| 1. |
- Sikora, M., et al.
(författare)
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The population history of northeastern Siberia since the Pleistocene
- 2019
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 570:7760
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Tidskriftsartikel (refereegranskat)abstract
- Northeastern Siberia has been inhabited by humans for more than 40,000 years but its deep population history remains poorly understood. Here we investigate the late Pleistocene population history of northeastern Siberia through analyses of 34 newly recovered ancient genomes that date to between 31,000 and 600 years ago. We document complex population dynamics during this period, including at least three major migration events: an initial peopling by a previously unknown Palaeolithic population of 'Ancient North Siberians' who are distantly related to early West Eurasian hunter-gatherers; the arrival of East Asian-related peoples, which gave rise to 'Ancient Palaeo-Siberians' who are closely related to contemporary communities from far-northeastern Siberia (such as the Koryaks), as well as Native Americans; and a Holocene migration of other East Asian-related peoples, who we name 'Neo-Siberians', and from whom many contemporary Siberians are descended. Each of these population expansions largely replaced the earlier inhabitants, and ultimately generated the mosaic genetic make-up of contemporary peoples who inhabit a vast area across northern Eurasia and the Americas.
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| 2. |
- Etu-Sihvola, H., et al.
(författare)
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The dIANA database - Resource for isotopic paleodietary research in the Baltic Sea area
- 2019
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Ingår i: Journal of Archaeological Science. - : Elsevier BV. - 2352-409X .- 2352-4103. ; 24, s. 1003-1013
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Tidskriftsartikel (refereegranskat)abstract
- Paleodietary research is a complex field, which requires large sets of background information. Owing to increasing interest and activity in the field, a substantial amount of archaeological isotope baseline data exist for Northern Europe, consisting mainly of animal bone collagen delta C-13, delta N-15, and delta S-34 values. However, the data are scattered into dozens of publications written in multiple languages and less-accessible formats, making the data laborious to use. This article presents the first compilation work of this data, the open access dIANA database (Dietary Isotopic baseline for the Ancient North; https://www.oasisnorth.org/diana.html), aimed to support (paleo)dietary research in the Baltic Sea area. The database work is complemented with new analyses of archaeological and (pre-)modern domestic and wild fauna from Finland and Russia broadening the selection of analysed species in the database. We present and discuss data examples, which on one hand show existing spatiotemporal isotope patterns related to diet and differences in the environmental carbon sources and on the other, also visualize the current status of baseline research and the need for further analyses in the circum-Baltic area.
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| 3. |
- Yu, Changxun, et al.
(författare)
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Iron behavior in a northern estuary: Large pools of non-sulfidized Fe(II) associated with organic matter
- 2015
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Ingår i: Chemical Geology. - : Elsevier BV. - 0009-2541 .- 1872-6836. ; 413, s. 73-85
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Tidskriftsartikel (refereegranskat)abstract
- The estuaries of the Northern Baltic Sea (Gulf of Bothnia) receive an abundance of diagenetically reactive catchment-derived Fe, which is to a large degree complexed with organicmatter or present as Fe (hydr-) oxides. However, our understanding of sedimentary Fe diagenesis in these estuaries is limited. To address this limitation, the present study examines Fe geochemistry in a 3.5-m-thick estuarine benthic mud layer and three samples of suspended particulate matter of a catchment on the eastern Gulf of Bothnia. The age-depth model of the mud, constructed on the basis of sedimentary features as well as Cs-137 and aquatic plant C-14 determinations, revealed a high average rate of sedimentation (5 cm . yr(-1)) for the upper mud unit (0-182.5 cm, corresponding to 1973-2011), in response to intensive land-use (ditching) in the catchment since the 1960s and 1970s. The intensive land-use has resulted in a strong increase in the Fe accumulation rates, but has not caused a recognizable impact on the diagenetic processes of Fe including features such as degree of sulfidization and solid-phase partitioning. Iron X-ray absorption spectroscopy (XAS) indicated that in the suspended particulate matter, large proportions (47-58%) of Fe occur as Fe(III)-organic complexes and 2-line ferrihydrite. In the mud, the former is completely reduced, and reactive Fe (defined via extraction with 1 MHCl) was high throughout (52-68%, median = 61%) and strongly dominated by Fe(II). This reactive Fe(II) pool was sulfidized to only a limited extent (degree of reactive sulfidization = 11-26%, median = 17%). This phenomenon is attributed to the brackish-water conditions (i.e. low in sulfate) and the abundant input of reactive Fe(III) from the catchment, leading to a surplus of dissolved Fe2+ over dissolved sulfide in the sediment. The low availability of dissolved sulfide, in combination with the high average sedimentation rate, limits the formation of intermediate reduced sulfur compounds at the water-sediment interface, thereby retarding the conversion of FeS into pyrite (ratios of pyrite-S to AVS = 0.17-1.73, median = 0.37; degree of pyritization = 1-17%, median = 3%). Iron XAS, in combination with wavelet transform analysis, of representative sediment segments from the upper and lower mud units suggests that the non-sulfidized Fe(II) pool is dominantly complexed by organic matter, with the remaining Fe(II) occurring as mackinawite. This has implications for the understanding of early Fe diagenesis in settings with a high input of organic matter and relatively low supply of sulfate. (C) 2015 Elsevier B.V. All rights reserved.
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