Late Permian magnetostratigraphy on the eastern Russian platform

The Late Permian is characterized palaeomagnetically by the transition from the long-lasting Permo-Carboniferous reversed polarity superchron (PCRS; also called: Kiaman reversed superchron) to the subsequent Permo-Triassic mixed polarity superchron, often called Illawarra mixed polarity superchron. Many discussions have been devoted to the exact time of the onset of the Illawarra reversals. Apparently contradictory data have been obtained from magnetostratigraphic sediment successions formed in different environments in many regions of the world. These sediments have been dated using classical geological or palaeontological correlation methods without the possibility of absolute age control because volcanogenic materials are missing. Application of the local or regional stratigraphic schemes leads to difficulties and apparent diachronous age estimates of the end of the PCRS. This paper shows that in agreement with earlier investigations, the continental red beds of the Upper Permian Tatarian stage on the eastern Russian platform record the Kiaman/Illawarra boundary. The Illawarra reversal sequence measured in a type section at the Volga river can be correlated well with the corresponding polarity pattern found in the Tethyan realm if one assumes a longer duration of the Tatarian than previously suggested.     

Petrophysical zoning of the Natalka ore field

The petrophysical properties of 1168 rock and ore samples collected across the sections of the Natalka ore field have been determined. 235 of them were prepared as thin and polished sections and studied by geological-mineralogical methods. The general two-level petrophysical zoning of the ore field was established and substantiated. Its relations with ore areas, the interzonal space, altered wall rocks, and the mineral composition were determined. Both levels of the revealed petrophysical zoning are traced in the ore field over 4 km along the strike and 800 m down the dip. The subvertical conductivity zone (confined to the Omchak ore cluster) has spatial-genetic relations with the petrophysical changes, which reflect the established mineralogical composition and structure of the metasomatites and ores.     

The deep structure of the Kulu earthquake-generating zone in the upper Kolyma highland from geophysical data

We measured and interpreted 30 physical magnetotelluric sounding sites using an SGS-E station and 20 km of electrical profiling observations using SDVR-4M instrumentation. We constructed a map of seismicity, an interpretation map, and four geoelectric sections, which give an idea of the deep structure for the Kulu earthquake-generating zone. A general geoelectric upper crustal model was developed for the zone down to depths of 20–22 km. Three nearly vertical conductive volumes were identified (thickness 3–5 km, depth 10–22 km), which provide the positions of seismically active deep-seated faults that pinpoint the Kulu earthquake-generating zone. The preliminary boundary of the zone was determined. It was found that earth-quake epicenters are confined to lithosphere volumes with increased concentrations of conductive layers and zones.     

First finding of a mammoth female (<Emphasis Type="Italic">Mammuthus primigenius</Emphasis> Blum.) on the Taimyr Peninsula

The first finding of a mammoth female skeleton from the Kastykhtakh River valley, Taimyr Peninsula, is described. The skeleton consists of 104 elements including the skull and lower jaw; small distal limb bones, tail vertebrae, and one tusk are absent. There are teeth of the two last changes in the jaws. The skeleton elements have individual features: sigmoid contact of the low second and third molars, crack in the neural arch of the atlas, and false joint and calluses on places of the rib fractures. The calibrated radiocarbon dating of the tubular bone is 32 070-30 565 yr (Kargin interglacial time).     

Kushan Period rice in the Amu Darya Basin: Evidence for prehistoric exchange along the southern Himalaya

The origins and prehistoric spread of rice agriculture between East and West Asia are hot topics in the current archaeological community. In this study, we present the results from a preliminary archaeobotanical study at the Khalchayan site in Uzbekistan, where we recovered the oldest securely dated rice thus far identified in Central Asia. We directly dated the rice grains to 1714–1756 cal yr BP(Kushan period), and morphologically compared them with other contemporaneous cultivated rice remains from China and India. The morphological results showed that the rice remains found at Khalchayan are more similar to cultivated japonica rice from southern China and northwestern India. Integrated archeological and chronological results from the surrounding area show that the rice remains found at Khalchayan likely spread along a southern Himalayan route from southwest China to northern India and finally reached the Amu Darya. The rice remains from Khalchayan are the first directly dated and well-reported rice remains found in Central Asia. By the Islamic period, rice was an important culinary aspect of the culture in Central Asia, but the cultural affinity towards rice only developed over the past two millennia. This study provides new information on the spread of rice agriculture globally, especially in arid-semiarid inland regions.