1

Spokane, WA 99201

2Reno, NV 89557

U.S. DEPARTMENT OF THE INTERIOR

U.S. GEOLOGICAL SURVEY

Digital mineral resource maps of phosphate and natural aggregate for the

Pacific Northwest: a contribution to the Interior Columbia River Basin

Ecosystem Management Project

by

Arthur A. Bookstrom1, Gary L. Raines2, and Bruce R. Johnson1

Open File Report 95-681

Prepared in cooperation with the U.S. Forest Service and Bureau of Land

Management.

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

Geological Survey editorial standards. Any use of trade, product, or firm names is

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

Government.

1995
i

CONTENTS

ACKNOWLEDGEMENTS....................................................................................1

INTRODUCTION..............................................................................................1

INTERIOR COLUMBIA BASIN ECOSYSTEM MANAGEMENT PROJECT (ICBEMP)...............................................1

PROJECT EXTENT AND SCALE .................................................................................................................3

U.S. GEOLOGICAL SURVEY INVOLVEMENT IN ICBEMP..............................................................................6

DATA SOURCES, PROCESSING, AND ACCURACY................................................6

DEFINITION OF PERMISSIVE AND FAVORABLE TRACTS.......................................7

PHOSPHATE MINERAL RESOURCES ..................................................................7

PHOSPHATE ORE DEPOSITS.....................................................................................................................7

PHOSPHATE PERMISSIVE AND FAVORABLE TRACTS ..................................................................................8

SOUTHEAST IDAHO PHOSPHATE..............................................................................................................9

MONTANA PHOSPHATE..........................................................................................................................9

PHOSPHATE TREATMENT PLANTS ...........................................................................................................9

FUTURE PHOSPHATE PRODUCTION..........................................................................................................9

NATURAL AGGREGATE RESOURCES ...............................................................10

AGGREGATE USES, DEMAND, AND VALUE .............................................................................................10

CRUSHED STONE................................................................................................................................10

SAND AND GRAVEL.............................................................................................................................11

EOLIAN SAND ....................................................................................................................................13

SILICA SAND .....................................................................................................................................14

NATURAL AGGREGATE REGIONS OF THE INTERIOR COLUMBIA BASIN.........................................................14

FUTURE PRODUCTION OF NATURAL AGGREGATE ....................................................................................16

ENVIRONMENTAL IMPACTS OF NATURAL AGGREGATE PRODUCTION..........................................................17

OBTAINING DIGITAL DATA ............................................................................17

OBTAINING PAPER MAPS ..............................................................................18

CONCLUDING REMARKS ...............................................................................18

REFERENCES CITED.....................................................................................20

APPENDIX A: GIS DOCUMENTATION ..............................................................23

FIGURES

1. MAP SHOWING LOCATION AND EXTENT OF INTERIOR COLUMBIA RIVER BASIN ECOSYSTEM MANAGEMENT

PROJECT STUDY AREAS.................................................................................................................4

2. MAP SHOWING LOCATIONS AND EXTENTS OF ECOLOGICAL REPORTING UNITS (ERUS) OF THE INTERIOR

COLUMBIA RIVER BASIN ECOSYSTEM MANAGEMENT PROJECT ..........................................................5

3. MAP SHOWING LOCATIONS AND EXTENTS OF NATURAL AGGREGATE REGIONS IN RELATION TO ECOLOGICAL

REPORTING UNITS (ERUS) OF THE INTERIOR COLUMBIA ECOSYSTEM MANAGEMENT PROJECT .............15

PLATES

1. PHOSPHATE MINERAL RESOURCES - EXPLANATION

2. PHOSPHATE MINERAL RESOURCES

3. SAND AND GRAVEL RESOURCES - EXPLANATION

4. SAND AND GRAVEL RESOURCES
1

Acknowledgements

Our products would not exist without the contributions of generations of

geologists whose work was essential to making both state geologic maps and

mineral resources databases. We had the comparatively simple task of digitizing

these maps, and using them to identify areas considered permissive to favorable for

deposits of phosphate and sand and gravel. This effort would not be possible

without those past products and others from the following agencies: the U.S.

Geological Survey, the California Division of Mines and Geology, the Idaho Bureau

of Mines and Geology, the Montana Bureau of Mines and Geology, the Nevada

Bureau of Mines and Geology, the Oregon Department of Geology and Mineral

Industries, the Utah Geological and Mineral Survey, the Washington State

Department of Natural Resources, and the Geological Survey of Wyoming. We

particularly acknowledge Patrick Geehan, the Bureau of Land Management Project

coordinator for the Interior Columbia River Basin Ecosystem Management Project

for recognizing the importance of geology to ecosystem management and for

supplying funds to digitize the Washington, Idaho, and Montana geologic maps.

We also acknowledge James D. Bliss for his helpful review of this report.

Introduction

Interior Columbia Basin Ecosystem Management Project (ICBEMP)

In January of 1994, the Chief of the U.S. Forest Service (USFS) and the Director of

the Bureau of Land Management (BLM) initiated what was then called the Eastside

Ecosystem Management Project to develop a scientifically sound and ecosystembased strategy for management of forests eastside forests. The project was further

directed to develop an ecosystem management framework and assessment for land

administered by the Forest Service and the Bureau of Land Management on those

lands east of the Cascade crest in Washington and Oregon and within the interior

Columbia Basin. The driving force behind the project was the need to develop a

strategy for dealing with anadromous fish habitat and watershed conservation in

eastern Oregon and Washington. When it subsequently became clear that similar

strategies were needed for anadromous fish in the remainder of the Columbia River

Basin (particularly in Idaho and Montana), the project was extended to include all of

the Columbia River drainage basin in the United States, east of the Cascade

Mountain divide plus the remainder of southeastern Oregon, which is not within

the drainage basin. At that time, the project was renamed the Interior Columbia

Basin Ecosystem Management Project (ICBEMP).

This report is one in a series of digital maps, data files, and reports generated by

the U.S. Geological Survey (USGS) to provide geologic process and mineral resource

information for the Interior Columbia Basin Ecosystem Management Project

(ICBEMP), a U.S. Forest Service and Bureau of Land Management interagency

project. The various digital maps and data files which were provided by the USGS,

and which are available in this and other reports, are being used in a geographic

information system (GIS)-based ecosystem assessment which includes a
2

comprehensive analysis of past, present, and future ecosystem conditions within the

general area of the Columbia River Basin east of the Cascade Mountains.

The ICBEMP is producing scientific assessments of current and historic landscape

conditions; of aquatic and terrestrial habitat, species distributions, and populations;

and of economic and social conditions. The project is also producing scientific

assessments of the potential future conditions and possible trade-offs likely to result

from a range of possible disturbances and management practices on public lands in

the basin. Although scientific assessments are being conducted for the entire basin,

management decisions that are based on the assessments will apply to public lands

(USFS and BLM) only.

The goal of the ICBEMP management strategy is to provide management tools to

sustain or restore ecosystem integrity and produce desired conditions, uses,

products, values, and services over the long term. The intent of the project is to

understand the ramifications of management practices or disturbances both in the

area subject to the practice or disturbance as well as effects which may be removed,

in time and space, from the area.

