Temporal evolution of hydrothermal processes used to be reconstructed based on chemistry and chronology of the sediments around vent fields. However particle-by-particle deposition of metalliferous sediments proximal to sulfide mounds is usually superimposed by mass-wasted events. Quantitative assessment of the relative amount of slumped sulfide debris and plume fallout matter in metalliferous sediments has been done for similar to 83 kyr on Pobeda hydrothermal site at the 17 degrees 08' N, Mid Atlantic Ridge. Three sediment cores have been investigated for uranium series isotopes and rare earth elements (REE). Their distribution patterns with an enrichment in heavy REE, a weak positive Eu, and negative Ce anomalies give evidence to the contribution of slumped sulfides from nearby edifices. The Th-230-U radiochronology dataset for distal and proximal metalliferous sediments and sulfide deposits from different Atlantic and Pacific hydrothermal sites allowed for the distinction between sediments containing oxidized sulfide debris and those derived predominantly from plume fallout oxyhydroxide particles in terms of Th-230/Fe vs. U/Fe ratios. The calculated amount of plume particulates and the sedimentation rate for each core allowed accurate temporal reconstruction of the hydrothermal activity within the Pobeda site through a novel approach.

Metalliferous sediments associated with oceanic hydrothermal systems contain various amounts of metals of a dual origin: from suspended particulate matter of an overlying plume and from weathered massive sulfide edifices. This study investigates the influence of the latter component on metal enrichment in sediments proximal to sulfide bodies for the Pobeda hydrothermal fields of the Mid-Atlantic Ridge (MAR). This region consists of three separate venting fields Pobeda-1, 2, and 3 located at different depth levels in the MAR rift valley. Hydrothermal precipitates within the site occur as massive sulfide edificies and metalliferous sediments. Detailed mineralogical and geochemical analysis of all these components revealed that a significant amount of hydrothermally-derived material in the sediments derives from overlying plume particulate superimposed by mass wasted oxidized sulfides from the nearest edifices. This last component is mostly abundant in the sediments of the deepest Pobeda-2 field, which complicates using bulk geochemistry to decipher the history of hydrothermal activity there. For the two remaining fields, Pobeda-1 and Pobeda-3, a reconstruction of vent discharge history indicates that it began almost simultaneously at the time interval recorded in core sediments. However it waned steadily at the Pobeda-3 field, whereas at Pobeda-1 field it exhibited a significant decrease in intensity and then a reverse movement upward until recently.

A geochronological and mineralogical study on the seafloor massive sulfides from the Pobeda hydrothermal cluster at the Mid-Atlantic Ridge was carried out. To improve the reliability of geochronological data, the 230Th/U ages were measured for both the bulk samples and monomineral separates. The oldest age ca. 52 kyr within Pobeda-1 and ca. 107 kyr within Pobeda–2 fields have been obtained. Then, several episodes of hydrothermal activity were identified within both fields up to ca. 0.3 kyr ago and up to ca. 4.3 kyr ago, respectively.

Here, we present new results from seismic, geological, and geochemical studies conducted in 2015–2019 in the Petrozavodsk Bay of Lake Onego, NW Russia. The aims of these investigations were to (i) to characterize the structure of Quaternary deposits and (ii) provide new evidence of modern geodynamic movements and gas-seepage in Holocene sediments. The structure of the recovered deposits was composed of lacustrine mud, silt and sands from the Holocene, limno-glacial clays (varved clays) from the Late Glacial–Interglacial Transition, and glacial deposits (till) from the Late Pleistocene. The thickness of these deposits varied in different parts of the bay. Many pockmarks created by gases escaping and reaching sediment-water interface were observed in these deposits. Such pockmarks can play a significant role in the geochemical and biological processes in the bottom sediment surface, and gases that escape might modify the physicochemical characteristics of the environment.

