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mantle rock 風化層,土被,表皮巖。

mantlet

High - mg volcanic rocks approach the primitive mantle compositions , and their magmatic source is close to the composition of bse , derives from the lower mantle and formed by this type - mantle rocks “ fractional melting highly ( > 25 % ) . high - mg volcanic magma , formed in the axis of the emei mantle plume , underwent the crystallization differentiation of olivines and some pyroxenes ; some olivines reflect fair cumulus crystallization 高鎂火山巖接近于原始巖漿的組成,巖漿源區與地球平均成分bse的成分特征相近,起源深度為下地幔,為該地幔巖較高程度的部分熔融( 25 )而形成的。高鎂火山巖處于地幔柱的軸部,經歷了橄欖石及一定程度的輝石分異結晶,并且橄欖石顯示出一定的堆晶作用。

The pges abundance patterns of residual mantle rock with a peleo - subduction background is characterized by pd , pt depletion and ir , ru relatively enrichment , while the basalt and basic dyke by the processing of partial melt in the same background take an opposite feature of pd , pt enrichment and ir , ru depletion . the existence of fluid in the subduction zone increases the degree of partial melt on the one hand , and on the other , activates the activity of pd , pt compare to ir , ru , and thus reduces the pd ir and pt ru in residual mantle rock . the pges patterns for basalt and basic dyke from two carboniferous volcano zones to south qoltag and north turpan - hami basin , xinjing uigur autonomous region , take a shape of gentle positive inclined curve with lower pt and pd differentiation and lower pges . all these features are obviously different from that of basic dyke and basalt from typical ophiolite and therefore the author believe that their fluid - rich paleo - subduction zone environment can be ruled out 古俯沖帶背景下的殘余地幔巖的pges配分以pd , pt明顯虧損和ir , ru相對富集為特征,而部分熔融產物的玄武巖和基性巖脈則呈現相反的ir , ru明顯虧損和pd , pt相對富集特征。俯沖帶中流體的參與一方面增加了部分熔融程度,有利于pd , pt從原始地幔進入熔融相另一方面,流體的作用使得pd , pt相對于ir , ru遷移活動性效率提高,造成地幔巖中

Regolith mantle rock 地表巖屑