the major lakes and rivers 

are occupied seasonally. At the present time (1988) there 

are no settlements on the Pacific Ocean side of the 

peninsula within the map area. The former village of 

Kanatak, at the head of Portage Bay, has been abandoned for many years.

Access to the area is only by aircraft or boat. 

Moderate-sized twin-engine aircraft can lend at Pilot 

Point and near Painter Creek, but other landing areas are 

usable only by smaller aircraft. Most of the hunting and 

fishing camps maintain small, private airstrip^. There are 

no public roads within the map area. A few miles of

2 The Alaska Mineral Resource Assessment Program: Background Information to Accompany Maps
gravel roads are present around Pilot Point and near the 

camps. Most were constructed during exploration for 

petroleum.

Summary of Mineral and Petroleum 

Investigations

The Ugashik and western part of Karluk quadrangles have been the site of intermittent exploration for 

minerals and petroleum since the early 1900's, but no 

economic deposits have been located. The earliest authenticated exploration for minerals occurred in 1915, 

when placer gold claims were established at Cape 

Kubugakli (fig. 3). These claims were reported to have 

produced about 160 ounces of gold (Smith, 1925). Nothing is known concerning more recent activity on these 

claims, but mining equipment was found when the site 

was visited in 1977. Copper ore containing minor 

amounts of gold and silver was reportedly found near the 

head of Puale Bay in 1920 (Berg and Cobb, 1967). Our 

investigations failed to locate this deposit.

Recent mineral exploration was confined to the 

southern part of the area. Bear Creek Mining Company 

did some diamond drilling in 1977 and 1978 on a 

molybdenum porphyry prospect (Mike prospect) in the

mountains near the head of Painter Creek. During this 

same period they discovered a gold, silver, anc1 copper 

prospect (Rex prospect) in the mountains between Volcano Creek and Dog Salmon River.

Exploration for petroleum in the Ugashik and 

Karluk quadrangles has been much more intense than 

that for minerals, probably because the presen?.e of oil 

seeps and the exposure of a thick sedimentary rock 

section. The first wells in the area were drilled between 

1902 and 1904 near oil seeps on Oil Creek (Martin, 1904, 

1905; Capps, 1923; Smith, 1926). The locations of these 

wells and nearly all others are shown on the ger°.ralized 

geologic map prepared by Detterman and others (1983). 

Since the publication of that map, AMOCO Production 

Company completed the drilling of the Becharof #1 well 

in 1985. Data for exploratory wells drilled in the map 

area are listed in table 2.

Despite the presence of oil and gas seeps in the 

area, exploration to date has yielded only a modest show 

of oil. Diagenetic alteration of the abundant volcanic 

debris in the sediments has greatly reduced the porosity 

and permeability of these rocks. Thus, rocks with good 

reservoir characteristics have not been encountered in 

drilling. Most of the oil and gas seeps are located near 

faults that probably provide a pathway to the surface.

157- 156° 155°

57 D -

Figure 2. Area of study showing geographic features and physiographic provinces.

Introduction 3
Two areas of oil seeps are located within the 

quadrangles. The main area is along the crest of the Bear 

Creek anticline where it crosses Bear Creek and Oil 

Creek. These seeps were reported as early as 1869 

(Capps, 1923). The oil is seeping from rocks of the 

Shelikof Formation and has formed areas of tarlike 

residue on the surface. A second area of seeps is southeast of Mount Peulik, near the crest of the Ugashik 

anticline in an area known as Pearl Creek dome. Patches 

of bright-green, fresh oil can be seen on Ugashik Creek 

and Blue Creek. Areas of residue have formed where the 

oil collected and was exposed to the air for long periods. 

These mounds of tarlike residue were used to fuel boilers 

during early drilling operations. One additional area of 

seepage was found along Simeon Creek during the 

current investigation. All seeps on the Ugashik anticline 

are from the Naknek Formation.

In addition to seepages of oil, there are also 

seepages of gas in the region, some of which are associated with oil seeps and are of obvious biogenic origin. 

Other large seeps, such as around The Gas Rocks, are of 

inorganic origin. Gas collected and analyzed from The 

Gas Rocks seeps is about 98 percent carbon dioxide 

(Barnes and McCoy, 1979). The location and analyses of 

all oil and gas samples from the area were reported by 

Blasko (1976).

Acknowledgments

Geologic investigations in the Ugashik,. Bristol Bay, 

and western part of Karluk quadrangles were facilitated 

greatly by the efforts of many geologists, both from the 

U.S. Geological Survey and private industry, whose many 

contributions are greatly appreciated. The work of most 

visiting scientists, short-term workers, and laboratory 

specialists is acknowledged on individual maps in the 

folio. The contributions of some specialists, although not 

mentioned specifically on the maps, were of great benefit 

to the project. Among those to whom special tribute is 

due are J.A. Wolfe, R.W. Imlay, J.W. Milter, and C.D. 

Blome of the U.S. Geological Survey, and John Calloman 

of the University of London, paleontologists whose identifications of many collections of invertebrr^e and plant 

fossils helped in determining the stratigraphic succession 

of the sedimentary units. J.R. Riehle, M.L. Silberman, 

and Nora Shew made significant contributions to our 

understanding of the complex eruption history of the 

volcanoes as well as of the numerous intrusive events.

Work in such a remote project area would be 

impossible without the willing assistance of local residents. Among those who were of great service to the 

project were the people at Painter Creek Lodge, especially J.W. Smith, who provided the project with food and

159 - 158" 156 D

PACIFIC OIL #1,2 

COSTELLO#1,2

STANDARD V / .

EXPLANATION

Placer claim 

Lode claim 

Prospect 

Exploratory well

Mount 

Chiginagak^

AGRIPINA 

0 BAY Area of potential 

mineralization

Aniakchak 

Crater Thrust fault Sawteeth 

on upper plate. Dashed 

where uncertain

57 -

40 50 KILOMETERS

Figure 3. Area of study showing claims, prospects, exploratory wells, and areas of potential mineralization. 

4 The Alaska Mineral Resource Assessment Program: Background Information to Accompany Maps
Table 2. Data on exploratory wells drilled for petroleum in the Ugashik and western part of Karluk quadrangles 

[U., Upper; Do. (do.), ditto]

Well Company Year 

completed

Location Depth 

(in feet)

Formation 

at tola1 depth

Pacific Oil #1 Pacific Oil & Commercial -- 1903 NWK sec. 3, T. 29 S., R. 40 W. 1,421

Pacific Oil #2 - do. 1904 SEK sec. 3, T. 29 S., R. 40 W. 1,542

Costellotfl J.H. Costello ----- ----- 1903 NWtf sec. 10, T. 29 S., R. 40 W. 728

Costello#2 do. 1904 SEK sec. 10, T. 29 S., R. 40 W. Unknown

iLathroptfl Standard Oil Calif. - 1923 SEK sec. 17, T. 29 S., R. 43 W. 500

lMcNally#l-- -- - - -do.-- - - -- 1925 NWK sec. 29, T. 29 S., R. 43 W. 510

Lee#i - do. 1926 SWK sec. 20, T. 29 S., R. 43 W. 5,034

2Finnegan#l Tidewater Associated ------ 1923 NEK sec. 30, T. 29 S., R. 43 W. 560

2Alaska#l do. 1926 SWK sec. 20, T. 29 S., R. 43 W. 3,033

2Grammer#l Standard Oil Calif. 1940 SEK sec. 10, T. 30 S., R. 41 W. 7,596

Bear Creek Unit #1 ----- Humble Oil & Refining 1959 NEK sec. 36, T. 29 S., R. 41 W. 14,375

Great Basins #1 General Petroleum Co. 1959 SWK sec. 2, T. 27 S., R. 48 W. 11,080

Great Basins #2 do. 1959 SEK sec. 35, T. 25 S., R. 50 W. 8,865

Wide Bay #1 Richfield Oil and others 1963 NWK sec. 5, T. 33 S., R. 44 W. 12,568

Ugashik #1 Great Basins Oil Co. 1966 SE¥ sec. 8, T. 32 S., R. 52 W. 9,476

Painter Creek #1 Cities Service Oil Co. 1967 NWK sec. 14, T. 35 S., R. 51 W. 7,912

2Becharof/State#l - AMOCO Production Co. 1985 NWK sec. 10, T. 28 S., R. 48 W. 9,023

Shelivof

D-\

D-\

Unknown 

Nakrek

D-.