Recent revision of the eastern boundary of the last glaciation of Eurasia opened new perspectives in the search of the paleopedological records in the north of Eastern Europe and Western Siberia. We studied paleosol-sedimentary sequences in the Upper Volga and Middle Ob basins as a regional paleoecological record for the Late Pleistocene thermochrons. Two key sections Cheremoshnik and Belaya Gora containing MIS3 and MIS5 paleosol units and additional section Koskovo 2 with polycyclic MIS3 paleosol were investigated. Their timescale are based on C14 and U/Th datings as well as on stratigraphic and paleobotanical correlations. Macro-, meso- and micromorphological observations together with fossil insects and plant macrofossil were used as paleoenvironment proxy. MIS3 paleosols show abundant redoximorphic and cryogenic features that allow interpreting them as gleyic Cryosols. Sub-fossil insects and plant macrofossil reflect the cold climate conditions. Three incipient Ah horizons in Koskovo 2 pedocomplex point to multiple phases of pedogenesis, correlative to the MIS3 paleosol levels in different sections of the Eurasian loess belt and to the major interstadials of the Middle Pleniglacial of the NW Europe MISS paleosols are also characterized by gleyzation and peat accumulation, in this case we suppose geomorphological control on hydromorphic pedogenesis; however paleosol in Belaya Gora has clear signs of polygenesis including the phase of clay illuviation. Insect and plant remains from the lower paleosol level of the Belaya Gora section show the transition from cold (terminal phase of MIS6) to warm first, and then to a moderately cold climate (within MIS5). The obtained results contribute to understanding of soil and landscape zonality in the largest plains of Eurasia mostly during the warm phases of Late Pleistocene. (C) 2018 Elsevier Ltd and INQUA. All rights reserved.

Over recent decades a growing number of well-documented records from terrestrial last interglacial sites across central Europe have substantially improved our understanding of Eemian climate and landscape dynamics. Despite this progress, there are also large areas from which little information is available, thus constituting significant paleo-geographic gaps in the last interglacial record. Among the regions with still inadequate paleo-environmental information is the maritime-influenced area of NE-Germany at the southern margin of the Eemian (Baltic) Sea. Here we present first results from a geological investigation of a new last interglacial site, recently discovered during archaeological excavations near Beckentin (SW-Mecklenburg). The study area is located approximately 25 km to the south of the maximum MIS-2 ice limit of the Scandinavian Ice Sheet in NE-Germany, and thus lies outside the Weichselian belt of glaciation. Based on lithostratigraphic and sedimentological logging, complemented by geochemical (XRF) and palynological investigations, we divide the local succession into three sections: (1) a basal facies comprising Saalian till and associated glaciofluvial sand, overlain by section (2) consisting of a fen peat which grades into laminated organic to minerogenic mud. The organic deposits of section (2) preserve a near complete Eemian pollen inventory, encompassing pollen zones (PZ) I to VI (Menke and Tynni 1984). Above this rest poorly sorted periglacial sands (section 3) with ventifacts and evidence for cryogenic deformation. Geochronological results from Th-230/U dating of the buried organic-rich deposits at Beckentin, show that these units accumulated in a former dead ice depression between 118 +/- 7/6 ka and 114 +/- 6/5 ka during the Eemian Interglacial. High-resolution optically stimulated luminescence (OSL) profiling, undertaken with a portable luminescence reader, reveals a significant hiatus between the lacustrine fines and overlying periglacial cover sand. Five OSL ages obtained from these cover sediments and the sand-filling of an ice-wedge cast show that these strata formed between during the last glacial interglacial transition. (C) 2017 Elsevier Ltd and INQUA. All rights reserved.

Abstract Late Quaternary landscapes of unglaciated Beringia were largely shaped by ice-wedge polygon tundra. Ice Complex (IC) strata preserve such ancient polygon formations. Here we report on the Yukagir IC from Bol'shoy Lyakhovsky Island in northeastern Siberia and suggest that new radioisotope disequilibria (230Th/U) dates of the Yukagir IC peat confirm its formation during the Marine Oxygen Isotope Stage (MIS) 7a–c interglacial period. The preservation of the ice-rich Yukagir IC proves its resilience to last interglacial and late glacial–Holocene warming. This study compares the Yukagir IC to IC strata of MIS 5, MIS 3, and MIS 2 ages exposed on Bol'shoy Lyakhovsky Island. Besides high intrasedimental ice content and syngenetic ice wedges intersecting silts, sandy silts, the Yukagir IC is characterized by high organic matter (OM) accumulation and low OM decomposition of a distinctive Drepanocladus moss-peat. The Yukagir IC pollen data reveal grass-shrub-moss tundra indicating rather wet summer conditions similar to modern ones. The stable isotope composition of Yukagir IC wedge ice is similar to those of the MIS 5 and MIS 3 ICs pointing to similar atmospheric moisture generation and transport patterns in winter. IC data from glacial and interglacial periods provide insights into permafrost and climate dynamics since about 200 ka.

