South Kanto district 1. The Naganuma Unconformity observed near Yokohama between upper and middle Pleistocene formations is traced over the south Kanto district. The author describes its shapes and the basis of the areal correlation. He comes to the conclusion based on those observations that it is formed closely connected with the eustatic movement. 2. The author proposes the schematic diagram of the development of the sedimentary basin from Miocene to Pleistocene (Fig. 5). He divides the sedimentation stage into several subitages on the basis of the segular character (Sedimentary Imbricate structure). He shows the existence of tectonic epoch in the folds and faults systems. 3. The geologic structures of this district are controlled by those with east to west and north to south directions, and the undulated ones which are composed form the former and latter ones. The sedimentations proceed closely connected with those structures. 4. The Miocene, Pliocene and lower Pleistocene formations are deposited in the basin formed by the collapse subsidence from the east of Boso Peninsula to the northeast of Kanto basin. At the middle Pleistocene the upheaving area is formed in the basin and the collapse basins appear in the northwest of Kanto Plain and the interior of the Tokyo Bay. At the same time the steps-like faults come into being along the coast of the Pacific ocean. It is also this time when the volcanoes begin to go into eruption in the inner side of the Honshu. Some of them are accompanied by the calderas. The earth's crust are broken accompanied by the upheavals and the blocks come into existence which go up and down. The author believes that they are controlled not by the horizontal compressive forces but by the vertical ones generated in the upper mantle. Niigata district 1. The thick Tertiary and Quaternary formations are found in the Niigata Tertiary basin and surrounding areas. Their tectonic frameworks are controlled by the structures with NE-SW trend and those with NW-SE one, though the former is more distinguished in the neogene formations. The author proposed the schematic diagram of the development of the basin (Fig. 12). The Kanto and Niigata districts are situated in the central Japan where are exactly the places of intersection of the Izu-Bonin island arc and the Honshu one. The complex structeres of the areas might be attributed to the interactions of the tectonic movements of both arcs.

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Concerning the eastern half of the Cenozoic Setouchi Geologic Province, Southwest Japan, Pliocene and Pleistocene tectonic movements were briefly reviewed. The movements of the Setouchi Geologic Province started out of the accumlation of the Middle Miocene marine sediments, viz. the First Setouchi Series, in the First Setouchi Inland Sea which extended from the Chugoku district in the west to the Southern Shinshu district in the east. In this connection, those sediments were subjected to the tectonic movements along the latitudinal trend (so-called Setouchi trend). After then, the Late Miocene upheaval brought forth the retreat of the sea from this area and the succeeding peneplanation. As the renewal of the movements, the regional subsidence in the Kinki and Tokai districts originated the appearance of three lacustrine sedimentary basins in the early Pliocene. Those were the Paleo-Bay of Osaka (including Osaka, Kyoto and Nara Basins), Paleo-Lake Biwa (including Iga and Oomi Basins) and Paleo-Lake Tokai (the area around Ise Bay). The sediments which filled those basins during the late Pliocene and the early Pleistocene are generically called as the Second Setouchi Series and are named as the Osaka, the Kobiwako and the Tokai Groups respectively. To correlate the basal horizon of each Group, it is clarified that the depreression of basin started from the area around Ise Bay (Paleo-Lake Tokai) and went along to Iga Basin (Paleo-Lake Biwa) and Osaka and Nara Basins (Paleo-Bay of Osaka) successively, namely from east to west. Further more, it is conspicuous that those basins were separated with one another by low relief barriers of meridional trend. As to the formation of each basin, it is general that the center of deposition shifted from southern or eastern part to northward or westward. During these process proceeded, the mountain ranges of meridional trend in the Kinki district upheaved gradually, accompanied by steeply dipping reverse faults at their feet. As a result, the meridional structural trend (so-called Suzuka trend) became distinct with sharp contrast of mountain and basin topography. Such conspicuous tectonic movements of the Second Setouchi Stage have been explained by "foundation folding" of MAKIYAMA (1956), and IKEBE (1956) gave the term of "Rokko Movements" to those geological phenomena. Regarding the tectonic movements of the Second Setouchi Stage, following four stages are discriminated. 1) The stage of depression in the early time of lacustrine basins. 2) The stage of basin separation in the later half time of lacustrine basins. Birth of steeply dipping reverse faults at the foot of mountains of meridional trend. Sharp contrast of mountain and basin topography. 3) The stage of general upheaval. Activation of reverse faults and further differentiation of the basin into small block masses, from the end of deposition of the Second Setouchi Series to the beginning of deposition of the terrace sediments 4) The stage of differential movements of separated block masses, during the time of deposition of the terrace sediments. In connection with them, the Rokko Movements are divided into four stages, early, middle, late and latest. Between the early and the middle stages, there was distinct difference in the mode of movements, that is from subsidence to upheaval. The gap between the late and the latest stages is represented respectively by the mode of sedimentation, such as the Quaternary strata with depositional surface and those without it. In other way, the late stage of the Rokko Movements is used to be treated as "the climax of the movements ".

