The Chacarilla mine is one of the largest copper mines in Bolivia. It is located in the so-called Corocoro basin that extends over a distance of more than 750 km, and at an elevation more than 3, 800 m above the sea-level.
The mine area is composed entirely of continental sediments of the middle Tertiary age, presenting a typical anticlinal structure by which the distribution of ore bodies is largely controlled, that is, the ore deposits are found along the limbs of the anticline.
The ore deposits comprise two types, chalcocite deposits and native copper deposits. Ore mineral in, the chalcocite deposits is mainly chalcocite, and that in the native copper deposits is native copper. Oxidized supergene copper minerals, such as cuprite, tenorite, malachite and chrysocolla, occur near the surface. Mineralization of both chalcocite and native copper is noticed always in the sandtones and conglomarates which are characterized by a bleaching zone, so that the ore deposits apparently seem to be an ore bed type.
Distribution of the ore bodies is stratigraphicaly defined as chalcocite, native copper, and carboniferous chalcocite deposisits, in ascending order. Although the occurrence of ore deposits of these types has been studied in detail in the Corocoro mine by several authors, it is still being discussed. However, the location of chalcocite in a particular bed seems to be related to the process of sedimentation, and native copper seems to have been deposited secondarily by the action of copper-bearing solution which was derived from primary syngenetic chalcoctic ore deposits. This ore-forming process is presumed by the procipitation of native copper during the drainage of old mine water.

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Ore deposits of the Bagacay mine are the first"Kuroko"type deposit discovered in the Philippine Islands. The mining area is composed of Tertiary pyroclastic sediments and volcanic rocks, underlying carbonaceous shale and coral limestone. The main working deposits, Guila-guila ore bodies, is considered sa a"Kuroko"type deposit which is blanket-like in shape directly underlying dolerite flow. "Black ore" consisting mainly of sphalerite, chalcopyrite, and pyrite, "yellow ore" chalcopyrite pyrite ore and"pyrite ore"are main component of the deposits. Marcasite, tetrahedrite, enargite and galena are not rare. Gypsum and barite are also common in argillized host rock, but smaller in amount. A part of carbonaceous shale has been mineralizod and formed high grade copper ore. It is presumable that carbonaceous shale and part of pyroclastics, capped by volcanic flow, have been secondarily replaced under submarine volcanic environment.

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Igneous activities which followed to the Laramide Revolution gave rise to the intrusion of an intermediate or acidic composite stock into the Guichon Batholith. This composite stock consists mainly of the Bethlehem quartz diorite, but intrusion of dacite-porphyry took place successively, forming a marginal facies or later phase of the stock. On this occasion tiny cupolas around the composite stock formed several intrusive breccia pipes due to brecciation by explosions. Owing to the deformation resulting from the intrusion of the stock and breccia pipes, fractures appeared in the earlier quartz diorite. On the other hand, magmatic differentiation of the stock, cooling and cementing began, and, alteration was performed by hydrothermal solution at high temperatures.
In the later stage of differentiation of the stock, mineralization, composed of chalcopyrite, bornite and a small quantity of molybdenite, occurred selectively in the breccia pipes and fractures. It also formed network and vein-disseminate deposits.The mineralization is represented by several combined masses near the contact between the earlier quartz diorite and the later composite stock.Up to date, three economical ore deposits have been confirmed in the zones of East Jersey, Jersey and Huestis. Except that pyrite is very rare and supergene enrichment is unobserved, the mineralizations, in their mode of occurrence, have many points of similarity to the so-called porphyry copper deposits in South America and South western U.S.A.

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Exploration of the Santo Tomas copper deposit has been conducted by the Philex Mining Corporation since 1955. The mine now produces about 100, 000 metric tons of crude ore per month on an average, which is equivalent to approximately 2, 500 metric tons of copper concentrates. The mine is located at about 20km south of Baguio City, Mt. Province, Philippines. Ore deposit of the mine is a low grade gold-bearing copper ore deposit belonging to the so-called "porphyry copper". The huge ore body is made up of numerous. scattered veinlets and impregnation of quartz, Pyritc chalcopyrite, magnetite and other minerals.
The mineralization has been developed principally in the meta-volcanics of Jurassic age, and extended over a short distance to the diorite-porphyry of Late Cretaceous. The fracture pattern of these veinlets is mainly controlled by the effect of diorite-porphyry intrusion in the fractured zone along the direction of off-shoot of the Agno diorite batholith.

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The Nan-etsu mine, situated at about 15km west of Muika-machi in the southern part of Niigata prefecture, is characterized by lead, zinc and copper vein deposits. Monthly production of crude ore from the mine is about 5, 000tons, containing 4.0% lead, 8.0% zinc and 0.6% copper.
The mine area is composed of Palaeozoic formation which consist of clayslate, sandstone, chert and pyroclastic basic rocks, intruded by an older intrusive, i. e. hornblende-gabbro. Both Palaeozoic formations and hornblende-gabbro have been converted to hornfels by intrusion of stocks of the younger biotite granite. Dike rocks, such as porphyrite, quartz-porphyry and dacite, are found in the mine area, and are thought to have been derived form a source similar to that of the younger intrusive.
The principal ore deposits of the mine are hypothermal or mesothermal fissure-filling veins, occurring along faults of ENE trend and in fissures around the younger granite stocks. The principal veins are seen to penetrate the dikes, especially those of dacite and quartz-porphyry, thus suggesting their formation during the latest stage of younger igneous activity.

