Accession Number:

ADA102893

Title:

The Identification of Rock Types in an Arid Region by Air Photo Patterns.

Descriptive Note:

Research note,

Corporate Author:

ARMY ENGINEER TOPOGRAPHIC LABS FORT BELVOIR VA

Personal Author(s):

Report Date:

1981-06-01

Pagination or Media Count:

57.0

Abstract:

Air photo pattern criteria to identify rock types in an arid environment were evaluated for their usefulness and accuracy by stereo air photo analysis and field verification. The criteria came from published literature and from unpublished in-house research. In general, the unpublished criteria proved the most useful. New criteria to identify granitic rocks were successfully tested, and criteria for quartzite and andesitic rocks were identified. In addition, a basis was laid to develop criteria to identify metamorphic rocks by composition on aerial photography. Sixteen lithologic units were identified and mapped on 1100,000 scale stereoscopic panchromatic aerial photography. Lithologic predictions were based on detailed analyses of the photo pattern elements of landform, drainage, photo tone, and photo texture. Limited field checking showed that the lithologic predictions were generally correct. In addition, the boundaries of the lithologic units, not verified in the field, but determined from detailed photo analysis, compared favorably with boundaries shown on published geologic maps. Author

Subject Categories:

  • Cartography and Aerial Photography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE