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1. On the basis of tectonic lines, geological features and crustal movements, Fujian Province is divided into the three geological districts : north-west uplift, south-west depression and east volcanic depression districts. There are 6 deep and large fault zones, four of which run north-east (Sinian direction) and two of which run north-west.2. Caledonian granites are mainly found in the north-west uplift district and Variscan-Indosinian granites in the south-west district, but Jurasso-Cretaceous (Yanshanian) granites distribute in all of the three districts. Thus, Jurrasso-Cretaceous granites are most prominent in Fujian Province throughout the whole of the geological age.3. It is remarkable that the Jurasso-Cretaceous granites are closely related to the four fault zones running north-east. The intrusive and volcanic rocks, derived from the same magma source, took place in the similar tectonic environment and formed polygenetic intrusions. The magmatism was most active in the late Jurassic period with four intrusions.4. Cretaceous granites, emplaced mainly in the east volcanic depression district, compose of many kind of rocks such as granite, granodiorite, quartz diorite, monzogranite and so on. The intrusion in the Cretaceous period took place four times with miarolite granite comming into being in the third intrusion, but their granites show the same absolute age of 100-80 Ma by radioactive isotopes.5. Miarolite granite runs north-east from Shantou in Guangdong Province through east Fujian Province to Zhoushan in east Zhejiang Provice, and then across the East China Sea to Masan in South Korea. This is one of the most remarkable features of the geological structure of East Asia.6. Details of the petrological characteristics of Fujian Province are described in the paper.

The Amatsu Formation and the Toyooka Subgroup consisting of the Kiyosumi and the Anno Formations are well exposed along the Inokawa River, the uppermost tributary of the Obitsu River which runs northwestward from the northern foot of the Kiyosumi mountain (315m) in the Boso peninsula.The valley of the Inokawa River is one of the areas well-known for the distribution of the Toyooka Subgroup and the basal member of the Kazusa Group. The writers observed on the stratigraphy of the Kiyosumi and the Anno Formations along the Inokawa River paying the special attention to the rhythmic aspects of sediment, the development of conglomerate, and the existences of pyroclastic layers, such as white or pink or so-called gomashio tuffs, pumice and scoria. Some results of the present work are as follows:1) The Kiyosumi Formation, consisting mainly of sandstone with thin bedded siltstone and conglomerate, is subdivided into three members, namely the lower conglomeratic sandstone (about 45m thick), the middle sandstone (about 140 m thick) and the upper sandstone (about 80 m thick) by the lithologic facies and the sedimentation of the strata.2) The Anno Formation which is characterized by the alternation of tuffaceous sandstone and siltstone with many kinds of pyroclastic sediments, is subdivided also into three members, i. e., the lower siltstone (about 95m thick), the middle alternation of sandstone and siltstone (about 85 m thick) and the upper sandstone (about 120m thick).It is remarkable that the middle alternation contains abundantly so-called gomashio tuff in several horizons, but that the upper sandstone is interbedded frequently with rather thin scoria which is black or dark in colour.3) In this surveyed area the thickness of the Anno Formation is more or less larger than that of the Kiyosumi Formation, compared with the case in other areas where two Formations are distributed.4) The thickness of the Kiyosumi Formation in the Inokawa River area is almost same as that of the Formation in the Ubara area along the Pacific Ocean, but the lithologic facies is somewhat different from each other between two areas, namely the conglomerate facies is developed considerably in the Inokawa River area, but it is very rare in the Ubara area.5) In the Inokawa River area the carbonaceous layers which contain fossil pollen grains and spores are abundant, but in the Ubara area they are rather few.6) The Kiyosumi and the Anno Formations in this area yield microfossils such as foraminifers and calcareous nannoplanktons, but macrofossils are very rare.