The project staff is divided in two teams—the Scientific Integration Team and

the Environmental Impact Statement Team. Each is further sub-divided by topic, as

follows: landscape ecology, aquatic/riparian habitat, terrestrial habitat, forest policy

and economics, and social sciences. Many staff scientists work on both the Scientific

Integration Team and the Environmental Impact Statement Team.

The project objectives are to:

• Conduct a broad scientific assessment of the resources within the

interior Columbia River basin to characterize and assess landscape,

ecosystem, social, and economic processes and functions and

describe probable outcomes of various management practices and

trends.

• Develop an ecosystem management framework that includes

principles and processes which may be used in a National

Environmental Protection Act (NEPA) process to develop

management direction for federal agencies at all levels with the

basin.

• Write an Eastside Environmental Impact Statement (EIS) proposing

a broad array of alternative strategies for an area that encompasses

ten national forests and portions of four BLM districts in eastern

Washington and Oregon (fig. 1).

• Write an Upper Columbia River Basin EIS with a similar array of

alternative strategies for an area that encompasses lands

administered by the BLM and USFS in Idaho, western Montana,

Wyoming, Utah, and Nevada within the Columbia River Basin (fig.

1).

• Conduct a scientific evaluation of issues and alternatives identified

through the NEPA scoping process for the Eastside EIS.
3

The ICBEMP is an intense, short term project to plan and develop a set of

regionally-consistent, land-management alternatives. These alternatives, derived

from basin-wide analyses of highly generalized data, will form a framework for

land-management decisions at the local level. This framework will be modified as

better data and understanding of the basin are developed. Under the project, a

flexible, basin-wide, digital database will be developed that will evolve and improve

as higher resolution data become available. All data are being collected in a GIScompatible format for digital display, analysis, and distribution. Information on the

availability of all digital data sets, paper maps, and other reports generated by the

ICBEMP can be obtained from:

Interior Columbia Basin Ecosystem Management Project

ATTN: Cindy Dean

112 E. Poplar Street

Walla Walla, WA 99362

(509) 522-4030

or from:

Bureau of Land Management

ATTN: Becky Gravenmeier, OR99.2

Oregon - Washington State Office

P.O. Box 2965

Portland, OR 97208

(503) 952-6273

Project extent and scale

The ICBEMP study area is regional in extent. It includes The Eastside EIS area,

which covers eastern Washington and Oregon (east of the crest of the Cascades), and

the Upper Columbia EIS area, which covers most of Idaho and northwestern

Montana, and extends into western Wyoming, northern Utah, and northern

Nevada (fig. 1). The scientific assessment includes all lands, not just those that are

federally managed, and since phenomena such as wildfires and wildlife migration

are not limited by the drainage divides or political boundaries that define the

ICBEMP, some scientific assessment sub-teams have extended their work beyond the

limits of the formal ICBEMP area. For example, the Landscape Characterization area

(fig. 1) extends across northeastern California, northern Nevada, northwestern

Wyoming, and western Montana. Much of the data included in the scientific

assessment was derived from source maps at scales of 1:500,000 or larger, but because

of the regional extent of the ICBEMP, and the limited time allowed for its

completion, the information has been compiled at a scale of 1:1,000,000.

For purposes of ecosystem analysis, and reporting, the ICBEMP study area is

divided into Ecological Reporting Units (ERUs). ERU areas and boundaries fig. 2)

are based on combinations of Ecoregions, as defined and described by Bailey (1976,

1978), and hydrologic drainage areas.

terior Columbia Basin study area showing Ecological Reporting 

boundaries.

 Legend

ICBEMP Ecological 

 Reporting Units

1. Northern Cascades2. Southern Cascades3. Upper Kalamath4. Northern Great Basin5. Columbia Plateau6. Blue Mountains7. Northern Glaciated Mountains8. Lower Clark Fork9. Upper Clark Fork10. Owyhee Uplands11. Upper Snake12. Snake Headwaters13. Central Idaho Mountains

Explanation

Landscapecharacterizationboundary forICBEMP 

Ecological Reporting Unit Boundary

7

8

9

13

5

10

11 12

12

1

4

6

7

5

ICBEMP Study area
6

U.S. Geological Survey involvement in ICBEMP

In June, 1994, the USGS was asked to provide estimates on the value of

undiscovered mineral resources for the Columbia basin. In the course of

discussions with members of various sub-teams from both project teams, it became

apparent that additional earth science information was also highly relevant to the

assessment of historic, current, and future ecological, economic, and social systems,

and that the USGS could provide this information in a digital format. Within the

ICBEMP’s tight schedule (7 months from the USGS start date until the information

had to be available to the rest of the Science Integration Team), the USGS was able to

provide basin-wide, integrated, digital information about bedrock lithology, rock

chemistry, potential animal habitat, stream sediment geochemistry, volcanic and

earthquake hazards, and mineral resources. The bedrock lithology information is

summarized in Johnson and Raines (1995). The bedrock chemistry information is

summarized in Raines and others (1996). Potential animal habitat information is

summarized in Frost and others (1996), and stream sediment geochemistry is

summarized in Raines and Smith (1995). Digital hazards information was derived

from Algermissen and others (1990), and Hoblitt and others (1987). Mineral

resources information is summarized in Box and others (1996); Bookstrom and

others (1996); Zientek, Bookstrom, Box, and Johnson (1996); and in this report. The

reports on bedrock lithology, rock chemistry, potential animal habitat, and portions

of this report were derived from interpretation of state geologic maps at scales of

1:500,000 to 1:750,000. Johnson and Raines (1995) summarize the strategy that was

used for the rapid analysis of geologic map data using GIS techniques. Considerably

more information was identified as potentially useful to the ICBEMP, but integrated

digital products could not be provided for the entire study area within the time

frame of the assessment.

Data Sources, Processing, and Accuracy

The sources of geologic information for the phosphate and natural aggregate

maps were the geologic maps of California (Jennings, 1977), Idaho (Bond and Wood,

1978), Montana (Ross, Andres and Witkind, 1955), Nevada (Stewart and Carlson,

1978), Oregon (Walker and MacLeod, 1991), Utah (Hintze, 1980), Washington

(Hunting and others, 1961), and Wyoming (Love and Christiansen, 1985). The

individual state geologic maps were combined to produce a composite geologic map

of the Pacific Northwest with over 800 rock units, as described in Johnson and

Raines (1995). The state geologic maps were processed digitally, as follows: the source

material was scanned, the scanned image was vectorized and topologically

structured, the lines and polygons were edited and proofed, attributes were added

and proofed, the map was transformed from scanner units to geographic

coordinates, and finally, map distortions were removed by rubber-sheeting. With

the state geology available as a composite digital map, new interpretations and reclassifications of the bedrock geology were easily derived. Geology shown on maps

presented in this report was derived from the composite geologic map.

Locations of phosphate mines and prospects were extracted from digital data files

of the U.S. Geological Survey Mineral Resource Documentation System (MRDS).
7

Swanson, McKelvey, and Sheldon (1953) also provided information on western

phosphate deposits. Locations of rivers and perennial streams used on the Sand and

Gravel Map were obtained from USGS 1:2,000,000 scale Digital Line Graphs (U.S.

