|
封面故事：羌塘地块西缘泽错地堑边界正断裂系及其伸展变形机制。青藏高原南部和中部分布一系列近南北走向的地堑系, 构成高原最年轻的构造变形体系。最新获得的羌塘地块最西缘泽错地堑的晚第四纪伸展速率远高于中部和藏南地区, 表明羌塘地块乃至整个青藏高原西部目前处于非稳态的加速伸展变形状态。在青藏高原中部羌塘活动地块, 印度与欧亚板块俯冲碰撞的直接效应减弱, 在其西缘, 持续的斜向碰撞引起的伸展变形依然强烈。因此, 西部物质以更高的伸展速率弥散式向东运移, 并与中、下地壳非完全解耦。这项由地质研究所李海兵研究员主持的研究成果, 当选中国地质科学院2024年度十大科技进展, 排名第二。详见本期1-16页。(图片提供: 郑勇)
Cover Story：The boundary normal fault of the Chem Co half-graben and its conceptual model for the accelerated extension mechanism. A series of grabens trending nearly north-south are dis-tributed in southern and central Tibet. They are the youngest tectonic deformation features. The latest results show that during the Late Qua-ternary, the extension rate of the Chem Co graben in the westernmost segment of the Qiangtang Block was much higher than that in the central segment and the South Tibet, indicating that the Qiangtang Block and even the entire western Tibetan Plateau are in an unsteady state with accelerated extensional deformation. In the active Qiangtang Block of central Tibet, the direct effects of subduction and collision be-tween the Indian and Eurasian plates are weak, except in its westernmost segment, where rapid uplift is ongoing driven by oblique colli-sion. As a result, the eastward migration of ma-terial has been characterized by a diffuse manner with higher extension rate, reflecting an incomplete decou-pled from the middle-lower crust. The research achievement, led by Professor LI Haibing of the Insti-tute of Geology, CAGS, ranks the second among the “Top Ten Sci-tech Progresses of CAGS in 2024”. For details, see pp. 1-16 of this issue. (Photo by ZHENG Yong)
|
