常総台地の成田層の形成史 : とくに霞ヶ浦・北浦の成因に関連して

概要

論文の詳細を見る
In this paper, writers studied the morphological features of the bottom of the basin during the course of the sedimentation of the Narita Formation and the Ryugasaki sand and gravel bed in relation to the origin of their stratofacies. As a result of it, it has been cleared that the undulating structure of the base of these sediments took an important role as to the synthesis of them. Especially, the origin of the Lakes of Kasurniga-ura and Kita-ura closely related with the former structure and the change of lithofacies of these sediments. And the Ryugasaki sand and gravel bed corresponded the regressive facies of the basin of the Narita Formation. They assumed a small basin distributed around the Lakes of Kasumiga-ura and Kitaura during the course of the regresion of the Narita basin, and named it as a "Lake of Paleo-Kasumigaura". However, further study will be necessary to clear the relation of this ancient lake and the recent one.
日本地質学会の論文
1972-12-25