We present the first record of Holocene fossil insect assemblages from Central Yakutia. A stratigraphic sequence in the locality within the Vilyuy River valley is a buried oxbow. The late Holocene water body inherited an impervious stratum from the late Pleistocene. The organic layer preserved rich fossil assemblages of macrofossils including insects and other invertebrates, plants, and charcoal. The ancient flora and fauna include species that are common in Yakutia as well as those that are rare and absent in the region. The most abundant finds are leech cocoons and bogbean seeds. The macrofossils of some insects were found along with remains of their host plants. Despite the absence of intensive human land use in the area, traces of fires were recorded. The oxbow represents the environment of a floodplain wetland that developed separately from the ecosystem of the adjacent sand dunes.

The U–Pb (LA-ICP-MS) dating of detrital zircons from the Upper Cretaceous Derevyannye Gory Formation in the Novaya Sibir Island revealed that tuffites and tuffaceous sandstones contain zircons widely ranging in age from Archean to Upper Cretaceous. The weighted average age of the youngest zircon population is 88 ± 1.0 Ma, which constrains the lower age limit for sedimentation of the Derevyannye Gory Formation to the Coniacian. The clastic material was transported from the southwest and south to the north and northeast. The main source areas for the Upper Cretaceous sedimentary basin in the Novaya Sibir Island were the Upper Jurassic–Neocomian terrigenous sequences of the New Siberian–Chukotka fold area, lithotectonic complexes of the South Anyui suture, as well as the northern part of the Verkhoyansk–Kolyma fold area, and post-orogenic Aptian–Albian volcanic and plutonic rocks from the Lyakhov Islands and Svyatoi Nos Cape. Triassic terrigenous rocks of the northern Verkhoyansk region could serve as additional sources of clastics. It is also possible that the clastic material was partially supplied from the western Anjou Islands as a result of erosion of the Aptian–Lower Albian volcaniclastic–siliciclastic rocks. The Late Cretaceous zircon population is related to the Late Cretaceous explosive acid volcanism in the eastern Arctic region.

A stag-moose Cervalces sp. (Cervidae) skull with antler beams of substantially different lengths has been analyzed. This skull was found in the lower reaches of the Yana River along with the lower jaw and four vertebrae. Its geological age has been assigned to the range from the very end of Eopleistocene to the first half of the early Neopleistocene. The unequal lengths of the beams in the individual analyzed was reproduced during each antler regeneration throughout the animal's life. This may be indicative of the genetic nature of the phenomenon, even though a nongenetic cause of this disproportion is also possible, as many field observations and experimental data demonstrated frequent asymmetric disturbances in antler growth in modern deer due to injuries, especially forelimb injuries. If the genetic hypothesis is true, such an anomaly may be a manifestation of intensive form genesis, a putative adaptive reaction to the first substantial cooling of the climate in the Pleistocene. Antler beam proportions are the most valuable criterion for species and subspecies taxonomy and diagnosis of fossil moose. The case described by us does not render this trait useless, since the case is exceptionally rare. However, this genetic anomaly may be indicative of an increase in evolutionary trait variability during periods of significant climate change, which should be borne in mind when the morphology of animals that lived during such epochs is interpreted.

New plant fossils collected in 2016 from the Derevyannye Gory Formation on the New Siberia Island are studied. Thirty species of fossil plants are identified and illustrated. They belong to liverworts, ferns, ginkgoaleans, conifers and angiosperms. Sixteen of them have not beed found in the New Siberia Flora before. A new angiosperm species Dalembia (?) gracilis Herman is described. The New Siberia Flora is characterised by a moderately high taxonomic diversity, predominance of conifers and angiosperms with large-leafed platanoids and trochodendroids being the most abundant among angiosperms, by predominance of dentate-margined angiosperms and rarity of plants with entire-margined leaves, and by absence of cycadaleans and bennettitaleans. The flora existed during the Turonian–Coniacian time interval and most probably should be dated as Turonian. Plants of the New Siberia Flora experienced a warm-temperate humid climate with warm summers, mild frost-free winters and insignificant seasonality in precipitation.

