In dieser Abhandlung wird das Problem von Zufalligkeit und Notwendigkeit jeweils in der objektiven und in der subjektiven Dialektik behandelt. Daraus schlieBt der Autor, daB in der objektiven Dialektik die Hegelsche Auffassung von Zufalligkeit und Notwendigkeit fur deren ontogenetischen EntwicklungsprozeB giiltig und ubernehmbar ist. Im phylogenetischen Entwicklungs- bzw. EvolutionsprozeB dagegen sieht der Autor an, daB die Zufalligkeit jede wirkliche Moglichkeit darstellt, wahrend es sich bei der Notwendigkeit um eine auf die vergangene Wirklichkeit gegriindete richtunggebende Tendenz handelt, der entlang die Veranderung (die Entstehung und Entwicklung) vor sich geht. Was das Problem in der subjektiven Dialektik betrifft, gelangt der Autor noch nicht zu einem festen SchluB.

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Concentration of ammonium in biotites from Precambrian rocks in Finland has been determined under an assumption that ammonium in biotites of metasediments may be useful as a chemical fossil. Biotites from the Svecokarelian metasediments which were originally products of sedimentation about 2400-1900 Ma ago, have high ammonium contents (hundreds ppm). While biotites from the Postsvecokarelian igneous rocks (rapakivi granite, 1650-1700 Ma) and the Svecokarelidic plutonic rocks (1800-1900 Ma) have low ammonium contents (tens ppm). The results suggest that life activity was predominant during the sedimentation of Svecokarelian strata. This suggestion is consistent with a fact that valid signs of ancient life have been found from dolomites and graywacke-slates of the Svecokarelides. Biotites from the Presvecokarelidic schists of more than 2600-2800 Ma old have only tens ppm of ammonium. This value is in the same order as those of biotites from the Postsvecokarelian igneous rocks and the Svecokarelidic plutonic rocks. The results suggest that there was no life or less activity of life during the sedimentation of the original rocks of the schists. This is also consistent with a report that no evidence of fossils has been known in the Presvecokarelidic rocks. From these data, it is concluded that ammonium in biotites of metasediments is a useful chemical fossil in discussing on appearence and evolution of life in Precambrian time.

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The Sambagawa zone of this area can be divided into the following three regions. a) Northern region with igneous activity b) Central region with no igneous activity c) Southern region with igneous activity In the northern region with igneous activity on the southern bank of the Kinokawa, the Shibuta and linori formations are composed largely of basic volcanic ejecta, overlain by the Ryumon formation which consists chiefly of pelitic schist. As the geologic map (Fig. 4) indicates, these formations do not extend indefinitely in the strike direction, near the town of Kudoyama the limori formation pinches out. In this region the intrusion of igneous rocks took place during the erogenic movement, as proven by the occurrence of mafic to ultramafic rocks. These igneous rocks are distributed in the direction of the strike of the sedimentary rocks. The mode of intrusion is conformable with the surrounding sedimentary rocks. The mafic to ultramafic rock comprise dunite, cortlandite, syenitic gabbro, serpentinite and meta-gabbro. The larger ultramafic body consists of dunite, wehrlite, and gabbro occurs near the summit of Ryumondake, and recrystallized olivines are found in dunite. The ultramafic rocks of this region are mostly characterized by the presence of cortlandite which consists of titaneierous augite, kaersutite, olivine, and titanobiotite. Also in this region syenitic mafic rocks occur in two localitites. In the southern igneous activity region excepting so-called Mikabu zone the ultramafic rocks are mostly cortlandite. Mafic intrusive rocks conformably intruded into the surrounding sedimentary rocks. Whether these rocks can not be determined mostly alkaline or non-alkaline by the chemical composition of the clinopyroxene, but in one locality, the mafic rock is found to be an alkaline rock by the chemical composition of the clinopyroxene and the rock. The rock is composed to titanaugite, kaersutite, plagioclase and olivine. The locality is situated in the southern part of the southern igneous activity region. In the central non-igneous activity region, cortlandite is rarely found as lenticular bodies parallel to axial plane cleavage in pelitic schist. In the northern and southern igneous activity regions, the transformation of the subsided area into the upheaval area with gentle folding structure is attributed to the intrusion of the ultramafic and mafic igneous rocks. The formation of higher grade metamorphic rock in the upper horizon of the Sambagawa Zone is related to the intrusion of the mafic and ultramafic intrusive rocks. Namely, the author assumed that the reversal thermal structure originate in the combination of the presence of impermiable bed and heat transfar with evaporation of water in the sedimentary rocks due to intrusion of intrusive rocks, excepting the contact metamorphism by intrusion and emplacement of the mafic to ultramafic rocks.