Geological Survey, 1990). Locations of cities and towns used on the Sand and Gravel

Map were obtained from a GIS coverage supplied by the ICBEMP. The following

sections describe the phosphate and sand and gravel maps of the Pacific Northwest.

Definition of Permissive and Favorable Tracts

Permissive tracts are areas where the geology permits the existence of mineral

deposits of a specific type (Singer, 1993). Geologic criteria for permissive tracts are

derived from descriptive mineral deposit models that are based on studies of known

deposits. Geologic maps, mineral-occurrence maps, geochemical and geophysical

maps, and mineral-exploration literature and files are searched for features that

include or exclude the permissive geologic criteria, and permissive tracts are

outlined accordingly. The possibility of the occurrence of the specified deposit type

outside the permissive tract should be negligible. However, because of the small

scale and generality of the geologic maps used as the basis of this preliminary

regional study, it is likely that some deposits of the specified types to occur outside

the permissive tracts outlined here.

Favorable tracts are indicated where known deposits are clustered, as on the

Phosphate Map (plate 2), or where geologic maps indicate materials that are

favorable for deposits of good-quality material, as on the Sand and Gravel Map

(plate 4).

Phosphate Mineral Resources

The Phosphate Mineral Resource Map for the ICBEMP Study Area (plates 1 and

2) shows locations of surface expressions of potential supplies of phosphatic rock

(from state geologic maps), and locations of known phosphate mines and prospects

(from MRDS).

Phosphate ore deposits

Phosphate ore deposits consist of phosphatic rock that can be economically

mined to produce phosphate concentrate (called phosphate rock). Ninety-three

percent of domestic phosphate rock is used in the manufacture of fertilizers, and the

rest is used to produce chemicals from elemental phosphorus (U. S. Bureau of

Mines, 1993a). Fluosilicic acid, vanadium, uranium, and rare-earth elements are

possible byproducts. Within the northwest United States, phosphate ore occurs

within marine sedimentary strata of the Permian Phosphoria Formation and its

lateral equivalents, over an area of about 130,000 sq mi, centered in southeastern

Idaho and extending into western Montana, western Wyoming, and northern Utah

(plate 2). The deposits within these strata have previously been classified as

"upwelling-type" (Mosier, 1986a), in contrast to Tertiary deposits of Florida, for

example, which have been classified as "warm-current-type" deposits. Both types of

phosphate deposits probably formed under conditions of upwelling seawater, which

brings nitrate and phosphate (essential and limiting nutrients of marine plants) into
8

the photic zone. The Florida phosphate deposits accumulated quickly, under

conditions of high biological productivity, on an open-ocean continental shelf. By

contrast, phosphate the Phosphoria deposits accumulated slowly, on the floor of a

shallow inland sea, under conditions of moderate biological productivity, and

bottom-water oxygen depletion (D.Z. Piper, written communication, 1995).

Mosier (1986b) compiled a grade-tonnage model for districts of “upwelling-type”

deposits. However, this model cannot be used to estimate probable resources of

individual undiscovered deposits, because the model is based on examples that

represent entire districts, not individual deposits. The distribution of phosphatic

rocks in the ICBEMP study area that it is unlikely that undiscovered phosphate

districts exist there. However, it is likely that there are individual phosphate

deposits that have not been sufficiently characterized in terms of size and grade to be

considered as known (or discovered) resources.

Phosphate Permissive and Favorable Tracts

Permissive and favorable tracts for the presence of phosphate mineral resources

are defined by outcrop patterns of phosphate-bearing sedimentary rocks, and by the

distribution of known phosphate mines and prospects. State geologic maps do not

provide sufficient detail to separate favorable from permissive tracts. Some

phosphate mines and prospects are located on bodies of phosphatic rock too small to

be depicted at 1:500,000 scale. Therefore, some mines and prospects lie outside the

areas of phosphate-bearing sedimentary rock units that are shown on 1:500,000-scale

state geologic maps. Nevertheless, most of these mines and prospects are near to

and(or) on-trend with outcrop patterns of phosphatic rock shown on the state

geologic maps, and the areas containing such mines and prospects are considered

permissive and favorable for the presence of phosphate mineral resources. Listed by

state, permissive and favorable tracts for the presence of phosphate mineral

resources generally coincide with the following phosphate-bearing sedimentary rock

units:

Washington — None identified (Hunting and others, 1961)

Oregon — None identified (Walker and MacLeod, 1991)

Idaho — Permissive and Favorable unit from the geologic map of Idaho

(Bond and Wood, 1978): P — Permian phosphatic sandstone, mudstone

and chert of southeastern Idaho (where phosphate mines and prospects

are abundant, and phosphate mining is an important industry)

Montana — Favorable unit from the geologic map of Montana (Ross, Andres,

and others, 1955): Pu — Permian undivided, mainly Phosphoria

Formation (chert, sandstone, limestone, quartzite, and shale, with rock

phosphate mostly at the base)

Wyoming — Favorable unit in western Wyoming, from the geologic map of

Wyoming (Love and Christiansen, 1985): Pp — Permian Phosphoria

Formation and related rocks of the Shedhorn Sandstone and the Park

City Formation)
9

Utah — Favorable unit in northern Utah, from the geologic map of Utah

(Hintze, 1980): P2 — Phosphoria and Park City Formations

Nevada — None identified (Stewart and Carlson, 1978)

California — None identified (Jennings, 1977)

Southeast Idaho Phosphate

Although phosphate resources of the Interior Columbia Basin are vast, tonnages

that can be economically mined are limited. Phosphate deposits that can by mined

by open-pit methods are concentrated in southeast Idaho, where the thickest part of

the phosphate section occurs, and the phosphate beds are repeatedly exposed on the

steeply dipping limbs of tight folds. Weathering residually enriches near-surface

phosphate, and renders it more amenable to extraction. Closely spaced faults and

fractures locally serve to enhance the degree and depth of residual enrichment by

weathering.

The phosphate mines of southeast Idaho produce about 4 percent of global

phosphate and 12 percent of United States phosphate (U.S. Bureau of Mines 1993a,b).

Most of the phosphate deposits of southeast Idaho are located Caribou County, in

ERU 12 (Snake Headwaters), and in adjacent parts of ERU 11 (Upper Snake). Seven

major active open-pit mines in the southeast Idaho phosphate district are the

Conda, Henry, Maybe Canyon, Wooley Valley, Enoch Valley, Mountain Fuel, and

Smokey Canyon mines (Randol, 1994; Kraus, Henning, and Schmidt, 1984). The

open-pit Gay mine, in Bingham County, Idaho was recently depleted, and is being

reclaimed.

Montana Phosphate

Montana is a relatively minor producer of phosphate rock from underground

mines, located in west-central Montana (ERU 9, Upper Clark Fork), and on the

Idaho-Montana border (ERU 11, Upper Snake).

Phosphate Treatment Plants

Three major phosphate treatment plants are located at Soda Springs, Idaho; two

others are located at Pocatello, Idaho. A vanadium-recovery plant is also located at

Soda Springs (Bennett and Gillerman, 1994). Five parts of gypsum result from the

production of every part of phosphate, and efforts to use significant amounts of

byproduct gypsum have been unsuccessful (Bartels and Gurr, 1994). Large quantities

of gypsum waste that accumulate near phosphate processing plants may have a local

detrimental environmental impact.

