試錐結果からみた鹿児島地溝西縁部姶良町の地下地質と温泉貯溜層

概要

論文の詳細を見る
Kagoshima Graben of southern Kyushu is a volcano-tectonic depression, which is presumed to have been formed ca. 2.9 Ma. The depth of the graben considerably exceeds 1,000 meters. A bore hole deeply dri11ed in the search for hot water is situated in western margin of the graben. Our study of the boring samples has reveals that the subsurface stratigraphic sequence is mainly divided into three formations. The lower formation consists of subaqueous pyroclastic rocks and siltstone with foraminifera and pollen fossils ; both the middle and upper formations are composed of welded tuff. These are correlative with the graben-fill marine deposits (Kekura Formation) of the middle Pleistocene and the terrestrial pyroclastic flows from gigantic calderas of the upper Pleistocene respectively. A fault between here and western adjacent area is inferred, and its vertical displacement after the deposition of the lower formation is estimated to be about 500 meters. The fault may be one of the western marginal normal faults of Kagoshima Graben. We present a structural model of geothermal reservoir based on the analyses of alteration minerals, chemical compositions of thermal water, temperature, change of water level，etc. The geothermal water is embedded in two horizons of the lower formation. The reservoirs are accompanied by superior cap rocks resulted from self-sealing. The water of this well belongs to that of a sea coast-type hot spring. However it is richer in Ca^<2+>, Mg^<2+> and SO_4^<2-> and poorer in K^+ than typical one.
秋田大学鉱山学部附属資源地学研究施設の論文
1988-03-00

試錐結果からみた鹿児島地溝西縁部姶良町の地下地質と温泉貯溜層

スポンサーリンク

概要

著者

関連論文

スポンサーリンク

試錐結果からみた鹿児島地溝西縁部 姶良町の地下地質と温泉貯溜層

スポンサーリンク

概要

著者

関連論文

スポンサーリンク

試錐結果からみた鹿児島地溝西縁部姶良町の地下地質と温泉貯溜層