TY - JOUR T1 - Paleoenvironmental proxy records from Lake Hovsgol, Mongolia, and a synthesis of Holocene climate change in the Lake Baikal watershed JF - Quaternary Research Y1 - 2007 A1 - Prokopenko, A. A. A1 - Khursevich, G. K. A1 - Bezrukova, E. V. A1 - Kuzmin, M. I. A1 - Boes, X. A1 - Williams, D. F. A1 - Fedenya, S. A. A1 - Kulagina, N. V. A1 - Letunova, P. P. A1 - Abzaeva, A. A. AB - Here we discuss palcoenvironmental evolution in the Baikal region during the Holocene using new records of aquatic (diatom) and terrestrial vegetation changes from Hovsgol, Mongolia's largest and deepest lake. We reconcile previous contradictory Baikal timescales by constraining reservoir corrections of AMS dates on bulk sedimentary organic carbon. Synthesis of the Holocene records in the Baikal watershed reveals a northward progression in landscape/vegetation changes and an anti-phase behavior of diatom and biogenic silica proxies in neighboring rift lakes. In Lake Baikal, these proxies appear to be responsive to annual temperature increases after 6 ka, whereas in Lake Hovsgol they respond to higher precipitation/runoff from 11 to 7 ka. Unlike around Lake Baikal, warmer summers between 6 and 3.5 ka resulted in the decline, not expansion, of forest vegetation around Lake Hovsgol, apparently as a result of higher soil temperatures and lower moisture availability. The regional climatic proxy data are consistent with a series of 500-yr time slice Holocene GCM simulations for continental Eurasia. Our results allow reevaluation of the concepts of 'the Holocene optimum' and a 'maximum of the Asian summer monsoon', as applied to palcoclimate records from continental Asia. (c) 2007 University of Washington. All rights reserved. VL - 68 IS - 1 N1 - 187enTimes Cited:71Cited References Count:58 JO - Paleoenvironmental proxy records from Lake Hovsgol, Mongolia, and a synthesis of Holocene climate change in the Lake Baikal watershed ER - TY - JOUR T1 - Basin-wide sedimentation changes and deglacial lake-level rise in the Hovsgol basin, NW Mongolia JF - Quaternary International Y1 - 2005 A1 - Prokopenko, A. A. A1 - Kuzmin, M. I. A1 - Wlliams, D. F. A1 - Gelety, V. F. A1 - Kalmychkov, G. V. A1 - Gvozdkov, A. N. A1 - Solotchin, P. A. AB - A study of 15 gravity cores reveals consistent patterns of lithologic change throughout the Lake Hovsgol basin. Sediments of the last glacial are composed of calcareous clayey silt with an admixture of coarse material from sand to gravel. During the last deglaciation, a basin-wide deposition of finely laminated carbonate mud took place and was ultimately succeeded by the deposition of diatomaccous clayey ooze during the entire Holocene interval. Diatom productivity in Lake Hovsgol during the early Holocene was higher than today, but declined by ca. 6.6 cal ka BP. Sedimentation rate estimates for post-glacial section range from 1.5 to over 6.7 cm/ka for different parts of Lake Hovsgol. Rates appear to have decreased in the late Holocene.The last glacial maximum (LGM) corresponded to a dramatic low stand of Lake Hovsgol on the order of 100 m below today's level, as reflected by littoral facies retrieved in cores from intermediate depths. Age dating of plant fragments in these sediments suggests that lake level started rising no later than 15.4 cal ka BP. By the beginning of the Holocene, Lake Hovsgol evolved from a low-level closed basin lake to an overflowing freshwater lake. The observed dramatic lithologic change and evidence for lake-level change suggest that Lake Hovsgol may in fact serve as a sensitive 'water gauge' in continental interior Asia and that the Hovsgol sedimentary record preserves reliable proxies for past changes in effective moisture balance in the Lake Baikal catchment area. (c) 2004 Elsevier Ltd and INQUA. All rights reserved. VL - 136 N1 - 926rlTimes Cited:51Cited References Count:16 JO - Basin-wide sedimentation changes and deglacial lake-level rise in the Hovsgol basin, NW Mongolia ER -