摘要
发育在冈底斯岩浆弧与雅鲁藏布江蛇绿岩带之间的日喀则群是残留型弧前盆地沉积。盆地的南部基底和前缘脊由雅鲁藏布江蛇绿岩带构成。盆地形成初期是一套蛇绿质碎屑沉积即冲堆组,沉积物源主要来自盆地南部前缘脊;盆地发育中期主要是一套浊流成因的深海扇,沉积物源主要来自盆地北部的岩浆弧,少量来自前缘脊蛇绿岩;盆地发育晚期为一套浅海-滨海沉积,物源来自北部岩浆弧。至始新世末期或渐新世早期,盆地结束沉积。
Xigaze Group, which developed in the Xigaze forearc basin between Gangdise Granites and Tsangpo Ophiolite in the Himalayan Orogenic Belt. was deposited on Tsangpo Ophiolite at the southern part of the basin, and was deposited on Gangdise Granites at the northern margin of the basin. We think that the southern basement and fore-ridge of the basin was composed of the Tsangpo super-subduction zone ophiolite, so the basin is classed under the Remnant-type forearc basin. During the early period of formation of the basin (K13), the ophiolitifeous slide deposit and radiolarian chert were developed in the basin, the sedimenst came from the fore-rigde; During the middle period (K21), the turbidite fan was well developed in the basin, the sediments came mainly from the northern Gangdise Arc; During the late period (K22-E2) - the basin evolved into littoral environment, and terrestrial deposit was developed in the northern margin of the basin and sorthen side of the fore-ridge. The collision between Indian Plate and Asian Plate probably occurred in Oligocene.
出处
《中国科学院研究生院学报》
CAS
CSCD
1997年第1期51-56,共6页
Journal of the Graduate School of the Chinese Academy of Sciences
基金
中国科学院地质研究所所长基金支持课题
关键词
日喀则群
残留型弧前盆地
沉积演化
Xigaze group, remnant-type forearc basin, super-subduction zone ophiolite, evolution
