The mafic rocks of Shao La (Kharta, S. Tibet): Ordovician basaltic magmatism in the greater himalayan crystallines of central-eastern Himalaya

Andean-type orogeny in the Himalayas of south Tibet: Implications for early Paleozoic tectonics along the Indian margin of Gondwana

“…This cannot be the effect of a simple magmatic arc but requires a broad back-arc region of high heat flow . Recent studies have revealed minor coeval mafic rocks mingled with the granites (Miller et al, 2001;Visonà et al, 2010) and the Nd isotope in this study also presents evidence for mafic magmatic contamination. Therefore, it is possible that the granites formed in a back-arc environment close to the continental volcanic arc, and they resulted from the melting of the crust with heat input from underplated mafic magmas in the lower crust.…”

“…Data on the GHC granites are from Miller et al (2001). Data on the Mandi mafic rocks are from Miller et al (2001) and data on the Shao La mafic rocks are from Visonà et al (2010). ε Nd (t) values are recalculated at 485 Ma.…”

U–Pb geochronology of basement rocks in central Tibet and paleogeographic implications

“…They occur in Turkey (Gessner et al, 2004;Ustaömer et al, 2009), Iran , the Arabian-Nubian shield (Stern, 1994), Madagascar (Tucker et al, 1999;Collins et al, 2003), the Himalaya (Schärer and Allègre, 1983;Garzanti et al, 1986;Le Fort, 1986;Lee et al, 2000;Godin et al, 2001;Gehrels et al, 2003a;Cawood et al, 2007;Visonà et al, 2010), and the northwestern Indochina peninsula and references therein). The Himalayan granitoids, combined with CambroOrdovician metamorphic monazite ages from rocks of the Greater Himalaya Sequence, have been used to suggest a tectonic event along the Indian margin at this time (e.g.…”

Late Cambrian deformation in the Lesser Himalaya

“…In addition to the above, evidence of an Early Paleozoic metamorphism has been also recorded in the crystalline rocks of the Himalaya that are exposed between the Tethyan and the Lesser Himalaya (Ferrara et al, 1983;Bhargava and Bassi, 1994;Marquer et al, 2000;Visona et al, 2010). Visona et al (2010) also report basic magma of supra-subduction zone, the representative of which is possibly present in the Mandi Granite (EPG) forming part of the crystalline thrust sheet, now exposed in the Lesser Himalaya (Miller et al, 2000).…”

“…Visona et al (2010) also report basic magma of supra-subduction zone, the representative of which is possibly present in the Mandi Granite (EPG) forming part of the crystalline thrust sheet, now exposed in the Lesser Himalaya (Miller et al, 2000). Metamorphism of this age is also reported in the Peninsular India (Hansen et al, 1985;Harris et al, 1994;Bartlett et al, 1995Bartlett et al, , 1998Soman, 2002).…”