Concerning the mechanism of the deposition of the Kurotaki Formation in this district along the Pacific coast of the Boso peninsula, many problems still remain unsolved. There are, however, some facts and considerations clarified in this work as follows:1) The thick sediments with colossal boulders of the Kurotaki Formation distribute only at the Boranohana and the Kurogahana areas, Ubara, Katsuura city, throughout the areas in the Boso peninsula where the Formation distributes, and are observed to be extraordinary in sediments.2) The Formation is about 35 m thick, and contains various kinds of pebbles and boulders, such as massive medium-grained sandstone, silty sandstone, tuffaceous siltstone, chert, andesite and so forth. They came mainly from the Kiyosumi Formation below, and some of them might have come from the Anno Formation and Mesozoic and Palaeozoic Groups.3) The conglomeratic facies of the Formation in the area distribute in the direction of NE-SW. And the sedimentary cycles shown in conglomerate, coarse-grained sandstone and fine-grained sandstone, have been repeated several times. The diameter of a pebble at the lowermost horizon is larger than that at the upper horizon, and the form of the pebble at the lowermost horizon is angular or subangular, and sometimes bladed. These conglomeratic facies are deposited on the concave plane which was made by the erosion of the Kiyosumi Formation.4) The Kurotaki unconformity seen at the Boranohana and the Kurogahana areas, has clearly been eroded at the sea-bottom by slumping or sliding.5) From the field evidences, it is presumed that the channel was formed, and then it was filled with the conglomeratic facies of the Formation.6) The phenomena mentioned above are regarded as the earliest appearanceof the sediments in the late Pliocene-early Pleistocene Kazusa Group.

The sedimentation of the base, litho-facies near the base, the key bed and the sedimentary environment of the formation, were studied on the Kurotaki Formation, which is distributed from the Minato river-section in the west, to the Obitsu river-section in the east, over the Boso Peninsula.1) The Kurotaki Formation lies on the Anno Formation unconformably at most places, for instance, the Takamizo-section, northern Mitsuishi mountain-section where the basal part of the formation varies its litho-facies and contains fossiliferous and impure limestone.2) Two types of litho-facies were recognized in the formation except at the basal conglomerate. One is the silty sandstone facies intercalated many tephras, the other is the massive tuffaceous sandstone facies that is very rare of tephra. Both facies are rhythmically repeated from the lower horizon to the upper one and useful for the observation of the correlation of the formation in the area.3) 2 set of tephras which had hitherto been known as Kd 23 (_??_TM 1) and Kd 38 (_??_TM 3) in the area were investigated. As the result, it is clear that the former does not continue at a few sections, but the later continues roughly.4) Except above 2 tephras, 5 new tephras, namely TM 2, TM 4-7 in descending order were found. Among them, TM 2 consisting of coarse-grained scoria is most important as a key bed because this tephra ranges horizontally so long all over the area.5) The beginning of the deposition of the formation in this area was roughly the same period. But more exactly speaking, from the distribution of new tephra TM 4-7, the sedimentation of the basal part of the formation was formed in different time.Therefore it is assumed that the Kurotaki transgression might be brought to fill up the depressed ground which had been formed by folding before the Kurotaki transgression.6) Judging from the tephra of TM 3-7, the Mitsuishi mountain area was the land until the beginning of the deposition of TM 3.7) After the deposition of TM 3, the area surrounding the western and eastern sides of the Sasa river-section was deposited in the deeper sea than the Mitsuishi mountain area was.8) We knew by the litho-facies that the eastern part of the surveyed area was deeper in the sea than the west area, when TM 1, 2 were deposited.

In the Boso Peninsula, the Cenozoic marine strata, especially of younger Cenozoic age, are well exposed successively, and full of fossils along the Yoro, Obitsu and Minato Rivers. Although calcareous nannoplanktons are abundant in these strata, the study on them has rarely been done except by TAKAYAMA (1967), NISHIDA (1976, 77) and MAEDA and SAWANO (1978).This study was planned in order to find out the stratigraphic distribution of the assemblages of calcareous nannoplankton from the Anno Formation along the Inokawa River, which is the uppermost tributary of the Obitsu River in the Central Boso.Calcareous nannoplankton floras were obtained from 32 horizons as shown in Fig. 2. A total of 16 species of calcareous nannoplankton belonging to 10 genera were identified. Among calcareous nannoplankton floras, Reticulofenestra japonica was very abundant through the lower horizon to upper one of the formation. The lower horizon was characterized by the abundance of R. pseudoumbilica, Cyclococcolithina leptopora and Cy. macintyrei, and the middle horizon by existence of R. pacifica and Coccolithus productus. On the contrary, in the upper horizon, Pseudoemiliania lacunosa and Gephyrocapsa caribbeanica increased in number, while the genus of Discoaster decreased distinctly.It is worthy of note that R. pseudoumbilica could not be seen in the uppermost horizon of the formation. Based on the remarkable facts of the first appearance of R. pacifica, Ps. lacunosa and G. caribbeanica, and the extinction of Sphenolithus abies and R. pseudoumbilica, the calcareous nannoplankton floras of the Anno Formation were divided into 6 assemblage zones.Judging from the characteristics of the assemblages, it is thought that the Anno Formation was deposited from the late stage of early pliocene to middle pliocene in geologic age.