Future Phosphate Production

Large-scale, open-pit mining and processing of phosphate ore probably will

continue for the foreseeable future in ERUs 12 and 11 (Snake Headwaters and Upper

Snake). Smaller-scale, underground mining of phosphate ore will probably also

continue in ERU 9 (Upper Clark Fork). Krauss, Henning, and Schmidt (1984)

estimated resources of economically exploitable phosphate ore as 1 billion metric
10

tonnes in the Southeast Idaho, and 600 million metric tonnes in Montana, at

average grades of about 24 wt percent P2O5.

Recent total annual production from southeast Idaho has averaged about 5

million metric tonnes per yr (U.S. Bureau of Mines, 1993b). Assuming continued

production at similar rates and economic conditions, the known mineable resource

may be sustainable for about 200 years. Another 15 billion metric tonnes of

subeconomic phosphate-bearing rock probably lies within the southeast Idaho

phosphate district, according to Kraus, Henning, and Schmidt (1984). Over time,

mining probably will shift toward lower-grade and(or) deeper ores, as warranted by

changing technologies, economic conditions, and competitor activities.

Natural Aggregate Resources

Natural aggregate consists of rock fragments that are used in their natural state,

or are used after mechanical processing such as crushing, washing, and sizing

(Langer and Glanzman, 1993). Crushed stone, and sand and gravel are the two

primary sources of natural aggregate. Suitable aggregate consists of clean, uncoated

particles of proper size range, shape, physical soundness, hardness and strength, and

chemical properties (Langer and Glanzman, 1993). Crushed stone can substitute for

sand and gravel in most applications. Angular particles of crushed stone are

desirable in asphaltic mixes, because intergranular contact between the angular

particles provides strength. However, the rounded particles of sand and gravel are

preferable in cement concrete, because rounded particles improve the workability of

the wet concrete (Langer and Glanzman, 1993).

Aggregate Uses, Demand, and Value

Natural aggregate is used primarily in construction and repair of physical-societal

infrastructure (buildings, roads, bridges, runways, railways, dams, canals, and sewer

systems, for example). Urban areas and highways are major consumers of natural

aggregate. Sources are needed near markets, because the product is bulky, low in

unit value, and expensive to transport.

Urban areas of high demand for natural aggregate are shown on Plate 4. Areas of

high urban demand for natural aggregate are shown as zones within 15 kilometers

of cities or towns within the Columbia River Basin with 20,000 or more residents (as

identified in the populated places data base from the ICBEMP). There are also

higher demand areas along major transportation routes but these are not shown on

Plate 4.

According to the U.S. Bureau of Mines (written communication, 1995), the 1980-

92 cumulative value of natural aggregate produced in the Interior Columbia River

Basin was $1.3 billion, or 10 percent of the value of the total mineral production of

the region.

Crushed Stone

Competent, homogeneous, fine-grained rocks that are not too abrasive and have

not been decomposed by weathering generally are preferred as sources of crushed
11

stone for aggregate. For example, limestone, dolomite, and trap rock (basalt or

diabase) are good sources of crushed-stone for aggregate. Where these are not locally

available, other competent igneous and metamorphic rocks are used. However

some volcanic and volcano-sedimentary rocks are soft and friable, and some silicic

volcanic rocks tend to react deleteriously when used as aggregate in cement concrete.

Potential sources for good-quality crushed stone generally are available within

acceptable haulage distances throughout the Interior Columbia Basin region.

Bedrock in the entire region is therefore considered permissive for crushed-stone

aggregate. Locations of mining sites for crushed-stone aggregate are distributed in

suitable rocks located near areas of high demand, many of which correspond to

urban centers and transportation corridors. No quantitative estimates were made

for undiscovered resources of rocks suitable for crushed-stone aggregate, because the

required tonnage and grade models have not been compiled, and the potential

supply is limited less by geology than by land-use patterns.

Sand and Gravel

“Sand and gravel deposits consist of rock or mineral fragments in loose, noncohesive bodies” that result from “sedimentary processes, including fluvial,

lacustrine, marine, eolian and glacial” (Bliss, 1993, p. 4). “Sand and gravel aggregate

is a mixture (aggregation) of sand and gravel in which gravel constitutes about 25

percent or more of the mixture” (Langer and Glanzman, 1993, p. 5). Gravel typically

occurs in layers or lenses with sand. “Sand and gravel deposits are best when they

contain little silt” (Bliss, 1993, p. 5). Minor replenishment of sand and gravel

deposits may occur, especially during flooding.

Bliss (1993) developed a general volume model for sand and gravel deposits,

based on data for 275 deposits of various genetic types, located in California and the

United Kingdom. He also developed a model for sand and gravel deposits in

alluvial fans, which tend to be relatively thick, based on data from 18 deposits of that

type, located in California. The median volume for the general model is 5.4 million

cubic meters, whereas the median volume for sand and gravel deposits in alluvial

fans is 35 million cubic meters (Bliss, 1993; Bliss and Page, 1994). Although these

models are available, no quantitative estimates were made for undiscovered

resources of sand and gravel in the Interior Columbia Basin, because insufficient

time was available to compile the locations and sizes of known resources, and to

make well-informed estimates of the undiscovered resources. However, permissive

and favorable tracts for sand and gravel were delineated, and urban areas of

potential high demand for sand and gravel were identified, as shown on the Sand

and Gravel Map for the Columbia River Basin Ecosystem Study (plate 4).

State geologic maps provide a general source of information about the

distribution of sand and gravel deposits. Quaternary sedimentary map units shown

on each state map were classified for their potential sand and gravel content.

Surficial sedimentary units that contain sand and gravel as significant components,

and are unweathered and unconsolidated, were classified as favorable for the

presence of fair- to good-quality sand and gravel deposits. Surficial sedimentary

units that contain sand and gravel, but are predominantly finer grained, strongly
12

weathered, or partly consolidated, were classified as permissive for the presence of

poor- to fair-quality sand and gravel deposits.

Listed by state, the surficial sedimentary units classified as favorable for the

presence of deposits of fair- to good-quality sand and gravel, or permissive for the

presence of poor to fair sand and gravel deposits are as follows.

Washington—Favorable units from the geologic map of Washington

(Hunting and others, 1961) are: Qa—alluvium (silt, sand, and gravel);

and Qg—glacial and glacio-fluvial sand, gravel, and till (includes Qg1,

Qg1t, and Qg1o). Permissive units from the geologic map of

Washington are: Qt—terrace deposits (unconsolidated to partly

consolidated sand and gravel, with minor silt and clay); Qg2 -- older

glacial drift (weathered pre-Wisconsin till, outwash, sorted and

unsorted gravel, sand, silt, and clay); and Qgl—glacio-lacustrine

deposits (silt with some sand and gravel)

Oregon—Favorable units from the geologic map of Oregon (Walker and

others, 1991) are: Qal—alluvium; Qt—terrace gravels; Qgf, and Qgs—

glacio-fluvial deposits. Permissive units from the geologic map of

Oregon are: Qg—glacial deposits (unsorted); Qf—fanglomerate; QTg—

older terrace gravels; and Qs—lacustrine and fluvial sedimentary rocks

(unconsolidated to semi-consolidated clay, silt, sand, and gravel)

Idaho—Favorable units from the geologic map of Idaho (Bond and Wood,

1978) are: Qa—alluvium; QPa—Pleistocene waterlaid detritus; and

QPg—Pleistocene glacial outwash (includes QPug, QPmg, and QPlg).

