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411.
Our study at this natural analog site contributes to the evaluation of methods within a hierarchical monitoring concept suited for the control of CO2 degassing. It supports the development of an effective monitoring concept for geological CO2 storage sites—carbon capture and storage as one of the pillars of the European climate change efforts. This study presents results of comprehensive investigations along a 500-m long profile within the Hartou?ov (Czech Republic) natural CO2 degassing site and gives structural information about the subsurface and interaction processes in relation to parameters measured. Measurements of CO2 concentrations and investigation of the subsurface using electrical resistivity tomography and self-potential methods provide information about subsurface properties. For their successful application it is necessary to take seasonal variations (e.g., soil moisture, temperature, meteorological conditions) into consideration due to their influence on these parameters. Locations of high CO2 concentration in shallow depths are related to positive self-potential anomalies, low soil moistures and high resistivity distributions, as well as high δ13C values and increased radon concentrations. CO2 ascends from deep geological sources via preferential pathways and accumulates in coarser sediments. Repetition of measurements (which includes the effects of seasonal variations) revealed similar trends and allows us to identify a clear, prominent zone of anomalous values. Coarser unconsolidated sedimentary layers are beneficial for the accumulation of CO2 gas. The distribution of such shallow geological structures needs to be considered as a significant environmental risk potential whenever sudden degassing of large gas volumes occurs.  相似文献   
412.
A comprehensive record of lake level changes in the Dead Sea has been reconstructed using multiple, well dated sediment cores recovered from the Dead Sea shore. Interpreting the lake level changes as monitors of precipitation in the Dead Sea drainage area and the regional eastern Mediterranean palaeoclimate, we document the presence of two major wet phases ( 10–8.6 and  5.6–3.5 cal kyr BP) and multiple abrupt arid events during the Holocene. The arid events in the Holocene Dead Sea appear to coincide with major breaks in the Near East cultural evolution (at  8.6, 8.2, 4.2, 3.5 cal kyr BP). Wetter periods are marked by the enlargement of smaller settlements and growth of farming communities in desert regions, suggesting a parallelism between climate and Near East cultural development.  相似文献   
413.
Within the past decade, the sugarcane ethanol industry in Brazil has increased its production capacity to meet rising domestic demand for ethanol. However, to achieve this growth the industry has had to expand into new frontiers in the Brazilian Cerrado, specifically in the states of Goiás and Mato Grosso do Sul, which is now the second largest producing area of ethanol in Brazil. We argue that the expansion into the Brazilian Cerrado is a result of the interactions between the increase in demand, governmental policies, infrastructure, and factors that have prevented traditional sugarcane producing regions from meeting the increasing demand for ethanol. This paper analyzes the policies that have shaped the sugarcane industry in Brazil and the expansion of the industry across the country. The policies and issues examined include those that led to the concentration and consolidation of the sugarcane industry in the state of São Paulo and the consequences of this consolidation; the influence of governmental policies on the decision-making process of producers and industry; the state-level policies designed to expand the industry into Goiás and Mato Grosso do Sul states; infrastructure development; and the Sugarcane Agroecological Zoning policies. Through this study we conclude that the ethanol industry identified the Cerrado states as an opportunity for investment, given the good agricultural conditions for producing sugarcane, affordable land prices and favorable state-level fiscal incentive policies. In addition, there is a need for further regional development policies as the interaction between the sugarcane sector and regional government is likely to continue into the future.  相似文献   
414.
Mineralogy and Petrology - Tachylytes from rift-related volcanic rocks were recognized as: (i) irregular veinlets in host alkaline lava flows of the Kozákov volcano, Czech Republic, (ii)...  相似文献   
415.
416.
Shock-related calcite twins are characterized in calcite-bearing metagranite cataclasites within crystalline megablocks of the Ries impact structure, Germany, as well as in cores from the FBN1973 research drilling. The calcite likely originates from pre-impact veins within the Variscan metagranites and gneisses, while the cataclasis is due to the Miocene impact. Quartz in the metagranite components does not contain planar deformation features, indicating low shock pressures (<7 GPa). Calcite, however, shows a high density (>1/μm) of twins with widths <100 nm. Different types of twins (e-, f-, and r-twins) crosscutting each other can occur in one grain. Interaction of r- and f-twins results in a-type domains characterized by a misorientation relative to the host with a misorientation angle of 35°–40° and a misorientation axis parallel to an a-axis. Such a-type domains have not been recorded from deformed rocks in nature before. The high twin density and activation of different twin systems in one grain require high differential stresses (on the order of 1 GPa). Twinning of calcite at high differential stresses is consistent with deformation during impact cratering at relatively low shock pressure conditions. The twinned calcite microstructure can serve as a valuable low shock barometer.  相似文献   
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