Unknown 

Nakrek 

Shelikof 

Unknown

Unnrmed 

U. Triassic

U. Jr'-assic 

batl olith

Do.

Unnrmed 

U. Triassic

Mesl :k

Shelikof

Unknown

^General location of Standard Oil wells shown on map 1539-A (Detterman and others, 1983). 

^Locations not shown on map.

lodging during 1982 and 1983 and aided in many phases 

of the logistic support that made completion of the 

project possible. Thanks are due also to the personnel at 

Ugashik Lake Lodge, who provided similar services in 

1979.

Special commendations are due Captain A.C. 

"Frosty" Frothingham and the crew of the U.S. Geological Survey Research Vessel Don J. Miller II, who cheerfully provided us with a base of operations during the 

1980 and 1981 field seasons. Our helicopter pilots Lucky 

Wilson, Richard Rossiter, Edward Svec, and Tom Robbins often flew in adverse weather conditions to take us 

to our work sites, and we greatly appreciate their skill and 

professionalism.

GEOLOGIC INVESTIGATIONS 

Previous Investigations

The first important generalized contributions to 

the geology of this area were by Dall and Harris (1892) 

and Dall (1896). More detailed geologic investigations by 

Capps (1923), Smith and Baker (1924), and Smith (1925, 

1926) were made following the early petroleum exploration at Bear Creek anticline and Pearl Creel dome. 

Martin (1926) made the first major attempt to correlate 

the Mesozoic stratigraphic units and show how they 

relate to the rest of Alaska.

The first modern synthesis of the stratigraphy and 

structure of the Alaska Peninsula, including part of the 

Ugashik quadrangle, by Burk (1965) provided the foundation for the present geologic investigation.

Present Investigation

Field work and laboratory analyses for the present 

study were started in 1979 and completed in 19S2. The 

geologic mapping was at a scale of 1:63,360 (1 inch=l 

mile). Both geologic mapping and geochemical sampling 

were helicopter supported. Mapping of the Mounts Peulik and Chiginagak volcanoes, begun by T.P. Miller 

during 1974 and 1975, was continued during the present 

investigation.

This study was a part of the Alaska Mineral Resource Assessment Program (AMRAP) for the Alaska 

Peninsula and was supervised by R.L. Detterman. Most 

of the field-mapping personnel were also responsible for 

a particular topical phase of the work. F.H. Wilson

Geologic Investigations 5
obtained potassium-argon ages for the intrusive and 

extrusive rocks, J.E. Case was responsible for aeromagnetic interpretations, M.E. Yount and J.R. Riehle 

mapped the Quaternary volcanic rocks, and J.W. Miller 

carried out paleontological investigations.

During the course of this study, 1,360 sites were 

occupied for geologic data, and 585 stream-sediment 

samples and 569 heavy-mineral pan-concentrate samples 

were collected to provide a data base for the mineral 

resource assessment. In addition, 337 bedrock samples 

were collected at geologic stations for semiquantitative 

spectrographic analysis; these include both mineralized 

samples and unmineralized specimens for a background 

data base. Prior to the present study, only four published 

potassium-argon (K-Ar) ages were available for the 

rocks of the Ugashik and western part of Karluk quadrangles (Reed and Lanphere, 1969, 1972; Brockway and 

others, 1975; Wilson and others, 1981). A total of 57 new 

K-Ar ages have been added (Wilson and Shew, 1982, 

1988). These ages permit a determination of the intrusive and extrusive history of the quadrangles, as well as of 

the time of mineral emplacement. During the present 

investigation, 376 collections of fossil megafauna and 

megaflora were made from sedimentary rocks of the 

quadrangles; these collections provide a strong framework for relative dating of the sedimentary sequence and 

form a means of correlating the potassium-argon (K-Ar) 

ages from associated igneous rocks. Data from these 

fossil collections were listed by Detterman and others 

(1985).

Aeromagnetic surveys were flown for the eastern 

part of the map area by Fugro Geometries Inc. in 1980 

and by Diversified Technical Services, Inc. in 1982 (U.S. 

Geological Survey, 1984), under contract to the U.S. 

Geological Survey. The aeromagnetic interpretation map 

was compiled by Case and others (1988). Scintillometer 

data were collected at many of the bedrock sample 

localities (Detterman and others, 1981b, 1982).

DESCRIPTION OF COMPONENT FOLIO MAPS

Geology (MF-1539-A)

The Ugashik, Bristol Bay, and western part of 

Karluk quadrangles form a transverse segment across the 

active Aleutian volcanic arc. This map area also includes 

a segment of a middle Tertiary volcanic arc and plutonic 

rocks of a still older Mesozoic magmatic arc. The entire 

area is part of a collage of fragments sutured to Alaska 

during Jurassic and later time (Jones and others, 1978; 

Coe and others, 1985). Paleomagnetic data suggest that 

some Mesozoic rocks of the Alaska Peninsula may have 

originated a considerable distance south of their present 

latitude (Packer and Stone, 1974; Stone and Packer, 

1979). Continuing subduction of the Pacific plate beneath the North American plate along the Aleutian 

Trench at a rate of about 5 cm/yr (Kerr, 1987) accounts 

for numerous Pleistocene and Holocene volcanoes and 

for the earthquakes common to the area.

The oldest rocks of the Alaska Peninsula are 

exposed in this map area at Puale Bay. Permian limestone crops out on one small island at the mouth of Puale 

Bay. Along the north shore of the bay are exposures of a 

thick section of Upper Triassic limestone and volcanic 

rocks of an old magmatic arc. Both the Permian and 

Triassic limestones were probably deposited far to the 

south in seas warmer than the modern North Pacific 

Ocean.

We have determined, as a result of our investigations, that a nearly continuous sequence- of Jurassic 

sedimentary rock is exposed within the Ugashik and 

Karluk quadrangles. Minor hiatuses are present in the 

stratigraphic record, but no major unconformities are 

represented. This depositional record coincides with the 

period during which the land fragment that is now the 

Alaska Peninsula drifted from more southerly latitudes 

northward to near its present latitude. Ammonites from 

the Lower Jurassic strata at Puale Bay show a close 

correlation to forms now found in Lower Jurassic strata 

at the latitude of Mexico (Imlay, 1980). Ammonites of 

Middle Jurassic age correlate more close'y with those 

from areas north of Mexico. The Late Jurassic megafauna of the Ugashik and Karluk area consist almost entirely 

of the bivalve Buchia, found worldwide only in the boreal 

regions. Many changes in depositional environments 

accompanied the northward shift in latitude. The Permian and Triassic limestone was deposited on an open, 

shallow-water shelf in tropical seas. The Lower Jurassic 

sediments were also deposited in shallow water. But by 

the Middle Jurassic, deep-water turbidite? were being 

deposited in part of the area. Upper Jurassic strata are 

shallow-water shelf to nonmarine deposits.

Intrusive and extrusive igneous rocis of Jurassic 

age are also exposed in the map area, northwest of the 

Bruin Bay fault. A small exposure of Mi-idle Jurassic 

plutonic rocks formed an island in Becharof Lake near 

The Gas Rocks (Reed and Lanphere, 1969,1972). Similar 

Jurassic plutonic rocks also have been encountered in 

boreholes on the Bristol Bay coastal plain (Frockway and 

others, 1975).

An extended period of erosion and nondeposition 

followed the Jurassic, and thus the next overlying strata 

preserved are of Late Cretaceous age. Cont'nued tectonic activity has caused the removal of most Upper Cretaceous shelf and slope deposits, leaving no more than 50 

to 75 m of strata. Lower Tertiary strata uroonformably 

overlie the older beds. The oldest Tertiary strata in the 

map area are early Eocene continental deposits commonly containing abundant petrified logs and coal seams. 

Orogenic activity during the Tertiary probably resulted 

from subduction along the proto-Aleutian ^rench.

