Mg-CHLORITE AND INTERSTRATIFIED Mg-CHLORITE/SAPONITE ASSOCIATED WITH KUROKO DEPOSITS

抄録

X-ray, chemical, DTA (micro and macro), TG, and infrared data for five Mg-chlorites and four interstratified Mg-chlorite/ saponites collected from the intensively argillized zone of Kuroko and Kuroko-type gypsum deposits in Japan are presented. The Mg-chlorites with variable aluminum contents belong to trioctahedral series but are deficient in octahedral cations by a substitution of 2A1 for 3Mg. The interstratified Mgchlorite/ saponites, being relatively rich in silicon compared with the Mg-chlorites, are composed of an irregularly interstratified mineral having small amounts of saponite layers and a 1: 1 regularly interstratified mineral. Discussions are made on the characteristics of these minerals in relation to well-crystallized Mg-chlorite, on previous data of magnesian chlorite clay minerals from Kuroko deposits, and also on possible interlayer structures of the interstratified minerals.