青函トンネルの粘土鉱物(第2報) : 本州方について

概要

論文の詳細を見る
Clay mineralogical investigation was carried out on 70 core samples obtained from the pilot and service tunnels at the Honshu side of the Seikan Undersea Tunnel by means of X-ray diffraction technique, tbermal analysis, and electron microscopy. Some of the core samples were observed under petrographic microscope. The results obtained are as follows : The above core samples contain di-octahedral and tri-octahedral smectites, chlorite, interstratified mineral of chlorite/smectite, and mica clay mineral as clay minerals. Among them, di-octahedral smectite occurs most dominantly and is widely distributed in pyroclastic and sedimentary rocks, whereas tri-octahedral smectite is mainly found in basalt. The Kunnui formation of this area can be divided into two mineral zones near the location 5.8 km from the portal of the pilot tunnel and near the location 5.6km from the portal of the service tunnel. One, extending from these locations to the land, is correlative with the lower part of that formation by the presence of interstratified mineral of chlorite/smectite, and the other, extending to the central part of the straits, is correlative with the upper part by the absence of that mineral. Further, based on the distribution of zeolites, it is found that the lower part of that formation is characterized by the analcime zone and the upper part by the clinoptilolite-mordenite zone.
日本粘土学会の論文
1982-12-25