Multistage metamorphism of orogenic garnet–lherzolite from Zhimafang, Sulu UHP terrane, E. China: Implications for mantle wedge convection during progressive oceanic and continental subduction

Linking continental deep subduction with destruction of a cratonic margin: strongly reworked North China SCLM intruded in the Triassic Sulu UHP belt

“…1d), and sporadically throughout the belt. The Zhimafang peridotitic body, intersected by the prepilot hole of the Chinese Continental Scientific Drilling project (CCSD-pp1), shows disequilibrium in its radiogenic and stable isotopic systems (Zheng et al 2003a) and has been interpreted as a fragment of refractory but metasomatized subcontinental lithospheric mantle (SCLM) with affinity for the North China craton (Zheng et al 2006a, c;Zhang et al 2008), or as part of the mantle wedge during the subduction of oceanic and subsequent continental slabs (Ye et al 2009). …”

“…The complex history assigned to this rock was described above ) and implies a similarly complex tectonic evolution for the SCLM beneath the continental margin. This complexity probably has been responsible for the variety of interpretations put forward for the CCSD-pp1 peridotites: refractory but metasomatized SCLM (Zheng et al 2006a, c;Zhang et al 2008), or the progressive convection of mantle wedge material during subduction of oceanic and subsequent continental slabs (Ye et al 2009). …”

Origins of orogenic dunites: Petrology, geochemistry, and implications

“…The crustal peridotites originated from mafic magmas that underwent magmatic differentiation in the lower continental crust before subduction (Brueckner and Medaris, 2000;Yang et al, 2009;Zhang et al, 2010), whereas the latter are considered as slices of mantle wedge above the slab or the subducted lithospheric mantle trapped by the slab (Beyer et al, 2006;Scambelluri et al, 2006;Yuan et al, 2007;Ye et al, 2009;Zhang et al, 2009;Brueckner et al, 2010). Although these two types of orogenic peridotites have been distinguished based on petrological and geochemical studies (Zhang et al, 2000;Reverdatto et al, 2008), the intense fluid/melt activity at the slab-mantle interface may cause the mantle-derived peridotites to simultaneously exhibit the geochemical features of both crustand mantle-derived peridotites (Vrijmoed et al, 2013), which makes it difficult to identify the nature of their protoliths.…”

Comparison of mantle-derived matierals from different spatiotemporal settings: Implications for destructive and accretional processes of the North China Craton

“…(1) the disappeared oceanic lithosphere, (2) the subducted continental lithosphere, (3) the SCLM wedge overlying the subduction zone, (4) the asthenospheric materials [96][97][98] . In the Dabie orogen, Raobazhai ultramafic massif is interpreted as a fragment of SCLM reequilibrated under granulite-amphibolite facies conditions [99,100] .…”

“…Based on its Paleoproterozoic Re-Os isotopic model ages, the Xugou peridotite is interpreted as from the YC [103] . In contrast, the Zhimafang (CCSD-pp1) peridotite nearby the Xugou area exhibits some affinity with the North China lithosphere [7,68,98,104] . Reasons are as follows: (1) The nature of the mantle and information of metasomatic agents, recorded by major elements of the rock and minerals and trace elements of clinopyroxene, are very similar to those of the ancient North China mantle, whereas some small differences are related to the reason that orogenic peridotites are subjected to the complex UHP metamorphosed re-equilibrium because peridotitic xenoliths don't undergo these processes.…”