RUSSIAN JOURNAL OF EARTH SCIENCES VOL. 7, ES3004, doi:10.2205/2005ES000173, 2005

Brief Characteristics of the Objects of Our Study

[4]  Lake Khubsugul in North Mongolia occupies a depression in the Baikal Rift zone, the coordinates of its center being 51o N, 100o30 prime E, 1645 asl. The mountains north and east of the lake reach an altitude of 2800-3400 m asl. It is the second largest lake (after Baikal Lake) in East Asia, which stores 383 km 3 of water with its total water salinity of 180-200 mg l -1. Its maximum depth is 262 m. The lake is 2760 km 2 in area, its watershed area being 5130 km 2. The outlet from the lake is the Egerin River flowing from its southernmost part. The mean atmospheric precipitation in the catchment area is 10-50 mm in winter and 300 mm in summer [Fedotov et al., 2004a, 2004b]. The bulk of this moisture is delivered from the North Atlantic area via Kazakhstan and Middle Asia [Kuznetsova, 1978]. The bottom sediments of Lake Khubsugul and of the other lakes of Mongolia have long since attracted a great interest of paleoclimatologists and were studied by Soviet-Mongolian expeditions at the end of the 20th century. It was found that many of the Mongolian lakes had been dry in the Pleistocene and were filled with water at the beginning of the Holocene. As to the Khubsugul Lake, a few sediment cores samples were collected and subject to qualitative analyses. It was reported [Altunbaev and Samarina, 1977] that the cores consisted of silt in their upper parts and of clay in the lower parts [Altunbaev and Samarina, 1977].

[5]  Drilling was performed from ice by a team from the PBU Irkutskgeologiya Company (Russia) in the middle of the lake (51o58 prime 24 primeprime N and 100o24 prime 33 primeprime E, at a depth of 232 m. The high-frequency hydro-pulse drilling technique was able to raise undisturbed sediment cores ranging from 2 m to 6 m long. Most of the core samples consisted of silty clay with a minor admixture of sand and occasional gravels. The lower part of the lake sediments (19-53 m) was enriched in sand beds and lenses. The color of the sediments varied from gray to olive-gray, to olive-green, and to black. The total number of samples collected for magnetic and mineralogical studies was 1026 with a distance of 4 cm between them. The samples were dried in a refrigerator to protect them from oxidation and then subject to magnetic-mineralogical studies.


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Citation: Nourgaliev, D. K., P. G. Iassonov, L. R. Kosareva, A. Yu. Kazanskii, and A. P. Fedotov (2005), The origin of magnetic minerals in the Lake Khubsugul sediments (Mongolia), Russ. J. Earth Sci., 7, ES3004, doi:10.2205/2005ES000173.

Copyright 2005 by the Russian Journal of Earth Sciences

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