西南三江地区新生代走滑造山

Cenozoic strike slip orogeny in Sanjiang area, Southwestern China

关键词:  西南三江  新生代  走滑造山

Key words:  Sanjiang in Southwestern China  Cenozoic  strike slip orogeny

摘要:

本文系统论述了西南三江地区那邦、高黎贡山、崇山-澜沧江、点苍山-哀牢山-红河剪切走滑带、区域性伸展与变质核杂岩、新生代盆地及走滑过程中的碱性岩浆活动等特征，认为西南三江地区经历了挤压收缩变形（60~40Ma）、走滑伸展热隆（40~38Ma）、走滑剪切深熔（38~23Ma）、走滑剪切伸展（23~11Ma）、走滑剥蚀隆升（11~5Ma）5个时空演化阶段，并对应5种运动机制及动力学机制：碰撞挤压、走滑拉张热隆（岩浆）、走滑剪切深熔、剪切伸展、走滑垮塌，主要表现为走滑造山。西南三江造山带是印度板块向欧亚板块斜向俯冲形成的多条巨型顺时针走滑剪切带，其间的块体向南逸出并顺时针旋转。走滑断层系起了位移量调节和构造变换的作用，西南三江造山带为典型的走滑造山带。

Abstract:

This paper systematically discusses the characteristics of strike slip shear zones, regional extensions and metamorphic core complexes, Cenozoic basins, and alkaline magmatic activities in the process of strike slip in Sanjiang area of Southwest China. It is considered that Sanjiang area has experienced five temporal and spatial evolution stages:the compression contraction deformation period (60-40Ma), strike slip extension thermal uplift period (40-38Ma), shear deep melting period (38-23Ma), strike slip shear extension period (23-11Ma), and strike slip denudation uplift period (11-5Ma), corresponding to five kinds of motion mechanism and dynamic system:collision and compression, strike slip tension thermal uplift (magma), strike slip shear deep melting, shear extension, strike slip collapse, which are mainly manifested as strike slip orogeny. The Sanjiang Orogenic Belt in Southwest China is the result of the oblique subduction of the Indian plate to the Eurasian plate, forming a number of giant clockwise strike slip shear zones in which the blocks escape to the South and rotate clockwise. The strike slip fault system plays a role in orogeny in the form of displacement adjustment and structural transformation, and the Sanjiang Orogenic Belt in Southwest China is a typical strike slip orogenic belt.