depleted mantle 中文意思是什麼
depleted mantle
解釋
虧損地幔-
Secondly, based on the microbeam analytical technique, on the one hand, through investigating the characteristic of major elements in the mantle minerals the author acquired the static information from mantle ; on the other hand, through multi - point analysis of a part of the minerals from mantle, the auther got dynamic information from mantle. finally, generalizating the fruits of this study and predecessors, the autor holds that the constituents of lithospheric mantle possibly includes spinel lherzolites, clinopyroxenites, websterite, dunite, harzburgites, garnet lherzite, phlogopite lherzite, eclogites, clinopyroxene megacrysts ; compared with east china and north china platform, the research field mantle shows the characteristics of higher degree of partial melting processes and more depleted mantle ; the. upper mantle beneath north hetian area is heterogeneous, with a tendency of deficit in a12o3 and lree from kaliyang in west hetian to the river basin of kalakshi river and yulongkashi river ; the subduction of the crust beneath north hetian has ever occurred in geological history and caused the mixing of mantle - crust ; the depth of the origination of basaltic magmas beneath north hetian exceeds 73km ; the thickness of the lithosphere beneath the research area amounts to 204. 9km ; the mantle beneath north hetian has geological condtions for forming diamond deposits
最後，綜合本區幔源礦物和地幔巖石的特徵以及地球物理資料，得出如下結論：本區上地幔的物質組成有尖晶石二輝橄欖巖、二輝巖、單斜輝石巖、純橄欖巖、方輝橄欖巖、石榴石二輝橄欖巖、金雲母二輝橄欖巖、榴輝巖；與中國東部以及華北地臺上地幔相比，研究區上地幔具有富集主元素中相容元素和虧損其中的不相容元素的特徵，局部熔融程度較高；上地幔存在橫向和縱向的不均一性，從西部的克里陽到喀拉喀什河和玉龍喀什河流域， al和lree富集程度呈下降趨勢，不同來源的相同礦物中主元素的含量差異較大；地質歷史時期這里可能發生過地殼俯沖並產生殼幔混合作用；玄武巖漿的起源深度73km ；從幔源重砂礦物的溫壓估算結果，可以推斷出巖石圈厚度可達204 . 9km ；綜合巖石圈物質組成特徵、巖石圈熱狀態、地幔溫壓狀態、氧逸度以及幔源巖石和幔源礦物的化學成分，認為研究區具備了金剛石成礦地幔地質條件。 -
The early tertiary alkali basalts from yangyuan which contain abundant mantle xenoliths exhibit very homogeneous sr - nd isotopes with snd = 5. 5. their pb isotopes are similar to those of the depleted mantle ( dm ) and their trace element characteristics resemble those of oceanic island basalts ( oib )
含幔源包體的陽原早第三紀堿性玄武巖具有均一的sr - nd同位素組成（ nd 5 . 5 ） ，其pb同位素組成與虧損地幔（ dm ）相似。 -
All of the abovementioned facts suggest that the neoproterozoic diabases from the xuzhou area of the north china block were derived from nd isotopically - depleted mantle sources with variable enrichment in fertile components and produced through variable degrees of melting at different p - t conditions
結合新元古代全球rodinia超大陸裂解事件及其巖漿活動與地幔柱的密切關系，徐州地區晚元古代輝綠巖墻群為地幔柱作用在華北陸塊邊緣的記錄。 -
Substance of rock - forming and ore - forming in both jianchaling and jinchuan nickel deposit mainly derived from the upper mantle, but the former source is relatively depleted mantle. on the other hand, there exsisted the crustal contamination during the formation of the two mineral deposits, the later contaminated poorly and gave priority to deep contamination. ( 5 ) by the comparative study of jianchaling with jinchuan nickel sulflde deposit, it is pointed that small basic - ultralbasic complexes which dis
（ 5 ）通過對煎茶嶺和金川鎳礦床的比較研究，結合對國內外有關巖漿鎳礦床的比較分析，根據我國的地質特點，提出沿較老地塊邊緣分佈的特別是沿華北地塊北緣分佈的基性?超基性小雜巖體，是找尋大而富的硫化鎳礦床之有利找礦方向；而對較老地塊內部的鎂鐵質侵入體，亦應給予高度注意。 -
The zircons we studied were depleted in oxygen 18 relative to the mantle, and such depletion occurs only if the crystals formed from rocks that interacted with rain or snow
