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Experiments on the Element Distribution between the Granodiorite JG‐1a and 2M NaCl Hydrothermal Solution at Temperatures of 300 to 800°C and a Pressure of 1 kb
Author(s) -
Uchida Etsuo,
Haitani Takuro,
Suetsugu Takayuki,
Kashima Takahiro,
Tsutsui Ken
Publication year - 2003
Publication title -
resource geology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 43
eISSN - 1751-3928
pISSN - 1344-1698
DOI - 10.1111/j.1751-3928.2003.tb00166.x
Subject(s) - aqueous solution , hydrothermal circulation , chloride , partition coefficient , divalent , analytical chemistry (journal) , mineralogy , chemistry , nuclear chemistry , geology , chromatography , organic chemistry , seismology
. The distribution of Na, K, Ca, Mg, Mn and Fe between the granodiorite JG‐la, one of the geochemical standard rocks, and 2M NaCl aqueous solution was experimentally determined at temperatures of 300 to 800d̀C and a pressure of 1 kb using standard cold seal‐type pressure vessels. The solid run products melted partially at 800d̀C. Only K shows a significantly different behavior from the experiments using the basalt JB‐la (Uchida and Tsutsui, 2000) due to the presence of ortho‐clase in the JG‐la. The transition elements tend to be preferably partitioned into the aqueous chloride solutions with increasing temperature. At 800d̀C and 1 kb, the Fe concentration of the aqueous chloride solutions reached up to 5,000 ppm, and the Mn concentration up to 350 ppm. The distribution coefficient, K D, i = C i, sol /C i , rock, is in the order of Na>K>Mn>Ca> Fe>Mg at 300d̀C, but changed in the order of Mn>N>K>Fe>Ca>Mg at 800d̀C. The distribution coefficients of the divalent cations for the JG‐la are higher than those for the JB‐1a. The distribution coefficient of the transition elements, Fe and Mn, increases significantly with increasing temperature. The thermodynamic analysis for aqueous speciation revealed that this is attributable to the formation of the tri‐chloro complexes of the transition elements at higher temperatures.