西藏措勤地区中生代的构造变形

详细信息

Mesozoic Deformation in the Coqên area,Tibet

摘要: ：１∶１０万野外地质填图发现，在措勤地区北侧的白垩系中发育了一系列逆冲推覆构造和褶皱构造，且有侵入岩体分布，又被未变形的火山凝灰岩不整合覆盖。根据侵入岩的钾长石和角闪石及其不整合的火山凝灰岩中蚀变斜长石的ＡｒＡｒ法同位素年龄、沉积物质的组成和沉积地层的空间展布等特征，笔者推测这些逆冲断层和褶皱构造均发育于晚白垩世，并早于第三纪。
Abstract: ?00 000 geological mapping reveals a series of thrust nappes and folds in the Cretaceous in the Coqên area, west central Tibet, which are cut by plutons and overlain unconformably by undeformed volcanic tuffs. Ar Ar ages of the K feldspar and hornblende in plutons and altered plagioclase in the tuffs, composition of sedimentary materials and spatial distribution of the sedimentary strata suggest that the thrusts and folds developed in the Late Cretaceous, earlier than the Early Teritary. Regional geological data shows that Late Mesozoic structural deformation was prevalent in the Lasha block.
- tectonic deformation /
- west central Tibet /
- Coqên area /
- Mesozoic