6 The Alaska Mineral Resource Assessment Program: Background Information to Accompany Maps
Meshik arc volcanism (as defined by Wilson, 1985) 

started in the late Eocene and deposited a thick sequence 

of subaerial basaltic-to-andesitic fragmental volcanic 

rocks and massive lava flows from vents along the west 

side of the modern mountains. Activity along the arc 

continued for 12 to 15 m.y. and tapered off during the 

Oligocene. A thick section of these volcanic rocks is 

exposed in the southwestern part of the map area. Owing 

to the strong magnetic character of these rocks (Case and 

others, 1981), it is possible, based on aeromagnetic data, 

to trace them partly across the map area beneath a 

mantle of glacial drift.

Volcanic activity along the Meshik arc ceased in 

this area about 24 to 23 m.y. ago (Wilson, 1985). Thereafter, these deposits, along with the older rocks, were 

uplifted and reworked by erosion into the overlying 

sedimentary sequence. A thick late Tertiary sedimentary 

section is preserved mainly in the subsurface of the 

Bristol Bay coastal plain, where it is covered by glacial 

drift but has been penetrated by the Great Basins #1 and 

#2 wells and by the Ugashik #1 well (Brockway and 

others, 1975). A thin sequence of the Upper Miocene 

Bear Lake Formation is exposed along faults near the 

Ugashik Lakes.

Volcanic activity along the Aleutian volcanic arc 

probably originated about 10 to 5 m.y. ago with the 

renewal of igneous activity along the Alaska Peninsula. 

In the Ugashik and Karluk quadrangles area this was 

restricted mainly to the emplacement of quartz diorite 

plutons, such as the Agripina Bay batholith, along the 

Pacific coast side of the mountains. Dacite intrusions 

associated with mineral deposits also occurred during 

this interval. Minor extrusive activity accompanied the 

emplacement of these plutons. Large-scale volcanic activity along this part of the arc commenced about 1.9 to 

1.5 m.y. ago at Blue Mountain, The Gas Rocks, Mount 

Yantarni volcano, and possibly other sites; it has continued until the present with the eruption at Ukinrek Maars 

in 1977.

Tectonic activity associated with subduction along 

the proto-Aleutian Trench has resulted in numerous 

high-angle reverse faults and some thrust faulting. The 

Bruin Bay fault, a major fault in southern Alaska, enters 

the northern edge of the study area, but disappears 

beneath surficial deposits south of Becharof Lake. Transverse faulting and fracturing is very common. The northeast trend of Aleutian Range volcanoes is offset about 20 

km in the Ugashik and Karluk quadrangles. This may be 

due to plumbing or structure of the downgoing slab 

rather than offset of crustal segments.

Megafossil Data (MF-1539-B)

Considerable amounts of new data on the fossil 

megafauna and megaflora were obtained during the

present investigation. A total of 353 collections cf marine 

megafauna and 23 collections of megaflora from nonmarine Tertiary strata were made during the inverHgation, 

adding considerably to the data base for the area. Collections were made from rocks ranging in age from Late 

Permian to Eocene. These collections permit time-stratigraphic correlations to be made for the various rock 

units.

The Kialagvik, Shelikof, and Naknek Formations, 

of Middle and Late Jurassic age, are abundant!}' fossiliferous and account for 67 percent of all fossil collections. 

Ammonites constitute the main elements of the megafauna in the Talkeetna, Kialagvik, and Shelikof Formations, including 36 species belonging to 23 genera. 

Marine bivalves of the genus Buchia are the age-diagnostic fossils in the Upper Jurassic Naknek Formation. Four 

species from closely controlled sections permit a precise 

zonation for this genera that can be used throughout the 

Alaska Peninsula (Miller and Detterman, 1985).

Nonmarine megaflora obtained from the Tolstoi 

Formation were identified by J.A. Wolfe (written commun., 1985) as early Eocene. This indicates that the 

Tolstoi Formation in the Ugashik and Karluk quadrangles is equivalent to only the upper part of the same 

formation exposed farther south on the peninsula (Detterman and others, 1981c).

Bedrock Geochemistry (MF-1539-C)

As an aid to the mineral resource assessment of the 

mapped area, 337 rock samples were collected and 

analyzed using 30-element semiquantitative emission 

spectrometry, additional atomic absorption spe^trophotometry, and other analytical methods. Sampling was 

conducted throughout the area in an effort to determine 

background concentrations; however, sampling was concentrated in areas of known or suspected mineralization 

and may be somewhat biased.

Anomalous samples were collected in a number of 

areas on the periphery of the Agripina Bay batholith, 

near the plutons at Mount Becharof and Cape Ip>ak, and 

at Cape Kubugakli. Additionally, numerous anomalous 

samples were collected at the Mike .and Rex prospects. 

No sampling or mapping was able to locate the reported 

copper mineralization at the head of Puale Bay (Perg and 

Cobb, 1967).

The data were statistically analyzed to select background and anomalous levels. Anomalous metal assemblages are consistent with mineralization models 

predicting copper and molybdenum porphyry-tjpe mineralization with associated gold and silver. However, it 

was not possible to evaluate the background levels of 

metals in individual stratigraphic units because of insufficient sampling for statistical validity.

Description of Component Foiio Maps
Aeromagnetic Map and Interpretation 

(MF-1539-D)

Aeromagnetic surveys of most of the Ugashik and 

western part of Karluk quadrangles were flown in 1980 

and 1982. The data obtained from the two surveys were 

combined, and some data from National Uranium Resource Evaluation (NURE) surveys were incorporated to 

produce a smoothed final map for publication.

Over the Bristol Bay Lowland, broad ovoid highs of 

200 to 500 gammas are produced by deep-seated granitoid plutonic bodies, which are thought to be part of the 

Alaska-Aleutian Range batholith of Jurassic to Tertiary 

age (Reed and Lanphere, 1969, 1972). Gentle gradients 

on the flanks of the anomalies indicate that the sources of 

the anomalies are buried at depths of 3 to 4 km or more. 

One of the anomalies, near Cape Greig, coincides with a 

positive gravity anomaly of about 15 mGal (Barnes, 

1977b), and the source may be a dense and magnetic 

phase of the batholith, perhaps dioritic or gabbroic.

Conglomerate and sandstone derived by erosion of 

the batholith form the Upper Jurassic Naknek Formation. The conglomerate and some of the sandstone 

contain a high proportion of magnetite. Elongate 

northeastern-trending magnetic highs of 200 to 500 gammas are produced by magnetite-rich sandstone in the 

Naknek near the Ugashik Lakes. Another northeasttrending high of 400 gammas over covered areas to the 

northwest is interpreted to be caused by the Naknek on 

the northwest limb of an anticline.

Volcanic rocks of the Meshik Formation (Eocene 

and Oligocene) produce elongate positive anomalies as 

much as 1,000 gammas in amplitude along the northwestern front of the mountain belt. Other Tertiary volcanic rocks elsewhere in the Ugashik and Karluk 

quadrangles cause irregular highs and lows of about 50 to 

200 gammas.

Many of the Tertiary granitoid plutons cause ovoid 

magnetic highs of 200 to 1,000 gammas or more. Similar 

anomalies are in water-covered areas east of Cape 

Kilokak, east of Hartman and Terrace Islands, and 

elsewhere, and these are interpreted to result from 

Tertiary plutons. Most of the known ore deposits, prospects, and geochemical anomalies of the area are associated with the Tertiary plutons or their hornfelsed and 

altered wall rocks. Thus, the ovoid magnetic anomalies 

constitute guides to exploration, as in the Chignik and 

Sutwik Island quadrangles to the south (Case and others, 

1981). A few magnetic lows or magnetically flat areas 

associated with Tertiary intrusive and extrusive rocks 

may indicate hornfelsing or hydrothermal alteration and 

may serve as a secondary guide to exploration.

Quaternary volcanic centers at Mount Chiginagak, 

Mount Kialagvik, Mount Peulik, and Blue Mountain 

cause short-wavelength positive anomalies of 200 to 

1,000 gammas or more.

Regional Gravity Anomalies

Gravity data are sparse in the mountainous parts of 

the Ugashik and western part of Karluk auadrangles. 

Barnes' (1977b) map shows a negative anom aly of about 

10 mGal in the southwestern part of the Bristol Bay 

Lowland, continuing northeast to near the Kejulik River. 

This low is caused by the thick accumulation (3 to 4 km 

or more) of Tertiary sedimentary rocks of low density. 

