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Research about Russia

Source-linked reports with geographic coverage including Russia.

106 records · Page 6Linked to original sources
USGS1994

Origin, transport, and emplacement of an exotic island-arc terrane exposed in eastern Kamchatka, Russia

The regional stratigraphy of eastern Kamchatka includes an exotic, Early-Late Cretaceous ophiolite and Late Cretaceous island-arc volcanic sequence. Integrating the existing geologic and geophysical data, we examine the origin, transport, emplacement, and postemplacement deformation of the island-arc terrane, which is named the Olyutorsky island arc. Results from several paleomagnetic studies consistently indicate that the island-arc terrane originated >1000 km to the south of where it is presently exposed. Although the formative paleolatitudes of the island-arc rocks approximately correspond to the location of the Izanagi-Farallon subduction zone, the age of the volcanic rocks postdates the cessation of Izanagi-Farallon convergence, thus indicating that an unnamed plate or back-arc basin existed in the northwest Pacific during Late Cretaceous time. We examine two possible models for northward transport of the island-arc terrane to Kamchatka: (1) infra-oceanic transport with the Pacific or Kula plates and (2) coastwise translation of the island-arc terrane after accretion to the Eurasian margin far to the south of Kamchatka. For both models, the dominant Eocene and Miocene deformation ages observed in eastern Kamchatka are used as two possible age limits for the cessation of northward transport. Although the observed paleolatitudes from paleomagnetic data correspond best with the infra-oceanic transport model, the provenance of the Paleogene "transport" stratigraphy indicates a near-shore sediment supply. Our preferred interpretation is that the island-arc terrane (1) accreted onto the Eurasian margin concurrent with cessation of island-arc volcanism (Maastrichtian-Danian) and (2) underwent northward coastwise translation along a major strike-slip fault zone ending by middle-late Eocene time (43-50 Ma). It is unclear whether the ophiolite was exposed during arc-continent collision or whether the ophiolite was obducted onto the island arc prior to collision. A consequence of either infra-oceanic transport or coastwise translation is that an open corridor between the western terminus of the Aleutian Arc and Kamchatka must have existed until middle to late Eocene time. Spreading within the Komandorsky Basin, subduction of sea-mounts, and collision of the Aleutian Arc with Kamchatka are proposed to have instigated the second Miocene phase of deformation, which uplifted and reexposed the island-arc terrane.

Kamchatka Peninsula↗
USGS1993

Seismic survey of Lake Baikal, Siberia cruise report: RV Balkhash 25 August to 25 September 1992

Introduction A comprehensive multichannel seismic-reflection (MCS) and ocean bottom seismometer (OBS) seismic-refraction survey of Lake Baikal, Siberia was undertaken during August-September 1992 as a collaborative research project by U.S. and Russian scientists. This project was supported by funding from the U.S. Geological Survey, the U.S. National Science Foundation and the Russian Academy of Sciences. Over 2200 km of multichannel seismic-reflection data on 42 profiles and over 500 km of seismic-refraction data on 4 OBS profiles were acquired during this study. On board seismic processing facilities were utilized for quality control and demultiplexing of seismic data during the cruise. Lost survey time due to weather was about 7 days, but most planned seismic profiling was completed, including the reshooting of profiles where necessary. This seismic study was carried out on two vessels, the RV BALKHASH for MCS work and the TITOV for OBS deployments. This report summarizes the general seismic program and the operations on the BALKHASH. Operations on the TITOV are summarized in a companion report by tenBrink and others. A detailed description of the logistical and technical aspects of the seismic program, including all seismic systems, is given in the companion report by Nichols and others.