Permissive units from the geologic map of Idaho are: Qg—colluvium

(fanglomerate, talus, and unsorted glacial debris); QPc -- Pleistocene

upland deposits; QPt—Pleistocene till; and QPd—basin-fill deposits

Montana—Favorable units from the geologic map of Montana (Ross, Andres,

and Witkind, 1955) are: Qal—alluvium (includes valley-fill and terrace

deposits); and Qg—glacial drift (Qg). Permissive units from the geologic

map of Montana are: Qgl—glacial lake deposits; QTt—terrace remnants

(gravel, sand, and silt of Quaternary and Tertiary alluvial terrace

remnants); and Tf—Flaxville gravel (Miocene gravel, sand, and silt,

with marl and volcanic ash, locally)

Wyoming—Favorable units in western Wyoming, from the geologic map of

Wyoming (Love and Christiansen, 1985) are: Qa—alluvium and

colluvium; Qg—glacial till and outwash; and Qu—Quaternary units,

undivided. Permissive units of western Wyoming, from the geologic

map of Wyoming, are: QTg—terrace gravel (partly consolidated), and

QTb—Bug Formation (lake deposits)

Utah—Favorable units in northern Utah, from the geologic map of Utah

(Hintze, 1980) are: Qa—alluvium and colluvium; and Qg—glacial

deposits. Permissive units of northern Utah, from the geologic map of

Utah, are: Qao—older alluvial deposits (weathered).
13

Nevada—No favorable units were identified in northern Nevada on the

basis of unit descriptions on the explanation of the geologic map of

Nevada. Permissive units of northern Nevada, from the geologic map

of Nevada (Stewart and Carlson, 1978) are: Qa—alluvial deposits

(poorly sorted); QTa—older alluvial deposits (poorly sorted, semiconsolidated); Qls—landslide deposits (very poorly sorted), and

morainal deposits (small, poorly sorted)

California—No favorable units were identified in northern California on the

basis of unit descriptions on the explanation of the geologic map of

California. Permissive units of northern California, from the geologic

map of California (Jennings, 1977) are: Q—alluvium (alluvial and

lacustrine deposits, playa, and terrace deposits—unconsolidated to

semi-consolidated); Qg—glacial till and moraines (poorly sorted); and

QPc—Plio-Pleistocene clastic sediments (loosely consolidated sand,

shale, and gravel).

In addition to the surficial geologic units listed above, the sediments of modern

streams and rivers (shown in blue on plate 4) and their valley bottoms are

considered to be permissive for the presence of sand and gravel deposits. Sand and

gravel deposits tend to occur along the channels, banks, braidplains, and terraces of

such rivers and streams. We used the rivers data from the 1:2,000,000 scale DLG

CDROM (U.S. Geological Survey, 1990), because it was available in digital form.

Only major drainages are represented at this scale, but deposits of sand and gravel

also occur along minor drainages, which are not shown at this scale. Therefore,

more-detailed future studies should use larger-scale maps of streams and rivers.

Sand and gravel are not evenly distributed along the gradients of streams and

rivers, which flatten toward their baselines. Segments of streams and rivers with

high gradients and rapid flow tend to have bouldery to gravely channels and

margins. Sand and gravel tend to be deposited abundantly where gradients flatten,

and streams and rivers have braided channels. Grain size generally decreases

downstream and(or) down-gradient. Segments of streams and rivers with low

gradients and slow, laminar flow tend to have sandy to silty bed deposits. Moredetailed future studies should combine stream locations with gradients and peak

flow rates to identify segments of streams and rivers that are favorable for the

presence of sand and gravel deposits.

Eolian Sand

Deposits of eolian (wind-deposited) sand are shown on Plate 4 as possible sources

of sand. Locations of these deposits were compiled from state geologic maps, where

they are depicted as follows.

Washington—Qe—Eolian deposits (Hunting and others, 1961)

Oregon—Qd—Dune sand (Walker and others, 1991)

Idaho—Qrw—Dune sand (Bond and Wood, 1978)

Wyoming—Qs—Dune sand and loess (Love and Christiansen, 1985)
14

Utah—Qe—Eolian deposits (Hintze, 1980)

California—Qs—Sand only (Jennings, 1977)

Eolian sands of the Interior Columbia Basin have not been mined significantly.

Most construction sand comes from alluvial sand and gravel deposits, and most

eolian sands are not the high-purity quartz sands required for most industrial uses.

Although impure sands can be upgraded, it generally is more economical to find

high-purity quartz sands, sandstones or quartzites, which have been naturally

upgraded by undergoing several cycles of erosion and deposition.

Silica Sand

Silica sand is used in making glass, ceramics, and ground silica. It also is used as

foundry sand, filtration sand, blasting sand, and hydraulic fracturing sand.

Currently, the Ordovician Addy Quartzite is being mined for silica sand at a location

in northeastern Washington (Zdunczyk and Linkous, 1994). Other silica sand

resources of Interior Columbia Basin are present in the Eocene Puget Group of

western Washington, and the Miocene Payette Formation of southwestern Idaho

(Zdunczyk and Linkous, 1994, fig. 3, p. 883).

Natural Aggregate Regions of the Interior Columbia Basin

Langer and Glanzman (1993, p. 14) have characterized the natural aggregate

resources of United States by region. The Interior Columbia River Basin contains

parts of three Natural Aggregate Regions—the Western Mountain Ranges, the

Columbia Plateau, and the Basin and Range (fig. 3). The Northern Glaciated

Mountains are here considered a distinctive Natural Aggregate Subregion (of the

Western Mountain Ranges Region), and are characterized separately below.

The Northern Glaciated Mountains Natural Aggregate Subregion (fig. 3)

coincides with ERU 7 (Northern Glaciated Mountains), and is located along the

southern margin of Pleistocene continental glaciation. Regionally glaciated

mountains and valleys are underlain by igneous and metamorphic rocks (including

some metamorphosed limestones and dolomites), which provide potential sources

of good-quality crushed stone. Mountains are drained by streams that flow into

large rivers and lakes, located in broad valleys, containing abundant deposits of sand

and gravel, and(or) deposits of sand, silt, and clay. Stream-channel and streamterrace deposits of sand and gravel are common. The giant sand and gravel deposits

of the Spokane-Rathdrum Valley were deposited by a series of catastrophic floods,

caused by rapid and repeated draining of glacial Lake Missoula.

The Western Mountain Ranges Natural Aggregate Region (fig. 3) includes ERU

1 (Northern Cascades), ERU 2 (Southern Cascades), ERU 3 (Upper Klamath), the

eastern part of ERU 6 (Blue Mountains), ERU 8 (Lower Clark Fork), ERU 9 (Upper

Clark Fork), ERU 12 (Snake Headwaters), and ERU 13 (Central Idaho Mountains).

