The peridotite xenoliths from Wangqing display a downward\|concave PGE pattern with Pt at maximum due to Pt-Pd fractionation, which is different from the flat or negatively sloped patterns commonly observed for worldw...The peridotite xenoliths from Wangqing display a downward\|concave PGE pattern with Pt at maximum due to Pt-Pd fractionation, which is different from the flat or negatively sloped patterns commonly observed for worldwide peridotite xenoliths and massifs. Taking into account the difference in partition coefficients of Pt and Pd between alloy and sulfide melt, it is suggested that some of the Wangqing peridotites must have been equilibrated with a melt in which alloy and sulfide coexisted. Segregation of Pt-rich alloy from Pd-sulfide melts due to density contrast and extraction of residual melts without sulfide saturation resulted in the fractionation of Pt from Pd.展开更多
Spinel peridotite xenoliths from Wangqing, NE China exhibit correlative variations in texture, temperature, geochemistry and radiogenic isotopes. This suggests that the Wangqing xenoliths may come from a mantle diapir...Spinel peridotite xenoliths from Wangqing, NE China exhibit correlative variations in texture, temperature, geochemistry and radiogenic isotopes. This suggests that the Wangqing xenoliths may come from a mantle diapir. It is possible that the fertile and undeformed lherzolites were situated in the interior of the diapir, whereas the refractory and deformed harzburgites and clinopyroxene_poor lherzolites were within the diapiric flanks.展开更多
文摘The peridotite xenoliths from Wangqing display a downward\|concave PGE pattern with Pt at maximum due to Pt-Pd fractionation, which is different from the flat or negatively sloped patterns commonly observed for worldwide peridotite xenoliths and massifs. Taking into account the difference in partition coefficients of Pt and Pd between alloy and sulfide melt, it is suggested that some of the Wangqing peridotites must have been equilibrated with a melt in which alloy and sulfide coexisted. Segregation of Pt-rich alloy from Pd-sulfide melts due to density contrast and extraction of residual melts without sulfide saturation resulted in the fractionation of Pt from Pd.
文摘Spinel peridotite xenoliths from Wangqing, NE China exhibit correlative variations in texture, temperature, geochemistry and radiogenic isotopes. This suggests that the Wangqing xenoliths may come from a mantle diapir. It is possible that the fertile and undeformed lherzolites were situated in the interior of the diapir, whereas the refractory and deformed harzburgites and clinopyroxene_poor lherzolites were within the diapiric flanks.
