Abstract

Studies of the paleogeographical properties of the Ubsunur Basin located on the territory of northwestern Mongolia and southern Tuva are based on the discovery of buried ice veins under Aeolian sediments in the region of Lake Khar-Nur in the eastern mountainous frame of the Great Lakes Basin of Western Mongolia. Satellite images have shown outlines of fields along the periphery of the sand deposits, the natural irrigation of which, in our opinion, was due to the melting of the abovementioned ice. Deposits similar to glacial ones have been found in the river valleys of the northern mountainous framing of the Ubsunur Basin, in its foothill part, suggesting the presence of Pleistocene glaciers extending into its flat plains. It is also assumed on this basis that, similarly to Lake Khar-Nur, the peculiar sandy massifs located in the basin could preserve relic zones of permafrost, the thawing of which contributed to the moistening of local landscapes. Such humidification zones have been seen on satellite images. There are no glacial deposits in this territory in geological legends. At this stage of research, we confirm the presence in the past of thin glaciers in the study site, caused by mountain-forming processes, and the eruption of Quaternary volcanoes on the territory of Tuva and Mongolia. Tectonic processes contributed to the damming of the Tes Khem River, the main waterway flowing along the northern mountain rim of the basin, the formation of dammed lakes, and their subsequent descent. Extended original sandy massifs located in the basin within the Agardag mountain range, previously considered fluvioglacial deposits, are a result of the descent of dammed lakes.

中文翻译：

---

2022年乌布苏努尔盆地古地理特征

摘要

对位于蒙古国西北部和图瓦南部领土的乌布苏努尔盆地的古地理特征的研究是基于在大湖盆地东部山架卡努尔湖地区风成沉积物下发现的埋藏冰脉。蒙古西部。卫星图像显示了沙沉积物周边田地的轮廓，我们认为，这些田地的自然灌溉是由于上述冰的融化造成的。在乌布苏努尔盆地北部山区山麓的河谷中发现了与冰川沉积物类似的沉积物，这表明更新世冰川的存在延伸到其平坦的平原。在此基础上还假设，与卡努尔湖类似，位于盆地内的特殊沙地块可以保存永久冻土遗迹区，永久冻土的融化有助于湿润当地景观。在卫星图像上可以看到这样的加湿区。在地质传说中，这片领土上并没有冰川沉积物。在这一阶段的研究中，我们确认研究地点过去存在薄冰川，这是由造山过程以及图瓦和蒙古境内第四纪火山喷发造成的。构造过程促成了特斯坎河（沿着盆地北部山区边缘流动的主要水道）的筑坝、堰塞湖的形成及其随后的下降。位于阿加达格山脉盆地内的延伸的原始沙地块以前被认为是河流冰川沉积物，是堰塞湖下降的结果。