This region is characterized by tall mountains alternating with relatively narrow,

steep-sided valleys. Mountain ranges are underlain by igneous and metamorphic

rocks, flanked by sedimentary rocks (including some limestones) which provide
                                                   

    

 Legend

ICBEMP Ecological 

 Reporting Units

1. Northern Cascades2. Southern Cascades3. Upper Kalamath4. Northern Great Basin5. Columbia Plateau6. Blue Mountains7. Northern Glaciated Mountains8. Lower Clark Fork9. Upper Clark Fork10. Owyhee Uplands11. Upper Snake12. Snake Headwaters13. Central Idaho Mountains

Explanation

Landscapecharacterizationboundary forICBEMP 

Ecological Reporting Unit Boundary

7

8

9

13

5

10

11 12

12

1

4

6

7

5

ICBEMP Study area

Columbia Basin study area showing natural aggregate regions. 





 

Natural Aggregate Regions

Northern Glaciated Mountains
Western mountain ranges
Columbia plateau
Basin and Range
16

potential sources of good-quality crushed stone. Most sand and gravel resources are

located in stream-channel deposits, but larger valleys may have higher terraces of

sand and gravel. Some broad, flat-bottomed valleys are fault-bounded, and such

valleys may contain alluvial fans, and thick valley-fill deposits of poorly sorted sand

and gravel.

The Columbia Plateau Natural Aggregate Region (fig. 3) includes ERU 5

(Columbia Plateau), the eastern part of ERU 6 (Blue Mountains), ERU 10 (Owyhee

Uplands), the northern part of ERU 4 (Northern Great Basin), the northern part of

ERU 11 (Upper Snake River), and the western margin of ERU 13 (Central Idaho

Mountains). This region is characterized by gently sloping plateaus, underlain by a

thick sequence of extensive lava flows, separated by soil zones and interbedded

sediments. The northern part of this region is underlain by basalt, a potentially

suitable source of crushed stone. The southern part is underlain by basalt and

siliceous volcanic rocks. Some volcanic and volcano-sedimentary rocks are soft and

friable; and silicic volcanic rocks of the southern part of the region tend to react

deleteriously when used as aggregate in cement concrete. Sand and gravel deposits

are well distributed throughout the northern parts of the region. In the rest of the

region, limited sand and gravel are restricted to river and terrace deposits, which

commonly contain clasts of silicic volcanic rocks that may be reactive in cement

concrete.

The Basin and Range Natural Aggregate Region (fig. 3) includes the southern

part of ERU 4 (Northern Great Basin) and the southern part of ERU 11 (Snake

Headwaters). This region is characterized by alternating basins (broad, elongate

valleys), flanked by fault-bounded mountain ranges. Mountain ranges of the Basin

and Range Natural Aggregate Region commonly are underlain by igneous,

metamorphic, and consolidated sedimentary rocks, some of which are potential

sources of good quality crushed stone. Large alluvial basins commonly contain

marginal alluvial fans and thick, extensive deposits of poorly sorted sand and

gravel, which are coarser-grained near basin margins and finer-grained toward basin

centers. Poorly sorted basin-fill deposits may be reworked, cleaned of fines and

weathering products, and re-sorted in modern stream channels. Some basins

contained Pleistocene lakes, in which deposits of sand and gravel accumulated

locally at inlet deltas, and along shorelines. Other areas are deficient in sand and

gravel. Quality problems tend to be localized.

Future Production of Natural Aggregate

The U.S. Bureau of Mines (written communication, 1995) estimates that about 11

tons of natural aggregate are produced per person per year in the Interior Columbia

River Basin (from a total of 449 operations). If this continues, and population

increases as predicted, “total production could rise from 46.4 million tons in 1992...to

over 100 million tons per year” (U.S. Bureau of Mines, written communication,

1995). Areas of likely urban demand for natural aggregate in the Interior Columbia

River Basin are indicated by circular zones that extend 15 km outward from symbols

that represent cities or towns with populations of at least 20,000 people (plate 4).

Narrow linear zones of high-demand for natural aggregate also occur along
17

transportation routes, which are not shown.

Deposits of sand and gravel are, for practical purposes, a nonrenewable resource

and are being depleted in urban areas. To ensure continuing and uninterrupted

supplies of sand and gravel to high-demand areas, nearby resources should be

identified, evaluated, and protected from being overbuilt or otherwise made

unavailable (Langer and Glanzman, 1993). Protection of sites on ten-mile spacings

in areas of high demand would minimize future hauling costs and conserve energy.

Nevertheless, in the long term, sand and gravel probably will be progressively

depleted and(or) built-over in urban market areas, and aggregate production will

shift toward crushed rock, as it has in heavily populated eastern and mid-western

states.

Environmental Impacts of Natural Aggregate Production

Increased airborne particulates, increased sediment load to streams, and

increased noise are short-term environmental impacts of aggregate production.

Mine-induced changes to landscapes are long-term environmental impacts. If

gravel pits extend below the water table, groundwater can become exposed to direct

contamination and evaporation. Reclamation to return the land to beneficial use

should be planned before extraction, so that equipment can be used for both mining

and reclamation, and mined-out areas can be reclaimed concurrent with extraction

in other parts of the operation (Langer and Glanzman, 1993).

Obtaining Digital Data

Plates 1 to 4 are reduced versions of 1:2,000,000 scale digital plates. The digital

files that were used to make the phosphate and sand and gravel maps are available

as GIS coverages and associated data files. All data files and map images are

maintained in the projection used for all ICBEMP products:

Projection: Albers Equal Area

1

st Standard Parallel: 43° N

2

nd Standard Parallel: 48° N

Central Meridian: 117° W

Origin of Projection: 41° N

Y-offset (digital files): 700,000 meters

To obtain copies of the digital data, Download the digital files from

http://pubs.usgs.gov/of/1995/of95-681/

This Internet sites contain the phosphate and sand and gravel GIS coverages in

Arc/Info Export file format as well as the associated data files and Arc/Info macro
18

programs which are used to plot the maps at a scale of 1:2,000,000. Use of this data

requires a GIS that is capable of reading Arc/Info Export formatted files and a

computer capable of reading UNIX ASCII files. To use these files on a DOS

computer, they must be put through a unix-to-dos filter. Or,

Obtaining Paper Maps

Paper copies of the phosphate and sand and gravel maps are not available from

the USGS at this time. However, with access to the Internet and access to a largeformat color plotter, a 1:2,000,000-scale paper copy of the map can be made, as

follows:

1. Download the digital versions of the complete maps from the USGS public access

World Wide Web site on the Internet.

KWWSSXEVXVJVJRYRIRIPDSVWDU=

This Internet site contains two files, phos2m.hp (phosphate map), and sg2m.hp

(sand and gravel map), which are in HPGL2 language.

2. These files can be plotted by any large-format graphics plotter which can interpret

HPGL2 language. The finished plots are 27 by 38 inches.

Paper copies of the map can also be created by obtaining one of the versions of

the digital files as described above, and then creating a plot file in the GIS.

PDFs of the HPGL2 on this site were made with an evaluation copy of a conversion app. 

