摘要
青藏高原普遍发育的南北向裂谷对认识青藏高原陆内造山过程和变形机制,探讨岩浆活动、成矿成藏机制具有重要的意义。位于青藏高原南部的申扎裂谷,发育在班公—怒江缝合带和雅江缝合带之间,垂直切割了冈底斯成矿带。本文针对申扎裂谷地震波信号弱、干扰强、频率变化大的特点,利用多道面波成像方法处理申扎裂谷及其邻区的81 km深地震反射剖面数据,获得了高质量的S波速度剖面。结合已有地质、地球物理资料对S波速度结构进行解释,重点研究了申扎地区的沉积层厚度以及S波高速异常特征,探讨了申扎裂谷的延伸情况,分析了浅部矿产分布与断裂的关系,讨论了热泉形成的可能成因,获得以下认识:申扎裂谷处的沉积厚度约1000 m;在剖面0~30 km范围下方1000 m以下有成矿潜力;热泉的存在印证了高温岩体的存在,为热液成矿提供了证据。
The north-south trend rift in the Qinghai-Tibet Plateau is of great significance for understanding the intracontinental orogenic process and deformation mechanism,magmatic activity and metallogenic accumulation mechanism.Xainza Rift,located in the west of Qinghai-Tibet Plateau,developed between Bangong-Nujiang suture and Yajiang Suture,and cut Gangdisi metallogenic belt vertically.In view of the characteristics of weak seismic signal,strong interference and large frequency variation in Xainza Rift,this paper uses multi-channel surface wave imaging method to process 81 km deep seismic reflection profile data in Xainza Rift and its adjacent areas,and obtains high quality S-wave velocity profile.Based on existing geological and geophysical data,the S-wave velocity structure is explained,the sedimentary layer and S-wave high-speed anomaly characteristics in Xainza Rift area are studied,the extension of Shenza Xainza Rift is discussed,the relationship between shallow mineral distribution and fault is analyzed,and the possible causes of hot spring formation are discussed.The following conclusions are obtained:Xainza Rift may extend down wards at least 1000 m;There is ore-forming potential below 1000 m in the 0-30 km range of the profile.The existence of hot springs confirms the existence of high temperature rock mass and provides evidence for hydrothermal mineralization.
作者
蔡玉国
卢占武
李文辉
王光文
陈司
程永志
吴国炜
蔡蔚
CAI Yuguo;LU Zhanwu;LI Wenhui;WANG Guangwen;CHEN Si;CHENG Yongzhi;WU Guowei;CAI Wei(Chinese Academy of Geological Sciences,Beijing 100037,China;China University of Geosciences,Beijing 100083,China;SinoProbe Laboratory of Ministry of Natural Resources,Beijing 100037,China)
出处
《矿产勘查》
2023年第10期1988-1998,共11页
Mineral Exploration
基金
国家自然科学基金项目(42274135,42174124,42174094)
中国地质调查局项目(DD20221647)
第二次青藏高原综合科学考察研究(2019QZKK0701-02)联合资助。
关键词
申扎裂谷
S波速度结构
沉积层
多道面波成像
深地震反射剖面数据
Xainza rift
S-wave velocity structure
sedimentary layer
multi-channel surface wave imaging
deep seismic reflection profile date
