Some Notes on BORSUK's Tertiary Plant Fossils From North Saghalin and on the Correlation of the Agnevo Coal Bearing Formation to South Saghalin
Journal of Geography (Chigaku Zasshi)
M. O. BORSUK (1956) in his abstract (in Russian) on the Paleogene flora of Saghalin stated that the lower Due formation and the conglomerate bed contain many plant fossils, although the species are not much variable. The age of these fossils is defined as Late Eocene to Oligocene. These plantfossils from North Saghalin are illustrated in 21 figures. The difference in flora between the Upper Due formation and the Lower Due formation chiefly depends upon the climatic changes. The Agnevo formation
... is very similar to the Upper Due formation. The Agnevo formation was primarily defined by A. I. KRYSHTOFOVICH (1925). On the basis of the columnar section, the translator believes that this formation is not the upper part of the Khoinji volcanic effusives. According to the translator's experience in South Saghalin, the Agnevo formation may be correlated to the Kiyokawa coal-bearing formation. So, the translator wanted to make this relation clear by adding the geologic map compiled from previous data. The lower coal-bearing formation (Naibuchi group) may be correlated with the upper half of the Yubari group in Hokkaido and may be Oligocene in age.