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The Late Neogene-Quarternary Sedimentary basins in the middle part of the Fossa Magna are classified as follows: 1. Around the Nagano Basin, the geologic structure between the Neogene and Quarternary sediments are concordant with each other. Each basin had a tendency to migrate gradually from the southwest to the northeast. These facts indicate that the characters of the basin-forming movement in these areas hadn't changed from Neogene to Quarternary. 2. Aqueous pyroclastic sediments which are widely distributed over the Motojuku, Kirizumigawa and Akima districts, were formed in the Late Miocene sedimentary basins. In these areas the basin-forming-movements were characterized by the depression along the faults and the succeeding volcanisms. In the Pliocene-Pleistocene, no sedimentary basin have been formed in these areas. 3. The Komoro Group, and the Enrei and the Sanjiro Formations, which are the Middle Pliocene-Middle Pleistocene pyroclastic sediments, are distributed extensively around the Yatsugatake volcano and adjacent areas. Their lithologic features are mainly aqueous in their lower part but terrestrial in the upper part. It seems that a shape and size of a basin, and volcanisms in this area were controlled by some tectonic lines formed in the Early-Middle Pliocene. 4 The large amount of gravels are accumulated in the Matsumoto Basin. Most of them had been derived from the Northern Alps and eastern Uchimura mountain areas in the Middle-Late Pleistocene. In this area the Itoigawa-Shizuoka Tectonic Line and subparallel faults run from north to south. It may be that these faults had play an important part in a basin forming process. There is no volcanism in this basin, but the basin-forming movement may be assumed to connect with the volcanism on the Japanese Alps complex.

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Niigata Plain Collaborative Research Group consists mainly of science teachers of elementary and high schools who have devoted themselves to the study of plains and terraces of Niigata Prefecture since 1960. Their ultimate aim was to furnish an example of geological education which makes efficient use of geological features of the given region. The twelve years' research has resulted in the discovery of the utmost importance of Uonuma Formation, which forms the basis of most of those plains and terraces. The several problems found in the investigation of Uonuma Formation are presented as the material for debate in the present symposium. (1) It is confirmed that the volcanisms of the Yoneyama district took place from Pliocene to early Diluvium epochs. Those volcanisms may be structurally differentiated from the last Green Tuff activity, but further study is require for the confirmation. (2) According to the difference of altitude at the plains and in-lands, and of geological structre, it may be pointed out that the Uonuma group underwent a large fluctuation. (3) It is appreciated that acidic volcanisms took place through the overall Uonuma age, and basic ones did from the earliest to early Uonuma age. Interrelation of the both volcanisms and the relation between the volcanisms and tectonisms are problems which should be studied furthermore. (4) Geological study of the Yashiroda formation is required to clarify whether the tectonism of Uonuma age and the formation and fluctuation of the terraces are of serial.

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The Kanto Basin is well known as a typical Quaternary tectonic basin and following discussions have taken with regard to its development and its crustal movement. 1) Stratigraphical and sedimentological examination-Crustal movement of the Kanto Basin began at so called 'Kurotaki phase' in Miocene, and thick deposit, ranged from Kazusa group to Narita group, filled up the basin. According to Naruse (1968) based on Kawai (1965) and others, the N-S section of these neptons, lower Kazusa group, upper Kazusa group and Narita group, suggest that the center of the basin gradually moved to northward during every nepton being built. Especially the axis of submergence shifted the direction from E-W to NW-SE. 2) Examination on the structural geology-Studies of this field were based on the analysis of subsurface structure. According to Kakimi (1968a), on the minor structre of Kazusa group and Sagami groug in Boso and Miura peninsula, both E-W-normal and reverse faults are remarkable in Miura group and Kazusa group. While in Sagami group NE-SW-normal faults are remarkable. These facts were acknowledged geophysically, hydrogeologically, geomorphologically, etc., and they suggest the structural direction was shifted from E-W to N-S at about the same age. 3) The period of the shift can be known better on the more detailed field survey. Such a survey was advanced by Kanto Quaternary Research Group in the southwest of Yokohama city and its vicinity. Following examinations can be extracted from the new knowledge. i) The stratigraphy in the area-There are middle-upper Pleistocene neritic deposits covering the Miura group (Plio-Pleistocene deposits) unconformably. They are from lower formations, redefind "Nagnuma" and "Byobugaura", and newly named "Maioka", "Kamikurata", "Totsuka" and "Shimosueyoshi". They are divided into three formations, "Naganuma", "Byobugaura" and "Shimosueyoshi" up to the present.

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During the Lower and Middle Miocene, the marine sediments which consist of green tuff, mud, sand and lava had been formed throughout the Green Tuff Area of the Southern part of Tohoku District, Japan. The uplifting movements characterized by the tilting or flexure with the axis of NW-SE or N-S direction were caused in the several parts during the Late Miocene, and consequently the inland basins (i. g. the Palaeo-Aizu Basin) were formed. The terrestrial sediments had been formed in these inland basins from the Upper Miocene to Lower Pleistocene, though the basins more or less migrated through these ages. These sediments were transformed by the tectonic movements during the latter half of Early Pleistocene or the early half of the Middle Pleistocene. The subsiding movement which may be caused by the depression or flexure began anew crossing with the inland basins mentioned above during the Middle Pleistocene. This movement formed the recent basins which are represented by the Aizu, Koriyama and Fukushima Basins. The volcanic activities changed in the nature and situation with the changes of the sedimentary basins since the Miocene.

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