In Southeast Kalimantan of Borneo, the Martapura Cretaceous System is widely distributed. The stratigraphical and paleontological studies of the system were carried. out by mostly Dutch geologists during the end of the 19 th to the begining of this century. According to the workers, the Martapura System yields rich fossils such as pelecypods, gastropods, cephalopods and foraminiferas and the age of the system is Cenomanian to Senonian. In June of 1972 the present authors visited Southeast Kalimantan to establish the detail stratigraphy and collect useful fossils from the Cretaceous rocks along the upper stream of the Riam Kanan River, east of Bobalis mountainlands, where was already sank under the water after the completion of the Riam Kanan Dam in July of the year. As a result of the survey, they divided the Cretaceous strata called the Manunggul Formation into five units, Kalaän, Benuariam, Tabatan, Rantaulajon Formations, in ascending order. The Kalaän Formation unconformably overlies the schist and consists of conglomerates, sandstones and siltstones and contains Turonian ammonids, Reesidites sp., Inoceramus teraokai MATSUMOTO and NODA I. latus SOWERBY. The Benuariam Formation is composed of porphyritic lavas, agglomerates and tuffs, and conglomerates. The Tabatan Formation consists of sandstones and conglomerates. Orbitolina of Apto-Albian form is obtained from the limestone pebbles in the conglomerates of this and the Benuariam Formations. The Rantaulajon Formation is composed of fissil shale which contains rich estheriids, Pseudocyclograpta hashimotoi KOBAYASHI n. sp. and Lioestheria sp. These estheriids indicate that the formation is nonmarine origin and probable Senonian. The authors also survey Cretaceous strata distributed along the Riam Kiwa River and in Batotiris and its vicinity, west of Bobalis mountainlands. The Cretaceous strata exposed along the Riam Kiwa River were subdivided into four formations Buntutriam, Rantau Lingitan, Riam Lingitan and Atiin Formations, in ascending order. The Buntutriam Formation is composed of conglomerates of porhyrite cobbles and thin sandstone and mudstone layers. The Rantau Lingitan Formation comprises mudstone which yields late Turonian ammonoids, Subprionocyclus neptuni (GEINITZ). The Riam Lingitan Formation is made up of sandstone which contains many pelecypods. The Atiin Formation consists of purple colored tuffs and sandstones. The Rantau Lingitan and Riam Lingitan Formations are correlated with the Kalaän Formation and the Atiin Formation with the Benuariam Formation along the Riam Kanan River. Eocene to Miocene strata exposed along the Riam Kiwa River were also surveyed in detail. Based on the study of larger foraminiferas, the authors found that Td stage of Oligocene seems to be lacked in this area.
Recently some ice-wedge casts or pseudo structures have been reported in the lowlands of Hokkaido. In present paper ice-wedge casts in three localities (Fig. 1) are surveyed and described in detail. Ice-wedge casts consisting of fine materials driven from superficial deposits cut through stratified volcanic ash or terrace gravel. They have V-shaped structure normally and it's variations in some cases as much as about 2 m long and as much as 1-2 m wide at the top. Along the side walls of wedges there are found clay flaps and distortion, especially up-turning of strata, and within the walls aligned stones. Large scale polygons and white patches are interpreted from air photos at Shimosahoro and Kamishunbetsu. At Chiraibetsu the wedges are supposed to form polygonal patterns on the densely vegetated ground surface judging from strikes of the wedges in vertical exposures. Erimo Volcanic Sand, which had been the uppermost active layer of frozen ground and filled up wedges when ice melt, dates approximately 32, 000 14C years. No ice-wedge cast has yet been found in another horizon of air-laid volcanic deposits. Thus the coldest phase of climate during the Last Glacial is thirties thousand years BP. Based on Péwé's observations (1966), decreasing of temperature at the time should be estimated as 12°C-14°C in the lowlands of eastern Hokkaido where present mean annual temperature is nearly + 6°C.