摘要
本文在花岗岩类岩体地质的研究基础上,选择有代表性的各类花岗岩体进行了同位素地质年代学、岩石学、岩石化学、稀士元素和微量元素地球化学研究。初步查明:区内花岗岩的形成时代主要为海西期;同时,存在着加里东期和燕山期的花岗岩类。在此基础上,作了成岩系列及成因类型(I.S、I-S、A)的划分,并且论述了它们的特征。
Based on investigation: of geotectonic development history and field geology of granitoid bodies, a systematic study has been made in the paper on the representative granitoids, Altai Mrs., China, in such aspects as isotopic chronology, petrology, petrochemistry, REE and trace element geochemistry. The granitoids in the region have been produced chiefly during the Hercynian orogeny, but a number of Caledonian granitoids and a minor number of Yanshanian ones, small in scale, are also present. Three petrogenetic series, the Caledonian-, Altai-, and Wulungu-series, and four genetic types, I, S, I-S transitional, and A-types have been recognized and expounded. The Caledonian series includes:gabbro→diorite→tonalite-granodiorite-quartz diorite→biotite granite→gneissic biotite granite. They evolved in genetic type from M→I→S→I-S transitional. In the process the orogenesis got progressively strengthened in intensity and the continental crust rose in thickness. The Altai series, however, were developed from gneissic biotite granite→megaporphyritic biotite (two-mica) granite→medium grained biotite granite→leucogranite. In genetic type they evolved from I-S transitional to S-type. Their forming tectonic setting saw a transformation from synorogenic folding compression (C_1)—synorogenic faulting ductile shear (P_1)—postorogenic relaxation (P_2).Regarding Wulungu series, they changed in rock type from gabbro-diorite, alkali granite-k-feldspar granite→tonalite-granodiorite-hornblende biotite granite→biotite granite→alkali granite and quartz syenite. In genetic type they evolved from A→I→A type. Their forming tectonic setting varied from compression (C_1)→relaxation(C_2)→compression(P_1)—relaxation(P_2).
出处
《大地构造与成矿学》
EI
CAS
CSCD
1990年第1期43-56,共14页
Geotectonica et Metallogenia
基金
<额尔齐斯构造带构造演化与成矿系列研究>课题的阶段成果
关键词
中国
新疆
花岗岩
时代
成因
类型
Petrogenetic epoch of granitoids, genetic type, Altai Mts. of China.
