南羌塘地体多玛-鄂雅错地区地质填图、地质年代学和低温热年代学数据

为了重建南羌塘地体多玛-鄂雅措地区白垩纪-渐新世的生长过程，本文提供了新的野外地质填图、地质年代学和低温热年代学数据。首先，基于新的野外地质填图和已发表的地震反射数据，结合平衡剖面技术，提出该地区在阿布山组沉积之前和之后分别经历了79.6 km（33.4%）和76.0 km（32.2%）的地壳缩短。在平衡剖面绘制中，本文利用线平衡技术进行绘制，还考虑到不同地层单元的厚度，以保障数据的准确性。其次，基于区域性不整合事件，结合火山岩的锆石U-Pb测年结果和磷灰石裂变径迹的结果，限定了两期构造事件的时间分别是白垩纪中期（约125-96 Ma）和始新世早期（约55-40 Ma）。其中阿布山组的火山岩夹层（L-6）年龄为69.8 Ma，康托组的火山岩夹层（D011-U1，U2）年龄为32.6 Ma，30.0 Ma，上述地层年龄初步限定了构造变形的边界时间；在磷灰石裂变径迹数据处理过程中，本文提供了可靠的磷灰石裂变径迹年龄和径迹长度数据，并采用HeFTy软件进行反演模拟。每次模拟均迭代10000次，以确保获得最大最佳拟合结果。上述研究为南羌塘地体的地壳增厚与隆升过程提供了关键证据，并对理解高原中部的形成具有重要的地质意义。

To reconstruct the Cretaceous-Oligocene evolutionary history of the Duoerma-Eyacuo area in the South Qiangtang Terrane, this study presents new field geological mapping, geochronological, and low-temperature thermochronological data. First, based on newly acquired field geological mapping and published seismic reflection data, combined with balanced cross-section techniques, we propose that the area experienced crustal shortening of 79.6 km (33.4%) and 76.0 km (32.2%) before and after the deposition of the Abushan Formation, respectively. During the construction of balanced cross-sections, we employed the line-balancing technique and accounted for the thicknesses of different stratigraphic units to ensure data accuracy. Second, based on regional unconformity events, combined with zircon U-Pb dating results of volcanic rocks and apatite fission-track data, we constrain the timing of two tectonic events to the mid-Cretaceous (approximately 125–96 Ma) and early Eocene (approximately 55–40 Ma), respectively. Specifically, the volcanic interlayers (L-6) within the Abushan Formation yield an age of 69.8 Ma, while those of the Kangtuo Formation (D011-U1, U2) yield ages of 32.6 Ma and 30.0 Ma; these stratigraphic ages preliminarily constrain the boundary timing of tectonic deformation. During the processing of apatite fission-track data, we provide reliable apatite fission-track ages and track length datasets, and performed inversion simulations using the HeFTy software. Each simulation was iterated 10,000 times to ensure the acquisition of the optimal maximum-fitting results. This study provides critical evidence for the crustal thickening and uplift processes of the South Qiangtang Terrane, and holds important geological implications for understanding the formation of the central Tibetan Plateau.

搜集汇总

背景与挑战

背景概述

该数据集提供了南羌塘地体多玛-鄂雅错地区的地质填图、地质年代学和低温热年代学数据，旨在重建该地区白垩纪-渐新世的生长过程。数据包括基于野外填图和平衡剖面技术计算的地壳缩短量（约79.6 km和76.0 km），以及通过锆石U-Pb测年和磷灰石裂变径迹限定的两期构造事件时间（白垩纪中期和始新世早期），为理解南羌塘地体的地壳增厚与隆升过程提供了关键证据。