Engineering geology of loess and loess-like deposits: a commentary on the Russian literature

Loess and loess-like deposits were much studied in the Soviet Union, and are currently under investigation in Russia and surrounding countries. There is a vast literature in Russian, which touches on all aspects of loess science and technology. In particular, the studies of the origin of collapsibility are almost totally in Russian, and of course studies on the various regions of Russia and the countries of the Former Soviet Union FSU appear in Russian. This review looks at the literature in Russian and attempts to pick out key contributors, major topics and works and to identify the critical regions and zones of investigation. Because so many regions of the FSU had people living on loess ground, there is a vast literature on engineering geology and ground engineering topics, and this tends to dominate all the literature on loess in Russian. Following Russian practice, the fine-grained deposits under consideration are divided into loess and loess-like deposits. Three main topics are recognised across the whole spectrum of loess research: formation and distribution of loess deposits; stratigraphy, cyclicity and palaeoclimatology; and engineering topics, in particular hydrocollapse and subsidence, and we concentrate on the engineering geology topics. An attempt is made, based on the map of Abelev and Abelev [Abelev, Yu.M., Abelev, M.Yu., 1968. Fundamentals of design and construction on collapsible macroporous soils, 2nd ed. Stroiizdat, Moscow, 431 pp. (in Russian)] of collapsing loess deposits, to define seven loess regions within the geographical limits of the old USSR. The seven regions are those where geotechnical problems might be expected.     

Application of Deuterium Excess for Identification of Freshwater Sources in the Bays of Novaya Zemlya Archipelago

Doklady Earth Sciences - An isotopic–geochemical study was carried out for waters of Tsivolkii and Sedov bays (southeastern coast of the Novaya Zemlya Archipelago). The waters of these bays...     

Granitoids of the Ufalei block (South Urals): Sr-Nd isotope systematics, geodynamic position and genetic reconstructions

Petrogeochemical and isotopic-geochronological signatures in granitoids developed in structures with complex geological history represent an important feature for reconstructing paleogeodynamic settings. Granitoids are widespread in the western slope of the Urals, where the Uralian Orogen contacts via a collage of different-age blocks of the east European Platform. The Ufalei block located in the Central Urals megazone at the junction between the South and Middle Urals’ segments represents one such boundary structure with multistage geological evolution. The isotopic ages obtained by different methods for acid igneous rocks range from 1290 to 245 Ma. We determined close Rb-Sr and Sm-Nd ages (317 Ma) for granites of the Nizhnii Ufalei Massif. By their petrochemical parameters, granitoids and host granite-gneisses differ principally from each other: the former are close to subduction-related, while the latter, to continental-riftogenic varieties. The primary ratio (⁸⁷Sr/8⁶Sr)₀ = 0.70428 and ?_Nd ≈ +4 values indicate significant contribution of oceanic (island-arc?) material to the substrate, which served as a source for granites of the Nizhnii Ufalei Massif. Model Nd ages of granites vary from 641 to 550 Ma. Distinct oceanic rocks and varieties with such ages are missing from the surrounding structures. New isotopic dates obtained for ultramafic and mafic rocks from different zones of the Urals related to the Cadomian cycle imply development of unexposed Upper Riphean-Vendian “oceanic” rocks in the central part of the Ufalei block, which played a substantial role in the formation of the Nizhnii Ufalei granitoids. Such rocks could be represented, for example, by fragments of the Precambrian Timanide-type ophiolite association. The analysis of original materials combined with published data point to the heterogeneous composition and structure of the Ufalei block and a significant part of the western segment of the Central Uralian Uplift and extremely complex geological history of the region coupling the Uralian Orogen with the East European Platform in the present-day structure.     

Linking multi-temporal analysis and community consultation to evaluate the response to the impact of Hurricane Stan in coffee areas of Chiapas,Mexico

This paper analyses the responses related to land use of coffee growers in Chiapas, Mexico to the impact of Hurricane Stan (October 2005). A multi-temporal analysis of the effect on land cover was performed through the combination of unsupervised classification of SPOT multispectral images and visual interpretation of panchromatic images (8 months previous to the hurricane, and 2, 14, and 40 months after the hurricane). The information provided by this geographic analysis was interpreted in light of information gathered though household surveys. Although the hurricane wrecked havoc across the region, the main impact in the study area was in the riparian zones where the extent of the loss experienced in terms of coffee harvest and soil was such that, even 14 months after the event, households with land in those areas were struggling to recover. Nevertheless, after 40 months, the zones that had suffered total soil loss began to support soil and vegetation, indicating the possibility of replanting coffee in those areas. Although the hurricane occurred when the coffee sector was particularly fragile as a result of the preceding several years of poor prices, the impact did not trigger extensive land use change. The surveys showed, however, that people are now more informed of the risk of living and farming on the river margins and are now performing soil conservation practices and planting trees to reduce risk.     

