大韓民国の14の熱水成の金・銀鉱床から得られた硫化鉱物の硫黄同位体組成を測定した.δ³⁴S(CDT)値は-0.2～+9.8‰の変化を示すが,その90%は+1～7‰の比較的狭い範囲におさまる.個々の鉱床からの硫化鉱勅の硫黄同位体比はさらに狭い範囲に入り,通常その変化は3‰内である.このような狭い変化幅と,鉱物間の³⁴Sの分配が実験的に予測される傾向と一致している事実は,硫化鉱物が鉱液中のH₂Sから平衡に近い状況で沈殿したことを示している.
文献にみられるデータも含めて検討すると,地質環境・生成時代・稼行対象金属が異なっていても,同一の地域に属する鉱床中の硫黄同位体には一定の傾向があることがわかる.すなわち,京畿マシーフの無極鉱山地域
内およびその周辺では鉱床中の硫黄は相対的に高いδ³⁴S値を示す.これに対し嶺南マシーフ中の鉱床は,いくらかの例外的な値も発表されているが,相対的に低いδ³⁴S値を示している.この事実は,鉱床中の硫黄は主として周辺の母岩からもたらされている可能性が高いことを示しており,同時に京畿・嶺南両マシーフの地球化学的性質が幾分異なっていることを示していると解釈される.

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新礼美マグネシウムスカルン型磁鉄鉱鉱床は,オルドビス紀のマッコル石灰岩層とNNW方向の断層に沿って貫入する白亜紀の斑状質岩との接触部に発達する.スカルンは,苦灰岩,苦灰質石灰岩および石灰岩を各々交代し同時に形成されたマグネシウムスカルン,中間型スカルンおよびカルシウムスカルンに分けられる.かんらん石,単斜輝石,ざくろ石,ドロマイト,方解石および閃亜鉛鉱等のスカルン鉱物に含まれる流体包有物の均質化温度と塩濃度が測定された.包有物は,殆どCO₂(<0.07)を含まない気液2相の液相包有物である.測定された流体包有物の均質化温度は190℃から590℃の範囲であり,その塩濃度(NaCl相当濃度)は12～23%の値を示す.均質化温度に対する圧力補正(500bar)後の温度は240℃から620℃の範囲を示す.その中で,累進スカルンの形成温度は400℃から650℃の範囲と推定され,同位体地質温度計による温度範囲(400℃-610℃)と殆ど一致する.この温度範囲は他の多くの鉱床におけるスカルン鉱物形成温度範囲(400℃-650℃)によく一致するが,塩濃度は他の多くの鉱床の塩濃度範囲(10-50%)より多少低い値を示す.
マグネシウムスカルンと中間型スカルンには2回の磁鉄鉱鉱化作用が認められるが,特に,マグネシウムスカルンの早期鉱化作用(第1ステージ;440-540℃)と後期鉱化作用(第3ステージ;340-400℃)は,カルシウムスカルンの硫化物鉱化作用の早期(450-530℃)と後期(340-400℃)鉱化作用の各々と同時期に形成されたと推定される.本鉱床のスカルン鉱物中の流体包有物の均質化温度と塩濃度は,地質調査と鏡下で決められた鉱物の晶出順序に従って低下する傾向がある.これは,鉱液と岩石問の連続的反応と共に鉱液への天水の混入率が増加した為であると考えられ,この結果はまた酸素・水素同位体の研究結果とよく一致する.

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Japan and USA are the major copper consuming countries, and the refined copper consumption in both countries amounted for 33 % of the free world consumption. In order to clarify the copper demand trends in Japan and USA, copper consumption data from 1960 to 1989 are analyzed by using the following intensity of use technique;
IU=C/GDP=(Q/GDP)×(C/Q)=PCI×MCP(+Embodied copper consumption/GDP) where IU : Intensity of use measures copper consumed per real GDP
C : Copper contained final product
PCI : Product Composition of Income is the proportion of consumer's total income that is spent on this final product
MCP : Material Composition of Product measures the amount of metal used to make one unit of a product The results indicate the different trends of IU, PCI, MCP and embodied copper consumption between Japan and USA, which reflects different economic and trade policy in both countries.

