Geochemical constraints on the origin of the Hegenshan Ophiolite, Inner Mongolia, China

Early Permian plutons from the northern North China Block: constraints on continental arc evolution and convergent margin magmatism related to the Central Asian Orogenic Belt

“…They occur in the IMPU along the northern margin of the NCB and constitute an east-west intrusive belt that is more than 1,000 km long and 30-120 km wide. The emplacement ages of late Carboniferous to early Permian plutons on northern NCB is similar to those of the Baolidao arc plutons in the CAOB, which is considered to be related to northward subduction of the Palaeo-Asian oceanic plate (Robinson et al 1999;Chen et al 2000Chen et al , 2008Xiao et al 2003).…”

“…The development and amalgamation of the CAOB are related to subduction-accretion processes within the Palaeo-Asian Ocean from the latest Mesoproterozoic to late Palaeozoic (e.g., Sengör et al 1993;Badarch et al 2002;Kröner et al 2007;Windley et al 2007). The northern margin of the North China Block (NCB, or North China Craton), which serves as part of the southern boundary of the CAOB, was previously regarded as a passive continental margin during the late Palaeozoic (e.g., Hsu et al 1991;Robinson et al 1999), but recent sedimentary, geochronological, thermobarometric, and geochemical results show that it was an active margin and was strongly influenced by the Palaeo-Asian tectonic system during this period (Meng and Ge 2001;Xiao et al 2003;Cope et al 2005;Zhang et al 2006Zhang et al , 2007aZhang et al , 2008a. Therefore, the late Palaeozoic tectonic evolution of the northern NCB is closely related to that of the southern CAOB, and much attention has recently been paid to this issue (e.g., Zhang et al 2007a, 2008a, andreferences therein).…”

Geochronological and geochemical investigation of the late Mesozoic volcanic rocks from the Northern Great Xing’an Range and their tectonic implications

“…The distribution of ophiolite and tectonic nappes indicate the multi-episode oceanic subduction during the Paleozoic to Mesozoic in the eastern part of the CAOB (Robinson et al 1999;Badarch et al 2002), thus we suggested that the metasomatic components mainly comes from the fluids released from the subducted slab during the closure of the Paleo-Asian and Mongol-Okhotsk oceans.…”

End-Permian to mid-Triassic termination of the accretionary processes of the southern Altaids: implications for the geodynamic evolution, Phanerozoic continental growth, and metallogeny of Central Asia

“…Many previous researchers considered the Hegenshan ophiolite to have formed as a result of closure of the Paleoasian Ocean (Nozaka and Liu 2002). However, mafic rocks of the Hegenshan ophiolite have suprasubduction zone (SSZ-type) geochemical characteristics (Robinson et al 1999), and accordingly it should be an arcrelated SSZ-type ophiolite. The presence of middle to late Devonian radiolaria in some cherts led to a notion that the ophiolite was of Devonian age (Liang 1991).…”