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谢米斯台一带志留纪火山岩主要为一套中酸性火山岩及其火山碎屑岩建造,流纹岩大面积出露,具有高Si(SiO_2>70.53%)、低镁(MgO=0.12%~0.58%)、富K贫Na(Na_2O=1.71%~4.45%,K_2O=4.21%~5.72%,Na_2O/K_2O=0.38~0.91)、富Al贫Ca(Al_2O_3=11.04%~15.2%,CaO=0.3%~1.94%)等特征,大离子亲石元素(LILE)相对富集,高场强元素(HFSE)相对亏损,Eu具有弱—中等的负异常,且Nb/La、Ti/Y比值较低,Hf/Ta、La/Ta、La/Yb、Ta/Yb等比值均较高,显示具典型岛弧火山岩地球化学特征。结合区域构造演化特征,推测在谢米斯台一带,准噶尔洋在志留纪开始进入强烈的俯冲消减作用,在壳幔结合部位可能俯冲板片与富集地幔局部熔融引起下地壳物质大规模的部分熔融或重熔,经历了一定程度的分离结晶和大量地壳物质的混染形成的酸性岩浆喷发形成流纹岩,是陆壳垂向增生的一个主要阶段。早古生代晚期,谢米斯台地区处于萨吾尔复合岛弧的南部边缘岛弧环境。
The Silurian volcanic rocks in the Cheese Station are mainly composed of medium-acidic volcanic rocks and their pyroclastic rocks. Rhyolite is exposed over a large area and has high Si (SiO 2> 70.53%) and low Mg (0.12% 0.58%), K-poor Na (Na_2O = 1.71% ~ 4.45%, K_2O = 4.21% ~ 5.72% and Na_2O / K_2O = 0.38 ~ 0.91) % ~ 1.94%). LILE is relatively enriched, HFSE is relatively depleted, Eu has a weak-moderate negative anomaly, and the ratio of Nb / La and Ti / Y is relatively low , Hf / Ta, La / Ta, La / Yb, Ta / Yb ratio are higher, showing the typical island arc volcanic geochemical characteristics. Based on the regional tectonic evolution characteristics, it is speculated that in the area of Chemisite, the Junggar Ocean entered a strong subduction reduction effect at the Silurian. At the junction of the crust and the mantle, local melting of the subducted slab and enrichment mantle caused a large-scale Part of melting or remelting, experiencing a certain degree of separation and crystallization and the formation of a large number of crustal contamination of acidic magmatic eruption rhyolite formation, is a major stage of vertical crustal hyperplasia. In the late Early Paleozoic, the Chemisite area was in the arc of the southern edge of the SAW composite island arc.