Geochemistry and petrogenetic implications of a Late Devonian mafic–ultramafic intrusion at the southern margin of the Central Asian Orogenic Belt

Paleozoic magmatism and metamorphism in the Central Tianshan block revealed by U–Pb and Lu–Hf isotope studies of detrital zircons from the South Tianshan belt, NW China

“…( asthenosphere upwelling during slab breakoff (Xie et al, 2012), further support this mantle-upwelling event at ca. 360 Ma.…”

Early Late Cretaceous (ca. 93Ma) norites and hornblendites in the Milin area, eastern Gangdese: Lithosphere–asthenosphere interaction during slab roll-back and an insight into early Late Cretaceous (ca. 100–80Ma) magmatic “flare-up” in southern Lhasa (Tibet)

“…They can be produced by melting of subcontinental lithospheric mantle, depleted MORB (middle oceanic ridge basalt)-type mantle, plumerelated enriched mantle, or subduction component-enriched lithospheric mantle (e.g., Hall and Hughes, 1987;Piccardo and Guarnieri, 2011;Pirajno, 2004;Torsvik et al, 1998). Their formation is commonly linked to dynamic processes such as asthenosphere mantle upwelling due to slab break-off (Xie et al, 2012), a spreading ridge or continental rifting (Andronicos et al, 2008;Olson, 1992), the ascent of a deep-seated mantle plume (Torsvik et al, 1998), subduction-metasomatism of continental lithospheric mantle (Hall and Hughes, 1987) and slab roll-back or ridge subduction (Sisson et al, 2003). The compositions of early-crystallized minerals (e.g., olivine, hypersthene and clinopyroxene) in norites likely record important information regarding the temperature conditions and magmatic evolution of their parental magmas (e.g., Beard, 1986).…”

Syncollisional tholeiitic magmatism induced by asthenosphere upwelling owing to slab detachment at the southern margin of the Central Asian Orogenic Belt

“…( 86 Sr/ 87 Sr) i values for these complexes (0.7031-0.7052) are lower than those of the Heishan and Jingbulake complexes (0.7035-0.7090) and those of the Tarim plume-related rocks (0.7045-0.7085), whereas ( 143 Nd/ 144 Nd) i values of the former group (0.5123-0.5127) are higher than those of the latter two groups (0.5121-0.5125 and 0.5117-0.5126, respectively; Fig. 5a; Zhang et al 2008;Zhou et al 2009;Xie et al 2012). As shown in Figure 5b and c, the Huangshan-Jingerquan complexes have larger ranges of Pb isotope values than the Heishan and Jingerquan complexes.…”

“…These mafic-ultramafic rocks are characterized by low K 2 O contents and positive correlation between TiO 2 and (Fe 2 O 3 ) T /MgO ( Fig. 3a and b), and demonstrate a tholeiitic affinity similar to that of the Heishan and Jingbulake complexes (Ewart 1982;Wilson 1989;Xie et al 2012). The clinopyroxene compositions of the peridotites further suggest that the complexes were most probably crystallized from tholeiitic magmas, although some data plot in the field of calc-alkaline basalts ( Fig.…”

“…A few Devonian and Silurian magmatic Ni-Cu sulphide mineralized mafic-ultramafic complexes (e.g. the 357 ± 4 Ma Heishan complex in the Beishan Fold Belt and the 430 ± 6 Ma Jingbulake complex in the Central Tianshan) have also been discovered in the Chinese Tianshan Xie et al 2012). …”