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Pyrometa somatic lead-zinc deposits of the Nakatatsu mine consist of five main ore deposits. Minamisenno, one of these ore deposits, has been prospected since 1955. As a result of this prospecting severeral new lead-zinc deposits with molybdenite and chalcopyrite, and two magnetite deposits have been discovered. Predominant contact minerals associated with these deposits are hedenbergite and garnet. Ore deposition is structurally contrrolled, as the ore is found in the outer side of shale or sandstone in limestone layers, in the axis of folding, in the fructured zone, and in the boundary between limestone and shale or sandstone. The mineralization is closely related to the quartz-porphyry. The magnetite deposits occur in the inner zone of the skarn masses adjacent to the quartz-porphyry, and sphalerite and galena deposits are found in the outer zone. An appreciable amount of molybdenite is disseminated throughout the skarn zone.

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In the Taro mine, there are several types of deposits producing lead-zinc sulphide ore, pyritic ore, ccupriferous pyritic ore and so on. The deposits are concordant with the bedrock.
The ore-bearing formation, consisting of sandstone and slate, lies between quartz porphyrite of the upper part and graywacke of the lower part.
After the mineralization, the deposits suffered a slight thrust movement and intrusion of granitic rocks and diabasic rocks.
These deposits show no distinctly mineralized potentiality, but the abnormal distribution of graywacke and quartz porphyrite suggests the center of igneous activity in the sedimentary basin.
As a guide of prospecting, it has been decided that for drifting and drilling sedimentary rock area should be searched. Other important things are lineation, controlled ore shape pattern and so on, but these are useful only for already-explored ore bodies.
We have prospected the drift for a distance of 200m from the Ogiri main adit; we intend to continue the drifting for 150m or more.

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Various methods of geophysical prospecting have been applied to sulphur or iron sulphide ore deposits of the Hokkaido mine since 1951. They are spontaneous polarization, apparent resistivity, seismic, AFMAG and induced polarization methods. Many drillings have been done in the area of geo-physical anomalies, and several new ore deposits have been discovered. In this paper, the writer discusses the relations between the geophysical prospectings and the result of drillings.

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The Kishu mine is located in the southern part of Miye prefecture, Japan.
The ore deposits of the mine are the so-called fissure-filling veins of whose country rocks are Mioc-ene sediments (sandstone, shale and their alternations).
The principal ore minerals are chalcopyrite and pyrite; the principal gangue minerals are quartz and calcite.
In the Kishu mine, we were successful in obtaining some good results of ore prospecting, using various kinds of boring machines in both underground and open prospectings.
In the meantime, we adopted the wire-line boring method in the Amase area of the mine for the first time, and since we found it much more effective than the former method, the writer is pleased to introduce here the resultus of the boring by this new method.

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The Uchinotai ore deposits which are typical "Kuroko" deposit were discovered in the summer of 1959. In the next three years all constructions required for development were completed, and regular production was commenced in July 1962.
With progress of geological prospecting by underground core-drillings and drifting in the deposits, geological structures and ore reserves became known much better. The ore deposits seem to be dis-continuous, comprising three main ore deposits. At least, three lava-domes of white rhyolite, accom-panied by volcanic breccia, are recognized. The ore deposits are generally distributed on the eastern slope of these lava-domes, partly on the western slope also. In these ore deposits, a zonal arrange-ment of "black ore" (sphalerite-galena-chalcopyrite-tetrahedrite-barite), "yellow ore" (chalcopyrite-pyrite), "gypsum ore" and "siliceous ore" (pyrite-chalcopyrite-quartz), in descending order, is gene-rally observed, but distribution of the ores is complex in detail.

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The Kamikita mine belongs to the so-called "Black Ore (Kuroko)" deposits in the "Green Tuff" region of northeastern Japan, although mineral assemblages and mode of occurrence of ore deposits of the mine are not typical. The ore deposits vary greatly in type, occurrence, country rock, and wall rock alteration, even small limited mining area. The ore deposits are found in the Miocene Okunosawa formation, consistinp of pyroclastic rocks characterized by rhyolitic volcanism.
Black ore deposits are classified into two types, irregular massive type and bedded type. The Kam-inosawa ore deposit is composed especially of several bedded black ores which resulted from crushing of the primary black ore by the violent intrusion of the Honko plagioliparite.

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The Shakanai mine is located at abont 2km east of the Hanaoka mine in the Green Tuff region of the northeastern part of Honshu. Prospecting of the mine has been performed since April 1961, and five Kuroko ore bodies have been found. Date of discovery and dimensions of the ore bodies are as follows:
It is very interesting that the Kuroko ore deposits of the Shakanai the Hanaoka, the Dowa-Matsumine, the Mitsubishi-Matsuki, the Kosaka-Motoyama and the Kosaka-Uchinotai mines occur in the marginal zone of the Hokuroku basin.

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