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Experiments on Water‐ Rrocks Iinteraction and Mmetal Ttransport at Hhigh Ttemperatures within the Wwater Ccritical Rregion
Author(s) -
ZHANG Xuetong,
ZHANG Ronghua,
HU Shumin
Publication year - 2014
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/1755-6724.12379_73
Subject(s) - metallogeny , beijing , chinese academy of sciences , mineral , mineral resource classification , zhàng , geology , mineral exploration , mining engineering , geochemistry , china , archaeology , pyrite , chemistry , geography , sphalerite , organic chemistry
Hydrothermal metal transport is characterized of alteration zoning due to water rock interactions. The distinct alteration zonings were found in Cu-porphyry, near and in the vent at Mid-Ocean Ridge, etc. Usually, the inner part of alteration zone is composed of metal ores, Fe-Mg silicate mineral and feldspar. The silicified, argillized and sericite rocks were present at its outer part. In the volcanic basins, Mid-Lower Yangtze river valley, China, magnetite-anhydrite (apatite) deposits occurred associated with strong alteration zoning. The melanocratic alteration (pyroxene, albite, anhydrite, apatite and magnetite) occurred in the deeper part and pyrite and silicified, argillized and sericite rocks were in the shallow. Experiments provide new message to reveal the mechanism of metal transport during alteration. A series of kinetic experiments on water-rock interactions in aqueous solutions are performed using flow through reactors at temperatures from 20 to 550°C, 22-36 MPa, such as: basalt-water, syenite-water, granodioritewater interactions. The maximum release rates for different metals from rocks vary with temperatures from 20 to 550°C. Na, Mg, Ca, Fe are easily released at 20 to 200°C, but releases of Fe, Mg, Ca are prohibited from 300 to 550°C. K and Al are easily released at about 350°C. Si is strongly released at 300 to 400°C. The experiments indicated that hydrothermal release and transport of different metals from rocks are dependent upon the temperatures and water nature.