The Geochemical Characters Research Of Seafloor Hydrothermal Chimney Of Kueishaotao Island Of Northeastern Taiwan

The Kueishantao hydrothermal activity zone lies in the west extended part of the Okinawa Trough, Where Philippine Sea Plate is subducting under the Eurasia Plate. The occurrence of hydrothermal activity give a chance for exploring the development of the zone. There are some prominent characters about Kueishantao hydrothermal activity : high content native sulfur in the chimneys which comprise few minerals, however there are clear layers in the chimney bodies according with the colors. On the other hand, that the native sulfur concentration ascends from outside to inside is coincided with the color layers. And theδ34S‰ values focus on about 2‰,so we distinguish three types chimneys according with theδ34S‰ values which are ascending type, "V"type, descending type. we discuss the chimneys' formation and the materials resource on the base of the facts as mentioned in above. We think both the fundus' andesites of the hydrothermal activity zone and mantle are Kueishantao hydrothermal activity's materials resource, but how mantle materials contaminate the hydrothermal fluid is not clear.