The ultraslow-spreading Southwest Indian Ridge （SWIR） to the east of the Melville fracture zone is characterized by very low melt supply and intensive tectonic activity. Due to its weak thermal budget and extremely ...The ultraslow-spreading Southwest Indian Ridge （SWIR） to the east of the Melville fracture zone is characterized by very low melt supply and intensive tectonic activity. Due to its weak thermal budget and extremely slow spreading rate, the easternmost SWIR was considered to be devoid of hydrothermal activity until the discovery of the inactive Mt. lourdanne hydrothermal field （27°51＇S, 63°56＇E） in 1998. During the COMRA DYl15-20 cruise in 2009, two additional hydrothermal fields （i.e., the Tiancheng （27°51＇S, 63°55＇E） and Tianzuo （27°57＇S, 63°32＇E） fields） were discovered. Further detailed investigations of these two hydrothermal sites were conducted by Chinese manned submersible liaolong in 2014-2015. The Tiancheng filed can he characterized as a low- temperature （up to 13.2℃） diffuse flow hydrothermal field, and is hosted by fractured basalts with hydrothermal fauna widespread on the seafloor. The Tianzuo hydrothermal field is an inactive sulfide field, which is hosted by ultramafic rocks and controlled by detachment fault. The discovery of the three hydrothermal fields around Segment #11 which receives more melt than the regional average, provided evidence for local enhanced magmatism providing heat source to drive hydrothermal circulation. We further imply that hydrothermal activity and sulfide deposits may be rather promising along the easternmost SWIR.展开更多
The effects of feed strength, hydraulic residence time （HRT）, and operational temperatures on soluble microbial product （SMP） production were investigated, to gain insights into the production mechanism. A carrier...The effects of feed strength, hydraulic residence time （HRT）, and operational temperatures on soluble microbial product （SMP） production were investigated, to gain insights into the production mechanism. A carrier anaerobic baffled reactor （CABR） treating dilute wastewater was operated under a wide range of operational conditions, namely, feed strengths of 300-600 mg/L, HRTs of 9- 18 h, and temperatures of 10-28℃. Generally, SMP production increased with increasing feed strength and decreasing temperature. At high temperature （28℃）, SMP production increased with decreasing HRT. As the temperature was decreased to 18 and 10℃, the SMP production was at its peak for 12 h HRT. Therefore, temperature could be an important determinant of SMP production along with HRT. A higher SMP to soluble chemical oxygen demand （SCOD） ratio was found at high temperature and long HRT because of complete volatile fatty acid degradation. SMP accounted for 50%-75% of the SCOD in the last chamber of the CABR. As a secondary metabolite, some SMP could be consumed at lower feed strength.展开更多
During January–May in 2007,the Chinese research cruise DY115-19 discovered an active hydrothermal field at 49°39′E/37°47′S on the ultraslow spreading Southwest Indian Ridge (SWIR).This was also the first ...During January–May in 2007,the Chinese research cruise DY115-19 discovered an active hydrothermal field at 49°39′E/37°47′S on the ultraslow spreading Southwest Indian Ridge (SWIR).This was also the first active hydrothermal field found along an ultraslow-spreading ridge.We analyzed mineralogical,textural and geochemical compositions of the sulfide chimneys obtained from the 49°39′E field.Chimney samples show a concentric mineral zone around the fluid channel.The mineral assemblages of the interiors consist mainly of chalcopyrite,with pyrite and sphalerite as minor constitunets.In the intermediate portion,pyrite becomes the dominant mineral,with chalcopyrite and sphalerite as minor constitunets.For the outer wall,the majority of minerals are pyrite and sphalerite,with few chalcopyrite.Towards the outer margin of the chimney wall,the mineral grains become small and irregular