Investigation of impact spherules — a new promising method for the correlation of Quaternary deposits
Investigation of impact spherules — a new promising method for the correlation of Quaternary deposits
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DOI：
10.1016/s1040-6182(00)00047-1
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发表时间：
2000-06
影响因子：
2.2
通讯作者：
A. Raukas
中科院分区：
文献类型：
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作者：
A. Raukas
在过去的一百年里，不同成因（外星、火山、工业、生物、成岩、爆炸等）的微观磁铁矿和玻璃球粒。在不同的地质构造中经常被发现。除了传统的地质学方法外，对地外和爆炸性球粒的研究可以提供有价值的信息，并促进大面积的地层对比。在地球的历史上，似乎有几个全球性的小球体出现的高峰，最著名的是在K/T边界上记录的。在芬诺斯堪的纳维亚-波罗的海地区的古东欧陆块的结晶基底和沉积盖层中，发现了数十个年龄从新元古代到全新世，直径从小于100米到大于50公里的撞击坑。仅在波罗的海国家，就记录了至少18个撞击坑和大量陨石福尔斯坠落。迄今为止，波罗的海国家已知的最古老的古风化物被封闭在下寒武统砂岩中。本文介绍了在爱沙尼亚全新世陨石坑周围进行的小球研究的一些有希望的结果。在小球研究的基础上，可以精确地确定撞击事件的年代。含球粒地层是进行沉积层序对比的良好地层标志。
During the course of the last hundred years, microscopic magnetite and glassy spherules of different genesis (extraterrestrial, volcanic, industrial, biogenic, diagenic, explosive, etc.) have often been found in various geological formations. Alongside classical geological methods, research into extraterrestrial and explosive spherules can provide valuable information, and facilitates stratigraphical correlations over large areas. During the history of the Earth, there seem to have been several peaks in the global occurrence of spherules, the best known being recorded on the K/T boundary. Several tens of impact craters, ranging from Neoproterozoic to Holocene in age, and from less than 100m to more than 50km in diameter, occur both in the crystalline basement and in the sedimentary cover of the old East European Craton in the Fennoscandian-Baltic region. In the Baltic States alone, at least 18 impact craters and a large number of meteorite falls have been recorded. The oldest palaeometeorite matter known in the Baltic States to date is enclosed in Lower Cambrian sandstone. This paper presents some promising results of spherule studies which were carried out surrounding Holocene meteorite craters in Estonia. On the basis of spherule studies, impact events can be precisely dated. The spherule-bearing layers serve as excellent stratigraphical markers for the correlation of sedimentary sequences.