Добрый день, Коллеги. Важное сообщение, просьба принять участие. Музей Ферсмана ищет помощь для реставрационных работ в помещении. Подробности по ссылке
Geologic setting of the Colorado Plateau ores, by Alice D. Weeks and R. M. Garrels Characteristics of the host rock, by Robert A. Cadigan Elemental composition of the sandstone-type deposits, by E. M. Shoemaker, A. T. Miesch, W. L. Newman, and L. B. Riley Occurrence and chemical character of ground water in the Morrison formation, by David A. Phoenix Summary of the ore mineralogy, by Alice D. Weeks, Robert G. Coleman, and Mary E. Thompson Behavior of uranium minerals during oxidation, by R. M. Garrels and C. L. Christ
All major Appalachian tectonostratographic zones in Gaspesie, Quebec and New Brunswick (i.e. Humber, Dunnage, Gander, and Avalon) are intruded by Paleozoic granites. Granite petrological and geochemical data assist in evaluating the economic potential of the plutons and provide insight into the crustal and tectonic evolution of the orogen. Based on Na2O and Al index values (generally >3.2 wt.% and <1.1 respectively) and high-field strength element contents, most of the granites are 1-types; some have "А-type affinities". Granite chemical and isotopic characteristics distinguish three contrasting groups of granites: Humber-Dunnage, Gander, and Avalon. Positive eNd values for Humber, Dunnage, and Avalon granites indicate melting of predominately juvenile sources. Negative e Nd and elevated 201РЫШРЬ and 518 values for Gander granites are consistent with reworking of older (1.1-1.8 Ga) crust containing a significant supracrustal component. Neodymium isotopic data effectively rules out Grenville basement as a source for Humber-Dunnage granites. Gander zone is apparently the autochthonous surface expression of a distinct lower crustal block. Contrasting e Nd signatures from Avalon and Gander granites indicates that Gander and Avalon zones are underlain by different crustal blocks, i.e. Precambrian Avalon basement is not a suitable protolith for Gander granites.<...>
Исследованиями последних лет установлена прямая связь между образованием месторождений различных полезных ископаемых и поствулканическими процессами, т. е. процессами, протекающими в областях действия вулканов. Этим исследованиям посвящены новейшие работы французских, японских, американских и новозеландских геологов, вошедшие в сборник. Материалы сборника содержат большое количество фактических данных о вулканических газах, водах и геохимии связанных с ними' элементов, раскрывают представления зарубежных геологов о механизме поствулканического процесса и дают возможность советским специалистам ознакомиться с теорией и практикой исследования современных вулканических областей мира. Учитывая огромный интерес, который вызывает у советских геологов проблема промышленного использования тепловых ресурсов действующих вулканов, выход в свет настоящего сборника представляется весьма современным. Сборник рассчитан на студентов и преподавателей геологических вузов и геологических факультетов университетов, на специалистов-геологов, ведущих поиски полезных ископаемых, геохимиков и вулканологов.
The phase discontinuity that occurs at the mineral-water interface greatly influences the geochemical cycles of many elements. The composition of natural waters and the flux of material through the hydrosphere are largely controlled by the weathering of minerals and the precipitation of new phases -- processes in which the mineral-water interface plays a fundamental role.
In the field of groundwater numerical flow modelling has become a standard tool for scientific and also for most of the practical problems. The modelling software has matured during the past 10 years from being user-unfriendly with complex interfaces to a powerful, easy-to-use, windows-based system. For porous media flow in the saturated zone, the basic principle pertinent to all common programmes like MODLFOW, FEFLOW etc. is the solution of the linear DARCY- and continuity-equations. The numerical problems associated with the limitations in discretisation known in earlier days are not a serious burden any more because of the high-speed PCs with hundreds of Mbytes memory available nowadays.
The disposal of low-level radioactive waste generated by the U.S. Department of Energy (DOE) during the Cold War era has historically involved shallow land burial in unconfined pits and trenches. The lack of physical or chemical barriers to impede waste migration has resulted in the formation of secondary contaminant sources where radionuclides have moved into the surrounding soil and bedrock, as well as groundwater and surface water sources.
One of the main outcomes of the eleven meetings of the Working Party was the recognition of the importance of interdisciplinary studies linking regional geochemistry with plant, animal and human health. The effects of major element deficiencies or excesses on plant health are well known; this is not the case for trace elements. In fact, rapid and reliable analytical methods for determining trace element abundances have only recently become available, and it is to be expected that important new information on trace element levels will be forthcoming.
Mills, C. F. Geochemical aspects of the aetiology of trace element related diseases Plant, J. A., Baldock, J. W. & Smith, B. The role of geochemistry in environmental and epidemiological studies in developing countries: a review Fordyce, F. M., Masara, D. & Appleton, J. D. Stream sediment, soil and forage chemistry as indicators of cattle mineral status in northeast Zimbabwe Jumba, I. O., Suttle, N. F., Hunter, E. A. & Wandiga, S. O. Effects of botanical composition, soil origin and composition on mineral concentrations in dry season pastures in western Kenya Maskall, J. & Thornton, I. The distribution of trace and major elements in Kenyan soil profiles and implications for wildlife nutrition
Karst bauxite deposits are currently investigated as a new resource for rare earth elements (REE) in order to avoid present and future supply shortfalls of these critical metals. The present work focuses on the geochemistry and mineralogy of the REE in karst bauxite deposits of the Catalan Coastal Range (CCR), NE-Spain. It is revealed that the studied bauxitic ores have a dominant breccia and local ooido-pisoidic and pelitomorphic texture.
