摘要
作者在前人研究的基础上,借助于野外地质调查、遥感、岩相学、矿物学、岩石化学和地球化学等手段,从区域构造和火山构造以及火山活动产物的时空分布入手,通过比较系统地对比全区岩浆作用产物的各类特征,认为本区存在线状构造与环状构造复合的火山构造带,论证了火山岩,次火山岩和深成岩“三位一体”的火山-侵入杂岩的存在,并提出本区火山-侵入杂岩属于典型的同熔型系列,其成岩物质来源属于壳幔混合源。
Three first-order ring volcanic structures and some second-order ring volcanic structures involved in the first-order ones have been recognized in the area by means of geological mapping, landsat image interpretation, and geophysical and geochemical investigations. The firstorder ring volcanic structures are distributed along a NE-trending deep fault, while that of the second-order on along the NW-trending secondary faults, forming a compound volcanic structural zone combining the linear with the ring structures. It is shown through field geological investigations and petrographical, mineralogical, petrochemical and geochemical studies that the volcanic, subvolcanic and plutonic rocks formed in the same stage of volcanism are closely associated in space and time and controlled by the same volcanic structure (commonly secondorder ring volcanic structure), and have the characteristics of consanguineous evolution in terms of their composition, forming a ring volcanic-intrusive complex controlled by the secondorder ring volcanic structure, a 'trinity' composed of the volcanic, subvolcanic and plutonic rocks. With initial Sr isotopic ratios of 0.706—0.712 (averagely 0.709), εNd(T)-5.2—11.0 and εSr(T)-39—95, the volcanic-intrusive complexes in this area belong to the typical syntectic volcanic-intrusive association and the source materials were mainly derived from the crust and the mantle.
出处
《地质学报》
EI
CAS
CSCD
北大核心
1990年第3期215-225,共11页
Acta Geologica Sinica
