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有关地幔的化学和同位素资料,可从几个来源获得,但全都需要某些假设: 1.假定球粒陨石是代表太阳系的原始物质。地幔化学模式通常还假定在地幔增生过程中和以后有挥发性元素可能包括碱性元素的丢失,以及分离的铁与镍(还有某些较轻元素如氧,硅和硫)进入地核及亲石元素进入地壳。 2.已知玄武岩源于地幔。实验岩石学能大致确定可能的原岩组份。但仍有许多含糊不清的地方,这包括不同实验室间实验结果的不一致,有关原岩熔融程度,结晶分异的程度及围岩混染程度的假定不一致,而最大的困难是熔体组份不受该系统各组份的比
Chemical and isotopic data on the mantle can be obtained from several sources, but all require some assumptions: 1. The chondrites are assumed to represent the original material of the solar system. The mantle chemical model also usually assumes that volatile elements may include the loss of alkaline elements during and after mantle accretion and the separation of iron and nickel (and some lighter elements such as oxygen, silicon and sulfur) into the earth’s core and Stone element into the crust. 2. Basalt is known to originate from the mantle. Experimental petrology can roughly identify possible raw rock components. However, there are still many ambiguities, which include the inconsistencies of experimental results between different laboratories, the assumption about the degree of original rock melting, the degree of crystal differentiation and the degree of rock contamination. The biggest difficulty is that the melt group The parts are not affected by the ratio of the system