1,721,045 research outputs found
Fish and fishing in Holocene Cis-Baikal, Siberia: a review
No full textEastern Siberia's Lake Baikal and its tributaries are productive fisheries, and the region's Holocene archaeological sites confirm that this is a long-standing phenomenon. Recent zooarchaeological investigations of sites here allow Holocene fishing practices to be examined in more detail than was previously possible. Along much of the lake's coast, bathymetry is very steep and the water very cold; here fishing appears to have been supplemental to other subsistence practices such as sealing and ungulate hunting. In shallower areas, waters were warmer and supported very productive fisheries for littoral species, perhaps through the use of nets or traps. The region's rivers offered their own resident species but also were used as spawning grounds by some lake fishes. The lake's littoral fisheries, while productive, likely produced fish throughout the year and did not require complex labor organization to be effectively used. Some sections of the region's rivers, particularly those that were spawning grounds for some lake fishes, may have required more complex sociopolitical organization to be exploited efficiently. Such fish runs were short-lived and the best fishing places likely were spatially restricted. This potentially created the need for pools of labor, required organization of harvesting and processing, and generated surpluses that could be stored and manipulate
Late Quaternary geology of the Tunka rift basin (Lake Baikal region), Siberia, Russia
No full textThe objective of this research is to obtain a better understanding of the evolution of the Tunka rift basin, part of the Baikal rift zone, and how it relates to the overall geologic history of the region, particular for the Quaternary period. The tectonically active Baikal rift zone began forming over 50 million years ago and continues today. In the Tunka basin, during the Oligocene and Middle Pliocene, relatively weak tectonic disturbances took place and thick accumulations of organic-rich sands, silts, and clays were deposited in lacustrine–marshy subtropical environments. Tectonism increased between the Miocene and Pliocene and thick units of coarse alluvium and floodplain sediments were deposited. During the Late Pliocene–Quaternary, tectonism formed basins that are now filled with a variety of coarse clastic materials. Early and Middle Pleistocene sediments are poorly exposed, covered by widespread Late Pleistocene deposits. Three Late Pleistocene sedimentary facies dominate: boulder–pebble gravels (proluvial, glacial fluvial, and alluvial sediments), alluvial sand, and loess-like sediments with associated slope deposits altered by post-depositional wind erosion. The relationship between these complexes, including radiocarbon and other chronological data and fauna and flora remains, indicates that they began forming c. 70 000 yr ago. Paleosols, glacial deposits and cryogenic material indicate that at times the climate was cool or cold. During the early Late Pleistocene renewed tectonism took place causing increased deposition of coarse sediments. The middle Late Pleistocene deposits consist mostly of sandy, floodplain alluvium. By the end of the Late Pleistocene–Holocene, alluviation was reduced and replaced by a high degree of erosion and aeolian depositio
Evaluating the transitional mosaic: frameworks of change from Neanderthals to Homo sapiens in eastern Europe
No full textDefining varying spatial and temporal analytical scales is essential before evaluating the responses of late Neanderthals and early Homo sapiens to Abrupt Environmental Transitions (AETs) and environmental disasters for the period 130–25 ka. Recent advances in addressing the population histories and interactions (using both genetic and archaeological evidence) of Neanderthals and H. sapiens have encouraged consideration of more subtle dynamics of archaeological change. Descriptions of change based on methodologies pioneered some 160 years ago are no longer adequate to explain the patterning we now see in the record. New chronological results, using multiple dating methods, allow us to begin to unpick the spatial and temporal scales of change. Isochronic markers (such as specific volcanic eruptions) can be used to create temporal frameworks (lattices), and results from other dating techniques compared against them. A combination of chronological lattices and direct dating of diagnostic artefacts and human fossils permits us, for the first time, to have greater confidence in connecting human (recent hominin) species and their behavioural responses to environmental conditions, and in quantifying scales of change over time and space (time-transgression). The timing of innovations, particularly those in bone, antler and ivory, can be directly quantified and tested, and used to re-evaluate longstanding models of cultural change. This paper also uses these new chronologies to explore the ecologies of late Neanderthals and early H. sapiens: their population densities, mobilities, resources exploited and possible interactions. Environmental productivity estimates are used to generate new questions of potential population densities and mobilities, and thus the sensitivity of these groups to environmental perturbations. Scales and intensities of effect on environments from natural disasters and AETs (notably Heinrich Events and the Campanian Ignimbrite eruption) are defined as a scale from “proximal” to “distal,” with local conditions (topographic shelter or exposure) serving to intensify or mitigate those effect
Arshan palaeoseismic feature of the Tunka fault (Baikal rift zone, Russia)
No full textThe traditional concept of the rift development of flank depressions in the Baikal rift zone is now doubted in view of some indicators for compression deformations identified by the seismogeological and geodetic methods. Besides, the paleoseismological investigations revealed seismogenic strike-slips and reverse faults in the Tunka fault zone that is a major structure-controlling element of the Tunka rift depression. However, a detailed study of the upslope-facing scarp in the Arshan paleoseismogenic structure zone has shown that its formation might be due to rift mechanism of basin formation. Age estimation has been made for the previously unknown pre-historic earthquake whose epicentral area coincides with the western flank of the Arshan paleoseismogenic structure. Judging from previously determined ages of paleoearthquakes, the mean recurrence period for faulting events on the central Tunka fault is 2780–3440 years
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Discovery of Holocene millennial climate cycles in the Asian continental interior: Has the sun been governing the continental climate?