In recent years, deep learning as a part of the artificial intelligence theory has formed the basis for many advanced developments, such as drone, voice and image recognition technologies, and etc. The concept of deep learning is closely related to artificial neural networks. On the other hand deep learning techniques work with unmarked data. For this reason, deep learning algorithms show their effectiveness in face recognition. But there are a number of difficulties related to implementation of deep learning algorithms. Deep learning requires a large amount of unmarked data and long training. In this presentation a new algorithm for automatic selection of face features using deep learning techniques based on autoencoders in combination with customized loss functions to provide high informativeness with low within-class and high between-class variance is proposed. The multilayer networks of feed forward type are used. The extracted features are used for face classification. The performance of the proposed system for processing, analyzing and classifying persons from face images is compared with that of state-of-art algorithms.

The Eemian Interglacial sequence was explored in the gravel pit 'Neubrandenburg-Hinterste Muhle' near Neubrandenburg (NE Germany). The sequence is situated in a former kettle hole depression between underlying Late Saalian till (s. str. Warthe) covered by a Late Weichselian till. Today still visible a 3 m long and max. 2 m wide profile is located on the edge of the former Eemian depression. The limnic sedimentation began during the Late Saalian in a landscape characterized by open herbaceous vegetation. Cool, clear and calcium carbonate-rich lake water dominated, inhabited by Characeae that indicates a presence of stonewort meadows, most typical of waters up to 10 m in depth. The beginning of the Eemian Interglacial succession was characterized by a dominance of scarce birch forest followed by pine forest. The beginning of the mesocratic phase of the Eemian was characterized by the appearance of warm climate indicators and by the development of thermophilic forest communities dominated by oak forest with the appearance of warm climate indicators. The ensuing climate optimum was defined by the encroachment of hazel-oak forest and later by mixed deciduous forest. Limnic sedimentation ceased in the basin during this phase and the end of predominantly limnic conditions is marked by a decrease in the frequency of aquatic plants and an increase in the amount of brown mosses. During the interglacial optimum mixed forests reigned. This phase bears a record of oligotrophication leading to transition mire and raised bog and the aquatic plants vanished. The depression gradually became shallower and was overgrown by a forest cover. During the telocratic phase of the Eemian, communities with pine, birch and fir spread. The end of the interglacial was characterized by a disappearance of the riparian forest and a sporadic appearance of reedswamp plants. At the beginning of the Early Weichselian, a deterioration of climatic conditions resulted in the formation of widespread heaths on acid soils and trees disappeared. In the studied basin the water level fluctuated. The Hinterste Muhle sequence shows the development of a small kettle hole lake and its transformation to an overgrowing mire, including terrestrialization processes, during the Eemian Interglacial. The U/Th data obtained for five samples from the upper part of the studied profile, which have been analyzed by the TSD technique, has yielded an age of 116 +/- 13/10 kyr. This date reflects the classification into the second half of the Eemian Interglacial and the Early Weichselian for the upper part of peat formation. (C) 2017 Elsevier Ltd and INQUA. All rights reserved.

A tracking system using a bank of adaptive linear filters is proposed. Tracking is carried out by means of multiple target detections. The linear filters are designed from multiple views of a target using synthetic discriminant functions. For each view an optimum filter is derived from noisy reference image and disjoint background model. An iterative algorithm is used to improve the performance of the synthesized filters. The number of filters in the bank can be controlled to guarantee a prescribed tracking accuracy. Computer simulation results show that the proposed algorithm is able to precisely track a target.

Layered ferromanganese crusts collected by dredge from a water depth range of 2770 to 2200m on Mendeleev Ridge, Arctic Ocean, were analyzed for mineralogical and chemical compositions and dated using the excess 230Th technique. Comparison with crusts from other oceans reveals that Fe-Mn deposits of Mendeleev Ridge have the highest Fe/Mn ratios, are depleted in Mn, Co, and Ni, and enriched in Si and Al as well as some minor elements, Li, Th, Sc, As and V. However, the upper layer of the crusts shows Mn, Co, and Ni contents comparable to crusts from the Atlantic and Indian Oceans. Growth rates vary from 3.03 to 3.97mm/Myr measured on the uppermost 2mm. Mn and Fe oxyhydroxides (vernadite, ferroxyhyte, birnessite, todorokite and goethite) and nonmetalliferous detrital minerals characterize the Arctic crusts. Temporal changes in crust composition reflect changes in the depositional environment. Crust formation was dominated by three main processes: precipitation of Fe-Mn oxyhydroxides from ambient ocean water, sorption of metals by those Fe and Mn phases, and fluctuating but large inputs of terrigenous debris.

