陕西师范大学查小春团队近日研究了青藏高原东部若尔盖盆地西缘末次冰消以来的地表过程与环境变化。相关论文发表在2025年5月13日出版的《中国地理科学》杂志上。

若尔盖盆地位于中国青藏高原东部，具有气候敏感性和复杂地表环境的特点。了解若尔盖盆地自上次冰川消融以来地表过程对环境变化的响应，以及青藏高原环境变化和地表过程对全球变化的响应至关重要。2020年8月，研究组在若尔盖盆地进行了实地调查。以盆地西部玛曲段冰洪积扇前缘高台地的一套完整地层剖面为研究对象。从关键层收集了光致发光（OSL）测年样品和沉积样品，并带回实验室进行实验分析，通过粒度分析和OSL测年研究了若尔盖盆地自上次冰消以来的地表过程和环境变化。

研究结果表明，在14.5 kyr之前的最后一个冰川期，由冰川融水和强降水引发的山洪过程形成了由砂砾层组成的大型冰川冲积扇。在14.5-11.7 kyr的Bølling-Allerød暖期，温暖湿润的气候盛行，在冰川冲积扇前沿的浅洼地形成了粉质沼泽环境，并发育了灰绿色沼泽土壤沉积物。 然而，在新Dryas时期，气候突然恶化，浅凹陷灰绿色沼泽土层的上部因地表冻融作用而发生褶皱和变形。在11.7 kyr至8.5 kyr的全新世早期，气候相对干燥，导致风沙活动盛行。由于高原表面的强风模式，粗粉土堆积在浅洼地中，沉积相在风成砂和沼泽土沉积物之间交替发育。在8.5 kyr至3.1 kyr的温暖湿润时期，风化作用和成土作用的增加提升了沉积物中粘土的含量，从而形成了古土壤。 

全新世晚期，从3.1 kyr开始，气候再次变得相对干燥，风沙活动盛行。由于温度和湿度的升高，全新世晚期积累的粗粉土转变为亚高山草甸黑土。这些发现表明，若尔盖盆地玛曲段高台地的发育过程，对于了解自上次冰川消融以来黄河源区的环境变化和地表过程具有重要意义。

附：英文原文

Title: Surface Process and Environment Change Since Last Deglaciation in Western Margin of Zoige Basin, Eastern Tibetan Plateau, China

Author: Bai, Xin, Zha, Xiaochun, Huang, Chunchang, Zhou, Yali, Pang, Jiangli, Zhang, Yuzhu, Wang, Na, Han, Yixin

Issue&Volume: 2025-05-13

Abstract: The Zoige Basin, located in the eastern region of the Tibetan Plateau of China, is characterized by its climate sensitivity and complex surface environment. It is vital to understand the response of the surface processes to environmental changes in the Zoige Basin since the last deglaciation, as well as the response of environmental changes and surface processes on the Tibetan Plateau relate to global changes. In August 2020, a field investigation was conducted in the Zoige Basin. A complete set of stratigraphic profile from the high platform at the front of the glacial-diluvial fan in the Maqu reach of the western basin was selected as the research subject. Optically stimulated luminescence (OSL) dating samples and sedimentary samples were collected from key layers and brought back to the laboratory for experimental analysis, and the surface processes and environment changes since the last deglaciation in the Zoige Basin were investigated through particle size analysis and OSL dating. The results showed that during the last glacial period before 14.5 kyr, a substantial glacial-alluvial fan composed of sand and gravel layers was formed by flash flood processes triggered by glacial meltwater and heavy precipitation. In the Blling-Allerd warm period of 14.5–11.7 kyr, a warm and humid climate prevailed, with the formation of silty bog environments in the shallow depressions at the glacial-alluvial fan’s forefront and the development of gray-green bog soil deposits. However, during the Younger Dryas period, an abrupt climate deterioration occurred, with the upper section of the gray-green bog soil layer in the shallow depression to experience folding and deformation due to surface freeze-thaw actions. During the early Holocene period from 11.7 kyr to 8.5 kyr, the climate was relatively dry, resulting in prevalent aeolian sand activitities. Coarse silt accumulated in the shallow depression, and sedimentary facies alternating between aeolian sand and bog soil deposits developed owing to strong wind patterns on the plateau surface. In the warm and humid period from 8.5 kyr to 3.1 kyr, increased weathering and pedogenesis enhanced clay content in sediments, which developed into the paleosol. In the late Holocene, starting from 3.1 kyr, the climate became relatively dry once more, with aeolian sand activity prevalent. The coarse silt that accumulated during the late Holocene transformed into subalpine meadow black soil because of rising temperature and humidity levels. These findings indicated that the developmental process of the high platform in the Maqu reach of the Zoige Basin, which was significant for understanding the environmental changes and surface processes in the source region of the Yellow River since the last deglaciation.

DOI: 10.1007/s11769-025-1513-6

Source: https://link.springer.com/article/10.1007/s11769-025-1513-6