The relative gravity high of 10 to 15 nrGal in the 

northwest, near Cape Greig, may indicate a mafic pluton 

at depth, or shallower depth to basement.

A positive anomaly of 30 to 50 mGal t-ends northeast along the mountainous part of the peHnsula. This 

positive anomaly is an extension of the major gravity high 

over the Aleutian Islands and may be caused by oceanic 

crust at depth (Case and others, 1981).

Geochronology and Major-element 

Geochemistry (MF-1539-E)

A total of 57 new K-Ar ages were determined in 

conjunction with the AMRAP mapping studies and help 

to provide a well-constrained time scale for Tertiary and 

Quaternary events and stratigraphic relations. In addition, 54 new and 12 previously reported major-element 

chemical analyses were compiled and analyzed.

The ages are approximately evenly divHed in number between the late Tertiary Aleutian magrratic arc and 

samples representative of the Meshik (early Tertiary) 

and Jurassic magmatic arcs. A number of samples were 

collected to date hydrothermal alteration associated with 

mineralization. Significant among these were samples 

collected on the periphery of the late Pliocene Agripina 

Bay batholith at Kilokak Creek and soutl of Mount 

Kialagvik. In both cases, hydrothermalfy altered phases 

yielded Oligocene ages, equivalent to that of the Meshik 

arc, which suggests that the area of the batholith was the 

site of magmatic activity and alteration during the timespan of both Tertiary magmatic arcs. Age determinations 

of Meshik-age plutonic rocks at the Rex prospect indicate hydrothermal and magmatic activity occurred in 

multiple phases, spanning approximately 4.5 m.y.

Major-element chemical analyses show rocks of 

both arcs to be of calc-alkaline affinity, though a few 

samples, including some from the Kejulik vohanic center 

of Quaternary age, lie in the tholeiitic field on a SiO2 

versus FeO*/MgO plot. The samples collected can be 

divided into a number of suites on the basis' of age and 

geologic setting. These suites are chemically distinct on 

many elemental plots and indicate varying ranges and 

trends of major elements with respect to silica. Both the 

Agripina Bay batholith suite and the suite cf plutons at 

Mount Becharof and Cape Igvak intrude similar rocks, 

are compositionally similar, and are of essentially the

8 The Alaska Mineral Resource Assessment Program: Background Information to Accompany Maps
same age, yet they differ chemically. The Agripina Bay 

suite has the highest K2O level (1.8 percent at 57.5 

percent SiO2 ), whereas the Mount Becharof-Cape Igvak 

suite has the lowest K2 O level (0.9 percent at 57.5 

percent SiO2 ) of all suites.

groupings can be determined from the pattern of the 

"star" at each sample locality. Histograms of the?e eight 

elements are also shown. A statistical summary is also 

given for the entire set of data reported by Detra and 

others (1981).

Geochemistry (MF-1539-F, -G, -H)

A reconnaissance exploration geochemical study 

was undertaken during the 1979 and 1980 field seasons. 

Two diffferent media were sampled: (1) stream sediments and (2) heavy-mineral concentrates panned from 

the stream sediments. A total of 585 minus-80-mesh 

stream-sediment samples and 569 panned-concentrate 

samples were collected from active channels of streams 

draining 5-16 km2 . The minus-80-mesh stream-sediment 

medium reflects changes in bedrock geology and geochemistry and indicates areas of extensive exposed mineralization. A 14-in. gold pan full of minus-2-mm stream 

sediment was collected from the high-energy part of the 

stream to obtain each panned-concentrate sample. Each 

sample was further processed in the laboratory through 

heavy liquids to remove the light-mineral fraction (sp 

gr<2.8) and through a magnetic separation process to 

remove magnetite as well as many of the more magnetic 

mafic minerals. The nonmagnetic, heavy-mineral fraction 

analyzed for this study contained high-specific-gravity, 

rock-forming minerals such as apatite, zircon, rutile, and 

sphene; the sulfide, sulfosalt, and some oxide minerals; 

and several of the accessory minerals associated with 

mineralization and alteration such as scheelite, fluorite, 

barite, epidote, and tourmaline. The nonmagnetic fraction of the heavy-mineral concentrates should reflect the 

presence of ore-related minerals and therefore may be 

useful in delineating areas of poorly exposed mineralization. All analyses were by the semiquantitative emission 

spectrographic method described by Grimes and Marranzino (1968) and by Motooka and Grimes (1976); 

supplementary determinations of Cu, Pb, and Zn concentrations were made by atomic absorption (Ward and 

others, 1969). A detailed description of the geochemical 

sampling, sample preparation, and analytical methods 

utilized is presented, along with the tabulated geochemical data and sample-locality maps, by Detra and others 

(1981).

Stream Sediments

The distribution of the elements Cu, Mo, Ag, Pb, 

Zn, B, Ni, and Co are shown on MF-1539-F (Church 

and others, 1988). Anomaly thresholds were chosen from 

an analysis of the bedrock geochemistry and vary depending upon the bedrock. Three classes of anomalous values 

for each element are shown using vectors surrounding a 

central point that indicates the sample locality. Elemental

Pan Concentrates

For the nonmagnetic heavy-mineral concentrates, 

the distribution of the elements Cu, Mo, Ag, Pb, Zn, B, 

Ni, and Co is shown on map A and of the elements As, 

W, Au, Bi, Cd, Ba, Mb, and Sn on map B of MF-1539-G 

(Frisken and others, 1988a). Thresholds were chosen 

from an analysis of the distributions of each element 

from the data and are shown on histograms. Three 

classes of anomalous values for each element ar?. shown 

using the "star" diagram; elements are grouped so that 

geochemically coherent sets of elements are presented 

on maps A and B. The set of elements displayed on map 

A of MF-1539-G is identical to that on the streamsediment geochemical map (MF-1539-F).

Mineralogy

Spatial distribution and abundance of pyrite, chalcopyrite, molybdenite, galena, sphalerite, cinnabar, barite, gold, tourmaline, zircon, and mafic minerals are 

presented in MF-1539-H (Frisken and others, 1988b). 

Abundances were determined by microscopic examination of the nonmagnetic heavy-mineral concentrates. 

Relative abundance is indicated by the lengtl of the 

vectors of the star diagrams, and the mineral vectors are 

chosen so that they correspond to the associated vectors 

on nonmagnetic heavy-mineral concentrate maps (MF1539-G).

Mineral and Energy Resource Assessment 

(MF-1539-I)

The mineral potential of the study area is summarized on MF-1539-I utilizing the mineral-deposit models 

outlined by Cox and Singer (1986). The geothe*-mal, oil 

and gas, and coal resources of the area are also assessed 

on MF-1539-I.

Previous mineral-exploration activity in the Ugashik-Karluk area was limited largely to gold prelecting 

near the turn of the century and to regional reconnaissance by major mining companies in the 1970's for 

porphyry deposits and related mineralization. Nine lode 

claims and 13 placer claims have been staked in the area. 

Detailed field mapping and geochemical sampling by 

Kennecott Corporation on the Mike and Rex prospects 

were made available to the U.S. Geological Survey.

Eight tracts of land, each having somewhat different geologic characteristics, have been outlined as potenDescription of Component Folio l\'*os 9
tial mineral resource areas. On the basis of our work in 

the area, the geochemical anomalies directly associated 

with young intrusives, of observed patterns of alteration, 

and of permissive geologic criteria, we estimate that 

there is a 10-percent chance for two or more undiscovered porphyry copper deposits in the Ugashik-Karluk 

study area. From the limited drilling information on the 

Mike prospect, we estimate that there is a 90 percent 

chance of one or more porphyry molybdenum deposits 

and a 10 percent chance of two or more such deposits in 

the study area. Based on the Cu/Au ratio in surface rock 

samples from the Rex prospect, we estimate a 90 percent 

chance of one or more porphyry copper-gold deposits in 

the study area.

The estimate of the abundance of smaller deposits 

is less concise because of the reconnaissance nature of 

our studies. The geologic environment in many of these 

tracts is permissive for polymetallic vein and epithermal 

gold-vein deposits. The mineralization exposed on David 

Island indicates a volcanic-hosted copper-arsenic-antimony deposit. The large magnetic anomalies surrounding the pluton at Cape Igvak and the geochemical signature associated with them suggest that an iron or 

tungsten skarn may be present.