in shape gradually,while minerals within interstices are abundant.These features are similar to those chimney edifices found on the East Pacific Rise and Mid-Atlantic Ridge.The average contents of Cu,Fe and Zn in our chimney samples were 2.83 wt%,45.6 wt% and 3.28 wt%,respectively.The average Au and Ag contents were up to 2.0 ppm and 70.2 ppm respectively,higher than the massive sulfides from most hydrothermal fields along mid-ocean ridge.The rare earth elements geochemistry of the sulfide chimneys show a pattern distinctive from the sulfides recovered from typical hydrothermal fields along sedimentstarved mid-ocean ridge,with the enrichment of light rare earth elements but the weak,mostly negative,Eu anomaly.This is attributed to the distinct mineralization environment or fluid compositions in this area.展开更多
In recent years, a series of cruises have been launched by China Ocean Mineral Resources Research and Development Association （COMRA） to conduct hydrothermal activity investigation at mid-ocean ridges （MOR）. Since...In recent years, a series of cruises have been launched by China Ocean Mineral Resources Research and Development Association （COMRA） to conduct hydrothermal activity investigation at mid-ocean ridges （MOR）. Since the first active hydrothermal field at 49.6°E Southwest Indian Ridge （SWIR） was found in 2007 by Chinese scientists on board R/V Dayangyihao, more hydrothermal fields have been found on the SWIR and equatorial East Pacific Rise （EPR） [1-4].展开更多
In recent years, Sub-Committee on Undersea Feature Names （SCUFN） has been conducting deliberations on naming undersea features that are entirely or mainly （more than 50%） outside the external limits of the territo...In recent years, Sub-Committee on Undersea Feature Names （SCUFN） has been conducting deliberations on naming undersea features that are entirely or mainly （more than 50%） outside the external limits of the territorial sea, adhering to the principles of not involving sovereignty dispute between countries. International concern for naming undersea features is limited to those features entirely or mainly （more than 50%） outside the external limits of the territorial sea, not exceeding 12 nautical miles from the baselines, in agree- ment with the United Nations Convention on the Law of the Sea.展开更多
基金The National Key Research and Development Program of China under contract Nos 2017YFC0306603,2018YFC0309901,2016YFC0304905,2017YFC0306803 and 2018YFC0309902the China Ocean Mineral Resources Research and Development Association Major Project under contract Nos DY135-S1-1-01 and DY135-S1-1-02
文摘The ultraslow-spreading Southwest Indian Ridge （SWIR） to the east of the Melville fracture zone is characterized by very low melt supply and intensive tectonic activity. Due to its weak thermal budget and extremely slow spreading rate, the easternmost SWIR was considered to be devoid of hydrothermal activity until the discovery of the inactive Mt. lourdanne hydrothermal field （27°51＇S, 63°56＇E） in 1998. During the COMRA DYl15-20 cruise in 2009, two additional hydrothermal fields （i.e., the Tiancheng （27°51＇S, 63°55＇E） and Tianzuo （27°57＇S, 63°32＇E） fields） were discovered. Further detailed investigations of these two hydrothermal sites were conducted by Chinese manned submersible liaolong in 2014-2015. The Tiancheng filed can he characterized as a low- temperature （up to 13.2℃） diffuse flow hydrothermal field, and is hosted by fractured basalts with hydrothermal fauna widespread on the seafloor. The Tianzuo hydrothermal field is an inactive sulfide field, which is hosted by ultramafic rocks and controlled by detachment fault. The discovery of the three hydrothermal fields around Segment #11 which receives more melt than the regional average, provided evidence for local enhanced magmatism providing heat source to drive hydrothermal circulation. We further imply that hydrothermal activity and sulfide deposits may be rather promising along the easternmost SWIR.
