New data on the most ancient early quaternary glaciation in Gornyi Altai

The data presented in this work introduce substantial corrections into the Upper Cenozoic stratigraphy and geological history of Gornyi Altai. They provide evidence for the most ancient Early Pleistocene glaciation in this region. This follows from finds of faceted boulders buried in the Bashkaus Formation. Pale-omagnetic investigations revealed in the latter a wide zone of negative polarity corresponding to the Matuyama Chron in the magnetostratigraphic scale and made it possible to correlate the formation with the Lower Pleistocene in the standard stratigraphic scale. It is shown that global cooling at the beginning of the Quaternary Period stimulated development of glaciation on the southern slope of the Kuraiskii Range exceeding in size its present-day scale.     

Geodynamic models and their application in the combined interpretation of geological and geophysical data (a review)

The paper presents a review of investigations in the field of the theory and practice of the interpretation of geological and geophysical data with geodynamic models that were carried out mainly by researchers of the Institute of Physics of the Earth, Russian Academy of Sciences. Evolutionary models of platform structures, passive continental margins, rift zones, and orogens are examined. The review presents formulations of inverse problems and results of interpretation for various regions, including sedimentary basins of the East European Platform, Atlantic Ocean margins, the Caucasus, the South Urals, and others.     

A computer-aided framework for subsurface identification of white shark pigment patterns

Subsurface video footage can be used as a successful identification tool for various marine organisms; however, processing of such information has proven challenging. This study tests the use of automated software to assist with photo-identification of the great white shark Carcharodon carcharias in the region of Gansbaai, on the south coast of South Africa. A subsurface photo catalogue was created from underwater video footage. Single individuals were identified by using pigmentation patterns. From this catalogue, two images of the head for each individual were inserted into automated contour-recognition software (Interactive Individual Identification System Beta Contour 3.0). One image was used to search the database, the other served as a reference image. Identification was made by means of a contour, assigned using the software to the irregular border of grey and white on the shark's head. In total, 90 different contours were processed. The output provided ranks, where the first match would be a direct identification of the individual. The method proved to be accurate, in particular for high-quality images where 88.24% and 94.12%, respectively, were identified by two independent analysts as first match, and with all individuals identified within the top 10 matches. The inclusion of metadata improved accuracy and precision, allowing identification of even low-quality images.     

Environmental changes in the northern Altai during the last millennium documented in Lake Teletskoye pollen record

A high-resolution pollen record from Lake Teletskoye documents the climate-related vegetation history of the northern Altai Mountain region during the last millennium. Siberian pine taiga with Scots pine, fir, spruce, and birch dominated the vegetation between ca. AD 1050 and 1100. The climate was similar to modern. In the beginning of the 12th century, birch and shrub alder increased. Lowered pollen concentrations and simultaneous peaks in herbs (especially Artemisia and Poaceae), ferns, and charcoal fragments point to colder and more arid climate conditions than before, with frequent fire events. Around AD 1200, regional climate became warmer and more humid than present, as revealed by an increase of Siberian pine and decreases of dry herb taxa and charcoal contents. Climatic conditions were rather stable until ca. AD 1410. An increase of Artemisia pollen may reflect slightly drier climate conditions between AD 1410 and 1560. Increases in Alnus, Betula, Artemisia, and Chenopodiaceae pollen and in charcoal particle contents may reflect further deterioration of climate conditions between AD 1560 and 1810, consistent with the Little Ice Age. After AD 1850 the vegetation gradually approached the modern one, in conjunction with ongoing climate warming.     