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The undifferentiated Mesozoic rocks of the Shimanto belt of the northern Akaishi mountains are divided into eight lithostratigraphic units which are separated by N-S trending faults (Fig. 1): namely, the Senjo-dake (3,100m thick), Kita-dake (2,500m), Akaishi-dage (1,000 m), Notori-dake (1,500 m), Nishimata (1,500 m), Hirogochi (1,500 m), Dentsukutoge (unknown), and Narada (1,600 m) Units. The Kita-dake Unit is conformably overlain by the Akaishi-dake Unit at the Akaishi-dake area, and by the Notori-dake Unit at the Notori-dake area, respectively, the mutual relation of the latters is unknown owing to intervening fault. The lack of marker beds beyond faulted boundaries in addition to the strong deformation and extreme scarcity of fossils in all units makes it impossible to correlate units among themselves. Some fossils roughly indicating the late Jurassic to Cretaceous age have been reported (OKUBO et al., 1958, 1959; KANO, 1981) from an area to the south of this study. Among the boundary faults, the Okaramatsu-yama fault seems to be the most significant one since it separates the Shimanto belt of the Akaishi Mountains into two lithologically and stratigraphically contrasting parts. Major strucure of the western part is characterised by several isoclinal folds of which the axial planes dip steeply to the east or west. The Kita-dake Unit, which consists mainly of pelitic and psammitic rocks accompanied by minor chert, acidic to basic volcanics and rare limestone especially in its basal part, crops out as the core of major anticlinorium. It is noteworthy that the Kita-dake Unit includes pebbly and/or block-like chert, green rock and sandstone in phyllitic pelitic rocks, and it is reffered to be sedimentary melange. The axial part of this anticlinorium occurs along the backbone of the Akaishi Mountains. In the western limb of the anticlinorium, most of the Senjo-dake Unit, in which psammitic sediments are predominant, is overturned. In the eastern limb, on the other hand, also psammitic sediments are predominant, and the Nishimata Unit dips to the east while the Hirogochi Unit dips to the west, both units being right-side-up. Pelitic sediments are predominant in the eastern side of the Okaramatsu-yama fault. Although the structure of the Dentsuku-toge Unit is not yet fully understood due to its complicated nature, that of the Narada Unit is a symmetric anticline in which the axial plane dips steeply to the west. Basic volcanics including pillow lava crop out along the axial part of the anticline. In the Shimanto belt of this district, deformation is intence and transposition structure is widespread. Metamorphic recrystallization is also marked throughout the area. Pumpellyite occurs in most rocks including psammitic rocks. Actinolite and prehnite are common. The metamorphism of the Shimanto belt of this district may correspond to a transitional facies between prehnite-pumpellyite meta-graywacke and pumpellyite-actinolite facies. In the northeastern part of this district, the Shimanto rocks are intruded by the Kaikoma-Hoo and Yakejizo granites and the contact-effect is superimposed on the regional metamorphism.

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The Usui Pass area is mainly composed of pyroclastic rocks and marine sedimentary rocks of Neogene system. The writers have carried out diatom and radiolarian analysis on marine sediments from the site A and B in this area. In this study, the diatom flora of site A is characterized by Actinocyclus ingens, Coscinodis cusendoi and Denticulopsis hustedtii. The radiolarians of site A are characterized by Cyrtocapsella japonica and Lychnocanoma nipponica magnacornuta. These facts show that the sediment of A had deposited during the upper Middle Miocene. The diatom flora of site B is characterized by Actinocyclus ellipticus var. moronensis, A. ingens, Coscinodiscus endoi, C. lewisianus, Denticulopsis lauta, D. nicobarica, D. ptmctata, Mediaria splendida, Melosira sol, Pyxilla americana, Synedra jouseana, Thalassionema hirosakiensis, T. robusta and Thalassiosira praeconvexa. Radiolarians of site B are characterized by Calocycletta costata and Eucyrtidium asanoi. These facts that the sediment of B had deposited during the lower Middle Miocene.

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