文摘The effects of feed strength, hydraulic residence time （HRT）, and operational temperatures on soluble microbial product （SMP） production were investigated, to gain insights into the production mechanism. A carrier anaerobic baffled reactor （CABR） treating dilute wastewater was operated under a wide range of operational conditions, namely, feed strengths of 300-600 mg/L, HRTs of 9- 18 h, and temperatures of 10-28℃. Generally, SMP production increased with increasing feed strength and decreasing temperature. At high temperature （28℃）, SMP production increased with decreasing HRT. As the temperature was decreased to 18 and 10℃, the SMP production was at its peak for 12 h HRT. Therefore, temperature could be an important determinant of SMP production along with HRT. A higher SMP to soluble chemical oxygen demand （SCOD） ratio was found at high temperature and long HRT because of complete volatile fatty acid degradation. SMP accounted for 50%-75% of the SCOD in the last chamber of the CABR. As a secondary metabolite, some SMP could be consumed at lower feed strength.
基金supported by the China Ocean Min-eral Resources Research and Development Association Program (DY115- 02-1-01)the State Oceanic Administration Youth Science Fund (2010318)
文摘During January–May in 2007,the Chinese research cruise DY115-19 discovered an active hydrothermal field at 49°39′E/37°47′S on the ultraslow spreading Southwest Indian Ridge (SWIR).This was also the first active hydrothermal field found along an ultraslow-spreading ridge.We analyzed mineralogical,textural and geochemical compositions of the sulfide chimneys obtained from the 49°39′E field.Chimney samples show a concentric mineral zone around the fluid channel.The mineral assemblages of the interiors consist mainly of chalcopyrite,with pyrite and sphalerite as minor constitunets.In the intermediate portion,pyrite becomes the dominant mineral,with chalcopyrite and sphalerite as minor constitunets.For the outer wall,the majority of minerals are pyrite and sphalerite,with few chalcopyrite.Towards the outer margin of the chimney wall,the mineral grains become small and irregular in shape gradually,while minerals within interstices are abundant.These features are similar to those chimney edifices found on the East Pacific Rise and Mid-Atlantic Ridge.The average contents of Cu,Fe and Zn in our chimney samples were 2.83 wt%,45.6 wt% and 3.28 wt%,respectively.The average Au and Ag contents were up to 2.0 ppm and 70.2 ppm respectively,higher than the massive sulfides from most hydrothermal fields along mid-ocean ridge.The rare earth elements geochemistry of the sulfide chimneys show a pattern distinctive from the sulfides recovered from typical hydrothermal fields along sedimentstarved mid-ocean ridge,with the enrichment of light rare earth elements but the weak,mostly negative,Eu anomaly.This is attributed to the distinct mineralization environment or fluid compositions in this area.
基金supported by China Ocean Mineral Resources Research and Development Association Program (Grant No. DY115-02-1-01)State Oceanic Administration Youth Science Fund (Grant No. 2010318)
文摘In recent years, a series of cruises have been launched by China Ocean Mineral Resources Research and Development Association （COMRA） to conduct hydrothermal activity investigation at mid-ocean ridges （MOR）. Since the first active hydrothermal field at 49.6°E Southwest Indian Ridge （SWIR） was found in 2007 by Chinese scientists on board R/V Dayangyihao, more hydrothermal fields have been found on the SWIR and equatorial East Pacific Rise （EPR） [1-4].
基金supported by National Basic Research Program of China(Grant No. 2012CB417305)China Ocean Mineral Resources Research and Development Association Program (Grant No. DY115-02-1-01)+2 种基金Public Science and Technology Research Funds Projects of Ocean (Grant No.201205004)State Oceanic Administration Youth Science Fund (Grant No.2010319)Scientific Research Fund of Second Institute of Oceanography (Grant No. JG1105)
文摘In recent years, Sub-Committee on Undersea Feature Names （SCUFN） has been conducting deliberations on naming undersea features that are entirely or mainly （more than 50%） outside the external limits of the territorial sea, adhering to the principles of not involving sovereignty dispute between countries. International concern for naming undersea features is limited to those features entirely or mainly （more than 50%） outside the external limits of the territorial sea, not exceeding 12 nautical miles from the baselines, in agree- ment with the United Nations Convention on the Law of the Sea.
