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A proposal that the yellow sands which commonly overlie Pleistocene eolianites along the west coast of Western Australia may have their origin from major extensions of inland deserts during times of severe aridity, is refuted on several grounds. The eolianites typically are deeply degraded remnants of the original coastal dunes, which contained a high content of non-calcareous detritus. Hence plentiful residual sand will accumulate during weathering of a dune. Studies on heavy mineral content of the yellow sands have shown that there is an inland ageing trend consistent with local derivation from successive dune belts, and have also pointed to local sources for yellow color in the sand, without need to postulate a distant source. Localized denudations have however occurred, during which sand is blown inland to leave tracts of bared limestone. No remnants of the alleged desert extensions exist in the hinterland of the coastal belt.  相似文献   

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The solar sources of the magnetic storms of November 8 and 10, 2004, are analyzed. The preliminary results of such an analysis [Yermolaev et al., 2005] are critically compared with the results of the paper [Tsurutani et al., 2008], where solar flares were put in correspondence with these magnetic storms. The method for determining solar sources that cause powerful magnetospheric storms is analyzed. It has been indicated that an optimal approach consists in considering coronal mass ejections (CMEs) as storm sources and accompanying flares as additional information about the location of CME origination.  相似文献   

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