Concluding Remarks

Composite maps were produced using state geologic maps. These derivative

maps, at 1:500,000 scale, help in land management decisions and are appropriate to

regional issues for the entire Columbia River Basin. Although some of the state

geologic maps are old, geologic knowledge since the 1970’s has been primarily

concerned with temporal correlation of rock units, with details of the compositions

of the individual rock units, and with how the present arrangement of rock units

came to exist. Thus, the dominant character of rock units is well represented in the

state geologic maps and the maps are useful for regional applications.

Geologic information is a critical portion of any ecosystem study and for making

land management decisions. Future ecosystem monitoring and adaptive

management planning within the Columbia River Basin should include studies to

improve the quality of the geologic data base and resource databases, particularly for

industrial minerals, including sand and gravel.

A more complete and rigorous estimation of phosphate resources would require
19

a compilation of production and remaining resources of known deposits, and a

thorough study of the phosphate contents, mineability, and recoverability of

phosphate-bearing strata of the ICBEMP region. Furthermore, if quantitative

estimates are to be made for individual phosphate deposits, a new tonnage-grade

model will have to be made for deposits of the western United States.

 Quantitative estimation of sand and gravel resources would require the

following: 1) compilation of locations, past production and remaining resources of

significant deposits of sand and gravel; 2) compilation of the geology of sand and

gravel deposits, as noted on relatively large-scale geologic maps that emphasize

surficial deposits; 3) classification of known and potential deposits of sand and

gravel, using the geologic and fragment-size classification schemes of Bliss and Page

(1994); 4) estimation of the size and quality of undiscovered resources of sand and

gravel, using the methods and models of Bliss and Page (1994) where appropriate.

Analysis of gradients and flow rates of rivers and streams might help identify

reaches of modern rivers and streams that are favorable for sand and gravel

deposits. Analysis of present and future patterns of demand for sand and gravel

would help identify areas of likely future development of sand and gravel resources.
20

References Cited

Algermissen, S. T., Perkins, D. M., Thenhaus, P. C., Hanson, S. L., and Bender, B. L.,

1990, Probabilistic earthquake acceleration and velocity maps for the United

States and Puerto Rico: U.S. Geological Survey Miscellaneous Field Studies Map,

MF-2120, scale 1:7,500,000.

Bailey, R.G., 1976, Ecoregions of the United States: U.S. Department of Agriculture,

Forest Service, Intermountain Region, Ogden, Utah.

 1978, Description of the Ecoregions of the United States: U.S.

Department of Agriculture, Forest Service, Intermountain Region, Ogden, Utah.

Bartels, J.J., and Gurr, T.M., 1994, Phosphate rock: in Carr, D.D., ed., Industrial

minerals and rocks: Society for Mining, Metallurgy, and Exploration, Inc., p. 751-

764.

Bennett, E.H., and Gillerman, Virginia, 1994, Mining, minerals, and the

environment in Idaho, 1993: Idaho Geological Survey Staff Report 94-1, 56 p.

Bliss, J.D., 1993, Modeling sand and gravel deposits--initial strategy and preliminary

examples: U.S. Geological Survey Open File Report 93-200, 31 p.

Bliss, J.D. and Page, N.J., 1994, Modeling surficial sand and gravel deposits:

Nonrenewable Resources, v. 3, no. 3, p. 237-249.

Bond, J.G. and Wood, C.H., 1978, Geologic map of Idaho: Idaho Department of

Lands, Bureau of Mines and Geology, 1 plate, Scale 1:500,000.

Bookstrom, A. A., Zientek, M. L., Box, S. E., Derkey, P. D., Elliott, J. E., Frishman,

David, Ashley, R. P, Evarts, R. C., Stoeser, D. B., Moyer, L. A., Cox, D. P., and

Ludington, Steve, 1996, Status and metal content of significant metallic mineral

deposits in the Pacific Northwest: a contribution to the Interior Columbia Basin

Ecosystem Management Project: U.S. Geological Survey Open-File Report 95-688,

93 p.

Box, S. E., Bookstrom, A. A., Zientek, M. L., Derkey, P. D., Ashley, R. P., Elliott, J. E.,

and Peters, S. G., 1996, Assessment of undiscovered mineral resources in the

Pacific Northwest: a contribution to the Interior Columbia Basin Ecosystem

Management Project: U.S. Geological Survey Open-File Report 95-682, 415 p.

Frost, T. P., Raines, G. L., Almquist, C. L., and Johnson, B. R., 1996, Digital maps of

possible bat habitats for the Pacific Northwest: a contribution to the Interior

Columbia Basin Ecosystem Management Project: U.S. Geological Survey OpenFile Report 95-683, 20 p.

Hintze, L.F., 1980, Geologic map of Utah: Utah Geological and Mineral Survey, 2

plates, 1:500,000 scale.

Hoblitt, R. P., Miller, C. D., and Scott, W. E., 1987, Volcanic hazards with regard to

siting nuclear power plants in the Pacific Northwest: U.S. Geological Survey

Open-File Report 87-297.
21

Hunting, M.T., Bennett, W.A., Livingston, V.E., Jr., and Moen, W.S., 1961, Geologic

map of Washington: Washington Dept. of Conservation, Division of Mines and

Geology, 1 plate, scale 1:500,000.

Jennings. C.W., 1977, Geologic map of California: California Divisions of Mines and

Geology, Map. No. 2, 1 plate, Scale 1:750,000.

Johnson, B.R. and Raines, G.L., 1995, Digital map of major lithologic bedrock units

for the Pacific Northwest: a contribution to the Interior Columbia Basin

Ecosystem Management Project: U.S. Geological Survey Open-File Report 95-680,

35 p. plus 2 plates.

Kraus, U.H., Henning, G.S., and Schmidt, H.W., 1984, International strategic

minerals inventory summary report — phosphate: U.S. Geological Survey

Circular 930-C, 41 p.

Langer, W.H., and Glanzman, V.M., 1993, Natural aggregate — building America’s

Future; public issues in earth science: U.S. Geological Survey Circular 1110, 39 p.

Love, J.D., and Christiansen, A.C., 1985, Geologic map of Wyoming: U.S. Geological

Survey, 3 Plates, Scale 1:500,000.

Mosier, D.L., 1986a, Descriptive model of upwelling type phosphate deposits: in Cox,

D.P., and Singer, D.A., 1986, Mineral deposit models: U.S. Geological Survey

Bulletin 1693, p. 234.

 1986b, Grade and tonnage model of upwelling type phosphate deposits:

in Cox, D.P., and Singer, D.A., 1986, Mineral deposit models: U.S. Geological

Survey Bulletin 1693, p. 234-236.

Raines, G. L., Johnson, B. R., Frost, T. P., and Zientek, M. L., 1996, Digital maps of

compositionally classified lithologies derived from 1:500,000 scale geologic

mapping for the Pacific Northwest: a contribution to the Interior Columbia Basin

Ecosystem Management Project: U.S. Geological Survey Open-File Report 95-685,

28 p.

