大连金石滩现代沉积中首次发现宇宙球粒

金石滩是大连地区的国家级风景旅游地,在玫瑰园景点的现代沉积物研究中,首次发现了铁质宇宙球粒,而且含量较多,在2.4 kg(<0.5 mm)的砂样中分离出18个宇宙球粒,其大小介于158～423μm,大多数宇宙球粒的表面具有典型的融熔-分凝构造,按其表面化学成分可分为:Fe质、Si-Al-Fe质、Cr-Fe质和Ti-Fe质等4种;笔者特别对其中的Ti-Fe质宇宙颗粒的成分及矿物演变进行了研究,认为宇宙球粒快速冷凝化学分异可在磁铁矿边缘形成钛磁铁矿;对大连、西藏泽当现代沉积物中、太平洋深海现代沉积物中,以及北京十三陵元古宙沉积岩中的宇宙球粒进行了比较,结果表明它们在化学成分上虽有差别,但在颗粒大小和表面结构上是类似的。

The first discovery of cosmic spherules in modern sediments of the Golden Pebble Beach (Jinshitan) in Dalian, Liaoning Province

Iron cosmic spherules were discovered for the first time in modern coastal sediments of the Rose Garden,which,as a part of the Golden Pebble Beach in Dalian City,is a nation-grade scenic spot where the quantity of cosmic spherules is fairly large.18 grains were separated from a 2.4 kg sample whose size is less than 0.5mm.The particle sizes of cosmic spherules range from 158 um to 423 um,and most of them possess segregation and mosaic structure on their surfaces.The cosmic spherules can be divided into four types according to their chemical composition,i.e.Fe,Si-Al-Fe,Cr-Fe,and Ti-Fe species.The relationship between minerals in the Ti-Fe cosmic grains,which constitute a species of cosmic spherules collected there,was studied specially in this paper,and the results show that the titanium magnetite was formed around magnetite by quick cooling segregation.Comparative studies of cosmic spherules collected from modern sediments of Dalian in Liaoning and Zedang in Tibet and those from the sediments in deep sea of the Pacific Ocean as well as from the Proterozonic sedimentary rocks in the Ming Tombs of Beijing have shown that their chemical compositions are different from each other,but their particle sizes and surface characteristics are similar to each other.