Small gold placers may exist in the study area, 

particularly around the area of the Rex prospect, where 

gold was seen in several panned samples.

There are adequate resources of sand and gravel, 

cinder, and pumice to satisfy local demand. Limestone on 

Cape Kekurnoi is suitable as building stone and is 

adjacent to a protected deep-water port. Given sufficient 

local demand, this limestone unit is considered marginally economic.

A geothermal energy resource at Mount Chiginagak is estimated to be similar in size (approximately 

1019 -1020 cal) to that calculated for Aniakchak Crater 

(Smith and Shaw, 1979), located just 8 km south of the 

study-area boundary. Ukinrek Maars, which erupted in 

1977, may represent an additional geothermal resource.

Oil and gas resources in the study area are probably small. Twelve dry holes have been drilled in the study 

area. The tract to the west (El), which consists mainly of 

Tertiary nonmarine sedimentary and volcaniclastic rocks, 

has been evaluated based on the drilling. Analysis of the 

rocks for hydrocarbons indicates that they are immature, 

with an organic-carbon content of less than 2 percent 

(McLean, 1977). Tract E2, located on the east side of the 

study area, is largely a Mesozoic sedimentary province. 

Although this area has several small oil seeps located 

along the crest of two large anticlines, analysis of the 

rocks indicates poor reservoir characteristics for most of 

the Mesozoic section. Furthermore, the organic-carbon 

content of the Mesozoic rocks is low. Of the 12 dry holes 

in the study area, eight have been drilled near the surface 

oil seeps on the crests of these two anticlines.

Coal beds are present in the Tols*oi Formation 

near the southern boundary of the study area. Field data 

indicate that the grade ranges from subbituminous to 

anthracite near the contact with small intrusive bodies. 

One tract (A5) contains several beds 1 to 2 m in thickness 

that have been seen in traverses made at 5-km spacings. 

If these beds are continuous, they could 1 ave economic 

potential.

BULLETINS

Stratigraphic Clarification of the 

Shelikof Formation, Alaska Peninsula

(Excerpts from Bulletin 1537-A dyW.H. Allaway, Jr., R.L Detterman, 

J.W. Miller, and L.B. Magoon)

Field investigations during the course of this 

AMRAP investigation determined that tl e contact between the Shelikof Formation and the underlying Kialagvik Formation had been placed based on faunal zones 

rather than on lithostratigraphic units. Thr report redefines the contact between the two formations.

Capps (1923, p. C97-C98) defined the Shelikof 

Formation (Middle Jurassic) on the Alaska Peninsula 

but did not establish a type locality. He divided the 

formation into three members: a lower shale (siltstone) 

member, a middle sandstone member with conglomerate, and an upper shale (siltstone) member. Rapid facies 

changes make these members impractical for mapping. 

Capps placed the lower contact at the base of a conglomerate bed that occurs at the base of the lower siltstone 

member at Puale Bay. This conglomerate does not 

persist laterally, and as a result other workers have 

mapped the contact based on the change in fauna between the Bajocian and Callovian Stages (Middle Jurassic).

Smith (1925) proposed to place the contact at the 

base of the lowermost massive sandstone bed. This is the 

most easily mapped unit and is herein defined as the base 

of the Shelikof Formation. The type sectior is defined as 

along the northeast shore of Puale Bay, between the 

southern half of sec. 9, T. 28 S., R. 38 W. and sec. 19, T. 

28 S., R. 37 W. in the Karluk C-4, C-5, and D-5 

15-minute quadrangles.

Petrography, Chemistry, and 

Geologic History of Yantarni Volcano, 

Aleutian Volcanic Arc, Alaska

(Excerpts from Bulletin 1761 dyJ.R. Riehle, M.E. Yount, and 

T.P. Miller)

In 1979, during the course of this AT 1RAP study, 

R.L. Detterman and J.E. Case discovered a previously 

unknown Quaternary volcano near the south boundary of

10 The Alaska Mineral Resource Assessment Program: Background Information to Accompany Maps
the map area, subsequently named Yantarni after the 

nearby bay of the same name. Yantarni volcano and 

neighboring Mounts Chiginagak and Kialagvik are located along the axis of the Wide Bay-Bear Creek anticline 

and the high-angle fault that extends southwest from the 

anticline; together, the three form a short segment of the 

Aleutian volcanic arc along which the volcanoes are 

approximately 35 km closer to the Aleutian Trench than 

those on either side. The Mike prospect, a locus of late 

Tertiary volcanism, is 5 km north of Yantarni dome.

Volcanic activity at Yantarni began in middle Pleistocene time with the eruption of andesite flows that now 

cap ridges to the west and south of the present summit. A 

catastrophic Holocene eruption (possibly 3,500 to 2,000 

years ago; Riehle and others, 1987) breached the small, 

late Pleistocene stratocone, produced the present dome, 

and filled the valley to the east with approximately 1 km3 

of pyroclastic flow deposits.

Yantarni volcanic rocks are calc-alkaline and range 

from 55 to 65 percent SiO2 (volatile free). Comparison of 

whole-rock chemistry and phenocryst chemistry suggests 

that small batches of magma feeding the volcanic system 

have occasionally intercepted one another beneath the 

volcano and mixed to form hybrid magmas (Riehle and 

others, 1987).

Although there is no historical record of activity at 

Yantarni, the possibility of future eruptions cannot be 

discounted.

Interpretation of Exploration Geochemical 

Data From the Ugashik, Bristol Bay, and 

Western Karluk Quadrangles, Alaska

(Excerpts from Bulletin 1858 byS.E. Church, J.G. Frisken, and 

F.H. Wilson)

The integration of the geochemical results from the 

geochemical maps (MF-1539-C, -F, -G, -H) are presented in an interpretative report in U.S. Geological 

Survey Bulletin 1858. Both drainage-basin analysis and 

factor analysis of the entire data sets are covered, and 

conclusions are drawn regarding the type of mineralization present.

Analysis of the geochemical data obtained from 

exploration geochemical studies has helped to define the 

limits of several porphyry Cu-Mo target areas, some of 

which were previously unknown. Widespread geochemical anomalies and hydrothermal alteration halos are 

associated with an inferred Oligocene to Pliocene intrusive complex in the southern part of the Ugashik-Karluk 

study area. Two of these areas are the Rex prospect, a 

porphyry Cu-Mo system associated with composite Oligocene intrusive rocks, and the Mike prospect, a porphyry Mo system associated with Pliocene intrusive activity. 

Both areas are outlined by Cu-Mo-W anomalies surrounding drainage basins that show base- and preciousmetal anomalies. Aeromagnetic data suggest that there 

are several buried plutons in the area beneath the 

geochemical anomalies of the Mike prospect (Crse and 

others, 1988). Further examination of several of these 

areas may be warranted.

Additional evidence of mineralization is associated 

with an area at Cape Igvak that shows possible hydrothermal vein or skarn mineralization, possibly associated 

with a pluton of Pliocene age. Gold, antimony, lead, and 

molybdenum mineralization at Cape Kubugakli appears 

to be restricted to quartz veins within the outcrop pattern 

of intrusive rocks. The intrusive rocks appear, from the 

aeromagnetic anomaly, to extend offshore to the east.

REFERENCES

The asterisks (*) denote references cited in this report. 

Plus signs (+) indicate uncited references that mainly or 

entirely pertain to the Ugashik, Bristol Bay, and western 

part of Karluk quadrangles. Unmarked references are 

uncited general, regional, or topical in scope but contain 

material relevant to the quadrangles.

+Albert, N.R.D., 1982, Preliminary photogeologic interpretation map of side-looking airborne radar imagery of 

Bristol Bay, Ugashik, and Karluk quadrangles, Alaska: 

U.S. Geological Survey Open-File Report 82-141, scale 

1:250,000, 2 sheets.

*Allaway, W.H., Jr., 1982, Sedimentology and petrolo-jy of the 

Shelikof Formation, Alaska Peninsula: San Jose, Calif., 

San Jose State University, M.S. thesis, 88 p.

*Allaway, W.H., Jr., Detterman, R.L., Miller, J.W., and Magoon, L.B., 1984, Stratigraphic clarification of the Shelikof Formation, Alaska Peninsula, in Stratigraphic 

notes, 1983: U.S. Geological Survey Bulletin 1537-A, p. 

A21-A27.

*Allaway, W.H., Jr., and Miller, J.W., 1984, Newly re-ognized 

sedimentary environments in the Shelikof Fcnnation, 

Alaska, in Coonrad, W.H., and Elliot, R.L., eds., The 

United States Geological Survey in Alaska: Accomplishments during 1981: U.S. Geological Survey Circular 868, 

p. 34-37.

Andreason, G.E., Dempsey, W.J., and Vargo, J.L., 1963a, 

Aeromagnetic map of part of the Naknek quadrangle, 

Alaska: U.S. Geological Survey Geophysical Investigation Map GP-353, scale 1:125,000.

*19635, Aeromagnetic map of parts of Ugashik and 

Karluk quadrangles, Alaska: U.S. Geological Survey 

Geophysical Investigation Map GP-354, scale 1:125,000.

Atwood, W.W., 1911, Geology and mineral resource: of parts 

of the Alaska Peninsula: U.S. Geological Survey Bulletin 

467, 137 p.

Barnes, D.F., 1967, Four preliminary gravity maps of parts of 

Alaska: U.S. Geological Survey Open-File Report, 

[67-10], 5 p.

*1977a, Bouguer gravity map of Alaska: U.S. Geological 

Survey Geophysical Investigations Map GP-913, scale 

1:2,500,000.

References 11
* 1979b, Gravity map of the western part of southern 

Alaska: U.S. Geological Survey Open-File Report 77- 

169-H, scale 1:1,000,000.

*Barnes, Ivan, and McCoy, G.A., 1979, Possible role of mantlederived CO2 in causing two phreatic explosions in Alaska: Geology, v. 7, no. 9, p. 434-435.

Beikman, H.M., 1975, Preliminary geologic map of Alaska 

Peninsula and Aleutian Islands: U.S. Geological Survey 

Miscellaneous Field Studies Map MF-674, scale 

1:1,000,000, 2 sheets.

*Berg, H.C., and Cobb, E.H., 1967, Metalliferous lode deposits 

of Alaska: U.S. Geological Survey Bulletin 1246, 254 p.

*Blasko, D.P., 1976, Oil and gas seeps in Alaska, Alaska 

Peninsula, western Gulf of Alaska: U.S. Bureau of Mines 

Report of Investigations RI 8122, 78 p.

*Brockway, R.G., Alexander, Bryan, Day, Paul, Lyle, W.M., 

Hiles, R.M., Jr., Decker, William, Polski, William, and 

Reed, B.L., 1975, Bristol Bay region, stratigraphic correlation section, southwest Alaska: Anchorage, Alaska, 

The Alaska Geologic Society.

Bruns, T.R., and von Huene, Roland, 1977, Sedimentary basins 

of the Shumagin Shelf, western Gulf of Alaska: Proceedings, Offshore Technology Conference, 9th Annual Conference, Houston, Texas, May 2-5, 1977, p. 41-50.

*Burk, C.A., 1965, Geology of the Alaska Peninsula island 

arc and continental margin: Geological Society of America Memoir 99, 250 p.

*Capps, S.R., 1923, The Cold Bay District, in Brooks, A.H., ed., 

Mineral resources of Alaska: U.S. Geological Survey 

Bulletin 739-C, p. C77-C117.

*1934, Notes on the geology of the Alaska Peninsula and 

Aleutian Islands: U.S. Geological Survey Bulletin 857- 

D, p. D141-D153.

*Case, J.E., Cox, D.P., Detra, D.E., Detterman, R.L., and 

Wilson, F.H., 1981, Maps showing aeromagnetic surveys 

and interpretation of the Chignik and Sutwik Island 

quadrangles, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1053-B, scale 1:250,000,2 

sheets.

*Case, J.E., Detterman, R.L., Wilson, F.H., Chuchel, B.A., and 

Yount, M.E., 1988, Maps showing aeromagnetic survey 

and geologic interpretation of the Ugashik and part of 

Karluk quadrangles, Alaska: U.S. Geological Survey 

Miscellaneous Field Studies Map MF-1539-D, scale 

1:250,000, 2 sheets.

*Church, S.E., Detterman, R.L., and Wilson, F.H., 1989a, 

Mineral and energy resource assessment of the Ugashik, 

Bristol Bay, and western Karluk quadrangles, Alaska: 

U.S. Geological Survey Miscellaneous Field Studies Map 

MF-1539-I, scale 1:250,000.

* Church, S.E., Frisken, J.G., Detra, D.E., and Wilson, W.R., 

1988, Geochemical maps showing distribution of selected elements in stream sediments from the Ugashik, 

Bristol Bay, and western Karluk quadrangles, Alaska: 

U.S. Geological Survey Miscellaneous Field Studies Map 

MF-1539-F, scale 1:250,000.

*Church, S.E., Frisken, J.G., and Wilson, F.H., 1989b, Interpretation of exploration geochemical data from Ugashik, 

Bristol Bay, and western Karluk quadrangles, Alaska: 

U.S. Geological Survey Bulletin 1858, 45 p.

Coats, R.P., 1950, Volcanic activity in the Aleutian arc: U.S.

Geological Survey Bulletin 974-B, p. B35-B49. 

Cobb, E.H., 1972a, Metallic mineral resources map of the 

Bristol Bay quadrangle, Alaska: U.S. Geological Survey 

Miscellaneous Field Studies Map MF-456, scale 

1:250,000.

*1972b, Metallic mineral resources map of the Karluk 

quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-459, scale 1:250,000.

*Coe, R.S., Globerman, B.R., Plumley, P.W., and Thrupp, 

G.A., 1985, Paleomagnetic results from Alaska and their 

tectonic implications, in Howell, D.G., ed., Tectonostratigraphic terranes of the circum-Pacific region: CircumPacific Council for Energy and Mineral Resources, Earth 

Science Series No. 1, p. 85-108.

Cox, D.P., Detra, D.E., and Detterman, R.L., 1981, Mineral 

resources of the Chignik and Sutwik Island quadrangles, 

Alaska: U.S. Geological Survey Miscellaneous Field 

Studies Map MF-1053-K, scale, 1:250,000, 2 sheets.

*Cox, D.P., and Singer, D.A., eds., 1986, Mineral deposit 

models: U.S. Geological Survey Bulletin 1693, 379 p.

*Dall, W.H., 1896, Report of coal and lignite of Alaska: U.S. 

Geological Survey 17th Annual Report, pt. 1, p. 763- 

908.

*Dall, W.H., and Harris, G.D., 1892, Correlation papers: 

Neogene: U.S. Geological Survey Bulletin 84, 349 p.

+ Detra, D.E., 1980, AMRAP geochemistry, Bristol Bay, 

Ugashik, and Karluk quadrangles, Alaska, in Reed, 

K.M., ed., U.S. Geological Survey in Alaska 1980 programs: U.S. Geological Survey Circular 823A, p. A52.

+Detra, D.E., Detterman, R.L., Cox, D.P., and Wilson, F.H., 

1982, Reconnaissance geochemical stud: ?-s in Bristol 

Bay, Ugashik, and Karluk quadrangles, Alaska, in Coonrad, W.L., ed., The United States Geological Survey in 

Alaska: Accomplishments during 1980: U.S. Geological 

Survey Circular 844, p. 87-88.

*Detra, D.E., Risoli, D.A., O'Leary, R.M., Hurrell, J.T., and 

Everman, W.E., 1981, Analytical data and statistical 

summary from analysis of stream-sediment and heavymineral-concentrate samples collected ir Bristol Bay, 

Ugashik, and Karluk quadrangles, Alaska: U.S. Geological Survey Open-File Report 81-963, 88 p.

Detterman, R.L., 1985, The Alaska Peninsula A-2 transect, in 

von Huene, Roland, ed., Continent-oceans transect A-2: 

Kodiak to Kuskokwin, Alaska: Geological Society of 

America Transect Series Map A-2, scale 1:500,000.

*Detterman, R.L., Allaway, W.H., Jr., Day, G.W., Hopkins, 

D.M., O'Leary, R.M., and Svec, Edward, 1982, Locality 

map for scintillometer and analytical data collected in 

1981, Ugashik and Karluk quadrangles, Alaska: U.S. 