Drainage evolution in south and east England during the Pleistocene

Two major river systems operated in southern and eastern England throughout the Pleistocene: the river Thames and the Solent river. Both rivers are axial streams of comparable size draining major basinal structures comprising similar Tertiary and Mesozoic rocks. Although the modem Thames flows broadly W-E in the London Basin, upstream of Reading it flows from the north to drain the south Midlands. It was diverted to its present course through London by glaciation in the Anglian (Elsterian) before which it flowed across East Anglia into the southem North Sea. The Solent river no longer exists since most of its course was drowned by eustatic sea-level rise during the Flandrian Stage (Holocene). Previously, it flowed eastwards across SE Dorset and S Hampshire as an extension of the modem river Frome in the Hampshire Basin. During periods of low sea-level (cold stages) it was a tributary of the 'Channel River'. Fluvial aggradations provide evidence of the former courses of these substantial rivers and their tributaries. The facies and sedimentary structures indicate that the bulk of the deposits in both systems accumulated in braided river environments under periglacial climates. Fossiliferous sediments provide biostratigraphical frameworks. During temperate periods the rivers adopted singlethread courses. Evolution of both rivers reflect their responses to climatic change, local geological structure and long-term tectonic activity. Both rivers are undoubtedly of considerable antiquity, their records potentially extend from the Early Pleistocene or Late Pliocene, but they may have originated in the early Tertiary.     

Debatable aspects of initial human colonization of Siberia and age of the Karama site in the Altai Mountains

Debatable aspects of age, stratigraphic position, and natural conditions of the oldest stratified Early Paleolithic Karama site in the Altai Mountains are critically revised. The extensive geological, stratigraphic, and paleontological data allow the sufficiently well-substantiated assumption that accumulation of the Karama Formation and existence of the Early Paleolithic Karama site correspond to a long period of climate warming in the Early Pleistocene correlated with the Tiglian of northwestern Europe lasting from 2.23 to 1.59 Ma. The age model proposed for the formation of the Quaternary sequence in the Anui River valley, which includes the artifact-containing deposits of the Karama site, seems to be the most probable one proceeding from interpretation of available data on the geological structure, stratigraphy, paleomagnetism, and paleontological and lithological properties of Upper Cenozoic sequences observable both in the Anui River valley and in Siberian areas adjacent to the Altai mountainous region.     

Time patterns of magmatic ore systems in circum-Pacific volcanoplutonic belts

Integrate statistical processing of more than 1000 isotope dates tracing the history of circum-Pacific magmatic ore systems and related mineral deposits in volcanoplutonic belts allows the following inferences: (1) magmatic ore systems (MOS) of volcanic arcs generate monoand polycyclic volcanoplutonic deposits (VPD) with notably different formation times (longevities); (2) the MOS chronology bears periodicity of events in the post-Paleozoic history of the Pacific continental margin; (3) the time series of magmatic ore systems from different circum-Pacific segments show quasi-periodic patterns but the respective metallogenic epochs within the same time intervals have different phases and amplitudes, especially over the past 30 Myr; (4) each mineral type of VPD has its own periodicity; (5) the periodicity in formation times of mono- and polycyclic VPD differs from that in the times of their origin.     

Natural periodic processes and climate variability in the Northern Hemisphere

Decomposition of five different paleoclimatic reconstructions of regional and hemispheric scale into different frequency periodic components has been performed for the extratropical zone of the Northern Hemisphere using spectral analysis methods (Hilbert–Huang transformation, wavelet transform, Fourier transform). The presence of ~1000, ~500, ~350, and ~200-year quasi-cyclic periodicities has been established, which determines climatic variability over the last 2–4 millennia. The presence of similar cyclicities, manifested in climatic and other geological processes, has been noted by many researchers and has been explained, as a rule, by changes in solar insolation. Thus, there is every reason to believe that the revealed quasi-periodic components in the climate variability of the extratropical zone of the Northern Hemisphere are natural, conditioned by natural cyclical phenomena and can serve as a basis for long-term predictive climatic constructions.

     

Climate prediction for the extratropical northern hemisphere for the next 500 years based on periodic natural processes

Five paleoclimatic reconstructions for the extratropical Northern Hemisphere are decomposed into quasiperiodic variations using the spectral analysis methods. The existence of ～1000-, ～500-, ～350-, and ～200-year periodicities is established which define the climatic variability over the past four millennia. Based on the identified quasiperiodicities, the climate forecast for the Northern Hemisphere extratropical zone is obtained. The forecast demonstrates that the currently observed warm climate will generally be kept for 500 years. However, the strongly pronounced trend towards the gradual cooling is expected in the 22nd century.