Mid-Eocene high Sr/Y granites in the Northern Himalayan Gneiss Domes: Melting thickened lower continental crust

Episodic crustal anatexis and the formation of Paiku composite leucogranitic pluton in the Malashan Gneiss Dome, Southern Tibet

“…Granites, migmatites, and high-grade metamorphic rocks are important components within these two belts and record distinct types of metamorphism and partial melting reactions of middle-lower crustal materials in response to the tectonic evolution of the Himalayan orogen [1,4,8,13,14,16,[26][27][28][29]. NHGD within the Tethyan Himalaya consists of a series of semi-continuous oval shape gneiss dome.…”

“…Experimental results have demonstrated that partial melting of Formation-I kyanite-bearing metapelite indeed can produce melts with elemental and isotopic compositions resembling the Himalayan Cenozoic leucogranites [6,7], however, increasing number of updated studies have documented that episodic anatexis occurred in the Northern Himalayan Gneiss Domes (NHGD) as well as in the High Himalayan Crystalline Sequence (HHCS) since the continental collision between India and Eurasia. These anatectic episodes include (1) dehydration melting of a source consisting dominantly of amphibolite with subordinate pelitic gneiss at thickened crustal conditions [8][9][10][11][12][13][14]. These melting events are represented by older than 35 Ma peraluminous granitoids with relatively high Na/K and Sr/Y ratios; (2) fluid-present melting of metapelite since ~38 Ma to produce granitic melts with high CaO and Sr contents and low Rb/Sr ratios [15][16][17][18]; and (3) late Eocene to early Oligocene anatexis recorded in syn-collision leucogranites and migmatites in the Gyirong area and the Mabja Gneiss Dome [19][20][21].…”

Eocene magmatic processes and crustal thickening in southern Tibet: Insights from strongly fractionated ca. 43Ma granites in the western Gangdese Batholith

“…43 Ma) (Zeng et al, 2011;Hou et al, 2012). This indicates that the crust on both sides of the Yarlung Zangbo suture zone was thickened by ca.…”

Early Cretaceous high-Ti and low-Ti mafic magmatism in Southeastern Tibet: Insights into magmatic evolution of the Comei Large Igneous Province

“…2) is from the second episode and intruded into the Triassic shale formation. This diabase, in turn, was later intruded by the third phase, early Eocene two-mica granites (Qi et al, 2008;Xie et al, 2010;Zeng et al, 2011a), and the fourth phase, granodioritic dykes of unknown age (Fig. 2).…”

“…Since the onset of collision between the Indian and Eurasian plates, these sediments have undergone multiple phases of structural deformation, sub-greenschist facies metamorphism, and intrusion by magmas of basaltic to granitic composition (Aikman et al, 2008;Qi et al, 2008； Zeng et al, 2009, 2011a& b, 2012a, 2015bHou et al, 2012;Gao et al, 2009Gao et al, & 2012Xie et al, 2010;Webb et al, 2013;Diedesch et al, 2016). Around the Dala area, cross-cutting relationships show that there are at least four episodes of magmatism (Figs.…”