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101.
L. T. Handoko 《Earth, Moon, and Planets》2009,104(1-4):331-336
This short paper is a progress report on our experiences in Indonesia of collecting, integrating and disseminating both global and local scientific data across the country through the web. Our recent efforts are concentrated on improving local public access to global scientific data, and encouraging local scientific data to be more accessible for global communities. We have maintained a well-connected infrastructure and web-based information management systems to realize these objectives. This paper is especially focused on introducing the ARSIP system for mirroring global data and sharing local scientific data, and the newly developed Indonesian Scientific Index for integrating local scientific data through an automated intelligent indexing system. 相似文献
102.
Karaevskaya E. S. Demidov N. E. Kazantsev V. S. Elizarov I. M. Kaloshin A. G. Petrov A. L. Karlov D. S. Schirrmeister L. Belov A. A. Wetterich S. 《Izvestiya Atmospheric and Oceanic Physics》2021,57(10):1254-1270
Izvestiya, Atmospheric and Oceanic Physics - The archaeal composition of permafrost samples taken during the drilling of frozen marine sediments in the area of the Barentsburg coal mine on the east... 相似文献
103.
This study provides SHRIMP-RG data on zircons from garnet gedritites, the products of retrograde metamorphism of eclogite-like rocks constituting belonging to the basement of the Omolon Massif. The earliest episode recorded by oscillatory-zoned cores having high HREE and Ti contents occurred at 3.25–3.22 Ga (Paleoarchean) and is interpreted to represent an upper age limit of a metamorphic or magmatic protolith. One zircon core with a pronounced negative Eu anomaly yielded a concordant age of 2.6 Ga, which is interpreted to mark a Neoarchean episode of granite formation. The studied population of zircons provides the most distinct record of a Paleoproterozoic (1.9 Ga) event, which is marked by formation of garnet gedritites under amphibolite-facies conditions. This event is recorded by transparent recrystallization rims of preexisting large zircon grains and small newly-formed grains, which are characterized, compared with their cores, by lower crystallization temperatures and one order of magnitude lower concentrations of U, Th, and HREE, and the presence of garnet micro-inclusions. 相似文献
104.
The entire width of the North American Cordillera in Alaska is made up of “suspect terranes”. Pre-Late Cretaceous paleogeography is poorly constrained and the ultimate origins of the many fragments which make up the state are unclear. The Prince William and Chugach terranes accreted since Late Cretaceous time and represent the collapse of much of the northeast Pacific Ocean swept into what today is southern Alaska. Greater Wrangellia, a composite terrane now dispersed into fragments scattered from Idaho to southern Alaska, apparently accreted into Alaska in Late Cretaceous time crushing an enormous deep-marine flysch basin on its inboard side. Most of interior eastern Alaska is the Yukon Tanana terrane, a very large entirely fault-bounded metamorphic-plutonic assemblage covering thousands of square kilometers in Canada as well as Alaska. The original stratigraphy and relationship to North America of the Yukon-Tanana terrane are both obscure. A collapsed Mesozoic flysch basin, similar to the one inboard of Wrangellia, lies along the northern margin. Much of Arctic Alaska was apparently a vast expanse of upper Paleozoic to Early Mesozoic deep marine sediments and mafic volcanic and plutonic rocks now scattered widely as large telescoped sheets and Klippen thrust over the Ruby geanticline and the Brooks Range, and probably underlying the Yukon-Koyukuk basin and the Yukon flats. The Brooks Range itself is a stack of north vergent nappes, the telescoping of which began in Early Cretaceous time. Despite compelling evidence for thousands of kilometers of relative displacement between the accreted terranes, and large amounts of telescoping, translation, and rotation since accretion, the resulting new continental crust added to North America in Alaska carries few obvious signatures that allow application of currently popular simple plate tectonic models. Intraplate telescoping and strike-slip translations, delamination at mid-crustal levels, and large-scale lithospheric wedging were important processes in northern Cordilleran tectonic evolution. 相似文献
105.
