Some Prolbems on Geologic Structure at Sazare Mine

Abstract

The Sazare mine is one of bedded cupriferous pyritic deposits occurring in the Sambagawa crystalline schists in the central Shikoku, and is well noted for the peculiar oblique intersection at high angle between the axis of ore shoot parallel to the unusual lineation in southwest direction and the regionally prevailing linear trend in the area.
For the purpose of prospecting the lower extension of the known ore bodies, and of finding new ore body, morphological and structrual analyses of both ore bodies and country rocks were made.
Planar and linear structures of the Kinsha ore body were analyzed and described on several levels, and the study of special features of "Sazare fold" was made in the western cross-cut on the 24th level.
The conclusion is as follows : (1) The ore bodies are morphologically classified into two types, named type I and type II. The former is a typical bedded deposit having a simple planar or sheetlike feature. The latter is an irregular shaped one with complicate foldings, and sometimes is called massive rather than planar. Authors consider that type I is a deformed equivalent of type II by later. tectonic movement. (2) Sazare fold is a kind of isoclinal fold plunging 40° in southwest direction with an axial plane trending east-westerly and dipping 40-45 to the south. This fold is considered to have 'been originally formed in the stage of the formation of the high angle lineation which plunges southwestwards and reformed by the later tectonic movement in which the transformation of the ore bodies was involved. (3) Kinsha ore body and Sazare fold are in close interrelation both in the original state and the later tectonic movement.