1) This research was carried out, in order to clarify the stratigraphic relationship between the Katsuura and the Kurotaki Formations, particular attention being given to the tephra key bed known in the Katsuura district, which is named Kr in this article. The tephra key bed, outcropping in the area around Kasugadai and the Katsuura Bridge, in Katsuura city, was dealt as typical Kr.2) In the eastern part of the area, the strike of Kr runs NNE-SSW, but ENEWSW in the western part. Since Kr is cut by several normal faults, its distribution is slided horizontally and vertically.3) The tephra key bed (Kr) consists of three members, KRl, KRm and KRu, in ascending order. Among them, KRm, the middle one, is divided into five beds, m0, m1, m2, m3 and m4.4) Kr extends from the east, where Katsuura Formation is distributed, to the west where the Kurotaki Formation is distributed, through the Ishikiri and the Aiyama valleys. In the Aiyama valley, Kr is situated stratigraphically about 8m above the plane of the Kurotaki unconformity, but Kr disappears at the cliffs cut by the city-road about 0.6km to the west of the Aiyama valley.5) Each member of Kr becomes thinner in the western part than in the eastern part. At Matsube its total thickness is about 12m, but becomes about 9m in the Ishikiri valley, and about 4.5m in the Aiyama valley.6) In the western part of Kr, its rock characteristic changes distinctly and becomes the facies of the coarsegrained tuffaceous sandstone with the pumice and the scoria.7) If Kr is considered as a standard horizon, the Kurotaki Formation, in the Kurogahana area in the most-eastern part of the district, could be regarded to be the lowest horizon in its distribution, and also as the oldest. On the other hand, the Formation distributed in the most-western part of this district is the upper horizon and also younger than that of the most-eastern part of the district.8) It is, therefore, concluded that the Kurotaki Formation was deposited at different times with same facies, and also that the Katsuura and the Kurotaki Formations were deposited at the same time with different facies. It is remarkable that the Kurotaki Formation in the Kurogahana area lies under the Katsuura Formation as its basement.

In the western district of the Northern Alps of Japan, the Tetori groups are scattered, each in rather small area on the high mountains, such as Yakushi-dake, Kitanomata-dake, Kurobegoro-dake and others. In this paper the writer treats especially the group in the Kitanomata-dake area. The area is covered mainly by the Oritate-toge conglomerate, which is the basal one of the Itoshiro subgroup occupying the middle division of the Tetori group and is composed of the rounded pebbles of granite, gneiss, quartz-porphyry, cherty rocks, sandstone, hornfels and so on. The conglomerate along the upper drainage of the Kitanomata River, forming a monoclinic structure, is a southeastern part of the large basin structure situating in the southern district of Toyama Prefecture. On the eastern margin of this basin, the conglomerate unconformably overlies the basement of the Shimonomoto-type granitic rocks which intruded in late Palaeozoic, whereas on the southeastern margin is normal fault contact with the plutonic rocks of the same type. In the valley of the Kitanomata River the fossil plants are found, such as Cladophlbis exiliformis (Geyler), Onychiopsis elongata (Geyler), Podozarnites lanceolatus (Lindley and Hutton) and Xenoxylon latiporosum (Gramen), the discovery of the last of which is significant of its extensive distribution on the Tetori group.

As the result of the writer's survey on the erosion surfaces in the Haku-san mountain ranges and its adjacent areas, 19481954, the following main facts are known : 1) The Bessan erosion surface having about 2200 m. to 2300 m. in height lies near the peak of Bessen (2399.4 m. high) which is composed mainly of coarse grained sandstone and conglomeratic sandstone of the Tetori group of Mesozoic. Bessan, which lies to the south of the Haku-san volcanoes, and protrudes about 100 m. from the Bessan erosion surface, is seemed to be a monadnock on this surface.2) The basement of the Haku-san volcanoes shows from 2200 m. to 2300 m. in height. Therefore it is thought that the surface on this basement is the northern extention of the Bessan erosion surface.3) The Shira-kawa erosion surfaces having 1700 m. to 1800 m. in height are distinctly observed at Sarugababa-yama, Gozen-dake, Hideri-dake and other places, and these surface are about 300500 m. lower than those of Bessan district.4) The flat plane west of Gankyoji mountain in the Koike area was formerly considered as an erosion surface by predecessors but it is now regarded as a deposited plane due to the volcanic activities of the Gankyoji mountain.5) The Bessan and Shira-kawa erosion surfaces have been formed during from post-Miocene to the pre-Haku-san volcanic activities in Quaternary, and the former erosion surface seems to be more or less older than the latter in age.