适度人口取决于生态、经济和土地等多要素的综合承载力。介绍了生态足迹模型的基本概念和计算方法,并运用该模型对兵团1995—2008年的生态足迹和生态承载力进行了计算,在此基础上对兵团的1995—2010年的生态适度人口进行了估算。结果表明,1995—1999年兵团的实际人口虽然在增加,但相对于生态适度人口并没有出现过剩;2000—2010年兵团生态适度人口在不断下降,实际人口和过剩人口却在不断增加。兵团目前已经出现了过度人口和生态赤字,人地矛盾相对紧张,生态适度人口规模是不合理的。 相似文献
106.
107.
108.
The way in which rocks and engineering materials heat‐up and dry‐out in the intertidal zone is of relevance to both weathering and ecology. These behaviours can be measured in the laboratory under controlled conditions designed to replicate those occurring in the field. Previous studies have demonstrated differences in thermal behaviours between rock types and through time as a result of soiling in terrestrial environments, but the influence of weathering and colonization on rock behaviours in the intertidal zone has not been previously assessed. We measured the warming and drying of blocks of rock (limestone and granite) and marine concrete during ‘low‐tide’ events simulated in the laboratory, before and after a period of exposure (eight months) on rock platforms in Cornwall, UK. As well as differences between the material types, temperatures of control (unexposed) and field‐exposed blocks differed in the order of 1 to 2 °C. Drying behaviours were also different after field exposure. Differences during the first few hours of exposure to air and heat were attributed to discolouration and albedo effects. Over longer periods of time, changes in the availability of near‐surface pore water as a result of micro‐scale bioerosion of limestone and the development of bio‐chemical crusts on marine concrete [observed using scanning electron microscopy (SEM)] are suggested as mechanisms enhancing and reducing, respectively, the efficiency of evaporative cooling. The retention of moisture by epilithic biofilms may also influence thermal and drying behaviours of granite. These observations represent one of the first examples of cross‐scalar biogeomorphic linkages in the intertidal zone. The significance of the results for the subsequent efficiency of weathering, and near‐surface micro‐climatic conditions experienced by colonizing organisms is discussed. The involvement of microorganisms in the creation of more (or less) ecologically stressful conditions through the alteration of substratum geomorphic properties and behaviours is suggested as an example of ‘biogeomorphic ecosystem engineering’. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
109.
Evidence for focused hot fluid flow within the Britannia Field, offshore Scotland, UK 总被引:1,自引:0,他引:1
S. G. Archer H. L. Wycherley G. R. Watt M. L. Baron J. Parnell H. Chen 《Basin Research》2004,16(3):377-395
Fluid inclusion and scanning electron microscope‐cathodoluminescence evidence indicates focused hot, saline, diagenetic fluid flow within the Eastern Flank of the Britannia Field, offshore Scotland, UK. The fluid was sourced from the Andrew Salt Dome, 10 km to the east. The fluids, which promoted quartz cementation of the upper zones within the field, were up to ~30°C hotter and had salinities up to ~10 wt% NaCl equivalent higher than fluids from lower in the reservoir section. During diagenesis hot saline fluids migrated westwards as part of a radiating ‘diagenetic front’ from the Andrew Salt Dome. Structural dip associated with the Eastern Flank of the Fladen Ground Spur impeded the westward movement of the diagenetic fluid. The quartz cements from the upper and lower reservoir zones can be distinguished by morphology. In the upper zones the quartz cements have well‐developed macro‐crystalline zoning and heterogeneous luminescence across the grain. In the lower zones, the cements are much less developed, unzoned and very weakly luminescent. The diagenetic fluids were primarily focused into Zone 45 within the upper reservoir. Furthermore, within the Main Platform Area the most prolific producing zone is Zone 45, indicating the importance of this interval as a permeable flow unit during both diagenetic and production timescales. Within the Eastern Flank, the quartz overgrowths have a major impact on reservoir permeability and thus well productivity. The overgrowths are most extensive in the originally clean sandstones with low clay content. Clay in optimum volumes (5–10%) can inhibit nucleation of the damaging quartz overgrowths without having a detrimental effect on pore connectivity. These observations provide a predictive concept for use in the search for relative reservoir sweetspots within the degraded Eastern Flank. 相似文献
110.