Seawater is constantly circulating through oceanic basement as a low-temperature hydrothermal fluid (<150 degrees C). In cases when ultramafic rocks are exposed to the fluids, for instance during the initial phase of subduction, ferromagnesian minerals are altered in contact with the water, leading to high pH and formation of secondary magnesium hydroxide, among other--brucite, that may scaveng...

[1] Observations from the East Pacific Rise (EPR) and the Endeavour segment of the Juan de Fuca Ridge show that local earthquake swarms can lead to increased hydrothermal venting temperatures after a delay of several days. I develop two models for this process. In the temperature perturbation model, a new pathway opens to a heat source, and the temperatures of fluids leaving the reaction zone i...

The fringing reef in Tutum Bay on the west side of Ambitle Island, Papua New Guinea is the only presently known coral reef exposed to the extensive discharge of a hot, mineralized hydrothermal fluid. There, aragonite and ferrihydrite, a hydrous ferric oxide, are the prominent hydrothermal precipitates. Aragonite forms two distinct crystal habits, (a) euhedral (pseudohexagonal) crystals up to 2 ...

Samples of young, outer surfaces of brucite-carbonate deposits from the ultramafic-hosted Lost City hydrothermal field were analyzed for DNA and lipid biomarker distributions and for carbon and hydrogen stable isotope compositions of the lipids. Methane-cycling archaeal communities, notably the Lost City Methanosarcinales (LCMS) phylotype, are specifically addressed. Lost City is unlike all oth...

Four distinct types of fluid inclusion are associated with brecciation, alteration and mineralization in the Ilkwang Cu–W breccia-pipe deposit in the southeastern Kyongsang Basin, South Korea. The earliest fluid inclusions in igneous quartz have salinities of 35–49 wt% NaCl equiv. and homogenize by halite dissolution. This fluid exsolved directly from the melt. A CO2-bearing fluid (2–4 wt% NaCl...

This contribution illustrates the procedures of calculating rare earth element (REE) patterns of magmatic fluids in equilibrium with granitic melts. These patterns can then be compared to those of altered and (or) mineralized rocks in order to investigate the source of the ore-fluids. This technique is applied to the Lake George Sb-Au-W-Mo mineral deposit, New Brunswick, Canada. The results sug...

Aid the Air Force modeling community by developing a “mid-level” approach to simulating the behavior of complex fluids, such as viscous incompressible fluids, hydrothermal fluids, inviscid fluids, multiphase fluids, and superfluids. Traditional approaches to complex fluid simulation include “low-level” molecular dynamics or “high-level” partial differential equation approximation schemes. MD su...

In this study, we present new data from microthermometry of fluid inclusions entrapped in hydrothermal veins along the Cocos Ridge from the IODP Expedition 344 Site U1414. The results of our study concern a primary task of IODP Expedition 344 to evaluate fluid/rock interaction linked with the tectonic evolution of the incoming Cocos Plate from the Early Miocene up to recent times. Aqueous, low ...

This paper reports the mineralogical compositions of super-low-sulfur (Yueliangtian 6-upper (YLT6U)) and high-sulfur (Yueliangtian 6-lower (YLT6L)) coals of the Late Permian No. 6 coal seam from the Yueliangtian coal mine, Guizhou, southwestern China. The mineral assemblages and morphology were detected and observed by X-ray diffractogram (XRD), optical microscopy and field-emission scanning el...