— Detailed lithological, stratigraphic, and structural studies of the fold-thrust structures were conducted on New Siberia Island. We have established that the jointly deformed complexes of the Upper Cretaceous–Middle Neopleistocene are overlapped by undeformed sediments of the Upper Neopleistocene. This fact confirms the completion of the deformation process at the end of the Middle Neopleistocene. An additional argument excluding the ancient age of dislocations is the result of the fission track dating for apatites. The resulting track ages of apatites significantly exceeded the age of deformed rocks, which was reliably established by the other methods. In deformed complexes, unlithified permafrost rocks predominate. Folded structures are characterized by joint deformation of sedimentary rocks, formation ice and ice-ground, inconsistency of fold orientation and different direction of structural evolution in the northern and southern parts of the island New Siberia. Considering the correspondence of the established age of dislocations to the age of the largest Pleistocene glaciation, all these facts allow us to state that the fold-and-thrust deformations of the island New Siberia are glaciodislocations.

To estimate the age of the glaciation in the New Siberian Islands, fossils of small mammals from the Sana-Balagan site (Faddeevsky Island, Russian Eastern Arctic) have been studied. The evolutionary degree of this fauna, which indicates the age of the sediments underlying the glacial deposits, suggests that the glaciation of the New Siberian Islands began no earlier than 190–210 thousand years ago. The new biochronological data in combination with 230 Th/ 234 U dates show that the geological event in question was synchronous with the Moscow glaciation or the Moscow stage of the Dnieper glaciation (the Vychegda glaciation, the final stage of the Saalian, the final stage of the Riss, the end of the MIS 6, 180–140 thousand years ago).

In recent years, new accumulations of mammoth faunal remains have been discovered in the northern part of the Yana-Indighirka lowland. Such areas are referred to as "mammoth graveyards" since the discovery of the Berelekh complex of geoarchaeological locales. It's been determined that all of these locales contain various amounts of evidence of past human activity associated with the use of bone accumulations as a valuable raw material source (mammoth ivory). These locales indicate that humans were widely spread in Arctic Siberia during the Late Pleistocene (MIS 3 and 2). At least some of these sites could have formed as a result of ancient people hunting mammoths. In this article we discuss two newly discovered sites, which currently represent the northernmost evidence of human presence in the Arctic at the end of the Pleistocene. They were found in the Maksunuokha River valley, to the south of the Shirokostan Peninsula. The Urez-22 site (MKR/U22) is located at 71 degrees 42' N and is currently the northernmost Paleolithic site in the world. The Lake Nikita site (NKL) is situated 40 km away from Urez-22, and both sites contain numerous remains of mammoth. The NKL site material represents the earlier of the two ancient human habitation episodes. This site's age is estimated at similar to 13,800 to 13,600 years ago. The NKL site is a complete chronological and cultural "duplicate" of the Berelekh site, which points to a relatively wide spread of this culture in Northeast Asia. NewWorld implements, similar to those found at the Berelekh site and NKL, are known as the Chindadn points. At this point, they represent the only tangible evidence of the cultural connection between the materials from Northeast Asia and Northwest North America. The age of Urez-22 can be estimated at the time slice of similar to 14,900 to 13,900 years ago. Archaeological material was encountered in redeposited concentrations, created by a low-energy stream. Artifacts from Urez-22 demonstrate the spread of microblade industry, older than the early Holocene, for the first time in the Siberian Arctic. This new material indicates noticeable cultural originality of the region during the Late Paleolithic and promises success in the future search for Paleolithic sites in the Yana-Indighirka lowland. (C) 2015 Elsevier Ltd and INQUA. All rights reserved.

Major and trace element composition of the Upper Cenozoic deposits of the Chuya section (the lower reaches of the Aldan River, Central Yakutia) made up of the Middle Miocene and Neopleistocene sediments was studied as indicator of paleoclimatic conditions. It was established that primary sediments were precipitated under moderately humid conditions in the Middle Miocene and under subarid climatic conditions at relatively high sedimentation rates in the Neopleistocene. Close contents of trace elements in all lithologies suggest that the source area remained constant. Variation trends of ICV index indicate an increasing role of fluvioglacial accumulation during formation of Pleistocene beds. It was determined that the Neopleistocene is marked by a sharp change in sedimentation conditions.

In 2001, the Yana RHS archaeological site was discovered in the lower Yana river valley, Arctic Siberia. Its radiocarbon age is about 28 000 BP. While enormous amount of Pleistocene mammal bones was excavated from the site, the mammoth bones occurred at an unexpectedly low frequency. That was interpreted as an indication of the limited role of mammoths in the subsistence economy of the Pleistocene Yana people. In 2008, next to the excavation local ivory miners opened a mass accumulation of mammoth accompanied by the artifacts. About one thousand mammoth bones from at least 26 individuals, and few wooly rhinoceros, bison, horse, reindeer, and bear bones have been unearthed there. Stratigraphy and radiocarbon dating provide evidence for cultural layer of Yana RHS and the mass accumulation of mammoth to be coeval. The geology and taphonomy of Yana mass accumulation of mammoth indicate its anthropogenic nature. Discovery of the anthropogenic mass accumulation of mammoth next to the Yana site suggests a greater role of mammoth in the subsistence practices of the Pleistocene Yana people than previously thought. (C) 2011 Elsevier Ltd. All rights reserved.

