国鉄新幹線新丹那トンネルの地質

概要

論文の詳細を見る
A new tunnel was excavated parallel to the old Tanna Tunnel from which it is removed for 50m to the north. The new tunnel passes through a thick section of older Miocene, Pliocene, and older Pleistocene volcanic rocks interbedded occasionally with thin layers of marine and lacustrine sediments. The Miocene Yugasima Group, Hudo Tunnel Basalt Group, Atami Tuffs, and Ohira Andesite Group were laid down under the sea, resulting in the prevalence of autobrecciated lava flows and water-quenched basaltic and andesitic glass breccias. The Pliocene and Pleistocene volcanic rocks were largely accumulated subaerially, and therefore the lavas are frequently interbedded with unconsolidated ash layers.
一般社団法人日本応用地質学会の論文
1964-03-10