On the Miocene Stratigraphy of the Sen-nan District, Northeast Honshu, Japan

1) The Miocene deposits in the surveyed area (Fig. 1) are subdivided into several formations and members as shown in Fig. 2. Each lithological unit is defined and described, and the stratigraphic relations among these units are summarized in Table 1. 2) The sedimentary history and some problems concerning the Miocene stratigraphy of the present district are briefly discussed as follows : - a) Judged from the local variation in the lithological and faunal facies of the deposits, three sub-units of the marine depositional basin are recognized. The differentiation of the respective basins may have become distinct in the upper Miocene. b) The stratigraphic position and faunal composition of the so-called Moniwa and Hatatate fauna in the Sendai district and its environs (S. Hanzawa et al. 1953) must be revised as the result of the stratigraphic survey by the writers