Geological Survey Open-File Report 82-53, scale 

1:250,000, 1 sheet.

*Detterman, R.L., Allaway, W.H., Jr., O'Leary, E .M., Gruzensky, A.L., Hurrell, J.T., and Risoli, D.A., 1980, Sample 

location map and analytical data for rock samples collected in 1979, Ugashik and Karluk quadrangles, Alaska: 

U.S. Geological Survey Open-File Report 80-142, scale 

1:250,000.

+ Detterman, R.L., Allaway, W.H., Jr., O'Leary, R.M., Houston, David, and Risoli, D.A., 1981a, Sample location 

map and analytical data for rock samples collected in 

1980, Ugashik and Karluk quadrangles, Alaska: U.S.

12 The Alaska Mineral Resource Assessment Program: Background Information to Accompany Maps
Geological Survey Open-File Report 81-173.

*Detterman, R.L., Allaway, W.H., Jr., and Rossiter, R.H., 

19815, Locality map and scintillometer data for the 

Ugashik and Karluk quadrangles, Alaska: U.S. Geological Survey Open-File Report 81-253, scale 1:250,000, 1 

sheet,.

*Detterman, R.L., Case, J.E., Wilson, F.H., and Yount, M.E., 

1987a, Geologic map of the Ugashik, Bristol Bay, and 

western part of Karluk quadrangles, Alaska: U.S. Geological Survey Miscellaneous Geologic Investigations 

Map 1-1685, scale 1:250,000, 1 sheet.

*Detterman, R.L., Case, J.E., Wilson, F.H., Yount, M.E., and 

Allaway, W.H., Jr., 1983, Generalized geologic map of 

the Ugashik, Bristol Bay, and part of Karluk quadrangles, Alaska: U.S. Geological Survey Miscellaneous Field 

Studies Map MF-1539-A, scale 1:250,000.

Detterman, R.L., and Miller, J.W., 1984, Late Mesozoic paleobiogeography and tectonics of the Alaska Peninsula 

[abs.]: Geological Society of America Abstracts with 

Programs, v. 16, no. 5, p. 278.

*Detterman, R.L., Miller, J.W., and Case J.E., 1985, Megafossil 

locality map, checklists, and pre-Quaternary stratigraphic sections of Ugashik, Bristol Bay, and part of Karluk 

quadrangles, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1539-B, scale 1:250,000,3 

sheets.

*Detterman, R.L., Wilson, F.H., Yount, M.E., and Miller, T.P., 

1987b, Quaternary geologic map of the Ugashik, Bristol 

Bay, and western part of Karluk quadrangles, Alaska: 

U.S. Geological Survey Miscellaneous Geologic Investigations Map 1-1801, scale 1:250,000, 1 sheet.

Detterman, R.L., Yount, M.E., and Case, J.E., 1981c, Megafossil locality map, checklists, and stratigraphic sections 

of the Chignik and Sutwik Island quadrangles, Alaska: 

U.S. Geological Survey Miscellaneous Fie Id Studies Map 

MF-1053-N, 2 sheets.

Dumond, D.E., 1980, The archaeology of Alaska and the 

peopling of America: Science, v. 209, no. 4460, p. 

984-991.

Fenians, O.J., Jr., 1965, Permafrost map of Alaska: U.S. 

Geological Survey Miscellaneous. Geologic Investigations Map 1-445, scale 1:250,000.

Fisher, M.A., Bruns, T.R., and von Huene, Roland, 1981, 

Transverse tectonic boundaries near Kodiak Island, 

Alaska: Geological Society of America Bulletin, v. 92, 

no. 1, pt. 1, p. 10-18.

*Frisken, J.G., Church, S.E., Detra, D.E., and Wilson, W.R., 

1988a, Geochemical map showing the distribution of 

selected elements determined in nonmagnetic heavymineral concentrates from Ugashik, Bristol Bay, and 

western Karluk quadrangles, Alaska: U.S. Geological 

Survey Miscellaneous Field Studies Map MF-1539-G, 

scale 1:250,000.

*Frisken, J.G., Church, S.E., and Wilson, W.R., 1988b, Mineralogical map showing the distribution of selected orerelated mineral concentrates from Ugashik, Bristol Bay, 

and western Karluk quadrangles, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1539- 

H, scale 1:250,000.

*Grimes, D.J., and Marranzino, A.P., 1968, Direct-current arc 

and alternating-current spark emission spectrographic

field methods for the semiquantative analysis of geologic 

materials: U.S. Geological Survey Circular 591, 6 p.

 fHanson, B.M., 1957, Middle Permian limestone on Pacific 

side of Alaska Peninsula: American Association of Petroleum Geologists Bulletin, v. 41, no. 10, p. 2376-2378.

Imlay, R.W., 1953, Callovian (Jurassic) ammonites fron- United 

States and Alaska, Part 2, Alaska Peninsula and Cook 

Inlet regions: U.S. Geological Survey Professional Paper 

249-B, p. B41-B108.

 1975, Stratigraphic distribution and zonation of Jurassic 

(Callovian) ammonites in southern Alaska: U.S. Geological Survey Professional Paper 836, 28 p.

* 1980, Jurassic paleogeography of the conte-minous 

United States in its continental setting: U.S. Geological 

Survey Professional Paper 1062, 134 p.

 1981, Early Jurassic ammonites from Alaska: U.S. Geological Survey Professional Paper 1148, 49 p. 

-1984, Early and Middle Bajocian (Middle Jurassic)

ammonites from southern Alaska: U.S. Geological Survey Professional Paper 1322, 38 p.

Imlay, R.W., and Detterman, R.L., 1973, Jurassic paleobiogeography of Alaska: U.S. Geological Survey Professional 

Paper 801, 34 p.

*1- 1977, Some Lower and Middle Jurassic beds in Puale 

Bay-Alinchak Bay area, Alaska: American Association 

of Petroleum Geologists Bulletin, v. 61, no. 4, p. 607- 

611.

Imlay, R.W., and Miller, D J., 1949, Reconnaissance geology of 

Wide Bay, Puale Bay, and Chinitna Bay areas, southern 

Alaska: U.S. Geological Survey Administrative Report, 

22 p.

Jones, D.L., and Miller, J.W., 1976, Preliminary geologic map 

of Alaska Peninsula showing post-Callovian Mesozoic 

fossil localities: U.S. Geological Survey Open-File Report 76-76, scale 1:500,000, 2 sheets.

*Jones, D.L., Silberling, N.J., and Hillhouse, J.W., 1978, Microplate tectonics of Alaska Significance for Mesozoic 

history of the Pacific coast of North America, in Howell, 

D.G., and McDougall, K.A., eds., Mesozoic paleogeography of western United States: Society of Economic 

Paleontologists and Mineralogists Symposium, v. 8, p. 

71-76.

Keller, A.S., and Reiser, H.N., 1959, Geology of the Mount 

Katmai area, Alaska: U.S. Geological Survey Bulletin 

1058-G, p. G261-G298.

+ Kellum, L.B., Davies, S.N., and Swinney, CM., 1945, Geology 

and oil possibilities of the southwestern part of the Wide 

Bay anticline, Alaska: U.S. Geological Survey C oen-File 

Report, 17 p.

*Kerr, R.A., 1987, Direct measurements confirm plat^ tectonics: Science, v. 236, no. 4807, p. 1425-1427.

+Kienle, Juergen, Kyle, P.R., Self, Stephen, Motyka, R.J., and 

Lorenz, Volker, 1980, Ukinrek Maars, Alasla; April 

1977 eruption sequence, petrology, and tectonic setting: 

Journal of Volcanology and Geothermal Research, v. 7, 

no. 1-2, p. 11-37.

+Kover, A.N., and Martin, S.E., 1984, Ugashik, Alarka, sidelooking airborne radar (SLAR): U.S. Geological Survey 

Image Map Set, 8 sheets.

+Le Compte, J.R., 1981, Preliminary map showing in*«rpretation of Landsat imagery of the Ugashik and Karluk

Reference 13
quadrangles, Alaska: U.S. Geological Survey Open-File 

Report SI-776, scale 1:250,000, 2 sheets.

*Martin, G.C., 1904, Petroleum fields of Alaska and the Bering 

River coal field: U.S. Geological Survey Bulletin 225, pp. 