Pressure-temperature and evolution of fluid compositions of Al2SiO5-bearing rocks,Mica Creek,B.C., in light of fluid inclusion data and mineral equilibria

Metamorphosed pelitic rocks from Mica Creek, British Columbia contain sillimanite, kyanite with minor fibrolite and andalusite-bearing quartz pods. Mineral equilibria were used to infer peak P-T conditions and fluid compositions in equilibrium with the solid phases. Fluid inclusions in three schist samples appear to be good indicators of conditions affecting those rocks during and after peak metamorphic conditions. In samples from two localities, fluid inclusions from schist and quartz-rich segregations have densities appropriate to the peak metamorphic conditions. The observed compositions for these fluids (low salinity with 12 mole % dissolved CO₂) agree with calculated values of 0.84 to 0.85, based upon paragonite-quartz-albite-Al₂SiO₅ equilibria. The fluids unmixed as the schists were uplifted and cooled; fluid inclusions trapped during this stage outline a solvus in the CO₂-H₂O-NaCl system. A later influx of fluids containing CH₄ and N₂ accompanied formation of andalusite-bearing plagioclaserich segregations. The restricted association of andalusite-bearing pods and low density fluids suggest a localized but pervasive fluid influx during uplift. Preservation of high density fluid inclusions during uplift and erosion, coupled with evidence for unmixing of H₂O- and CO₂-rich fluids on the solvus, provide constraints on the P-T uplift path.     

Lithostratigraphic correlation of Blaini Formation (late Proterozoic,Lesser Himalaya,India) with other late Proterozoic tillite sequences

The Blaini Formation of the Lesser Himalaya has long been considered Permo-Carboniferous in age on simple lithological correlation with Gondwana Tillites in southern India. Rare, and non-repeatable finds of fossils from the type area were thought to confirm this. Recently, Lower Cambrian faunas have been recorded from the overlying Tal and Krol Formations, and possible metazoan trails recorded from the Blaini itself. In addition, the Blaini Formation is, even on a lithostratigraphic comparison, much more like other late Proterozoic glacial sequences. The term Blaini Formation should only be used for rocks of the type area — not for widely scattered glacial deposits which may or may not be correlatable with the type section. The persistent belief in the Paleozoic age of the Blaini (and adjacent formations) has for long retarded unterstanding of Lesser Himalaya stratigraphy and tectonics.

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Zusammenfassung Die Blaini Formation des Niederen Himalaya wurde bisher aufgrund lithologischer Vergleiche mit Gondwana Tilliten aus Süd-Indien in das Permo-Karbon eingestuft. Seltene, nicht wiederholbare Fossilfunde schienen dieses zu bestätigen. Kürzlich wurden Faunen des Unterkambriums in den überlagernden Tal- und Krol-Formationen gefunden sowie vermutliche Metazoanspuren aus der Blaini Formation selbst. Darüberhinaus ist die Blaini Formation sogar über den lithostratigraphischen Vergleich eher mit spätproterozoischen Glazialfolgen zu vergleichen. Der Begriff Blaini Formation sollte nur für die Typlokalität verwendet werden, und nicht für ähnliche Glazialvorkommen in der weiteren Umgebung. Die fortdauernde Annahme des paläozoischen Alters der Blaini- und umgebenden Formationen hat über lange Zeit hinweg das Verständnis für die Stratigraphie und die tektonische Entwicklung des Niederen Himalayas behindert.

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Résumé La formation de Blaini, dans l'Himalaya inférieur, a été jusqu'ici placée dans le Permo-Carbonifère sur la base de ses analogies lithologiques avec les tillites gondwaniennes du Sud de l'Inde. Cette attribution a semblé pouvoir Être confirmée par la découverte de quelques fossiles rares et isolés. Récemment des faunes du Cambrien inférieur ont été identifiées dans les formations surincombantes de Tal et de Krol; dans la formation de Blaini elle-mÊme des traces possibles de métazoaires ont été relevées. De plus, au seul point de vue lithologique, c'est avec les séries glaciaires du ProtérozoÏque supérieur que la formation de Blaini présente le plus de similitude. L'emploi du terme »Formation de Blaini« doit Être restreint à sa localité-type et doit Être évité pour des formations glaciaires d'autres régions, qui peuvent Être d'âges divers. L'âge paléozoÏque, attribué régulièrement jusqu'ici à la formation de Blaini et aux formations adjacentes a constitué un obstacle permanent à une bonne compréhension stratigraphique et tectonique de l'Himalaya inférieur.

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Comparative discharges of fresh and waste water along the California coast

As the population of California grows, the discharge of domestic and industrial waste water and power-plant cooling water into coastal waters continuously increases. About 0.75 × 10⁶ m³ of industrial waste water, 3.75 × 10⁶ m³ of domestic waste water, and 26.5 × 10⁶ m³ of thermal effluent are discharged daily into California's nearshore waters. These waters do not have an infinite capacity to break down and disperse the pollutants. Waste water discharged near shore may remain there for considerable time and have a significant effect on water quality and marine life. The low population and wet climate of the northern coastal region have led to small discharges of waste water but very large inputs of fresh water to the ocean. Southward along the Pacific Coast the climate becomes more arid, and population increases. This combination leads to a large excess of waste-water over fresh-water discharge. Many individual waste-water discharges exceed the average daily discharge of most of the rivers which enter the coastal waters.     

Non-existence of five dimensional string cosmological models in Riemannian and Lyra geometries

In this paper, we have attempted to construct five dimensional string cosmological models in Riemannian and Lyra geometries. It is found that cosmic string models do not survive in both the theories. Subsequently, the vacuum cosmological models are constructed and discussed.