托云火山群的火山地质特征及其构造意义  

GEOLOGIC FEATURES AND TECTONIC IMPLICATIONS OF THE TUYON VOLCANO GROUP

作　　者：梁涛[1,2] 罗照华[1,2] 李文韬[2] 柯珊[2] 李莉[2] 詹华明[2] 

机构地区：[1]中国地质大学岩石圈构造,深部过程及探测技术重点实验室,北京100083 [2]中国地质大学地球科学与资源学院,北京100083

出　　处：《新疆地质》2005年第2期105-110,i005,共7页Xinjiang Geology

基　　金：国家自然科学基金(40272033;40472038)资助

摘　　要：结合托云盆地新生代火山岩的卫星影像解译与野外验证成果,发现托云盆地内的7个火山口和棋盘式走滑断裂系统,首次提出了托云火山群的概念.这些火山口可以划分成中心式火山和溢流玄武岩2种类型,形成的火山机构包括塌陷破火山口、火山颈和锥状岩席.火山岩主要为碱性玄武岩,部分玄武岩中可见橄榄岩类等深源岩石包体和普通辉石等矿物巨晶.因此,托云盆地新生代火山岩具有幔源岩浆的性质,断裂构造活动为其上升就位提供通道,火山岩应是由多个火山口近于同时喷发形成的,不具有由上、下两套火山岩系构成的双层结构.Through interpretation of remote sensing images and comprehensive field research on the Cenozoic volcanic rocks in the Tuyon Basin, seven volcanoes and tessellated strike-slip faults have been discussed in this paper. The term Toyon Volcano Group is proposed for the first time to describe this area. The volcanoes can be divided into two types: central-eruption-type and flood-basalt-type. They form a series of volcanic apparatus, including calderas, volcanic necks and cone sheets. Tuyon volcanic rocks are classified as alkali basalts, with pyroxene megacrysts, and deep-seated mantle xenoliths such as augite and peridotite have been observed in some basaltic layers. We consider the Cenozoic volcanic rocks in the Tuyon basin resulted from primary mantle magma that ascended along the faulted-channel and erupted from the several volcanoes almost at the same time. This differs from a previous idea that the products of eruption occurred during two periods (110-120Ma and 67-46Ma).

关 键 词：火山群 构造意义 地质特征 新生代火山岩 走滑断裂系统 深源岩石包体 断裂构造活动 碱性玄武岩 影像解译 破火山口 火山机构 幔源岩浆 双层结构 火山岩系 盆地 火山颈 塌陷 巨晶 矿物 辉石 上升 喷发 

分 类 号：P588.14[天文地球—岩石学]