The genesis of bedded manganese deposits and cupriferous pyrite deposits occurring in Paleozoic and older formations has been a frequent topic of discussion among Japanese mining geologists. More than ten years' work on these deposits leads the author to believe that most of the manganese deposits associated with cherty or siliceous sediments of the Paleozoic Chichibu formation are of syngenetic origin. The constant stratigraphic localization of a large number of manganese deposits in Paleozoic formations, especially in the Ashia Mountain district in Tochigi Prefecture, has been demonstrated by the author and his co-workers. Radiolarian remains have been well preserved in spherulitic masses of some mangaese carbonate ores found in that area. The progressive thermal metamorphism of the manganese deposits and the country rock has been observed within the contact aureoles of later granitic intrusions. The association of such manganese minerals as tephroite, alleghanyite, rhodonite, spessartite, manganophyllite, manganosite, pyrochroite, hausmannite and braunite is common in the highly metamorphosed manganese ores formed by recrystallization, Coarse-grained manganese skarns carrying various sulphides have been commonly formed metasomatically in layered manganese deposits in the contact zone.
The theoretical syngenetic origin of the bedded cupriferous pyrite deposits of Besshi type is still open to question, although the constant association of the green rocks and pyritic ores has been described by several authors. The relict texture of the colloform sulphide ores suggesting their low-temperature mineralization has been often observed in the metamorphosed ores. The relation of metamorphism to sulphide-mineralization is disscussed, Some geologic and petrographic data available on some cupriferous pyrite deposits are also presented.

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A zone of montmorillonitic clay is newly found in the alteration zones underlying the Matsuo sulphur deposits. Thus the zonal distribution of minerals from the shallower to the deeper is as follows: an iron-sulphide zone, a sulphur zone, an opal-alunite zone, a montmorillonite zone, and chloritized andesite.
Pale green clays, characteristic to the montmorillonite zone, occur in the form of disseminated particles, veinlets, and irregular masses in the altered rocks derived from the chloritized andesite. From microscopic, electron-microscopic, differential thermal, X-ray and chemical studies, it is con-cluded that these clays consist of a large amount of montmorillonite, with some halloysite, kaolinite, hydrated halloysite and an unusual 23-24Å mixed layer mineral which is probably composed of regular interstratified lattices of montmorillonite and a 7Å kaolin mineral.
The ore-forming fluid might have been an ascending hydrothermal solution that was weakly alkaline or very weakly acid at the beginning of the mineralization and contained a large amount of gases. From the arrangement of alteration zones and ore bodies as well as from the supposed geologic environment surrounding the deposits at the time of mineralization, it may be concluded that the alteration zones and ore-bodies were formed by the interaction of ascending solutions and wadose water at an approximate depth of 200 to 300 meters from the surface.

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Trace elements such as barium, strontium, gallium, boron, vanadium, lead, chromium, nickel, cobalt and tin were sought by spectroscopic analyses of clay specimens from altered zones of the Hanaoka and Hanawa Mines, Akita Prefecture.
The results obtained are as follows:
(1) Barium, vanadium, lead, chromium and nickel increase gradually toward an inner zone from the outermost fringe of the deposits. Gallium and boron show irregular distribution.
(2) Tin and cobalt were not detechted in any altered zone of these deposits.
(3) It is suggested that the analyses of trace elements will be an effective method for prosp ecting the Kuroko deposits.

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The prominent feature of the Komaki Mine is the strongly developed supergene enrichment displayed about the Shirane deposit, spreading downward 200-300 meters from the surface of the deposits, and working particularly upon the primary sphalerite-galena zone and the underlying massive chalcopyrite zone disposed zonally in the western part of the deposits. This supergene enrichment formed large amounts of chalcocite, covellite and zinc sulphide mineral and accessory bornite, native copper and wittichenite(?).
The upper part of the enrichment zone is composed of a covellite-zinc sulphide association, and in the lower part a chalcocite-zinc sulphide association is prominently developed.
Paragenetic relations and modes of occurrence of these supergene minerals may be briefly summarised as follows:
1) The supergene enrichment is related to the zonal distribution of primary are minerals and complete lack of carbonate minerals, the existence of so-called black are type deposits within the immediate neighbourhood, and the distinct contrast in the nature of the veins in the eastern and western parts.
2) The supergene enrichment originated with zinc sulphide replacing the primary chalcopyrite, and thereafter continued to the formation of covellite, chalcocite→bornite. Then the excluded Zn ion was again deposited in zinc sulphide. It seems probable that the enrichment was controlled by the variation of pH and the ratio of[Zn¨]:[Cu¨]in the descending water.
3) The copper ion, which was consumed in the formation of chalcocite, covellite and bornite, was derived from the replacement of primary chalcopyrite by the supergene zinc sulphide.

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Coal wash-out of typical fish-tail type has been discovered in Karatsu Coal Mine, Saga Prefecture. This wash-out occurred in the coal seams of the Karatsu Goshaku group of the Yoshinotani formation, which is the main coal-bearing formation of Karatsu Coal Field.
From consideration of this wash-out and other geologic data, the following conclusions are made:
1) This wash-out occurred by contemporaneous erosion during deposition.
2) The qualitative differences between the upper Sasaishi coal group and the Karatsu Goshaku coal group could be attributed to different depositional circumstances.
3) A few cores, from bore holes in the wash-out areas where the Goshaku coal group is absent, consist of thick disturbed deposits with crumpled laminae and intraformational conglomerates in place of the Goshaku coal.
4) These intraformational disturbances are caused by tilting of the bottom of the depositional basin as the result of crustal movements.

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