INVESTIGATION Of THE VOLCANOGENIC MASSIVE SULFIDE DEPOSITS BASED ON THE MINOR ELEMENT CONTENTS OF ORES

1. 与黑子矿床相比，别石型块状硫化物矿床富含Sn、Co、Se和To。锡含量特别高的是Hidaka带的Shimokawa矿床，这解释了别石型矿床的高平均锡含量。矿石中不含富硒矿物，且别石型矿床硫化物矿物Se/S比值普遍高于黑子型矿床。别石型矿床中碲酸钾含量高，表现为碲酸钾含量少。海底热液矿床的硫化物矿物学特征、微量元素含量和硫同位素比值在沉积覆盖型和无沉积型海底热液矿床中存在差异。在弧后盆地和大陆火山裂谷带的地壳演化过程中，硫化物矿床具有不同的化学和矿物学特征。武间带的日立（Hitachi）矿床和舞津带的Yanahara矿床可能形成于扩张弧后盆地或大陆裂谷带的大陆海底。赤父带Nanokawa矿床为富锰热液硅质沉积物覆盖，与硫化物矿床伴生的含锰硅质片岩和三巴川带的基性片岩可能来源于热液硅质沉积物。土仓矿床黄铁矿中闪锌矿的FeS含量明显高于黄铁矿颗粒间隙中的闪锌矿。沉积后的海底变质作用和成岩作用可能对应于矿石的硫化作用，就像现在的海底硫化物矿床一样。别石型火山块状硫化物矿床的成矿作用与日本岛弧的演化密切相关。

1. Compared with the Kuroko deposit, the Besshi-type massive sulfide deposits are rich in Sn, Co, Se and To. Sn contents are especially high in the Shimokawa deposit in the Hidaka belt which explains the high average Sn content of the Besshi-type deposits. No Se-enriched minerals are present in the ores and Se/S ratios of sulfide minerals are generally higher in the Besshi-type deposits than Kuroko deposits. Higher Te contents are reflected in the rare occurrence of tellurian tennantite in the Besshi-type deposits.2. Sulfide mineralogy, minor element contents and sulfur isotope ratios of ores are different between sediment-covered and sediment-starved present sea-floor hydrothermal deposits. The sulfide deposits are chemically and mineralogically different corresponding to the crustal evolution in the back-arc basin and volcanic rift zone in the continent. It is likely that the Hitachi deposit in the Abukuma belt and Yanahara deposit in the Maizuru belt were formed on the continental sea floor in the spreading back-arc basin or continental rift zone.3. The Nanokawa deposit in the Chichibu belt was covered by manganese-rich hydrothermal siliceous sediment The manganiferous siliceous schists associated with sulfide deposits and basic schists in the Sambagawa belt are probably derived from the siliceous sediments of hydrothermal origin.4. The FeS contents are remarkably higher in sphalerites included in pyrites than those occurring in interstices of pyrite grains in the Tsuchikura deposit. Post depositional sea-floor metamorphism and diagenesis probably correspond to the sulfidation of ores as like in the present sea-floor sulfide deposits.5. The metallogeny of the Besshi-type volcanogenic massive sulfide deposits are deeply related with the evolution of the Japanese island arc.