Abstract
In this paper, a description of the Tertiary system, which is named the Muroto Peninsula Group, in the northern part of Muroto peninsula, Kochi prefecture, is presented. The Muroto Peninsula Group in this area is divided into the Noneyama Formation, the Futamata Formation and the Takeyashiki Formation in ascending order by rock facies. The Noneyama Formation consists of massive sandstone, alternations of sandstone and shale, and shale. This is about 2,800 meters in thickness. The Futamata Formation is separated from the Noneyama Formation by the Jadani Fault, and consists of massive sandstone, alternations of sandstone and shale, and shale. This is about 3,000 meters in thickness. The Takeyashiki Formation is connected with the Futamata Formation by the Todoro Fault. The Takeyashiki Formation, about 2,000 meters in thickness, is massive sandstoue, alternations of sandstone and shale, shale and conglomerate which contains gravels of metemorphic rocks. The strikes of the strata of the Muroto Peninsula Group show E-W to EEN-WWS. The important folds observed in the Futamata Formation form a wavy succession of anticline and syncline. There are seven faults in this area, namely, from south to north, the Iwasa Fault, the Jadani Fault, the Hiranabe Fault, the Sugenous Fault, the Todoro Fault, the Otani Fault and the Kuki Fault respectively.