Siberia↗
USGS1993

Status of Pacific Black Brant Branta bernicla nigricans on Wrangel Island, Russian Federation

Abundance, distribution, and habitat selection of breeding and moulting Pacific Black Brant were studied on Wrangel Island in 1989-91. Two nests and <10 family flocks of Brant were found during ground searches in previously known nesting areas. The breeding population has declined from 1000-2000 pairs to probably <100 pairs. An estimated 4200 50 (Cl) moulting Brant were counted during the first aerial and photographic survey of the island in 1990. This population includes moult migrants from Alaska and mainland Russia. Most (67%) of the moulting flocks were concentrated in freshwater lakes and usually within 2 km of the coast. Lakes with low relief shorelines and adjacent preferred grasses were important habitats used by moulting birds. Breeding and moulting populations of Wrangel Island Brant are dependent on Izembek Lagoon Alaska, in autumn and disperse over the rest of eastern Pacific Flyway in winter and spring.

Wrangel Island↗
USGS1992

Depositional and tectonic framework of the rift basins of Lake Baikal from multichannel seismic data

Recent multichannel seismic reflection data from Lake Baikal, located in a large, active, continental rift in central Asia, image three major stratigraphic units totalling 3.5 to 7.5 km thick in four subbasins. A major change in rift deposition and faulting between the oldest and middle-rift units probably corresponds to the change from slow to fast rifting. A brief comparison of the basins of Lake Baikal with those of the East African rift system highlights differences in structural style that can be explained by differences in age and evolution of the surrounding basement rocks. -from Authors

Lake Baikal↗
USGS1991

Stratigraphy and paleoceanography of Pliocene deposits of Karaginsky Island, eastern Kamchatka, U.S.S.R.

The lithology and paleontology of Pliocene deposits from Karaginsky Island, off eastern Kamchatka Peninsula, U.S.S.R., are described in order to provide a paleoceanographic reconstruction of this region of the eastern North Pacific Ocean. The stratigraphic sequence is divided into three suites — the Limimtevayamian, the Ust-Limimtevayamian, and the Tusatuvayamian, which correspond to three standard Pacific diatom zones — the Thalassiosira oestrupii, Neodenticula koizumi-N. kamtschatica , and N. koizumi . The entire sequence is further subdivided into six members and 18 distinct beds on the basis of molluscan assemblages and three members and seven beds on the basis of benthic foraminiferal assemblages. Marine ostracodes are described from the Limimtevayamian suite. The marine invertebrate assemblages from Karaginsky Island provide evidence that: (1) ocean water temperatures were warmer than today about 4 Ma and again about 3.5-3.0 Ma; (2) several Arctic-Atlantic species of molluscs and ostracodes migrated to the eastern North Pacific between 4.2−3.0 Ma, presumably through the proto-Bering Strait; (3) many species found in the Karaginsky Island Pliocene represent Pacific taxa which migrated through the Arctic into the North Atlantic during the late Pliocene.

eastern Kamchatka, Karaginsky Island↗
USGS1986

The Tunguska comet or the great Siberian mystery explosion of 1908

It is dawn on a June morning in Siberia in 1908. The sky is cloudless, but even in summer this part of Russia the cold at dawn takes your breath away. Fur-clad nomads are beginning to herd their sheep and goats towards lush grazing on the banks of the river-one of the thousands that drift sluggishly across Siberia's vast featureless wilderness towards the Arctic Ocean. Swans glide in the dark shallows of the river. A phalanx of ducks spears into a nearby swamp and sends up a black cloud of ferocious mosquitoes; they settle again around a herd of reindeer browsing on the river bank. Here where the tiaga, the forbidding Siberia forest, obscures the sun, the cold is a sharp as the flint in the river bed. It cuts the farmer who has just emerged from his log cabin. He halts on the steps to decide whether this first task of the day will be to mend the plough that was broken yesterday when he dug too deep and reached permanently frozen ground, or whether he will hunt for rabbit for the evening meal; instead he lights his pipe. Two families of nomads are still asleep in their tents, the air strong with the scent of wet dog as the ice melts on their furs. At a trading post, trappers squabble over the price of ermine and sable pelts. On the edge of the settlement a tramp with pots and pans jingling on his back sets off on his day's journey to the nearest village, twenty miles away. At the edge of the village, a boatman pushes off from the river bank for his first crossing of the day, the crescent-shaped hull of his boat overloaded with squawking chickens, snarling dogs and silent peasants. Without warning there is a blinding blue flash in the sky, followed by a roar and a searing blast of heat; there is a thunderous clap, the ground shudders, and this air is filled with fire, black smoke and debris. The boat disintegrates, hurling men and animals into the freezing river. The farmer's shirt is scorched off his back; the tramp is blown off his feet, his ports and pans scattering like shrapnel. One of the trappers standing in the doorway of the trading post is knocked unconscious, overcome by the searing heat; the tents of the nomads are torn loose, the men and dogs inside being rolled over the ground like leaves in a gale. All that remain of the reindeer are charred carcasses. The forest has been turning into a crackling inferno, and a black fireball rises into the air.

