Petrology and mineralogy of pumice from the Iheya North Knoll, Okinawa Trough: Implications for the differentiation of crystal-poor and volatile-rich melts in the magma chamber

2018 ◽  
Vol 53 (6) ◽  
pp. 2732-2745 ◽  
Author(s):  
Yuxiang Zhang ◽  
Zhigang Zeng ◽  
Xuebo Yin ◽  
Haiyan Qi ◽  
Shuai Chen ◽  
...  
Keyword(s):  
Magma Chamber ◽  
Okinawa Trough ◽  
Iheya North Knoll

Geochemical characteristics of hydrothermal sediments from Iheya North Knoll in the Okinawa Trough

2016 ◽  
Vol 35 (4) ◽  
pp. 947-955 ◽  
Author(s):  
Qiannan Hu ◽  
Xin Zhang ◽  
Fuqing Jiang ◽  
Bing Wang ◽  
Zhendong Luan ◽  
...  
Keyword(s):  
Okinawa Trough ◽  
Geochemical Characteristics ◽  
The Okinawa Trough ◽  
Hydrothermal Sediments ◽  
Iheya North Knoll

scholarly journals Microbial sulfate reduction plays an important role at the initial stage of subseafloor sulfide mineralization

Geology ◽  
2020 ◽  
Author(s):  
Tatsuo Nozaki ◽  
Toshiro Nagase ◽  
Takayuki Ushikubo ◽  
Kenji Shimizu ◽  
Jun-ichiro Ishibashi ◽  
...  
Keyword(s):  
Sulfate Reduction ◽  
Secondary Ion Mass Spectrometry ◽  
Okinawa Trough ◽  
Sulfide Minerals ◽  
Sulfide Mineralization ◽  
Ambient Seawater ◽  
Microbial Sulfate Reduction ◽  
Framboidal Pyrite ◽  
Initial Stage ◽  
Iheya North Knoll

Seafloor hydrothermal deposits form when hydrothermal fluid mixes with ambient seawater, and constituent sulfide minerals are usually interpreted to precipitate abiogenically. Recent research drilling at Izena Hole and Iheya North Knoll in the middle Okinawa Trough (East China Sea), combined with secondary ion mass spectrometry determinations of δ34S in pyrite grains, provides compelling evidence that the initial stage of subseafloor sulfide mineralization is closely associated with microbial sulfate reduction. During the sulfide maturation process, pyrite textures progress from framboidal to colloform to euhedral. Pyrite δ34S has highly negative values (as low as –38.9‰) in framboidal pyrite, which systematically increase toward positive values in colloform and euhedral pyrite. Sulfur isotope fractionation between seawater sulfate (+21.2‰) and framboidal pyrite (–38.9‰) is as great as –60‰, which can be attained only by microbial sulfate reduction in an open system. Because framboidal pyrite is commonly replaced by chalcopyrite, galena, and sphalerite, framboidal pyrite appears to function as the starting material (nucleus) of other sulfide minerals. We conclude that framboidal pyrite, containing microbially reduced sulfur, plays an important role at the initial stage of subseafloor sulfide mineralization.

Formation of highly Zn-enriched sulfide scale at a deep-sea artificial hydrothermal vent, Iheya-North Knoll, Okinawa Trough

2020 ◽  
Author(s):  
Tatsuo Nozaki ◽  
Toshiro Nagase ◽  
Junji Torimoto ◽  
Yutaro Takaya ◽  
Jun-ichiro Ishibashi ◽  
...  
Keyword(s):  
Deep Sea ◽  
Hydrothermal Vent ◽  
Okinawa Trough ◽  
Iheya North Knoll
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