新疆阿什库勒盆地大黑山火山地质及地球化学特征  

Characteristics of geology and geochemistry in Daheishan volcano in Ashikule basin,Xinjiang

作　　者：赵波[1] 许建东[1] 肖旭[2] 孙洪亮[3] 张柳毅[1] 陈正全[1] 

机构地区：[1]中国地震局地质研究所,活动构造与火山中国地震局重点实验室,北京100029 [2]中国地震局地球物理研究所,北京100081 [3]中国石油塔里木油田公司,库尔勒841000

出　　处：《岩石学报》2014年第12期3531-3538,共8页Acta Petrologica Sinica

基　　金：中国地震局地震行业专项(201008004);中央级公益性科研院所基本科研业务专项(IGCEA1101);国家自然科学基金项目(41372344)联合资助

摘　　要：大黑山火山是新疆阿什库勒火山群最大的火山,通过野外地质调查和遥感解译,火山锥体由渣锥、溅落锥和寄生火山锥组成。大黑山岩石类型分别为玄武粗安岩、粗面安山岩和粗面岩,钾玄岩系列。岩浆分离结晶特征明显,斜长石晶体析出导致残余熔体中δEu形成明显负异常。大黑山锥体南侧发育一套长约1.3km的碎屑熔岩。该套岩石显微薄片上表现为发育玻晶交织结构和溶蚀结构等熔岩结构特征,少许凝灰结构。碎屑主要为5~6cm的角砾,含少量的火山弹。角砾可能来自于大黑山火山较强的爆发,生成岩屑以及少量凝灰质碎屑。后期熔岩喷泉式喷发形成熔岩流,在流动过程中裹带大量的岩屑以及少量凝灰质碎屑。该套碎屑熔岩的发现,加深了对整个地区火山活动类型的了解。According to the newspaper record, Ashikule volcano clusters in Xinjiang erupted in 1951. It is the latest eruption in Chinese Mainland. The products of volcano, eruption types and eruption scale in this area are still not well understood because it is hard plateau environments. In 2011, the Institute of Geology, China Earthquake Administration organized an expedition for Ashikule volcano clusters. Daheishan volcano is the biggest volcano in the Ashikule Volcano Clusters. According to the topography, geology survey and remote sensing interpretation, Daheishan volcano is compound volcano which is formed by scoria cone, spatter cone and parasitic cone. The contact between scoria cone and spatter cone is discontinuous. That characteristic indicates the activity of Daheishan volcano is multi-periods. The rock types contain basaltic trachyandesite, trachyandesite and trachyte. They belong to shoshonite. They are products from different stage of magmatic evolution. LREE/HREE is between 25. 36 and 28. 13. 8Eu is between 0. 63 and 0. 74. 8Eu is negative which may relate to the crystallization of plagioclase. In the south of Daheishan volcano, there is a 1.3km trachytic pyroclastic-lava which contains crystal dust and debris. Under the microscope, there are resorption texture, pilotaxitc texture and less tuffaceous texture. It is the first time that the pyroclastic lava is found in the Ashikule Volcano Clusters. The crystal dust and debris maybe came from large explosive eruption. And they were cemented by the products of. trachytic lava fountain eruption. It makes us learn more about the eruption processes of Ashikule volcano clusters.

关 键 词：阿什库勒火山群 大黑山火山 碎屑熔岩 溶蚀结构 新疆 

分 类 号：P588.14[天文地球—岩石学]