The Age measurement of the tephra layers, fill in the San in district since the middle Pleistocene. Using the Thermo luminescence technique

本研究首先研究了几种条件下热释光辐射电荷的累积速率。结果表明，厚度为10 cm的铅盒内未出现辐射电荷积累现象。黄铜或铜管中没有发生额外的辐射电荷。结果表明，埋设在地下的热释光元素的辐射电荷在不同的区域是不同的。因此，辐射电荷率必须在采集火山玻璃样品的同一地点进行测量。在萨宁地区，作者对火山玻璃的折射率、矿物成分等进行了检测。并对分布于北国地区的一些非洲菊标本进行了考察，作为参考。并测量了它们的热释光强度。结果表明，该技术能够适用于所有的陀螺。然而，由于矿物组成的原因，一些火山灰中的辐射电荷积累很少。例如，K-TZ含有大量的石英颗粒，具有大量的辐射电荷积累。另一方面，奥金森地区的特弗拉在地层上比K-TZ古老，其热释光强度较弱。与K-TZ相比，北国较古老的火山碎屑流沉积具有较强的热释光。代森粉尘浮石的热释光强度有明显的差异。火山灰的热释光强度可以计算出它们的尘埃年龄。

At first, the accumulation rate of radiation charge of thermoluminescence in several conditions are studied in this research. As the results, accumulation of radiation charge weren't occur in the lead box of the thickness 10cm. The additional radiation charge in the brass or copper tubes did not occur. It is revealed that the radiation charge of the thermoluminescence elements laid under the ground were different at each region. So, it is clear that the radiation charge rate must be measured at the same point where tephra were sampled.In San'in district, the author examined the tephra layers as to refractive index of volcanic glass, mineral composition and a so on. And as a reference, some samples of tephra distributed in Hokuriku district were examined. And also, the thermoluminescence intensity of these tephra were measured. It is revealed that this technique is able to apply for all of these tephra. However, the radiation charge accumulation is a very few in some tephra because of their mineral composition. For example, K-Tz, which contains large quantities of quartz particle, has large radiation charge accumulation. On the other hand, the tephra of Oginsen area, which are older than K-Tz as to stratigraphically, their thermoluminescence intensity are weak. And the thermoluminescence of the quite older pyroclastic flow deposits of Hokuriku is quite strong in comparison with the K-Tz. Daisen fallout pumices have a clear deference thermoluminescence intensity each other. The thermoluminescence intensity of tephra can be calculated into their fallout age.