论文部分内容阅读
西藏日喀则地区蛇绿岩中地幔方辉橄榄岩铂族元素总量 (w (∑PGE) =( 2 8 37～ 50 67)× 1 0 - 9)比原始地幔和世界范围内一些典型蛇绿岩中地幔橄榄岩及阿尔卑斯型地幔橄榄岩偏高 ,相对原始地幔富集Pt,Pd ,Ru ,Ir;其PGE分布型式为“正倾斜型”或“燕子型” ,与部分熔融残留成因地幔橄榄岩中通常所观察到的负斜率型或平坦型不同 ,暗示本区残留地幔方辉橄榄岩除经历了地幔部分熔融过程外 ,很可能还经历了具高度不相容组分的熔体 /流体的渗透混合过程———地幔交代。
The total platinum group elements in the mafic olivine in the ophiolite in the Shigatse area of Tibet (w (ΣPGE) = (2 8 37 ~ 50 67) × 10 ~ 9) are lower than the original mantle and some typical ophiolite Middle Permian peridotites and Alpine mantle peridotites are higher than that of the original mantle, and their PGE distribution patterns are “positive-tilted” or “swallow-shaped” The commonly observed negative slopes or flat types indicate that residual mantle olibites in the region are likely to have experienced melt / fluid-phase interactions with highly incompatible components, in addition to under-mantle partial melting Infiltration and mixing process --- mantle interpretation.