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火口湖的火山渣锥由高铝玄武质至安山质火山渣和熔岩组成.与来自梅扎马山的安山岩流不同,或廉斯(Williams)火山口是一个由夹有安山质至英安质熔岩流的玄武质火山渣锥组成的杂岩,它位于破火口的西部边缘.从威廉斯火山口喷出的火山弹含有条带状安山岩和英安岩岩核,这些岩核类似于梅扎马山喷发高峰期间的安山岩和英安岩。主要元素和微量元素的变化表现出不相容元素增加和相容元素减少与橄榄石、斜长石、单斜辉石、斜方辉石和磁铁矿的结晶分离作用一致.岩石中LREE 不规则,每一个相继的玄武岩相对前一个安山岩富集 LREE.火山渣锥中岩浆的成分变化表明有三种岩浆过程:即部分熔融作用,分离结晶作用和岩浆混合作用.一种以上的源岩经部分熔融形成了玄武质原始岩浆(S).其后的混合作用和分离结晶作用形成继续分异的玄武质至安山质岩浆.
The volcanic slag cone of the crater consists of high-aluminum basaltic andesitic volcanic slag and lava, which is different from the andesite flow from Mount Mezma or the Williams crater, Massive lava flow of basaltic volcanic slag Cone composed of complex rock, which is located in the western edge of the breach.The volcano eruption from the Williams crater has banded andesite and dacite rock nuclei, these rock cores are similar to Mei Zha Andesite and dacite during the peak of Mashan eruption. Changes of major elements and trace elements showed that the increase of incompatible elements and the decrease of compatible elements were consistent with the crystal separation of olivine, plagioclase, clinopyroxene, orthopyroxene and magnetite.The irregular LREE , Each successive basalt is enriched in LREE relative to the previous andesite.The composition of the magma in the volcanic slag cone indicates that there are three magmatic processes: partial melting, separation and crystallization, and magmatic mixing.One or more source rocks are partially melted Formed a basaltic magma (S), followed by mixing and crystallization to form a succession of basaltic andesitic magmas.