Liang Yu, Wang Huanye, Kemp David B, Liu Zerui Ray, Liu Weiguo, Liu Hu, Quan Cheng, Liu Xiaobo, Liu Zhonghui, Zhou Mei-Fu
School of Earth Resources, China University of Geosciences, Wuhan 430074, China.
Department of Earth Sciences, The University of Hong Kong, Hong Kong SAR, China.
Sci Adv. 2025 Jul 11;11(28):eadu5030. doi: 10.1126/sciadv.adu5030.
Paleoaltimetry data are essential for deciphering the growth trajectory of orogenic plateaus and underlying forcing mechanisms. However, paleoaltitude reconstructions using conventional paleotemperature analysis often have low resolution or large calibration uncertainties. Here, we use Group III alkenones, a marine paleothermometer normally not present in terrestrial basins, to reconstruct paleolake temperatures and refine the paleoelevation history of the Qaidam Basin, northern Tibetan Plateau, during the Late Miocene. Our results reveal a geologically rapid lake-surface cooling of 6.6° ± 1.8°C at either ~11.3 to 10.8 or ~7.7 to 7.6 million years ago (depending on the chronology used). This cooling, benchmarked against coeval sea surface temperatures, indicates a topographic rise of either 1650 ± 450 or 1525 ± 450 meters. Coupled with glycerol dialkyl glycerol tetraether-based paleotemperatures and existing tectonic records, our findings refine the timing and pace of a rapid uplift event within the final major phase of Tibetan Plateau growth, linked to mantle lithosphere detachment.
古高度测量数据对于解读造山高原的生长轨迹及潜在驱动机制至关重要。然而，利用传统古温度分析进行的古海拔重建往往分辨率较低或校准不确定性较大。在此，我们使用III族烯酮（一种通常不存在于陆相盆地的海洋古温度计）来重建古湖泊温度，并完善青藏高原北部柴达木盆地晚中新世期间的古海拔历史。我们的结果显示，在约1130万年至1080万年或约770万年至760万年前（取决于所使用的年代学），湖泊表面出现了6.6°±1.8°C的地质快速降温。以同期海面温度为基准，这种降温表明地形上升了1650±450米或1525±450米。结合基于甘油二烷基甘油四醚的古温度和现有的构造记录，我们的发现完善了青藏高原生长最后一个主要阶段内与地幔岩石圈拆离相关的快速隆升事件的时间和速度。