因為相較于地函，我們所研究的鋯石，氧18含量偏低，而這種情形只有可能是晶體的母巖曾經和雨水或雪發生交互作用。 -
Given their oib - type trace element pattern and depleted sr - nd isotop ic composition, the datong alkali basalts are interpreted to be generated within the asthenospheric mantle but at a shallow depth compared to the yangyuan alkali basalts. the datong tholeiitic basalts exhibit low snd values ( 1 - 4 ). their sr - pb and nd - pb isotopic correlations are consistent with a mixing between the depleted mantle and emi - like component
大同地區第四紀時期同時產出堿性和拉斑玄武巖，堿性玄武巖也主要來自於軟流圈地幔，巖漿起源深度小於陽原樣品；拉斑玄武巖具有較低的nd （ nd = 1 - 4 ） ， pb - nd以及pb - sr同位素相關關系暗示其可能是dm和型富集地幔（ emi ）組分之間混合的結果，反映了軟流圈和巖石圈地幔之間的相互作用，巖漿起源較淺。 -
Two ree distributed pattern, lree - depleted and flat, which display a specific character of typical mid - ocean ridge tholeiite, indicate that primary magma may be derived from near primary or a typical large ion lithophile element ( lile ) - depleted mantle
巖石稀土元素配分模式可分為lree平坦型和lree虧損型兩類，指示了其原始巖漿起源於近原始或典型的大離子元素虧損型的地幔，為典型的大洋中脊拉斑玄武巖的特徵。 -
The mafic rocks have high ( 87sr / 86sr ) j ( 0. 7046 - 0. 7077 ) and 207pb / 204pb ( 15. 47 - 15. 67 ), but relatively low in ( 143nd / 144nd ) i ( 0. 5125 - 0. 5127 ) and 206pb / 204pb ( 18. 26 - 18. 52 ). the negative correlation between 143nd / 144nd and 206pb / 204pb and the positive relationship between 87sr / 86sr - 206pb / 204pb suggest a mixing of a depleted mantle source and an em2 component in the study area. calculation reveals that the maopin - shaianjiao mafic rocks are formed by 5 - 15 % degree of partial melting of an lree - riched spinel iherzolite
模擬計算表明，該基性巖墻群是尖晶石二輝橄欖巖地幔5 - 15部分熔融的產物；微量元素配分模式及理論模擬表明茅坪?曬鞍角基性巖體的地幔源區在熔融前曾受到1俯沖沉積物熔體的源區混染和5流體交代作用。 -
The isotopic evidence indicates that they might be derived from a depleted mantle source, and probably contaminated slightly by continental materials
同位素組成特徵表明其來源於虧損地慢源區，可能受到輕微的地殼物質的混染。 -
Thus, they might be derived from a back - arc basin with an archipelagic system in paleo - tethys, instead of a large ocean basin. the isotopic geochemistry shows that the jinshajiang ophiolitic melange has higher e nd ( t ) values ( + 7. 42 - + 5. 44 ), suggesting that it may be derived from a lree depleted mantle source without significant contamination by the continental crust, but affected slightly by a fluid from a subducted ocean crust
同位素地球化學研究表明，金沙江蛇綠混雜巖具有較高的_ （ nd ） （ t ）值（ + 7 . 42 + 5 . 44 ）暗示蛇綠巖來源於lree長期較虧損的地幔源，演化過程中沒有受到陸源物質的明顯混染，而主要受到少量俯沖洋殼析出流體的影響。 -
The low - ti series show variable degrees of nb - ta depletion in primitive mantle - normalized spidergrams with slightly enriched to depleted nd isotopic compositions, whereas the transitional series exhibit similar geochemical features to emii - oib and have transitional characteristics between the high - ti and low - ti rocks. all three groups show no continuous shift in major and trace elements and cannot be regarded as different phases during magma differentiation process. on the basis of normalization to mgo = 8 %, the high - ti diabases have the lowest sig, nag and highest tig and peg
通過詳細的巖石學和元素-同位素地球化學研究，這些巖石具有各自不同的地球化學特徵，其中高ti系列的低la nb 、 zr nb比值和虧損的nd同位素組成顯示其類似於oib的特徵，過渡ti系列則顯示出emii - oib的特徵，而低ti系列則高la nb 、 zr nb比值和變化的nd同位素組成顯示出一定比例的富集巖石圈地幔或地殼物質的參與。
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