No full textWe conducted a high-resolution study of a unique Holocene sequence of wind-blown sediments and buried soils in Southern Siberia, far from marine environment influences. This was accomplished in order to assess the difference between North Atlantic marine and in-land climate variations. Relative wind strength was determined by grain size analyses of different stratigraphic units. Petromagnetic measurements were performed to provide a proxy for the relative extent of pedogenesis. An age model for the sections was built using the radiocarbon dating method. The windy periods are associated with the absence of soil formation and relatively low values of frequency dependence of magnetic susceptibility (FD), which appeared to be a valuable quantitative marker of pedogenic activity. These events correspond to colder intervals which registered reduced solar modulation and sun spot number. Events, where wind strength was lower, are characterized by soil formation with high FD values. Spectral analysis of our results demonstrates periodic changes of 1500, 1000 and 500 years of relatively warm and cold intervals during the Holocene of Siberia. We presume that the 1000 and 500 year climatic cycles are driven by increased solar insolation reaching the Earth surface and amplified by other still controversial mechanisms. The 1500 year cycle associated with the North Atlantic circulation appears only in the Late Holocene. Three time periods — 8400–9300 years BP, 3600–5100 years BP, and the last ~ 250 years BP — correspond to both the highest sun spot number and the most developed soil horizons in the studied sections
A Holocene molluscan succession from floodplain sediments of the upper Lena River (Lake Baikal region), Siberia
No full textFloodplainsediments of the upperLenaRiver near Basovo in south-central Siberia have yielded the most detailed Holocenemolluscansuccession yet reported from the entire eastern Palaearctic. Over 72,500 shells from at least 28 species of terrestrial and 23 species of freshwater mollusc have been recovered, an abundance and diversity far higher than previously reported from the region. The molluscan assemblages are dominated by land snails, especially members of the genus Vallonia, represented by five species including Vallonia tenuilabris and two poorly known species Vallonia kamtschatica and Vallonia cf. chinensis. Other noteworthy species recovered include Gastrocopta theeli, Carychium pessimum, Vertigo extima (southernmost record), Vertigo microsphaera and the first Asian records of three other taxa (Vertigo geyeri, Vertigo genesii and Vertigo parcedentata). Illustrations are provided for the critical species, since opinions differ about the status of various taxa and the correct names that should be used. The molluscan assemblages show clear successional trends during the early to mid-Holocene, reflecting episodes of dryness/wetness on the floodplain. Drier conditions at ca 6350 14C yr BP coincide with major changes in the archaeological record seen at other sites in the region but it remains unclear whether the two are linked. A prominent charcoal-rich horizon dated to ca 2800 14C yr BP marks a burning event in the catchment, which resulted in a two-fold increase in sediment accumulation rate. Remains of small mammals occurred throughout the sequence including a tooth of Microtus cf. maximowiczii, possibly the first occurrence of Ungar vole west of LakeBaikal. The faunal analyses have been integrated with a detailed pedological study of the sedimentary profile and a chronology was obtained by means of 12 AMS radiocarbon dates. This study provides the first detailed palaeoecological information relating to Holocenemolluscan assemblages from the Cis-Baikalregion and lays the foundation for future work in the eastern Palaearcti
The early Upper Palaeolithic of the Tunka rift valley, Lake Baikal region, Siberia
No full textThis paper presents recent results of geological and archaeological research at Late Pleistocene sites in the Tunka rift valley (Lake Baikal region, southern Siberia), including new radiocarbon dating of the Palaeolithic layers at Bol'shoi Zangisan, Slavin Yar and Tuyana. The sites range in age from ?26 to 45 ka 14C BP and represent the earliest evidence of human habitation in the area. Numerous faunal remains have also been identified in the archaeological horizons from which palaeoenvironmental conditions can be reconstructed. These data also provide important new information about the age, context, and development of an early microlithic industry in the Tunka-Pribaikal'e region during the late Karginskii interstadial, attributed to Marine Isotope Stage 3 (MIS3). Although further research is needed to verify the reconstructed site age models, archaeological evidence recovered at Tuyana and Bol'shoi Zangisan represent among the oldest known occurrences of microcore-microblade technology in North Asi
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