thumbnail

Preliminary evaluation of the landsat-4 thematic mapper data for mineral exploration

Advances in Space Research

By:
, , and
DOI: 10.1016/0273-1177(85)90252-2

Links

Abstract

Landsat-4 Thematic Mapper (TM) data recorded over an arid terrain were analyzed to determine the applicability of using of TM data for identifying and mapping hydrothermally altered, potentially mineralized rocks. Clays, micas, and other minerals bearing the OH anion in specific crystal lattice positions have absorption bands in the 2.2-??m region (TM channel 7, TM7) and commonly lack features in the 1.6-??m region (TM5). Channel ratios TM5/TM7, TM5/TM4, and TM3/TM1 were combined into a color-ratio-composite (CRC) image and used to distinguish hydrothermally altered rocks, unaltered rocks, and vegetation. These distinctions are made possible by using the TM5 and TM7, channels which are not available in the Landsat multispectral scanner (MSS). Digital masking was used to eliminate ambiguities due to water and shadows. However, some ambiguities in identification resulted between altered volcanic rocks and unaltered sedimentary deposits that contained clays, carbonates, and gypsum, and between altered volcanic rocks and volcanic tuffs diagenetically altered to zeolites. However, compared to MSS data, TM data should greatly improve the ability to map hydrothermally altered rocks in arid terrains. ?? 1985.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Preliminary evaluation of the landsat-4 thematic mapper data for mineral exploration
Series title:
Advances in Space Research
DOI:
10.1016/0273-1177(85)90252-2
Volume
5
Issue:
5
Year Published:
1985
Language:
English
Publisher:
Elsevier
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Advances in Space Research
First page:
13
Last page:
20
Number of Pages:
8