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Accueil du site → Master → Etats Unis → 1989 → Landsat Thematic Mapper and hand held radiometer analysis of the Hamisana Shear Zone, Northeast Sudan : Lithologic mapping in arid regions

University of Texas at Dallas (1989)

Landsat Thematic Mapper and hand held radiometer analysis of the Hamisana Shear Zone, Northeast Sudan : Lithologic mapping in arid regions

Best, Steven Eric

Titre : Landsat Thematic Mapper and hand held radiometer analysis of the Hamisana Shear Zone, Northeast Sudan : Lithologic mapping in arid regions

Auteur : Best, Steven Eric

Université de soutenance : University of Texas at Dallas

Grade : Master of Science (MS) 1989

Résumé
The distribution of ophiolitic rocks in the Nubian Shield is important for unravelling the region’s crustal evolution during the late Precambrian "Pan-African" event (900-550 Ma). Because logistical difficulties preclude detailed ground mapping but arid conditions are favorable for remote sensing, I use specially processed Landsat Thematic Mapper (TM) images to map ophiolitic rocks. Lithologically sensitive color images of the Hamisana Shear Zone in NE Sudan were generated by utilizing the band ratios 5/1 (sensitive to opaque mineral concentration), 5/7 (sensitive to minerals rich in hydroxyl and carbonate ions), and 3/4 x 5/4 (sensitive to ferrous aluminosilicate minerals). To test the accuracy of our interpretation of the TM images, the same ratios were measured on the major rock types in the field using a hand-held radiometer, and corroborated by laboratory continuous spectra measurements. The results suggest that desert varnish may be important for modifying spectral characteristics, and thus our ability to discriminate lithologies. Nevertheless, the distribution of the granitic, gabbroic, and serpentinitic lithologies are generally easily mapped. The mafic and ultramafic lithologies are associated with dismembered ophiolitic suites which delineate sutures which form terrane boundaries.

Mots clés : Geotechnology, Applied sciences, Geophysics, Earth sciences

Présentation (WorldCat)

Accès au document : Proquest Dissertations & Theses

Page publiée le 22 février 2015, mise à jour le 20 février 2018