The little known Achchagyi–Allaikha mass assemblage of mammoths and the well-known Berelyokh site (Lower Indigirka River, Arctic Siberia) were studied. Detailed study of the Achchagyi–Allaikha site provided ample data concerning its geology, stratigraphy, taphonomy, and the gender-age structure of the taphocoenosis. The Achchagyi–Allaikha assemblage included redeposited bones from numerous young (not less than 21) and some adult female mammoths, with limited quantities of Bison, Equus and Rangifer bones. Collagen from mammoth bones preserved at the Achchagyi–Allaikha site (n=6) was radiocarbon-dated at 12,490±80 to 12,400±60BP. At the Berelyokh site, eight mammoth bones were radiocarbon-dated at 12,720±100 to 11,900±50BP, one bison bone was dated at 12,380±150BP, and one mammoth bone dated at 36,500±1000 (redeposited bone included in younger sediments). The mass accumulations are synchronous and are similar in their mode of formation. The assemblage of mammoths in the Achchagyi–Allaikha and Berelyokh sites resulted from simultaneous deaths of a large number of animals (probably herd-family groups) in one or several seasons. It is very probable that the deposits in both cases were not of cultural origin. The formation of the burials is a direct consequence of short but strong climatic warming (Bølling Oscillation) that resulted in many unfavorable environmental conditions. Among these, the increase of snow cover and stronger spring floods were very notable. Bølling warming is a model of the large-scale Holocene event. Mass death of mammoths during the Bølling phase was a prelude to their final extinction.

A new method of permafrost dating with the cosmogenic radionuclide 36Cl is presented. In the first application, syngenetic ice wedges are dated using the ratio of 36Cl and Cl concentrations in ice as the signal. 36Cl is produced in the atmosphere by nuclear reactions of cosmic rays on argon. Stable chlorine enters the atmosphere from the oceans. Their ratio does not depend on chloride concentration in precipitations and on sublimation of snow. In situ production of 36Cl in permafrost ice via cosmic ray-induced reactions and neutron capture are calculated and the dating age limit is estimated as 3 million years. 36Cl/Cl ratios in permafrost samples from cape Svyatoy Nos (Laptev Sea coast), North-Eastern Siberia, are measured by accelerator mass spectrometry. Analysis of the first results and the calculated dates support the feasibility of the 36Cl permafrost dating method

A newly discovered Paleolithic site on the Yana River, Siberia, at 71°N, lies well above the Arctic circle and dates to 27,000 radiocarbon years before present, during glacial times. This age is twice that of other known human occupations in any Arctic region. Artifacts at the site include a rare rhinoceros foreshaft, other mammoth foreshafts, and a wide variety of tools and flakes. This site shows that people adapted to this harsh, high-latitude, Late Pleistocene environment much earlier than previously thought.

Study of glacial and marine sequences along the outer coast of Chukotka Peninsula, Bering Strait, is the basis for major revisions of the regional stratigraphy. The Val’katlen Suite at its type section at the mouth of the Enmelen River records the youngest high sea stand of the last interglaciation on Chukotka Peninsula. Marine deposits and glacial diamicton stratigraphically below the type section record, respectfully, the peak of the last interglacial (marine oxygen-isotope substage 5e) and rapid glacierization of the coastal mountains probably during substage 5d or 5b. Correlative deposits recording a similar sequence of intra-stage 5 events, but once thought to be of early and middle Pleistocene age, include the Upper and Lower Pinakul’ Suite at Cape Pinakul’ and marine deposits near the Nunyamo River on the Gulf of Anadyr, based upon amino-acid analyses, biostratigraphy, and supporting geochronology. These deposits enclose warmer-than-present faunas and floras comparible to last interglacial Pelukian marine deposits found along the coast of Alaska. The last major advance of glacial ice from Chukotka Peninsula across Anadyr Strait and onto St. Lawrence Island was likely initiated during the later part of stage 5 based on our reinterpretaion of the stratigraphy at Cape Pinakul’, near the Nunyamo River, and on northwestern St. Lawrence Island. Chukotkan ice probably reached St. Lawrence Island sometime during oxygen-isotope stage 4. Ice extend across Chukotka during the LGM was very imited.