TY  - JOUR
A1  - Syrykh, Lydmila S.
A1  - Nazarova, Larisa B.
A1  - Herzschuh, Ulrike
A1  - Subetto, D. A.
A1  - Grekov, I. M.
T1  - Reconstruction of palaeoecological and palaeoclimatic conditions of the Holocene in the south of the Taimyr according to an analysis of lake  sediments
JF  - Contemporary Problems of Ecology
N2  - A sediment core from Khatanga-12 Lake (Taimyr Peninsula, Krasnoyarsk krai) has been studied. The 131.5-cm-long core covers ca. 7100 years of sedimentation. Chironomid analysis, a qualitative reconstruction of the paleoenvironment in the region, and a quantitative reconstruction of variations of the mean July air temperature and in the water depth of the lake have been performed using Northern Russia chironomid-inferred mean July temperature models (Nazarova et al., 2008, 2011, 2015). Khatanga-12 Lake was formed during the Middle Holocene warming as a result of thermokarst processes. The development of the lake ecosystem at different stages of its development was influenced by climatic and cryolithogenic factors. The Middle Holocene warming, which occurred around 7100-6250 cal. years BP, activated thermokarst processes and resulted in the formation of the lake basin. Later, between 6250 and 4500 cal. years BP, a period of cooling took place, as is proved by chironomid analysis. The bottom sediments of the lake during this period were formed by erosion processes on the lake shores. The reconstructed conditions were close to the modern after 2500 cal. years BP.
KW  - Chironomidae
KW  - paleolimnology
KW  - Holocene
KW  - climate reconstructions
KW  - Russian Arctic region
KW  - Khatanga
Y1  - 2017
U6  - https://doi.org/10.1134/S1995425517040114
SN  - 1995-4255
SN  - 1995-4263
VL  - 10
SP  - 363
EP  - 369
PB  - Pleiades Publ.
CY  - New York
ER  - 
TY  - JOUR
A1  - Owen, Richard Bernhart
A1  - Muiruri, Veronica M.
A1  - Lowenstein, Tim K.
A1  - Renaut, Robin W.
A1  - Rabideaux, Nathan
A1  - Luo, Shangde
A1  - Deino, Alan L.
A1  - Sier, Mark J.
A1  - Dupont-Nivet, Guillaume
A1  - McNulty, Emma P.
A1  - Leet, Kennie
A1  - Cohen, Andrew
A1  - Campisano, Christopher
A1  - Deocampo, Daniel
A1  - Shen, Chuan-Chou
A1  - Billingsley, Anne
A1  - Mbuthia, Anthony
T1  - Progressive aridification in East Africa over the last half million years and implications for human evolution
JF  - Proceedings of the National Academy of Sciences of the United States of America
N2  - Evidence for Quaternary climate change in East Africa has been derived from outcrops on land and lake cores and from marine dust, leaf wax, and pollen records. These data have previously been used to evaluate the impact of climate change on hominin evolution, but correlations have proved to be difficult, given poor data continuity and the great distances between marine cores and terrestrial basins where fossil evidence is located. Here, we present continental coring evidence for progressive aridification since about 575 thousand years before present (ka), based on Lake Magadi (Kenya) sediments. This long-term drying trend was interrupted by many wet-dry cycles, with the greatest variability developing during times of high eccentricity-modulated precession. Intense aridification apparent in the Magadi record took place between 525 and 400 ka, with relatively persistent arid conditions after 350 ka and through to the present. Arid conditions in the Magadi Basin coincide with the Mid-Brunhes Event and overlap with mammalian extinctions in the South Kenya Rift between 500 and 400 ka. The 525 to 400 ka arid phase developed in the South Kenya Rift between the period when the last Acheulean tools are reported (at about 500 ka) and before the appearance of Middle Stone Age artifacts (by about 320 ka). Our data suggest that increasing Middle- to Late-Pleistocene aridification and environmental variability may have been drivers in the physical and cultural evolution of Homo sapiens in East Africa.
KW  - Quaternary
KW  - paleoclimate
KW  - paleolimnology
KW  - hominins
KW  - Lake Magadi
Y1  - 2018
U6  - https://doi.org/10.1073/pnas.1801357115
SN  - 0027-8424
SN  - 1091-6490
VL  - 115
IS  - 44
SP  - 11174
EP  - 11179
PB  - National Academy of Sciences
CY  - Washington
ER  -