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Z. Reiss B. Luz A. Almogi-Labin E. Halicz A. Winter M. Wolf D. A. Ross 《Quaternary Research》1980,14(3):294-308
The quantitative distribution of planktonic foraminifera, pteropods, and coccolithophorids, as well as oxygen-isotope variations were analyzed in four deep-sea cores from the Gulf of Aqaba (Elat) and the northernmost Red Sea. The core record covers about 150,000 yr. Detailed stratigraphic subdivision is facilitated by combining all calcareous plankton groups. Time-stratigraphic correlation and dating beyond the radiocarbon range are possible by comparison of the oxygen-isotope curves. During the glacial maximum salinity rose to more than 50‰, while winter temperature of the upper waters fell by at least 4°C compared to the present. The rise in salinity can be accounted for by sea-strait dynamics and lowering of sea level. The Gulf of Aqaba and the Red Sea were continuously connected through the Straits of Tiran, and there is no indication of desiccation during the glacial maximum. 相似文献
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Rainer Wolf Alicia B. Woodrow Richard A.F. Grieve 《Geochimica et cosmochimica acta》1980,44(7):1015-1022
Eleven impact melt and 6 basement rock samples from 4 craters were analyzed by neutron activation for Au, Co, Cr, Fe, Ge, Ir, Ni, Os, Pd, Re and Se. Wanapitei Lake, Ontario: the impact melts show uniform enrichments corresponding to 1–2% C1-chondrite material. Interelement ratios (, , ) suggest that the impacting body was a Cl-, C2-, or LL-chondrite. Nicholson Lake, North West Territory: Ni, Cr and Co are distinctly more enriched than Ir and Au which tentatively suggests an olivine-rich achondrite (nakhlite or ureilite). Gow Lake, Saskatchewan and Mistastin, Labrador: small enrichments in Ir and Ni; both the low ratios and low Cr content suggest iron meteorites, but the signals are too weak for conclusive identification.A tentative comparison of meteoritic signatures at 10 large, ≥4km craters and their presumed celestial counterparts (13 Apollo and Amor asteroids) shows more irons and achondrites among known projectile types, and a preponderance of S-type objects, having no known meteoritic equivalent, among asteroids. It is not yet clear that these differences are significant, in view of the tentative nature of the crater identifications (achondrites in particular), and the limited statistics. 相似文献
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Prof. Dr. Wolf von Engelhardt 《International Journal of Earth Sciences》1974,63(3):793-819
Geoscience forms — besides Physics, Astronomy, Chemistry, and Biology — a specific domain of Science, characterized by its subjects and objects. Geoscience embraces all disciplines which are inquiring into the present configuration of the earth and its spheres, which intend to explain by natural laws the evolution of the earth and the life and which try to predict future developments. Solid bodies of the planetary system are subjects of geoscience insofar geoscientific methods can be applied. Geoscientists have profoundly contributed to the growth of the technological civilisation by discovering and exploiting sources for the supply of energy and raw materials. During the last decades the annual production of most of these materials has grown exponentially. This is shown, exemplarily, for iron, copper and mercury. Considering the exponential growth of the world population, the future life of mankind on earth is at stake because conventional resources, necessary for the maintenance of agriculture and technology, are running short and physical conditions essential for life are, because of geological reasons, finite and deteriorated by human activities. It is only by changing moral, political, economic and technical foundations of culture and civilisation that mankind can avoid extinction which was the ultimate fate of all species in the geological past. In the attempts to overcome the impending difficulties Geoscience has to play an important role of great responsibility: Only Geoscience can provide and develop by further research methods and knowledge which are necessary in order to evaluate the finite potentials available in the earth and the geological processes which both form the framework to which the future life of mankind has to be adjusted. 相似文献
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R. Burrows I.A. Walkington N.C. Yates T.S. Hedges J. Wolf J. Holt 《Applied Ocean Research》2009,31(4):229-238
With concerns mounting over the UK’s energy future and the effects of climate change, it will soon become paramount that all viable sources of renewable energy are fully exploited. This study has examined the scope for reliable and fully predictable tidal electricity generation from the conjunctive operation of 5 major estuary barrages on the West Coast of the UK in an attempt to establish the potential scale of the extractable resources. Two levels of investigation have been undertaken: simple 0-D (‘two-tank’) modelling of barrage energy generation under different operational modes, using the hydraulic characteristics of turbine performance; and 2-D modelling of tidal hydrodynamics over a wide sea area in a computational grid incorporating the barrages with turbines and sluices. It has been demonstrated that more than 33TWh per year of electricity should be attainable, from 22GW of installed capacity, this representing close to 10% of present UK demand. 相似文献