Behaviours of Ore-forming Solutions in Seawater
1972 Volume 22 Issue 111 Pages 31-42
Details
1972 Volume 22 Issue 111 Pages 31-42
Possible behaviours of the ascending ore-forming solution in seawater are discussed on the basis of two assumptions, namely, (1) chemistries of both the ascending solution and seawater can be approximated by simple aqueous NaCl solutions, and (2) factors except for the heat capacity are negligible in the calculation of the temperatures of the mixed brines between the ascending solution and seawater. Density of any mixed brines is then calculable if the salinity and the temperature of the ascending solution are given. From a series of calculations, the following conclusions are obtained.
(1) Four basic types are recognized in patterns of the density variation caused by the successive degree of mixing (Fig.3).
(2) Factors responsible for this distinction is the temperature and salinity of the ascending solution discharged into seawater (Fig.4).
(3) Depositional features and textures of the mineral deposits formed in submarine environments from these mixed brines should be largely different according to the type of brine (Table 2).
(4) Application of the hypothesis to the "Kuroko" deposits leads to a conclusion that a type IIb brine is responsible for the bed-type ore of this group of deposits.
Acknowledgement; I wish to thank Dr. Akira SASAKI for his helpful suggestions and constructive criticism during the preparation of this paper.
