Evolution of the Himalayan structures

Conference · Tue May 01 04:00:00 EDT 1990 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:6720811

Bhatt, K ^[1]

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1. Iowa State Univ., Ames (USA)

Sedimentologically, the Himalayan sediments were deposited in the Tethyan Sea and represent rocks from the Paleozoic to the Holocene. During the early Paleozoic, localized movements divided the Tethyan Sea into two geosynclines separated by a geoanticline of Precambrian central crystallines. The northern deep basin which contains euogeosynclinal sediments, is known as the Tethyan zone, and the southern shallow basin which has miogeosynclinal sediments, represents the rocks of the Himalayan zone. Structurally, three major zones of tectonic movement have been recognized, all of which show similar structural trend: (1) along the Indus suture zone (ISZ), (2) along the Main Central thrust (MCT), and (3) along the Main Boundary thrust (MBT). The ISZ represents the subduction zone between the Indian and Asian plate. The origin of the MCT is related to initial subduction along the trench area and may have been formed during the Late Cretaceous-early Paleocene due to offscrapping of sediments in the subduction zone. Further compression between the two plates caused southward migration of the subduction zone and formed the MBT, during or after the Pliocene, which brought old Paleozoic rocks of lesser Himalaya in contact with younger Tertiary rocks (Siwaliks) of Sub-Himalaya. Both the MCT and MBT are parts of an imbricated system formed in the subduction zone representing different geological time periods. The present position of the subduction zone indicates that future subduction of Indian plate into the Asian plate and will cause tectonic activation of the MBT and movement along the MCT will diminish.

• OSTI ID: 6720811
• Report Number(s): CONF-900605--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (USA) Journal Volume: 74:5
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
CENOZOIC ERA
CRETACEOUS PERIOD
GEOLOGIC AGES
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
HIMALAYAS
MESOZOIC ERA
MOUNTAINS
PLATE TECTONICS
SEDIMENTARY BASINS
SEDIMENTATION
TECTONICS
TERTIARY PERIOD