摘要
构造作用是影响地球深部内热向地表传输和热能再分配过程的关键因素之一。青藏高原东北缘共和盆地发现高温地热资源,其热源成因机制一直是研究焦点。为理解构造作用对地热资源分布的控制过程,本文选取共和盆地高温地热异常区,分析边界断裂构造性质、活动期次、演化历程,结合钻井、大地电磁和背景噪声成像地球物理异常特征,提出新生代构造演化和地热异常形成的耦合关系。认为:1)青藏高原东北缘共和盆地及周缘变形区形成于昆仑断裂和海源断裂大型活动左旋走滑作用的滑动消减带;2)共和盆地新生代以来经历中新世(12–6 Ma)旋转泛湖盆凹陷、上新世—第四纪(6–3 Ma)盆内张扭变形两期主要演化阶段;3)共和盆地上地壳发育的与高温相关的地球物理低速-高导异常层(Vs<3.2 km/s,R<10Ω·m)是主导热源;4)上新世持续左旋走滑变形导致的岩石圈隆起变形是深部热能向浅层传输的主要动力学机制,浅部热能聚集成热过程至少延续到了3 Ma;5)预测青藏高原东北缘与共和盆地具有类似构造演化性质的次生盆地具有高温地热资源发育的条件。
Tectonic activity is one of the key factors affecting the process of heat transfer to the surface and energy redistribution in the deep earth.High-temperature geothermal resources have been discovered in Gonghe Basin,located at the northeastern margin of the Tibetan Plateau.The source of the heat has historically been the focus of research.In order to understand the impact of tectonic activity on the distribution of geothermal resources,in this study,we performed seismic background noise profile measurement in the area of Gonghe Basin that experiences high-temperature geothermal anomalies.We analyzed the structural properties,activity period,and evolution process of boundary faults,and propose a coupling relationship between Cenozoic tectonic evolution and geothermal anomaly formation based on the characteristics of drilling and geophysical anomalies.The following conclusions were drawn:1)Gonghe Basin was formed in the sliding subtraction zone of large-scale active left-handed strike-slip action at the Kunlun fault and the Haiyuan fault;2)Since the Cenozoic,Gonghe Basin has experienced two major evolutionary stages:the Miocene(12-6 Ma)rotating panlacusion depression and the Pliocene-Quaternary(6-3 Ma)tension and torsion deformation;3)The geophysical low-velocity and high-conductivity layer(VS<3.2 km/s,R>10Ω·m)developed in the upper crust of Gonghe Basin is the dominant heat source;4)The lithospheric uplift deformation caused by the continuous left-handed strike-slip deformation in the Pliocene is the main driving force for the intrusion of deep thermal energy into the shallow layer,and the heat transport extended at least to 3 Ma;5)It is assumed that the sub-basin on the northeastern margin of the Tibetan Plateau with tectonic evolution properties similar to those of Gonghe Basin will have conditions for the development of high-temperature geothermal resources.
作者
唐显春
王贵玲
张代磊
马岩
TANG Xian-chun;WANG Gui-ling;ZHANG Dai-lei;MA Yan(Chinese Academy of Geological Sciences,Beijing 100037;Technology Innovation Center of Geothermal and Hot Dry Rock Exploration and Development,Ministry of Natural Resources,Shijiazhuang,Hebei 050061;SinoProbe Center,Ministry of Natural Resources,Beijing 100037)
出处
《地球学报》
CAS
CSCD
北大核心
2023年第1期7-20,共14页
Acta Geoscientica Sinica
基金
国家自然科学基金项目(编号:41877197,41602257)
中国地质调查局地质调查项目(编号:DD20190132,DD20221677)联合资助。
关键词
地热
共和盆地
新构造
走滑
高导低速体
青藏高原东北缘
geothermal
Gonghe Basin
active structure
slipping fault
high conductivity-lower velocity zone
northeastern margin of the Tibetan Plateau