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Oxygen and hydrogen isotopic compositions of vein muscovite and host rocks, oxygen isotopic compositions of vein quartz and K-feldspar, and hydrogen isotopic compositions of fluid inclusions in vein quartz, drusy quartz, wolframite and scheelite from the Kaneuchi tungsten deposit, Kyoto Prefecture, are obtained in order to (1) examine the relation between the ore-forming fluid and the fluid equilibrated with host rocks at a low fluid/rock ratio, and (2) to obtain possible δ¹⁸O-δD region of the ore-forming fluid.
Oxygen isotopic compositions of vein muscovite range from 11.7 to 13.8 per mil (relative to SMOW). Based on muscovite-quartz oxygen isotope temperatures and previous works, most of vein muscovites precipitated at 400°C or above (possibly up to 600°C). The oxygen isotopic compositions of the ore-forming fluid show the-range from 10.4 to 13.7 per mil at 400° to 600°C. Host rocks show oxygen isotopic compositions ranging from 12.8 to 15.0 per mil. Using fluid-rock fractionation factors obtained from the bulk chemical compositions, oxygen isotopic compositions of the fluid equilibrated with host rocks at a low fluid/rock ratio are calculated at 300°to 600°C. These compositions show a good agreement with the estimated isotopic compositions of the ore-forming fluid either from vein quartz and vein muscovite.
The hydrothermal fluid at the earliest stage is ¹⁸O-enriched compared with a possible magmatic fluid, suggesting high temperature fluid-rock interaction. At the main stage of quartz mineralization, the ¹⁸O_fluid composition is equal to the possible magmatic fluid composition. However, the temperature of the fluid at this stage is too low (350°to 400°C), requiring significant cooling of the magmatic fluid. Simple mixing of the high-temperature ¹⁸O-enriched fluid (for the precipitation of muscovite) with the low-temperature ¹⁸O-depleted fluid (for the precipitation of calcite) does not account for the δ¹⁸O_fluid range determined from vein quartz. It is possible that the other factors, such as conductive cooling, influenced the temperature of the magmatic fluid. Otherwise, the discrepancy can be accounted for by considering fluid-rock interaction at a low fluid/rock ratio.
Hydrogen isotopic compositions of vein muscovite range from -61 to -104 per mil (relative to SMOW) and those of fluid inclusions in vein quartz and drusy quartz range from -53 to -73 per mil and from -53 to -63 per mil, respectively. Calculations of the hydrogen isotopic compositions of the hydrothermal fluid at the precipitation of muscovite show the range from around -100 to -70 per mil, suggesting relatively large variation compared with the variation in δ¹⁸O.
The hydrogen isotopic composition of the fluid from which vein and drusy quartz were deposited covers the same range as the magmatic fluid. However, the fluid responsible for muscovite precipitation is significantly depleted in deuterium. The large variation in hydrogen isotopic composition of muscovite is partly due to the temperature change of the ore-forming fluid. But the present results still suggest that the hydrothermal fluid mixed with deuterium-depleted and ¹⁸O-enriched fluid at the earliest stage of mineralization.

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The Tharsis mining area is one of the largest mining centers of the Iberian Pyrite Belt, which covers a large area in the SW part of the Iberian peninsula. Sedimentary structures in the sulfide deposits of the Filon Notrte, Tharsis mine were studied in the field and under the microscope. The sulfide deposits are classified into two types based on internal structures: (1) massive pyritic ores; (2) pyritic ores with sedimentary structures. In the latter type, several kinds of sedimentary structures are observed, such as graded bedding, parallel and cross lamination and slump structures. Distribution of the sedimentary structures indicates that slump breccias are commonly observed in the lower horizons and in the country rocks, massive ores rather in the upper horizons and cross lamination in the middle horizons. Cross lamination is also obsevable in the calst of the slump breccias. From these, depositional process is considered to be as follows. In the early stage, ore solutions flowed out in the mud on the sea-floor from the feeders and sedimentary structures were formed after the outflow. Some ores were moved by slumping before lithification. In the late stage, massive ores were rapidly precipitated on the pre-existing ores.

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