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

1.与黑矿存款相比，别志式块状硫化物矿床富含Sn、Co、Se和To。日高带下川存款中的锡含量特别高，这解释了百志型矿床平均锡含量高的原因。矿石中不存在富硒矿物，硫化矿物的Se/S比值在别志型矿床中普遍高于黑矿型矿床。在贝西型矿床中，碲碲铋矿的罕见产出反映了较高的Te含量.沉积物覆盖型和沉积物缺乏型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组成存在差异。与大陆弧后盆地和火山裂谷带的地壳演化相对应，硫化物矿床在化学和矿物学上也有很大差异。阿布熊带的日立存款和舞鹤带的柳原存款可能形成于扩张弧后盆地或大陆裂谷带的大陆海底。秩父带的Nanokawa存款被富锰的热液硅质沉积物覆盖，与硫化物矿床和Sambagawa带的基性片岩共生的含锰硅质片岩可能来自热液成因的硅质沉积物.土仓存款中黄铁矿中闪锌矿的FeS含量明显高于黄铁矿颗粒间隙中闪锌矿的FeS含量。沉积后的海底变质作用和成岩作用可能与现今海底硫化物矿床中的矿石硫化作用相对应。百志型火山成因块状硫化物矿床的成矿作用与日本岛弧的演化有着密切的关系。

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.