Geochronology of igneous rocks and formation of the Late Paleozoic south Mongolian active margin of the Siberian continent

Palaeomagnetic and structural constraints on 90° anticlockwise rotation in SW Mongolia during the Permo–Triassic: Implications for Altaid oroclinal bending. Preliminary palaeomagnetic results

“…The calc-alkaline pluton is formed by a cogenetic sequence of gabbro, diorite, granodiorite and granite. The age of crystallization of the magma was determined to be 290-310 Ma using U-Pb zircon LA ICP-MS dating Yarmolyuk et al, 2008b;Kröner et al, 2010;Economos et al, 2012). These data are concordant with 40 Ar-Ar 39 $290 Ma cooling ages from the KhurenDel-Khuduk granitoid massif and associated volcanites located to the west .…”

Sedimentological and geochronological constraints on the Carboniferous evolution of central Inner Mongolia, southeastern Central Asian Orogenic Belt: Inland sea deposition in a post-orogenic setting

“…12b; Shi et al, 2003;Bao et al, 2007;Yarmolyuk et al, 2008;Xue et al, 2010;Cheng et al, 2012;Xu et al, 2012;Liang et al, 2013). Nevertheless, geochemical studies of the Late Carboniferous granitoids from Sunidzuoqi and West-Ujimqin display calc-alkaline affinities Liu et al, 2009Liu et al, , 2013.…”

“…The CAOB formed by complicated subduction-accretion processes, with various fragments including microcontinents, island arcs, ophiolite complexes, seamounts, oceanic plateaus, and accretionary prisms (Windley et al, 2007;Safonova et al, 2011;Choulet et al, 2012;Wilhem et al, 2012;Safonova and Santosh, 2014). After the accretion and collision, the former united fragments re-activated, with intra-plate magmatism and deposition occurring in the extensional zones (Tang, 1990;Hong et al, 1994;Yarmolyuk et al, 2008;Zhang et al, 2008;Jahn et al, 2009;Yuan et al, 2010;Han et al, 2011;Chen et al, 2012;Yu et al, 2013). In this case study, we chose the north margin of North China Craton (NCC), located in the southeast of CAOB, to decipher the transition between accretion and post-accretional extension.…”

The Lost South Gobi Microcontinent: Protolith Studies of Metamorphic Tectonites and Implications for the Evolution of Continental Crust in Southeastern Mongolia

“…Multiple large latest Silurian-earliest Devonian copper/gold/molybdenum deposits have been discovered (e.g., Oyu Tolgoi), which also formed within the South Mongolia arc [40][41][42]. All of the units described above are intruded by younger Late Permian-Early Triassic granitoids [6,19,23,38,39]. Devonian-Carboniferous age rocks in the southernmost portion of Mongolia, near the border with China, are overlain by Upper Permian-Lower Triassic clastic sedimentary rocks derived from the collision between the South Mongolia arc and the North China and Tarim cratons [19,37,43].…”

“…Two Precambrian blocks, the Totoshan-Ulanuul block [10]; which contains the smaller Hutag Uul terrane of Badarch et al [6] and the Tsagaan-Khairkhan block [22]; a.k.a., the Tsagaan Uul terrane of Badarch et al [6] were previously proposed to underlie southeastern Mongolia on the basis of exposures of high-grade and/or high-strain tectonites ( Figure 1). These two blocks together make up a large portion of the inferred South Gobi Microcontinent [8][9][10][21][22][23]. Recent studies have claimed to vindicate or have called into question a Precambrian age at a number of locations throughout southeastern Mongolia (in some cases within the same general area) emphasizing the need for further study [9,10,[24][25][26].…”