和泉山脈の和泉砂岩層

Lately Mr., C., Kato, teacher of Kishiwada Middle School, informed me with a findeing of new fosseillocalities in the Izumi sandstone series to the south of City Osaka; so I made with him a short trip to those localities., What follow are the chief points ascertained by this trip., 1) Nothing has been known before of the base of the Izumi sandstone series in the Izumi sandstone belt., According to the previous work, it is said that the series is intruded by granite in its western portion and cut by a fault in its eastern portion., But I found at Akiyama a good exposure of the base of the Izumi sandstone series., There the series overlies, uncon formably upon a granitic rock mass., The basal congolmerate bed dipping about 30 degrees to the south, consists mainly of granitic pibbles and arkose cement, both of which must have been derived from the basement rock., Dr., S., Yehara's assumption of the fault-contact between the Izumi sandstone series and the granite mass is not correct, so far as my observation goes., (See the unconformity at Akiyama on Plate IX., ) 2) The Izumi sandstone sereis can be divided into the following (in the ascending order):- 1., Kasaya conglomerate., 2., Asenotani shale., 3., Kinyuji sandstone and conglomerate., 4., Warazuhata shale and sandstone., 5., Tsuzurahata sandstone and conglomerate., The series forms a syncline, running parallel to the Median Dislocation Line, which separates the series from the crystalline schist group in the Outer Zone of Southwestern Japan., 3) The fossile have been never found from this type-locality of the Izumi sandstone series, in contrast to their abandant occurrence at Anaga on the Awaji Island., I found however that the Asenotani shale contain many fossils and serves as a key-bed in the series., The fossils collected form the shale are shown in the table in the Japanese text, of which more important are Gaudryceras tenuiliratum Yabe (Plate X) and Parapachydiscus aff., Egertoni Forbes (Plate XI), the former being known from the Upper., Ammonite Bed of Hokkaido and Sachalin while the latter from the Upper Senonian of India and Europe., As summarized by Professor H., Yabe, the Urakawa, or Japanese Senonian, series overlies unconformably on the Palaeozoic rocks in the Abukuma mountainland and gneiss and crystalline schist in Kyushu., In connection with these facts, the unconformity relation between granite mass and the Izumi sandstone series treated in the present paper may be of significance for the consideration of the Senonian transgression in Japan.,