Earthquakes & Volcanoes (USGS)↗
USGS1983

Tectonic evolution of Gulf of Anadyr and formation of Anadyr and Navarin basins

New seismic reflectionand refraction data reveal that Anadyr basin is separated from Navarin basin by Anadyr ridge, a southeast-northwest-trending bedrock high that is characterized by high-amplitude, short-wavelength magnetic anomalies. Anadyr ridge may be an offshore extension of the melange belt underlying the Koryak Range. Sonobuoy refraction data indicate that the velocity profile of strata in East Anadyr trough is similar to that in Navarin basin. Structurally, the basins are different.

Siberia↗
USGS1980

Salym: potential W. Siberian oil giant

SALYM oil field is on the Lempa high of the Salym uplift in the eastern part of the Khanty-Mansiysk depression in the Middle Ob region of West Siberia. The Salym uplift is about 50 km long and 45 km wide and trends north. The Lempa high is 25 km long and 16 km wide; closure is 150 m. The Salym field is about 275 km west of the giant Samotlor field. Stratigraphy. The sedimentary cover overlying the Paleozoic Hercynide basement in the Middle Ob region consists of Jurassic, Lower and Upper Cretaceous, Paleogene, and Quaternary marine and continental sediments.

Salym, Siberia↗
USGS1965

Calculations of upper-mantle velocity from published Soviet earthquake data

The lack of information on mantle velocities and crustal structure of the U.S.S.R. has led to a preliminary examination of published Soviet earthquake bulletins in the hope of deriving useful velocity and structure information from the data they contain. Mantle velocities deduced from earthquake data on several Russian earthquakes are in excellent agreement with results of Soviet deep seismic sounding.

Soviet Union↗
USGS1943

Terrain intelligence Chita Oblast (U.S.S.R.)

The following folio of maps and explanatory tables outlines the principal terrain features of the Chita Oblast. Each map and table is devoted to a specialized set of problems; together they cover such subjects as terrain appreciations, rivers, surface-water and ground-water supplies, construction materials, fuels, suitability for temporary roads and airfields, mineral resources, and geology. These maps and data were complied by the United States Geological Survey.

Chita Oblast↗
USGS1942

Eastern Siberia terrain intelligence

The following folio of terrain intelligence maps, charts and explanatory tables represent an attempt to bring together available data on natural physical conditions such as will affect military operations in Eastern Siberia. The area covered is the easternmost section of the U.S.S.R.; that is the area east of the Yenisei River. Each map and accompanying table is devoted&middot; to a specialized set of problems; together they cover such subjects as geology, construction materials, mineral fuels, terrain, water supply, rivers and climate. The data is somewhat generalized due to the scale of treatment as well as to the scarcity of basic data. Each of the maps are rated as to reliability according to the reliability scale on the following page. Considerable of the data shown is of an interpretative nature, although precise data from literature was used wherever possible. The maps and tables were compiled by a special group from the United States Geological Survey in cooperation with the Intelligence Branch of the Office, Chief of Engineers, War Department.

Eastern Siberia↗