哀牢山—红河断裂带中南段新生代构造活动的年代学证据  

Chronological evidence of Cenozoic activity in the middle and southernpart of Ailao Mountain-Red River fault zone

作　　者：田鹏 杨周胜[1] 喻聪骏 孙滨[3] TIAN Peng;YANG Zhousheng;YU Congjun;SUN Bin(Yunnan Earthquake Agency,Yunnan Kunming 650224,China;Geological Environment Monitoring Institute of Jiangxi Geological Survey and Exploration Institute,Jiangxi Nanchang 330000,China;Faculty of Land and Resources Engineering,Kunming University of Science and Technology,Yunnan Kunming 650031,China)

机构地区：[1]云南省地震局,云南昆明650224 [2]江西省地质调查勘查院地质环境监测所,江西南昌330000 [3]昆明理工大学国土资源学院,云南昆明650031

出　　处：《中国地质调查》2023年第2期42-53,共12页Geological Survey of China

基　　金：云南省地震局青年基金项目“哀牢山—红河断裂带中段新生代活动性的年代学证据(编号:2020K10)”;云南省重点研发计划(社会发展专项)“云南重大地震灾害及其灾害链综合风险评估技术与应用(编号:202203AC100003)”联合资助。

摘　　要：运用同位素年代学研究哀牢山—红河断裂带的构造演化历史已获得众多成果,但尚未有从低温—中温—高温系统的角度构建热演化史过程的研究,断裂带左旋走滑的启动时间仍存在争议。总结了哀牢山—红河断裂带中南段的年龄数据,通过分析认为相同同位素体系厘定的年龄值从南东端到北西端变新,差异性减小;将研究区分为北、中、南3段,使用低温、中温、高温年龄构建时间-温度(T-t)变化曲线,热演化史表明断裂带经历了2期冷却历史,冷却速率和隆升剥蚀速率的时空变化记录了伸展应力自南向北依次传播、转换拉张强度在传递过程中逐渐减弱、断裂活动性明显减弱的过程;将断裂带构造活动划分为快速左旋走滑阶段(35~20 Ma)、左旋走滑逐渐减弱阶段(20~6 Ma)及右旋走滑阶段(6 Ma至今)。断裂构造活动反映了印度—欧亚板块碰撞过程中,青藏高原东南缘的应力持续调节过程。Many achievements have been made in studying the tectonic evolution of Ailao Mountain-Red River fault zone by using isotopic chronology,but the thermal history evolution process has not been constructed from the low-temperature to high-temperature system.And the controversy exists in the starting time of the left-lateral strike-slip of the fault zone.The age data in the south central section of Ailao Mountain-Red River fault zone were summarized,and the age values from the same isotopic system turned to be younger from the southeast to the northwest,with less differences.The study area is divided into:north,middle and south section section,and T-t change curve is constructed using the low,medium and high temperature ages.The thermal history evolution shows that the fault zone has experienced two stages of cooling history.The temporal and spatial changes of cooling rate and uplift and denudation rate recorded the transmission of tensile strain from southeast to north,with gradually weakening of transformation tensile strength and fault activity during the transmission process.The activity process of the fault zone is finally divided into three stages:The immediate left walking sliding stage(35-20 Ma),The gradual stop stage of left-handed slipping(20-6 Ma),and the right-handed slipping stage(6 Ma to the present).The fault tectonic activity reflects the continuous adjustment process of the stress in the southeast margin of Qinghai-Tibet Plateau during the India-Eurasian plate collision.

关 键 词：哀牢山—红河断裂带中南段 同位素年龄 构造-热演化史 

分 类 号：P542[天文地球—构造地质学] P533[天文地球—地质学]