Magmatic and tectonic evolution of the Ladakh Block from field studies

40Ar–39Ar dating of volcanic rocks of the Shyok suture zone in north–west trans-Himalaya: Implications for the post-collision evolution of the Shyok suture zone

“…This indicates that island-arc setting could be limited to the western margin of Eurasian plate facilitating intra-oceanic subduction of the neo-Tethys and thus forming Early Cretaceous Kohistan-Dras island-arc. However as mentioned above there are ample evidences of continental crust being present in the eastern side of the Kohistan-Dras arc in Early Cretaceous (Fuchs, 1979;Gregan and Pant, 1983;Raz and Honegger, 1989). Geochemical evidences (Rolland et al, 2000) confirm and support these geological evidences and suggest the simultaneous evolution of island-arc and continental arc along the south Asian plate boundary.…”

“…They further noted that the acidic volcanism of Khardung represents an Andean type margin like Tibet, while the western Ladakh sector's formations represent the suturing of an island-arc with the continent. Raz and Honegger (1989) provided field evidences for the presence of continental crust before the calc-alkaline magma intrusion in the northern Ladakh. They reported meta-sediments, shales, sandstones, quartzites and marbles indicating of the continental crust.…”

Early–Middle Eocene Exhumation of the Trans-Himalayan Ladakh Batholith, and the India–Asia Convergence

“…The Trans-Himalayan Mountains expose a long linear LB belt in Kargil-Leh-Demchuk region in India and the Kohistan-Deosai Batholith of Astor-Deosai-Skardu region in Pakistan 24,25 . This belt extends eastwards as the Kailash Tonalite and the Gangdese pluton in southern Tibet 26,27 , and the Lohit Batholith in Mishmi Hills, Arunachal Himalaya 25 ( Figure 1 a).…”

“…After pulsative crystallization of the LB between ~100 and 41 Ma (refs 15,17,24,26,36,37,47) with main phase at ~58.0 Ma (ref. 38) (U-Pb zircon ages), the batholith initially cooled by normal conductive cooling and then underwent much faster cooling, resulting from tectonically controlled uplift due to convergence of the India-Asia Plates.…”

“…LB is bound by the Indus Tsangpo Suture Zone (ITSZ) along its southern margin, while the Shyok Suture Zone (SSZ) frames its northern margin. These sutures demarcate Early Cretaceous subduction of the Neo-Tethyan oceanic lithosphere 28 and closure of this ocean between the Indian and Asian Plates 24,[29][30][31][32][33][34][35] ( Figure 1 a and b). The batholith trends WNW-ESE for nearly 600 km in a 30-80 km wide belt (Figure 1 b), with an exposed thickness of ~2 km.…”