Mapping of serpentinites in the Eastern Desert of Egypt by using Landsat thematic mapper data

Journal Article · Mon Dec 01 04:00:00 EST 1986 · Geology; (United States)

DOI:https://doi.org/10.1130/0091-7613(1986)14<995:MOSITE>2.0.CO;2· OSTI ID:5717760

Sultan, M; Arvidson, R E; Sturchio, N C

Serpentinites in the Eastern Desert of Egypt were mapped from Landsat thematic mapper (TM) data by using procedures that take advantage of the distinctive spectral reflectance of these rocks caused by the abundance of antigorite, lizardite, clinochrysotile, and magnetite. The method employs a threshold classifier based on three reflectance ratios: (1) band 5/7 for estimating the abundance of hydroxyl-bearing phases, (2) band 5/1 for magnetite content, and (3) the calculated value of reflectance for band 4, based on a linear interpolation between bands 3 and 5, divided by the observed band-4 reflectance. The third ratio was used to identify rocks in iron-bearing aluminosilicates and thereby to distinguish mafic rocks containing substantial amounts of magnetite and hydroxyl-bearing phases from serpentinites. The method was first successfully tested over the Meatiq dome and Wadi Ghadir areas, where serpentinites and ophiolitic melanges dominated by serpentinites have been mapped during the course of field work. A TM-based map was then generated; the map covered about 60,000 km/sup 2/ in the Eastern Desert. Results demonstrate that TM data can be used with reliability to distinguish serpentinites from surrounding rocks in arid regions and to generate detailed maps over wide regions by using quantitative, reproducible mapping criteria. Possibilities for locating suture zones over the less well known parts of arid continents are clear.

• Research Organization: Washington Univ., St. Louis, MO
• OSTI ID: 5717760
• Journal Information: Geology; (United States), Journal Name: Geology; (United States) Vol. 14:12; ISSN GLGYB
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580203* -- Geophysics-- Geophysical Survey Methods-- (1980-1989)
AFRICA
ARID LANDS
DESERTS
DEVELOPING COUNTRIES
EGYPTIAN ARAB REPUBLIC
LANDSAT SATELLITES
MAPPING
MEASURING INSTRUMENTS
METAMORPHIC ROCKS
OPTICAL PROPERTIES
PERFORMANCE
PHYSICAL PROPERTIES
REMOTE SENSING
ROCKS
SATELLITES
SERPENTINITES
SPECTRAL REFLECTANCE