1985 Volume 35 Issue 190 Pages 145-159
The Mozumi deposits belong to skarn-type, and consist of many small ore bodies which are controlled by fissures. The forms of deposits are tabular and/or pipe-like, which appear to have been formed along the intersections of limestone beds and fissures. The main projects of this study are to clarify the structural relations between fissures and folded limestone beds and the zonal distribution of the deposits.
It might be called "vein-type replacement deposits". As the result of studies on relationship between fissures and mineralization, the important targets for exploration work were newly detected as follows:
(1) It seems that ore solution mainly ascended through fissures with NW trend, partly flowed into fissures with NS trend, and was finally deposited in the traversing limestone beds.
(2) Plunges of ore body are controlled by the intersections between the fissures and folded limestone beds.
(3) Distributions of Ag/Pb and Pb/Zn ratios in the ores indicate the trends of mineralization. As the result of following exploration, some promissing targets are confirmed as follows;
(1)"East-south ore zone" is discovered between"East zone" and "South zone" in the Nantohbu area of the Mozumi deposits.
(2) A large amount of ore is obtained in the East No. 5 deposit.
(3) Probability of huge amount of ore is surely expected at the deeper part of the Nantohbu area.
