Hydrothermal vent deposits

Calcium Carbonates. Carbon Cycle. Hydrothermal Vent Deposits. Hydrothermal Vent Fluids, Chemistry of. Iron Fertilization. Nitrogen Cycle. River Inputs. Stable Carbon Isotope Variations in the Ocean. 

Hydrothermal Vent Deposits. Mid-Ocean Ridge Geochemistry and Petrology. 

Clay Mineralogy. Hydrothermal Vent Deposits. Platinum Group Elements and their Isotopes in the Ocean. Pore Water Chemistry. Rare Earth Elements and their Isotopes in the Ocean. River Inputs. Tracers of Ocean Productivity. Transition Metals and Heavy Metal Speciation. Uranium-Thorium Decay Series in the Oceans Overview. 

Cenozoic Climate - Oxygen Isotope Evidence. Hydrothermal Vent Deposits. Rare Earth Elements and their Isotopes in the Ocean. River Inputs. 

Hydrothermal vent deposits are thus a renewable source of metals and a record of the physical, chemical, biological, and geological processes at modern and ancient submarine vents. 

Fig. 2. Distribution of ( ) known and (o) suspected metalliferous sulfide deposits and active hydrothermal vents in the Pacific Ocean (42).

Positive Eu anomaly is observed for hydrothermal solution issuing from the hydrothermal vent on the seawater at East Pacific Rise (Bence, 1983 Michard et al., 1983 Michard and AlbarMe, 1986). Guichard et al. (1979) have shown that the continental hydrothermal barites have a positive Eu anomaly, indicating a relatively reduced environment. Graf (1977) has shown that massive sulfide deposits and associated rocks from the Bathurst-Newcastle district. New Brunswick have positive Eu anomalies. These data are compatible with positive Eu anomaly of altered basaltic rocks, ferruginous chert and Kuroko ores in Kuroko mine area having positive Eu anomaly and strongly support that Eu is present as divalent state in hydrothermal solution responsible for the hydrothermal alteration and Kuroko mineralization. 

As already discussed, /02 of Kuroko ore fluids is considered to lie in the predominance field of reduced sulfur species from the following two reasons (1) Selenium content of sulfides is very low (Yamamoto, 1974) and (2) H2S is dominant in hydrothermal solution venting from back-arc basins (section 2.3) from which hydrothermal ore deposits being similar to Kuroko deposits form. 

Emerson, D. Moyer, C.L. Neutrophilic Fe-oxidizing bacteria are abundant at the Loihi Seamount hydrothermal vents and play a major role in Fe oxide deposition. Appl. Environ. Microbiol. 2002, 68, 3085-3093. 

The rest of the chapter is organized as follows. In Section 6.07.2 we discuss the chemical composition of hydrothermal fluids, why they are important, what factors control their compositions, and how these compositions vary, both in space, from one location to another, and in time. Next (Section 6.07.3) we identify that the fluxes established thus far represent gross fluxes into and out of the ocean crust associated with high-temperature venting. We then examine the other source and sink terms associated with hydrothermal circulation, including alteration of the oceanic crust, formation of hydrothermal mineral deposits, interactions/uptake within hydrothermal plumes and settling into deep-sea sediments. Each of these fates for hydrothermal material is then considered in more detail. Section 6.07.4 provides a detailed discussion of near-vent deposits, including the formation of polymetallic sulfides and... 

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