The cruise is a joint expedition between Woods Hole Oceanographic Institution (WHOI) and Nautilus Minerals Inc. of Vancouver, British Columbia, a mining exploration company that holds exploration leases in the Bismarck Sea within the territorial waters of Papua New Guinea. Nautilus is the first firm to commercially explore the ocean floor for economically viable massive sulfide deposits, and is interested in understanding the size and mineral content of the seafloor massive sulfide systems.
The joint expedition includes a 32-day WHOI research program funded by the U.S. National Science Foundation to the Pacmanus vent sites in the Eastern Manus Basin. The remotely operated vehicle Jason will be used to survey and map the vent areas around an Ocean Drilling Program hole drilled in 2000. Nautilus will fund an additional 10-day program to explore and sample the Vienna Woods sulfide prospects on the Manus Ridge, northwest of the Pacmanus study area.
Geophysicist Maurice Tivey of WHOI will head the 42-day expedition, which begins July 21 from Rabaul, Papua New Guinea, aboard the research vessel Melville, operated by the Scripps Institution of Oceanography. Tivey and geochemists Wolfgang Bach of the University of Bremen (previously at WHOI) and Jeff Seewald and Meg Tivey of WHOI will map, collect samples and take high-resolution images of the seafloor at several locations within the territorial waters of Papua New Guinea. The cruise ends September 1 at Suva, Fiji.
Tivey and his co-investigators are interested in the geochemistry and structure of the seafloor and the formation of mineral deposits along mid-ocean and back-arc ridge systems, where new ocean crust is formed. The team will use the remotely operated vehicle Jason and the Autonomous Benthic Explorer (ABE), both developed and operated by WHOI and veterans of many expeditions to hydrothermal vent sites around the world.
Two areas will be explored, one in the Eastern Manus Basin in the Bismarck Sea known as the Pacmanus vent site and the other Vienna Woods, an area of exposed massive sulfide on the Manus Ridge, a small mid-ocean ridge spreading center to the northwest of the Pacmanus site. The Pacmanus site is in 1,700 meters of water (about 4,500 feet), while the Vienna Woods site is in 2,500 meters (about 8,000 feet).
“There are differences in the compositions of hosts rock at the two areas, as well as differences in the geologic and tectonic settings,” Tivey, an associate scientist in the WHOI Geology and Geophysics Department, said. In the Eastern Manus Basin at the Pacmanus vents, the host rocks are felsic or silica-rich compared to the more typical mid-ocean ridge basalt found at the Vienna Woods site, providing a contrast in host rock geochemistry.
“It has been suggested that the difference in the chemistry of the host rock is reflected in the composition of the sulfide chimneys and deposits, with deposits hosted in the more silica-rich rocks being richer in gold and other precious metals” Tivey said. “However, there are other factors that can affect vent fluid and sulfide deposit composition. For example, some hydrothermal fluids from back-arc sites appear to have a signature indicative of a magma chamber source, with magmatically-derived fluids possibly affecting the hydrothermal systems.”
The research program is designed to determine what factors may be affecting vent deposit chemistry, Tivey said. In addition to sampling the deposits and collecting fresh and altered host rock, the researchers will collect vent fluids using gas-tight samplers to study the possible influence of both magmatic volatiles and host rock composition. They will also map the seafloor, and below the seafloor using geophysical techniques, to better discern the geologic history and structure of the sites.
Tivey and other scientists and students from WHOI will be joined by colleagues from Towson University, University of South Florida, Bridgewater State College and the U.S. Geological Survey, the University of Bremen in Germany, Seoul University in South Korea, the Commonwealth Scientific and Industrial Research Organization (CSIRO) of Australia, the Geological Survey of Papua New Guinea, the University of Papua New Guinea, and Nautilus Minerals.
The expedition is funded by the National Science Foundation, Nautilus Minerals Inc., WHOI and the respective research agencies of the participants.
Shelley Dawicki | EurekAlert!
Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel
Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
23.04.2018 | Earth Sciences
23.04.2018 | Trade Fair News
23.04.2018 | Information Technology