The problem of consistent aligning of 3D point data is known registration task. The most popular registration algorithm is the Iterative Closest Point (ICP) algorithm. One of the main steps of the ICP algorithm is matching. We find a matching in at first time on the basis of the geometric similarity of individual groups of points. It allows to get a good first approximation of the required transformation, even for big angle rotations, translations, scaling and noisy data. The step of the error minimization is performed for an arbitrary affine transformation.

The iterative closest point (ICP) algorithm is one of the most popular approaches to shape registration. The algorithm starts with two point clouds and an initial guess for a relative rigid-body transformation between them. Then it iteratively refines the transformation by generating pairs of corresponding points in the clouds and by minimizing a chosen error metric. In this work, we focus on accuracy of the ICP algorithm. An important stage of the ICP algorithm is the searching of nearest neighbors. We propose to utilize for this purpose geometrically similar groups of points. Groups of points of the first cloud, that have no similar groups in the second cloud, are not considered in further error minimization. To minimize errors, the class of affine transformations is used. The transformations are not rigid in contrast to the classical approach. This approach allows us to get a precise solution for transformations such as rotation, translation vector and scaling. With the help of computer simulation, the proposed method is compared with common nearest neighbor search algorithms for shape registration.

Hydrothermal processes and seafloor massive sulfide (SMS) deposits have different characteristics at fast and slow spreading mid-ocean ridges. One such parameter is the age of a SMS deposit, which differs by 1-2 orders of magnitude between the fast spreading East Pacific Rise (EPR) and the slow spreading Mid-Atlantic Ridge (MAR). The large collection of SMS samples dated from the 18 hydrothermal fields of the northern equatorial part of the Mid-Atlantic Ridge (194 samples) demonstrates a relatively old average age of hydrothermal fields here (similar to 66 ka) with the oldest one estimated as ca. 223 ka (Peterburgskoye field). Based on geochronological data it was confirmed that hydrothermal discharge has an episodic character: active and inactive periods of the SMS formation alternate. The distribution of events at all hydrothermal fields demonstrates that maximum activity occurred at 38-35, 30-20, and 8-2 ka and increased with time. Based on statistical analyses, dating variations can be explained as a superposition of several periods of activity with the duration of similar to 15, 10 and 5 ka. Relationship between the age and distance from the axial rift zone as well as between the age and aerial distribution is different for SMS deposits hosted by basalts and by gabbro-peridotites depending on their geological setting on the particular MAR segment. This difference can be explained by a variety of hydrothermal processes determined by "tectonic" or "magmatic" segment evolution and symmetrical or asymmetrical mode of accretion (Escartin et al., 2008). (C) 2016 Elsevier B.V. All rights reserved.

Dating of late Pleistocene sediments remains a challenge in Quaternary chronology, due to the inherent limitations of the 14C and OSL methods. The 230Th/U radioisotope method is theoretically applicable to wood remnants contained within Pleistocene sediments, but few results have been pub-lished to date and in some cases, the age data are ambiguous. This paper tests the use of 230Th/U da-ting of fossil wood remnants dated earlier by radiocarbon method. We analyzed a buried larch trunk from a well-known stump layer in the Lipovka outcrop, located on the Tobol River bank in Western Siberia. The stump layer is preserved in situ. We determined the specific activities of U and Th iso-topes in samples of both modern pine and fossil larch and proposed a model for the incorporation and distribution of U and Th in the buried wood during aging. Complications related with the recognition of geochemical closed systems with respect to U did not allow obtaining completely reliable 230Th/U age. Despite this the 230Th/U age obtained for the uppermost heartwood sample and 14C ages of the same larch trunk and other wood and vegetation remnants gave consistent results. These age data in combination with previously obtained pollen data testify the stump layer formation during the late cooling stage of the Karganian time (MIS-3, Middle Valdai).