Raines, G. L. and Smith, C. L., 1995, Digital maps of National Uranium Resource

Evaluation (NURE) geochemistry for the Pacific Northwest: a contribution to the

Interior Columbia Basin Ecosystem Management Project: U.S. Geological Survey

Open-File Report 95-686, 22 p.

Randol, 1994, Randol mining directory 1994/95, U.S. mines and mining companies:

Randol International Ltd., Golden Colorado, 790 p.

Ross, C.P., Andres, D.A., and Witkind, I.J., 1955, Geologic map of Montana: U.S.

Geological Survey, 1 plate, Scale 1:500,000.

Singer, D.A., 1993, Basic concepts in three-part quantitative assessments of

undiscovered mineral resources: Nonrenewable Resources, v. 2, no. 2, p. 69-81.

Stewart, J.H. and Carlson, J.E., 1978, Geologic map of Nevada: U.S. Geological

Survey, 1 plate, scale 1:500,000.
22

Swanson, R.W., McKelvey, V.E., and Sheldon, R.P., 1953, Progress report on

investigations of western phosphate deposits: U.S. Geological Survey Circular

297, 16 p.

U.S. Bureau of Mines, 1993a, Mineral commodity summaries, 1993: United States

Department of the Interior Bureau of Mines, 201 p.

 1993b, State mineral summaries, 1993: United States

Department of the Interior Bureau of Mines, 165 p.

 1995, Economic assessment of mining and minerals-related

activities in the Interior Columbia River Basin: Draft report submitted to

ICBEMP, 86 p.

U.S. Geological Survey, 1990, 1:2,000,000-Scale Digital Line Graph (DLG) Data: U.S.

Geological Survey, Digital Data Series-4, CDROM.

Walker, G.W., and MacLeod, N.S., 1991, Geologic map of Oregon: U. S. Geological

Survey, 2 plates, scale 1:500,000.

Zdunczyk, M.J., and Linkous, M.A., 1994, Industrial sand and sandstone; in Carr,

D.D., ed., Industrial Minerals and Rocks: 6th edition, Society for Mining,

Metallurgy, and Exploration, Inc. , p. 879-891.

Zientek, M. L., Bookstrom, A. A., Box, S. E., and Johnson, B. R., 1996, Future

minerals related activity, Interior Columbia Basin Ecosystem Management

Project area: an overview: U.S. Geological Survey Open-File Report 95-687, 30 p.
23

APPENDIX A: GIS Documentation

Polygon attribute descriptions for MRPHOS.PAT are as follows:

ITEM

NAME

START

COLUMN

ITEM

LENGTH

ATTRIBUTE DESCRIPTIONS

phos 17 3 H - includes ‘Permian phosphatic sandstone,

mudstone, and chert of southeastern Idaho’

(Phosphoria, Shedhorn, and Park City

formations) in Idaho; ‘Permian

undivided, mainly Phosphoria Formation’

in Montana; and ‘Permian Phosphoria Formation and related rocks of the Shedhorn

Sandstone and the Park City Formation’ in

Wyoming.

M - includes ‘Park City Formation’ and

‘Goose Egg Formation’ (which contains

phosphate according to USGS Circular 297) in

Wyoming; and ‘Phosphoria and Park City

formations’ in Utah.

permis 20 3 P - permissive for the presence of phosphate

mineral resources

favor 23 3 F - favorable for the presence of phosphate

mineral resources

There are no point attribute descriptions for SITE_PHOS.PAT
24

Polygon attribute descriptions for SG.PAT are as follows:

ITEM

NAME

START

COLUMN

ITEM

LENGTH

ATTRIBUTE DESCRIPTIONS

sg 17 3 W - open water

fg - fair to good favorable area - Gravel, sand,

and silt; relatively well sorted, unweathered,

and unconsolidated.

fp - fair to poor permissive area - Silt, sand,

and gravel; poorly sorted, weathered, and/or

partly consolidated.

san - permissive area - sand only; dune or

wind blown sand.

blank or state abbreviation (wa, id, mt, wy, ut,

nv, ca, or) - No potential for significant sand

or gravel

stream 20 3 in - within 250 meters of stream mapped at

1:2,000,000

blank - More than 250 meters from stream

city 23 3 in - within a town or city site within the

Interior Columbia River Basin. Populated

area; no significant sand or gravel

development is likely.

buf - areas of high demand within Interior

Columbia River Basin. Area outside, but

within 15 km of city or town with population

greater than 20,000.

blank - More than 15 km from city or town

with population greater than 20,000.

sum 17 9 redefined item that links ‘sg stream city’ to

SG.LU1 lookup table
25

Attribute descriptions for lookup table for SG.LU1 are as follows:

ITEM

NAME

START

COLUMN

ITEM

LENGTH

ATTRIBUTE DESCRIPTIONS

sg 1 3 W - open water

fg - fair to good favorable area - Gravel, sand,

and silt; relatively well sorted, unweathered,

and unconsolidated.

fp - fair to poor permissive area - Silt, sand,

and gravel; poorly sorted, weathered, and/or

partly consolidated.

san - permissive area - sand only; dune or

wind blown sand.

blank or state abbreviation (wa, id, mt, wy,

ut, nv, ca, or) - No potential for significant

sand or gravel

stream 3 3 in - within 250 meters of stream mapped at

1:2,000,000

blank - more than 250 meters from stream

city 7 3 in - within a town or city site within the

Interior Columbia River Basin. Populated

area; no significant sand or gravel

development is likely.

buf - areas of high demand within Interior

Columbia River Basin. Area outside, but

within 15 km of city or town with population

greater than 20,000.

blank - more than 15 km from city or town

with population greater than 20,000.

symbol 10 5 calcomp1 shadeset symbol number

sum 17 9 redefined item that links ‘sg stream city’ to

SG.PAT polygon attribute table. There are 63

unique combinations of sg, stream, and city.
26

The unique combinations of SG, STREAM, and CITY are as follows:

$recno sg stream city symbol

1 0

2 in 688

3 W 424

4 W buf 156

5 W in 1

6 W in 688

7 W in buf 688

8 W in in 1

9 ca 0

10 ca in 688

11 fg 7

12 fg buf 170

13 fg in 1

14 fg in 688

15 fg in buf 688

16 fg in in 1

17 fp 97

18 fp buf 304

19 fp in 1

20 fp in 688

21 fp in buf 688

22 fp in in 1

23 id 0

24 id buf 156

25 id in 1

26 id in 688

27 id in buf 688

28 id in in 1
27

$recno sg stream city symbol

29 mt 0

30 mt buf 156

31 mt in 1

32 mt in 688

33 mt in buf 688

34 mt in in 1

35 nv 0

36 nv in 1

37 nv in 688

38 nv in in 1

39 or 0

40 or buf 156

41 or in 1

42 or in 688

43 or in buf 688

44 or in in 1

45 san 36

46 san buf 156

47 san in 1

48 san in 688

49 san in buf 688

50 ut 0

51 ut in 1

52 ut in 688

53 ut in in 1

54 wa 0

55 wa buf 156

56 wa in 1

57 wa in 688
28

$recno sg stream city symbol

58 wa in buf 688

59 wa in in 1

60 wy 0

61 wy in 1

62 wy in 688

63 wy in in 1

Albers Equal Area projection

Albers Equal Area projection