depleted mantle meaning in English
亏损地幔
贫化地幔
Examples
- The isotopic evidence indicates that they might be derived from a depleted mantle source , and probably contaminated slightly by continental materials
同位素组成特征表明其来源于亏损地慢源区，可能受到轻微的地壳物质的混染。 - 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
岩石稀土元素配分模式可分为lree平坦型和lree亏损型两类，指示了其原始岩浆起源于近原始或典型的大离子元素亏损型的地幔，为典型的大洋中脊拉斑玄武岩的特征。 - 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 )
含幔源包体的阳原早第三纪碱性玄武岩具有均一的sr - nd同位素组成( nd 5 . 5 ) ，其pb同位素组成与亏损地幔( 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
结合新元古代全球rodinia超大陆裂解事件及其岩浆活动与地幔柱的密切关系，徐州地区晚元古代辉绿岩墙群为地幔柱作用在华北陆块边缘的记录。 - 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
最后，综合本区幔源矿物和地幔岩石的特征以及地球物理资料，得出如下结论：本区上地幔的物质组成有尖晶石二辉橄榄岩、二辉岩、单斜辉石岩、纯橄榄岩、方辉橄榄岩、石榴石二辉橄榄岩、金云母二辉橄榄岩、榴辉岩；与中国东部以及华北地台上地幔相比，研究区上地幔具有富集主元素中相容元素和亏损其中的不相容元素的特征，局部熔融程度较高；上地幔存在横向和纵向的不均一性，从西部的克里阳到喀拉喀什河和玉龙喀什河流域， al和lree富集程度呈下降趋势，不同来源的相同矿物中主元素的含量差异较大；地质历史时期这里可能发生过地壳俯冲并产生壳幔混合作用；玄武岩浆的起源深度73km ；从幔源重砂矿物的温压估算结果，可以推断出岩石圈厚度可达204 . 9km ；综合岩石圈物质组成特征、岩石圈热状态、地幔温压状态、氧逸度以及幔源岩石和幔源矿物的化学成分，认为研究区具备了金刚石成矿地幔地质条件。