油气地质与采收率2024，Vol.31Issue(6)：65-73,9.DOI:10.13673/j.pgre.202407028
新疆北部卡拉麦里地区石炭纪火山岩成因及其构造意义
Genesis and tectonic significance of Carboniferous volcanic rocks in Karamali area,northern Xinjiang
摘要
Abstract
Volcanic rocks,such as andesite and tuff,are widely developed in the Carboniferous system in Karamali area,northern Xinjiang.The tectonic background of their formation is still controversial.In this paper,two typical Carboniferous profiles from Karamali Mountain were selected.Andesite and tuff samples from the lower Carboniferous Jiangbasitao Formation,the upper Car-boniferous Bashan Formation,and Huxingliang Formation were observed under a microscope,and their main trace elements were analyzed.The results show that the contents of MgO(0.5%-2.35%)and Mg#(15.7%-42.5%)are low to medium in samples,indi-cating that the crystallization differentiation of rock samples occurs during the formation process.The distribution curve of trace ele-ments in the samples is obviously different from that of N-MORB,E-MORB,and OIB.The samples are almost all in the calc-alkaline series in Ta/Yb-Th/Yb and La-Y-Nb diagrams,while the samples fall subduction components and approach the mantle se-ries in Nb/Yb-La/Yb diagrams.The Nb/Y-Rb/Y and Ba/La-Ba/Nb diagrams also show that the samples are affected by both fluid en-richment and melt enrichment.The Nb/U and Ce/Pb ratios of the samples are 1.6-11.1 and 0.47-12.2,respectively,which are close to the range of continental crust and indicate that the source of the material may be mixed with continental crust materials.Accord-ing to the Th-Hf/3-Nb/16 diagram,all the samples are located in the island arc basalt region.The comprehensive analysis shows that Karamali area was in the continental island arc environment of active continental margin from the early Carboniferous to the late Carboniferous,and this environment lasted at least from the early Carboniferous to the late Carboniferous.关键词
石炭系/火山岩/岛弧/卡拉麦里地区/准噶尔盆地Key words
carboniferous system/volcanic rocks/island arc/Karamali area/Junggar Basin分类
能源科技引用本文复制引用
高永进,张远银,朱德朋,陈夷,孙相灿,文磊,王千军,白忠凯,谭志龙,王信水,辛云路..新疆北部卡拉麦里地区石炭纪火山岩成因及其构造意义[J].油气地质与采收率,2024,31(6):65-73,9.基金项目
中国地质调查局项目"新疆西部地区油气地质调查"(DD20190090)、"全国油气基础地质调查"(DD20240052)、"新疆地区盆山结合部油气基础地质调查"(DD20242510). （DD20190090）
