@article{oai:nagasaki-u.repo.nii.ac.jp:00020570, author = {松岡, 數充 and 西田, 史朗}, issue = {1}, journal = {長崎大学教養部紀要. 自然科学篇}, month = {Sep}, note = {Since the last several years, we have obtained many geological and paleontological informations on the latest Pleistocene to Holocene period in the Nara Basin. Based on these data, we propose two new formations, namely the Yamanobe and Ikaruga Formations in ascending order. The Yamanobe Formation is latest Pleistocene in age (ca.34,000 Y.B.P. to 21,000 Y.B.P. based on 14C dating), and consists of sand, silt and peat beds intercalated with volcanic ash layers.Plant remains such as Picea, Menyanthes trifoliata and others indicate that this formation was formed under a cool temperate climate. On the other hand, the Ikaruga Formation was formed in the Holocene period (ca. 10,000? Y.B.P. to Present), and composed of medium to coarse sand with gravels and silt beds, and lacking peaty beds. In the upper part of this formation, a cultivated soil layer is always observed. This formation yields many macro - and microplant remains characterized by a predominance of warm temperate taxa such as Quercus gilva, Machilus thunbergii (?), Mallotus japonicus, Sapindus mukurossi and others. From the view points of the stratigraphy and fossil evidence, we become aware of a very important hiatus between the both formations., 長崎大学教養部紀要. 自然科学篇. 1980, 21(1), p.35-47}, pages = {35--47}, title = {奈良盆地の最上部更新-完新統}, volume = {21}, year = {1980} }