The leading edge of the Greater Himalayan Crystalline complex revealed in the NW Indian Himalaya: Implications for the evolution of the Himalayan orogen

Date

2007

Authors

Webb, Alexander G.
Yin, An
Harrison, T.M.
Celerier, Julien
Burgess, W.P.

Journal Title

Journal ISSN

Volume Title

Publisher

Association of Engineering Geologists

Abstract

The three Himalayan lithologic units, the Lesser Himalayan Sequence, the Greater Himalayan Crystalline complex, and the Tethyan Himalayan Sequence, have a specific structural correlation with the Main Central thrust and South Tibet detachment in the central Himalaya. There, the Main Central thrust places the Greater Himalayan Crystalline complex over the Lesser Himalayan Sequence, and the South Tibet detachment places the Tethyan Himalayan Sequence over the Greater Himalayan Crystallines. Although this division has formed the basis for all Himalayan tectonic models, it fails to explain aspects of the geology of the western Himalaya where the Main Central thrust places the Tethyan Himalayan Sequence directly above the Lesser Himalayan Sequence. Our mapping in NW India shows that this relationship results from southward merging of the Main Central thrust and South Tibet detachment. This finding, in conjunction with observed alternating shear senses on the South Tibet detachment, is inconsistent with the wedge-extrusion and erosion-induced channel-flow models (both require only top-to-the-N motion on the South Tibet detachment) but is consistent with a tectonic-wedging model.

Description

Keywords

Keywords: Orogen; Tectonic wedge; Wedge-extrusion; Channel flow; Crystalline rocks; Erosion; Geological surveys; Lithology; Structural geology; Tectonics; detachment fault; extrusion; lithology; orogeny; structural geology; tectonic evolution; tectonic wedge; thrus Himalaya; Main Central thrust; South Tibet detachment; Tectonic wedge

Citation

Source

Geological Society of America Bulletin

Type

Journal article

Book Title

Entity type

Access Statement

License Rights

Restricted until

2037-12-31