38°00'

37°50'

37°40'

37°30'

107°10'

107°20' 107°10'

107°30'

107°30'

107°40'

107°50' 107°40'

38°00'

37°50'

37°40'

37°30'

107°50' 107°20'

550

Map of Mineralogy, Vegetation, and Hydrothermal Alteration Type 

Generated From ASTER Satellite Data, San Juan Mountains, Colorado

Modeled Hydrothermal Alteration Type, Mineral Groups,

and Green Vegetation generated by Automated Analysis

By

Barnaby W. Rockwell

2012

550

550

Telluride

Sneffels

Trout

Lake

Engineer

Mountain

Potato

Hill

Silverton

Ophir

Red

Mountain

Ouray Lake City

Lake

San Cristobal

Continental 

Reservoir

Rio Grande

Reservoir

Animas River

Animas River

Min e ral

Creek

Cascade

Mountain

Red

Mountain

Broken

Hill

Gladstone

Williams Creek

Reservoir

149

149

149

U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Map 3190

Sheet 5 of 5

Pamphlet accompanies Map

Base image is derived from multiple sources and served by ESRI 

http://goto.arcgisonline.com/maps/World_Imagery

World Geodetic System 1984 (WGS 84)

Projection: Universal Transverse Mercator, zone 13

ASTER Scene ID SC:AST_L1B.003:2011894123, acquired September 12, 2000 at 

http://glovis.usgs.gov/

Map generated by automated analysis of ASTER radiance data involving compound 

band ratios. Mineral and vegetation groups displayed here are modeled from output 

material indexes using Boolean arithmetic of pixel occurrence in one or more indices.

ASTER data orthorectified using a Projective Transform to mosaicked TerraServer 

digital orthophoto quadrangles, digital raster graphics, and a 1/3-arc second digital 

elevation model (~10 m resolution) from the U.S. Geological Survey National

Elevation Dataset (NED, http://ned.usgs.gov/), provided by USGS Seamless Data 

Distribution System available at http://seamless.usgs.gov/.

Data file name: sanjuans_aster_autoalt55_merge_pt-utm.img

This and other USGS information products are available at

http://store.usgs.gov/. 

U.S. Geological Survey

Box 25286, Denver Federal Center

Denver, CO 80225

To learn about the USGS and its information products visit

http://www.usgs.gov/. 

1-888-ASK-USGS

This report is available at:

http://pubs.usgs.gov/sim/3190/

Suggested citation:

Rockwell, B.W., 2012, Description and validation of an automated methodology for 

mapping minerology, vegetation, and hydrothermal alteration type from ASTER satellite 

imagery with examples from the San Juan Mountains, Colorado: U.S. Geological Survey 

Scientific Investigations Map 3190, 35 p. pamphlet, 5 map sheets, scale 100,000.

For more information concerning this publication, contact:

Center Director, USGS Central Mineral and

Environmental Resources Sciences Center

Box 25046, Mail Stop 973

Denver, CO 80225

(303) 236-1562

Or visit the Central Mineral and 

Environmental Resources Science Center Web site at:

http://minerals.cr.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.

Although these data have been processed successfully on a computer system at the 

U.S. Geological Survey, no warranty expressed or implied is made regarding the display 

or utility of the data on any other system, or for general or scientific purposes, nor shall 

the act of distribution constitute any such warranty. The U.S. Geological Survey shall 

not be held liable for improper or incorrect use of the data described and/or contained 

herein.

APPROXIMATE MEAN

DECLINATION, 2000 TRUE NORTH

MAGNETIC NORTH

11°

37° 37°

41° 41°

109° 102°

109° 102°

30 × 60 minute series grid

1:100,000 scale

COLORADO

MAP LOCATION

DURANGO

SILVERTON

NUCLA MONTROSE

DOVE

CREEK

CORTEZ

SAGUACHE

DEL 

NORTE

ANTONITO

550

550

Potosi

Hill

RAILROAD

RAILROAD

Graysill Mountain

Ophir loop

Vermillion

Peak

Lookout

Peak

Ames

La Junta

Peak

Red Mountain Creek

Chattanooga

145

Sunshine

Peak

Rio 

Grande

Rio 

Grande

Table

Mountain

Ute Ridge

Rio Grande

Pyramid

Whitecross

Mountain

Publishing support provided by: 

Denver Publishing Service Center

Manuscript approved for publication on Nov. 14, 2011

ASTER SWIR detector "scratch":

advanced argillic and argillic alteration

detected in this region may be unreliable

because of sensor defect

ASTER SWIR detector "scratch":

dolomite, hydrous silica, or jarosite 

detected in this region may be 

unreliable because of sensor defect

Lake Fork

Gunnison

River

EXPLANATION

Advanced argillic (± ferric iron)

Carbonate-propylitic + ferric iron

Carbonate-propylitic + sericite

and (or) smectite + ferric iron

Ferrous iron (often occurs with propylitic

alteration and some carbonates)

Green vegetation

Hydrous silica

Jarosite ± sericite ± smectite, or

hydrous silica + ferric iron

Major ferric iron

Modeled alteration types, mineral groups, and vegetation grouped by

relative net acid production and acid neutralizing capacity

High net acid production (NAP)

Moderate to high NAP (variable pyrite content)

Low to moderate NAP

Moderate to high acid neutralizing capacity (ANC)

High ANC

No significant NAP or ANC Carbonate-propylitic

Dolomite (may include chlorite or

epidote in volcanic terranes)

Carbonate-propylitic + sericite and (or) smectite

Sericite + chlorite or Fe/Mg sericite + ferric iron

Carbonate-propylitic ± hydrous silica + ferric iron

(may include some dolomite)

Carbonate-propylitic ± hydrous silica

(may include some dolomite)

Dolomite + ferric iron (may include

chlorite or epidote in volcanic terranes)

Dolomite + ferrous iron (may include chlorite or

epidote in volcanic terranes)

Carbonate-propylitic + ferrous iron

Sericite + chlorite or Fe/Mg sericite

Argillic (kandite clay ± sericite ± smectite)

± minor advanced argillic

Minor ferric iron

Sericite and (or) smectite

Sericite and (or) smectite + ferric iron

(may include fresh phyllic)

Argillic + ferric iron or weathered phyllic

± minor advanced argillic

Outline of ASTER scene footprint

1 0 1 2 3 4 5 6 7 8 9 10 KILOMETERS

SCALE 1: 100 000

1 0 1 2 3 4 5 6 7 8 MILES