Mixed layer mica/smectite in the Miocene sediments of the area southeast of the Lake Towada, Northeast Japan
Mixed layer mica/smectite in the Miocene sediments of the area southeast of the Lake Towada, Northeast Japan
复制标题
日本东北部十和田湖东南部中新世沉积物中的云母/蒙脱石混合层
DOI：
10.2465/ganko1941.80.526
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
Yoshihiko Oyama
中科院分区：
文献类型：
--
作者：
Yukito Oda;Shunichi Suzuki;Yoshihiko Oyama
对十和田湖东南部地区18个钻孔的岩心样品进行了调查，以确定中新世沉积物中云母/蒙皂石的可膨胀性。在西部100 ~ 400 m范围内，膨胀性随深度的增加而减小，从80%左右减小到0%，而在东部600 m以上的范围内，膨胀性随深度的增加而减小。膨胀层在云母/蒙皂石中所占比例由东向西逐渐减小。四泽组顶部的可膨胀层等值线图显示，在约500 m处，可膨胀层从80%减少到10%。蒙脱石向云母/蒙脱石混合层的转化开始于0.6-0.8%的镜质组反射率，而向10%的可膨胀层的转化发生在1.2-2.8%的镜质组反射率。黑矿和铜铅锌矿脉的层状矿体局限于四泽组顶部膨胀层20%以下的区域。沉积物中云母/蒙皂石混合层的膨胀性对找矿有指导意义。
Core samples from 18 boreholes in the area southeast of the Lake Towada were investigated to determine expandability of mica/smectite in the Miocene sediments. The expandability decreases with depth from about 80 to 0% over intervals of 100 to 400m in the western part of the area, while intervals of more than 600m in the eastern part. The percentage of expandable layers in mica/smectite decrease from east to west. The expandable layer isopleth map at the top of the Yotsuzawa Formation shows a decrease in expandable layers from 80 to 10% at a distance of about 500m. The conversion of smectite to mica/smectite mixed layers begins at 0.6-0.8% vitrinite reflectivity, and the conversion to the 10% of expandable layers occurs in 1.2-2.8% vitrinite reflectivity. Stratiform ore bodies of Kuroko and copper-lead-zinc veins are restricted to the zone less than 20% of expandable layers at the top of the Yotsuzawa Formation. The expandability of mica/smectite mixed layer in sediments is useful as a guide to mineral exploration.