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对首次在南沙北部海域 1 795 7 2柱状样 ( 1 0°5 3.9′N ,1 1 5°1 8.3′E ,水深2 1 95m)柱深 7.80m至 8.1 0m层段中发现的大量微玻陨石进行了初步研究 .其形态多种多样 ,以圆球形为主 ;直径一般小于 1mm ;颜色以透明或半透明棕色为主 ;多数内部具气泡构造 .根据大洋粗组分地层学和有孔虫、超微化石生物地层事件 ,确定该层微玻陨石的地质时代在古地磁B/M界线附近约 780kaBP ,显然与印度洋、澳大利亚和我国黄土中的中更新世微玻陨石和大型玻陨石属同一次地外物体撞击事件的产物 .这不仅是海、陆第四纪地层划分与对比的可靠标志 ,也为古环境变化研究提供了依据 .
For the first time in the northern Nansha area of 1 795 7 2 column-like (1 0 ° 5 3.9’N, 1 1 5 ° 1 8.3’E, water depth 2 1 95m) column depth 7.80m to 8.1 0m layer found in a large number of micro-glassy The meteorites have been studied for a variety of ways, mainly in the form of spherical spheres, with diameters less than 1 mm, mainly of transparent or semitransparent brown color, most of the interior with bubble structures.According to the oceanic coarse stratigraphy and foraminifera , The formation of microfossil biostratigraphy, and the geological age of this layer of microlite glass is determined to be about 780kaBP near the B / M boundary of paleomagnetism, which is apparently the same as the middle Pleistocene microlite dolomite and large glassy meteorite in the loess of the Indian Ocean, Australia and China This is not only a reliable indicator of the division and contrast of the Quaternary strata in the sea and the land, but also provides the basis for the study of paleoenvironmental changes.