Carbonate residual material

Noncarbonate residual material

Alkaline intrusive volcanic rock

Silicic residual material

Extrusive volcanic rock

Colluvial sediment

Glacial till, clayey

Glacial till, loamy

Glacial till, coarse textured

Glacial outwash and glacial lake sediment, coarse textured

Glacial lake sediment, fine textured

Hydric, peat and muck

Eolian sediment, coarse textured (sand dunes)

Eolian sediment, fine textured (glacial loess)

Saline lake sediment

Alluvium and fine-textured coastal zone sediment

Coastal zone sediment, coarse textured

Water

State boundaries

EXPLANATION

Lithology Classes

Introduction

As part of an effort to map terrestrial ecosystems, the U.S. Geological 

Survey (USGS) has generated a new classification of the lithology of surficial 

materials to be used in creating maps depicting standardized, terrestrial ecosystem models for the conterminous United States. The ecosystems classification 

used in this effort was developed by NatureServe (Comer and others, 2003). A 

biophysical stratification approach, developed for South America (Sayre and 

others, 2008) and now being implemented globally (Sayre and others, 2007), 

was used to model the ecosystem distributions. This ecosystem mapping 

methodology is transparent, replicable, and rigorous (Sayre and others, 2009). 

Surficial lithology strongly influences the differentiation and distribution of 

terrestrial ecosystems, and is one of the key input layers in this biophysical 

stratification. 

These surficial lithology classes were derived from the USGS map “Surficial Materials in the Conterminous United States,” which was based on texture, 

internal structure, thickness, and environment of deposition or formation of 

materials (Soller and Reheis, 2004). This original map was produced from 

a compilation of regional surficial and bedrock geology source maps using 

broadly defined common map units for the purpose of providing an overview 

of the existing data and knowledge. For the terrestrial ecosystem effort, the 28 

lithology classes of Soller and Reheis (2004) were generalized and then reclassified into a set of 17 lithologies that typically control or influence the distribution of vegetation types (Kruckeberg, 2002).

This map depicts a smoothed and generalized image of these final 17 surficial lithology classes. Additional information about this map and any data 

developed for the ecosystems modeling of the conterminous United States 

is available online at: http://rmgsc.cr.usgs.gov/ecosystems/.

References Cited:

Comer, Patrick, Faber-Langendoen, Don, Evans, Rob, Gawler, Sue, Josse, 

Carmen, Kittel, Gwen, Menard, Shannon, Pyne, Milo, Reid, Marion, 

Schulz, Keith, Snow, Kristin, and Teague, Judy, 2003, Ecological systems 

of the United States—A working classification of U.S. terrestrial systems: 

NatureServe, Arlington, Va. (Available online at http://www.natureserve.	

	 org/library/usEcologicalsystems.pdf.)

Kruckeberg, A., 2002, Geology and plant life: Seattle, Wash.: University of 

Washington Press, 362 p.

Sayre, Roger, Yanosky, Alberto, and Muchoney, Doug, 2007, Mapping global 

ecosystems—The GEOSS approach, in Group on Earth Observations, ed.: 

London, U.K., Tudor Rose, p. 231–232. (Also available online at: http://	

	 www.earthobservations.org/docs_pub.shtml.)

Sayre, R., Bow, J., Josse, C., Sotomayor, L., and Touval, J., 2008, Terrestrial 

ecosystems of South America, in Campbell, J.C., Jones, K.B., and Smith, 

J.H., eds., North America land cover summit—A special issue of the 

Association of American Geographers: Association of American Geogra‐ 

phers, p. 131–152.

Sayre, Roger, Comer, Patrick, Warner, Harumi, and Cress, Jill, 2009, A new 

map of standardized terrestrial ecosystems of the conterminous United 

States: U.S. Geological Survey Professional Paper 1768, 17 p. (Also avail‐ 

able online at: http://pubs.usgs.gov/pp/1768.)

Soller, D.R., and Reheis, M.C., comps., 2004, Surficial materials in the 

conterminous United States: U.S. Geological Survey Open-File Report 

03-275, scale 1:5,000,000. (Available online at http://pubs.usgs.gov/	

	 of/2003/of03-275/.)

Terrestrial Ecosystems—Surficial Lithology of the Conterminous United States

By Jill Cress, David Soller, Roger Sayre, Patrick Comer1, and Harumi Warner2

2010fdsasdfa

Scientific Investigations Map 3126

Version 1.0

U.S. Department of the Interior

U.S. Geological Survey

Publishing support provided by:

Denver Publishing Service Center

Manuscript approved for publication on April 6, 2010

For more information concerning this publication, contact

USGS Central Region Geospatial Information Office

Federal Center

Box 25286

Denver, CO 80225

1-888-ASK-USGS or

Jill Cress

Rocky Mountain Geographic Science Center

U.S. Geological Survey

(303) 202-4275

jjcress@usgs.gov

Any use of trade, product, or firm names is for descriptive purposes only

and does not imply endorsement by the U.S. Government.

Although this information product, for the most part, is in the public

domain, it also contains copyrighted materials as noted in the text.

Permission to reproduce copyrighted items for other than personal use

must be secured from the copyright owner.

For sale by U.S. Geological Survey Information Services

Box 25286, Federal Center, Denver, CO 80225

1-888-ASK-USGS

This and other USGS products are available on the World Wide Web at:

http://store.usgs.gov/

This report is available at

http://pubs.usgs.gov/sim/3126

1 Ecology Department, NatureServe, Boulder, Colo.

2 Parallel Inc., Lakewood, Colo.

Prepared in collaboration with NatureServe

Suggested citation:

Cress, Jill, Soller, David, Sayre, Roger, Comer, Patrick, and Warner, Harumi, 2010, 

Terrestrial ecosystems—Surficial lithology of the conterminous United States: 

U.S. Geological Survey Scientific Investigations Map 3126, scale 1:5,000,000, 1 sheet

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