365-382.

* 1905, The petroleum fields of the Pacific coast of 

Alaska: U.S. Geological Survey Bulletin 250, 64 p. 

-1926, The Mesozoic stratigraphy of Alaska: U.S. Geological Survey Bulletin 776, 493 p.

*McLean, Hugh, 1977, Organic geochemistry, lithology, and 

paleontology of Tertiary and Mesozoic rocks from wells 

on the Alaska Peninsula: U.S. Geological Survey OpenFile Report 77-813, 63 p.

*Miller, J.W., and Detterman, R.L., 1985, The Buchia zones in 

Upper Jurassic rocks on the Alaska Peninsula, in 

Bartsch-Winkler, Susan, and Reed, K.M., eds., The United States Geological Survey in Alaska: Accomplishments 

during 1983: U.S. Geological Survey Circular 945, p. 

51-53.

Miller, T.P., 1973, Distribution and chemical analyses of thermal springs in Alaska: U.S. Geological Survey Open-File 

Report 73-187, scale 1:250,000.

*Miller, T.P., and Smith, R.L., 1977, Spectacular mobility of ash 

flows around Aniakchak and Fisher Calderas, Alaska: 

Geology, v. 5, p. 173-176.

* 1987, Late Quaternary caldera-forming eruptions in

the eastern Aleutian arc, Alaska: Geology, v. 15, p.

434-438. 

Moore, G.W., 1967, Preliminary geologic map of Kodiak Island

and vicinity, Alaska: U.S. Geological Survey Open-File

Report 67-271, scale 1:250,000.

*Motooka, J.M., and Grimes, D.J., 1976, Analytical precision 

of one-sixth order semiquantitative spectrographic analysis: U.S. Geological Survey Circular 738, 25 p.

*Packer, D.R., and Stone, D.B., 1974, Paleomagnetism of 

Jurassic rocks from southwestern Alaska and their implications: Canadian Journal of Earth Sciences, v. 11, p. 

976-997.

*Reed, B.L., and Lanphere, M.A., 1969, Age and chemistry of 

Mesozoic and Tertiary plutonic rocks in south-central 

Alaska: Geological Society of America Bulletin, v. 80, p. 

23-43.

* 1972, Generalized geologic map of the Alaska-Aleutian Range batholith showing potassium-argon ages of 

the plutonic rocks: U.S. Geological Survey Miscellaneous Field Studies Map MF-372, scale 1,000,000, 2 

sheets. 

-1973, Alaska-Aleutian Range batholith; geochronology,

chemistry, and relation to circum-Pacific plutonism: 

Geological Society of America Bulletin, v. 84, p. 2583- 

2610.

*Riehle, J.R., Yount, M.E., and Miller, T.P., 1987, Petrography, 

chemistry, and geologic history of Yantarni volcano, 

Aleutian volcanic arc, Alaska: U.S. Geological Survey 

Bulletin 1761, 27 p.

+ Self, Stephen, Kienle, Juergen, and Huot, Jean Paul, 1980, 

Ukinrek Maars, Alaska; Deposits and formations of the 

1977 craters: Journal of Volcanology and Geothermal 

Research, v. 7, no. 1-2, p. 39-65.

*Smith, R.L., and Shaw, H.R., 1979, Igneous related geothermal systems, in Muffler, L.J.P., ed., Assessment of geothermal resources of the United States, 1978: U.S. 

Geological Survey Circular 90, p. 12-17.

*Smith, W.R., 1925, The Cold Bay (Puale Bay)-Katmai district, 

in Brooks, A.H., ed., Mineral resources of Alaska: U.S. 

Geological Survey Bulletin 773-C, p. C183-C209.

* 1926, Geology and oil development of the Cold Bay 

(Puale Bay) district, Alaska: U.S. Geological Survey 

Bulletin 783-C, p. C63-C95.

*Smith, W.R., and Baker, A.A., 1924, The Cold Bay (Puale

Bay)-Chignik district, Alaska: U.S. Geological Survey

Bulletin 755-D, p. D151-D218. 

Stone, D.B., and Packer, D.R., 1977, Tectonic implications of

Alaska Peninsula paleomagnetic data: Tectonophysics, v.

37, p. 183-201.

*Stone, D.B., and Packer, D.R., 1979, Paleomagnetic data from 

the Alaska Peninsula: Geological Society of America 

Bulletin, v. 90, pt. 1, p. 545-560.

Stone, D.B., Panuska, B.C., and Packer, D.R., 1982, Paleolatirudes versus time for southern Alaska: Journal of Geophysical Research, v. 87, no. B5, p. 3697-3707.

Thrupp, G.A., and Coe, R.S., 1984, Paleomagnefism of Tertiary 

volcanic rocks from Alaska Peninsula: Is the Peninsular 

terrane a coherent tectonic entity? [aH.]: Geological 

Society of America Abstracts with Programs, v. 16, no. 5, 

p. 337.

*United States Geological Survey, 1984, Aeromagnetic map of 

parts of the Ugashik and Karluk 1X2 degree quadrangles, Alaska: U.S. Geological Survey Open-File Report 

84-351, scale 1:250,000, 2 sheets.

*Ward, F.N., Nakagawa, H.M., Van Sickle, G.H., and Harms, 

T.F., 1969, Atomic absorption methods of analysis useful 

in geochemical exploration: U.S. Geolog-'cal Survey Bulletin 1289, 45 p.

+ Westerman, G.E.G., 1964, The ammonite fauna of the Kialagvik Formation at Wide Bay, Alaska Peninsula Part 

1, Lower Bajocian (Alenian): Ithaca, N.A'., Paleontological Research Institution, v. 47, no. 216, p. 329-503.

+ 1969, The ammonite fauna of Kialagv;k Formation at 

Wide Bay, Alaska Peninsula Part 2, Sonninia sowerbyi 

zone (Bajocian): Ithaca, N.Y., Paleontological Research 

Institution, v. 57, no. 255, 226 p.

*Wilson, F.H., 1982, Map and tables showing preliminary 

results of K-Ar age studies in Ugashik quadrangle, 

Alaska Peninsula: U.S. Geological Survey Open-File 

Report 82-140, scale 1:250,000.

* 1985, The Meshik Arc an Eocene to earliest Miocene magmatic arc on the Alaska Peninsula: Alaska 

Division of Geological and Geophysical Surveys Professional Report 88, 14 p.

Wilson, F.H., Detterman, R.L., and Case, J.E., 1985, The 

Alaska Peninsula terrane: a definition: U.S. Geological 

Survey Open-File Report 85-450, 29 p.

*Wilson, F.H., Gaum, W.C., and Herzon, P.L., 1981, Map and 

tables showing geochronology and whole-rock geochemistry, Chignik and Sutwik Island quadrangles, Alaska: 

U.S. Geological Survey Miscellaneous Field Studies Map 

MF-1053-M, scale 1:250,000, 3 sheets.

*Wilson, F.H., and O'Leary, R.M., 1986, Maps and tables 

showing data and analysis of semiquantative emission 

spectrometry and atomic-absorption spectrometry of 

rock samples, Ugashik and western Karluk quadrangles,

14 The Alaska Mineral Resource Assessment Program: Background Information to Accompany Maps
Alaska: U.S. Geological Survey Miscellaneous Field * 1988, Geochronology and major-element geochemistry

Studies Map MF-1539-C, scale 1:250,000. of Ugashik, Bristol Bay, and western Karluk quadran-

*Wilson, F.H., and Shew, Nora, 1982, Preliminary results of gles, Alaska: U.S. Geological Survey Miscellaneoi^ Field

K-Ar age determinations from the Ugashik quadrangle, Studies Map MF-1539-E, scale 1:250,000, 4 sheets.

Alaska Peninsula, in Coonrad, W.L., ed., The United Wolfe, J.A., 1972, An interpretation of Alaskan Tertiary floras,

States Geological Survey in Alaska: Accomplishments in Graham, A., ed., Floristics and paleofloristics of Asia

during 1980: U.S. Geological Survey Circular 844, p. and eastern North America: Amsterdam, Else-der, p.

86-87. 201-233.

References 15
SELECTED SERIES OF U.S. GEOLOGICAL SURVEY PUBLICATIONS

Periodicals

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