Ice Complex deposits (locally known as the Buchchagy Ice Complex) are exposed at both coasts of the East Siberian Dmitry Laptev Strait and preserved below the Yedoma Ice Complex that formed during MIS3 and MIS2 (Marine Isotope Stage) and lateglacial-Holocene thermokarst deposits (MIS1). Radioisotope disequilibria (Th-230/U) of peaty horizons date the Buchchagy Ice Complex deposition to 126 + 16/-13 kyr and 117 + 19/-14 kyr until 98 +/- 5 kyr and 89 +/- 5 kyr. The deposit is characterised by poorly sorted medium-to-coarse silts with cryogenic structures of horizontal ice bands, lens-like, and lens like reticulated segregation ice. Two peaty horizons within the Buchchagy Ice Complex and syngenetic ice wedges (2-4 m wide, up to 10 m high) are striking. The isotopic composition (delta O-18, delta D) of Buchchagy ice-wedge ice indicates winter conditions colder than during the MIS3 interstadial and warmer than during MIS2 stadial, and similar atmospheric winter moisture sources as during the MIS2 stadial. Buchchagy Ice Complex pollen spectra reveal tundra-steppe vegetation and harsher summer conditions than during the MIS3 interstadial and rather similar vegetation as during the MIS2 stadial. Short-term climatic variability during MIS5 is reflected in the record. Even though the regional chronostratigraphic relationship of the Buchchagy Ice Complex to the Last Interglacial remains unclear because numerical dating is widely lacking, the present study indicates permafrost (Ice Complex) formation during MIS5 sensu lato, and its preservation afterwards. Palaeoenvironmental insights into past climate and the periglacial landscape dynamics of arctic lowlands in eastern Siberia are deduced from the record. (C) 2015 Elsevier Ltd. All rights reserved.

A variety of studies of the re-examined (new exposure) Late Pleistocene key section Cheremoshnik (East European plain, middle of the Volga Basin of Yaroslavl) was conducted on a new methodological level using modern methods. For the first time, a series of paleosols (MIS5-MIS1) from the section offering significant information in regard to chronostratigraphy and landscape evolution have been studied in detail and dated. An excavation similar to 7 m deep reveals a soil-sediment stratum which formed over the course of similar to 115 ka in an accumulative beam-like terrace and consists of five lithological layers and six pedos-tratigraphical units.The base of the section was determined to be an Early Mikulino peat-dark humus paleosol which marked incipient subaerial pedogenesis on the Moscow (Riss II) moraine and was covered with a thickness of gyttja with a peat horizon (Histosol) which had formed 114-115 ka and was reliably dated using uranium-thorium dating. The following paleosols were successfully identified within the series of weak stone gullied-channel sediments within the Valdai (Wurm) thickness (from bottom to top): (1) Bryansk paleosol (MIS3) - Gleysol - with three pedogenesis rhythms; (2) Trubchevskaya paleosol - Gleyic Turbic Cryosol (MIS2) and (3) pedosediment formed at the end of the Bolling interstadial (MIS2). Terminal Pleistocene formations are marked with a gravelly stratum on the section's surface formed during the Preboreal period. Recent Regosol formed on loess-like loam deposits was identified at the top of the whole soil-sediment stratum. The C-14 age of the paleosol humus varied between 27,500 and 11,400 cal. BP. The paleosols represent the northernmost occurrence of MIS5-MIS2 fossil soil in Europe, dominated by features of gleyzation, cryogenic aggregation, cracking, and humus and peat formation.Pollen analysis results allowed estimation of changes in vegetation cover, climatic conditions and the age of deposit sedimentation for the period from the Moskow Late Glacial to the Valdai Late Glacial and early Holocene times. Successive stages in the development of vegetation, high contents of alder and hazel pollen and the climax and distinct appearance of broadleaf trees relate the formation of biogenic sediments (LPAZ 2-6) in the Cheremoshnik section to the Mikulino Interglacial. Valdai (MIS4-MIS2) glacial sediment is absent within the investigated area. (C) 2014 Elsevier Ltd and INQUA. All rights reserved.

For images with sharp changes of intensity, the appropriate regularization is based on variational functionals. In order to minimize such a functional, the gradient descent approach can be used. In this paper, we analyze the performance of the gradient descent method in the frequency domain and show that the method converges to the sum of the original undistorted function and the kernel function of a linear distortion operator.

A geochronological and geochemical study on 10 samples of seafloor massive sulfides (SMS) from the inactive Peterburgskoye hydrothermal field at the Mid-Atlantic Ridge (MAR) was carried out. The 230Th/U ages of the SMS are the oldest for the Quaternary hydrothermal ores ever found at the ocean floor. According to them the hydrothermal activity at Peterburgskoye field started at least 170 ka and continued down to 63 ka. The oldest hydrothermal ores from this field consist mainly of pyrite and chalcopyrite and have geochemical properties typical for SMS associated with basalts.