Indus-Yarlung suture zone

{{Short description|Tectonic suture in southern Tibet}}

File:2 2 himal tecto units.png

File:CoupeHimal2.jpg

Image:MtKailash location.png. Indus-Yarlung Zangbo suture zone, the Yarlung Tsangpo River is sometimes called upper Brahmaputra River.]]

The Indus-Yarlung suture zone or the Indus-Yarlung Tsangpo suture is a tectonic suture in southern Tibet and across the north margin of the Himalayas which resulted from the collision between the Indian Plate and the Eurasian Plate starting about 52 Ma.Age of Initiation of the India-Asia Collision http://geosci.uchicago.edu/~rowley/Rowley/Collision_Age.html The north side of the suture zone is the Ladakh Batholith of the Karakoram-Lhasa Block. The rocks of the suture zone consist of an ophiolite mélanges composed of Neotethys oceanic crustal flyschs and ophiolites; the Dras Volcanics: which are basalts, dacites and minor radiolarian cherts – the remains of a mid- to late Mesozoic volcanic island arc; and the Indus Molasse which are an Eocene or later continental clastic sediments.Dèzes, Pierre, 1999, Major tectonic subdivisions of the Himalaya {{cite web |url=http://comp1.geol.unibas.ch/~zanskar/CHAPITRE2/page24.html |title=Chapter2: Major Tectonic Subdivisions of the Himalaya |access-date=2010-02-24 |url-status=dead |archive-url=https://web.archive.org/web/20100106105812/http://comp1.geol.unibas.ch/~zanskar/CHAPITRE2/page24.html |archive-date=2010-01-06 }}

The ophiolites within the Indus-Yarlung suture zone occur in two discontinuous belts. During the trench-continent collision, segments of the crust and upper mantle were emplaced onto the Indian Plate. However, following the collision of the Indian and Eurasian plates, the northern segment of ophiolitic rock was backthrust onto the edge of the Eurasian Plate, separating from the southern ophiolite group and forming two distinct belts.{{cite journal |last1=Xu |first1=Zhi-Qin |last2=Dilek |first2=Yildirim |last3=Yang |first3=Jing-Sui |last4=Liang |first4=Fend-Hua |last5=Liu |first5=Fei |last6=Ba |first6=Deng-Zhu |last7=Cai |first7=Zhi-Hui |last8=Li |first8=Guang-Wei |last9=Dong |first9=Han-Wen |last10=Ji |first10=Shao-Cheng |title=Crustal structure of the Indus–Tsangpo suture zone and its ophiolites in southern Tibet |journal=Gondwana Research |date=February 2015 |volume=27 |issue=2 |pages=507-524 |doi=10.1016/j.gr.2014.08.001 |url=https://www.sciencedirect.com/science/article/pii/S1342937X14002317 |access-date=11 February 2025|url-access=subscription }}

Some think that the many ophiolites that define the suture are not remnants of a very big ocean, but of a small back-arc basin structure.{{cite journal | last1 = Bédard | first1 = É. | last2 = Hébert | first2 = R. | last3 = Guilmette | first3 = C. | last4 = Lesage | first4 = G. | last5 = Wang | first5 = C.S. | last6 = Dostal | first6 = J. | year = 2009 | title = Petrology and geochemistry of the Saga and Sangsang ophiolitic massifs, Yarlung Zangbo Suture Zone, Southern Tibet: Evidence for an arc–back-arc origin | journal = Lithos | volume = 113 | issue = 1–2| pages = 48–67 | doi = 10.1016/j.lithos.2009.01.011 | bibcode = 2009Litho.113...48B }} More recently it has been suggested that these ophiolites formed during Early

Cretaceous subduction initiation (Hu and Stern, 2020). You can watch a video about this at https://www.youtube.com/watch?v=02Xojnf9sYA