Mongolian Geoscientist 2024-05-24T10:11:02+00:00 Bayaraa Batkhishig Open Journal Systems <p>published by the <a title="MUST" href="" target="_blank" rel="noopener">Mongolian University of Science and Technology </a>with support from <a title="Mongolian Geological Society" href="" target="_blank" rel="noopener">The Geological Society of Mongolia</a>.</p> <p><strong>Abstracting and indexing in <a title="Google Scholar" href="" target="_blank" rel="noopener">Google Scholar</a>, <a title="Dimensions" href="" target="_blank" rel="noopener">Dimensions,</a> <a title="DOAJ" href="" target="_blank" rel="noopener">DOAJ</a>, <a title="EBSCO Discovery service" href="" target="_blank" rel="noopener">EBSCO Discovery service,</a> <a title="CNKI" href="" target="_blank" rel="noopener">CNKI</a> and <a title="MGS in Scopus" href="" target="_blank" rel="noopener">Scopus</a></strong></p> <p><strong>Accepted for <a title="Georef" href="" target="_blank" rel="noopener">Georef</a>, </strong></p> Geomorphological study of the origin of Mongolian Altai Mountains Lake depressions: implications for the relationships between tectonic and glacial processes 2024-03-20T08:55:19+00:00 Altanbold Enkhbold Ulambadrakh Khukhuudei Yeong Bae Seong Yumchmaa Gonchigjav Li Dingjun Byambabayar Ganbold <p>The lake depressions in the Mongolian Altai Mountains, and the issues related to their formation have yet to be thoroughly examined in previous research. Previous studies primarily focused on the paleogeographical evolution and glaciation dynamics of the Altai Mountains. This study presents relationships between tectonic and glacial processes that have formed the lake depressions, such as<br />Khoton, Khurgan, Dayan, Khar (western), and Khar (eastern) in the Mongolian Altai Mountains. The depressions of Khoton, Khurgan, and Dayan lakes are situated along regional fault zones, extending in an northwest-southeast direction, forming intermontane depressions directly connected to the Mongolian Altai Mountains. <br />However, the depressions of Dayan, Khar (western), and Khar (eastern) lakes have been dammed by moraine deposits in the near portion of the depression. The compliance matrix of tectonic geomorphological criteria indicates that the Khoton, Khurgan, Dayan Lake, and Khar (western) Lake depressions are more than 50% compatible. Similarly, the compliance matrix for glacial eomorphological criteria indicates more than 60% compliance for all lake depressions. The Mongolian Altai intermontane depressions are thus of tectonic origin, whereas the lakes have a glacial origin, resulting from dammed moraine sediments. The significance<br />of this work lies in demonstrating how geomorphological research can be employed to provide a detailed understanding of the pattern of lake depressions.</p> 2024-03-26T00:00:00+00:00 Copyright (c) 2023 Altanbold Enkhbold, Ulambadrakh Khukhuudei, Yeong Bae Seong, Yumchmaa Gonchigjav, Li Dingjun, Byambabayar Ganbold Sedimentary basins, hydrocarbons, graphite, coal, and Cu-Au deposits - from Mongolia to the Pacific margin: Interplay between the ubiquitous orthogonal fracture network and Global Wrench Tectonics 2024-01-31T07:05:27+00:00 Karsten M. Storetvedt Per Michaelsen <p>Mongolia is exceptionally rich in coal and copper-gold resources - with world-class deposits like Tavan Tolgoi, Oyu Tolgoi and Erdenet. Thus, the mining industry has a crucial importance for the national economy, yet most of the country remain very underexplored. Within today's global tectonics, an acceptable understanding of metal enrichments - including leaching, the internal hydrostatic-hydraulic pumping system, and surface emplacement mechanisms - has remained unresolved. However, a broader view of the structural situation in the Mongolia-China region shows a close link between orientation of elongate sedimentary basins, important mineral belts, and the fundamental orthogonal fracture/fault system. In the east the tectonic trend is dominantly northeast, while it is northwest in western areas. The main east Mongolian graphite deposits have northeast structural trends like numerous regional Cu and Au belts. A new theory of the earth, Global Wrench Tectonics, offers an exciting approach to better understanding the various facets of Earth's geological history and its surface resources. Earth’s degassing, dynamo-tectonic consequences, inertia-driven crustal wrench tectonics, as well as surface products such as water, hydrocarbons and ore deposits are given a coherent system explanation. Many hydrocarbons are products from the interior of our slowly degassing Earth, with massive hydrocarbon fields such as Songliao and the Yamal megaproject producing from the basement. Crustal thinning in the Songliao region is about the same as in southeast Mongolia, suggesting that they may have had similar degassing and crustal evolution histories. As such, it is not unlikely that the underexplored Mesozoic basins of southeast Mongolia - particularly at the deepest levels and/or in the adjacent crystalline basement - may have important hydrocarbon potential.</p> 2024-06-17T00:00:00+00:00 Copyright (c) 2024 Karsten M. Storetvedt, Per Michaelsen Petro-chemical characterization and depositional setting of a late Permian high ash coal deposit, Central Mongolia 2024-05-24T10:11:02+00:00 Per Michaelsen Batbold Demberelsuren <p>Pan global Permian coal measures are unique in the evolution of the Earth, not matched in any period before or since. Middle and late Permian coal-bearing strata are widely distributed in Mongolia. In particular, a large concentration of transtensive coal-bearing sub-basins is located in southern Mongolia, some of which are well documented. However, the late Permian coal measures developed along the shores of the Mongol-Transbaikalian Seaway in central Mongolia, the focus of this contribution, has received very limited attention. This study focuses on the c. 420 m thick coal-bearing middle part of a c. 2,600 m thick Permo-Triassic succession in the Bayanjargalan district. The study draws on data from 38 drillholes, 3 km of trenches, mapping, petrological analysis of sandstone samples, analysis of macroflora, fauna and trace fossils, 82 coal quality samples as well as washability and ash XRD analysis from a 3t coal bulk sample. The unstable and wedge-shaped architecture of the coal seams strongly suggest a syn-tectonic influence on their development. Paleoclimatic indicators suggest the peat mire ecosystem developed during relatively cold - temperate climatic conditions. Peat-forming plants such as <em>Cordaites</em>, <em>Rufloria</em> and <em>Koretrophyllites</em> probably benefited from moist air currents along the seaway. Plant-arthropod interactions are reported from two sites, in particular DT228 and DT246 oviposition lesions, the latter being almost twice the size of a previous report from North America. Results from 82 proximate analyses returned consistent very high ash yields of 46.95% (db) and 43.45% (adb) from the 3t bulk sample, which are unusual for Permian coals in Mongolia.</p> 2024-06-11T00:00:00+00:00 Copyright (c) 2024 Per Michaelsen, Batbold Demberelsuren