風化変質により生成する粘土鉱物とその性質

抄録

Minerals comprising rocks are attacked by meteoric water and air and alter their structual and chemical properties. The minerals change to intermediate and/or new minerals in such weathering process. In this paper, relatively early products of the chemical weathering from mica minerals, chlorite and smectite are referred.
The vermiculite weathered from biotite in schalstein at Ofuku, Yamaguchi Pref. has cube-like materials in about 50Å size at the edge of the crack on surface and in an exforiated interlayer space. Chlorite-vermiculite interstratified minerals weathered from chlorite in schalstein and sedimentary rocks from Tobigamori, Iwate Pref. are estimated comprising about 50% of a vermiculite-like layer by X-ray diffraction analysis. The degree of swelling of their interlayers after various K⁺-treatments distinctively change among samples and with particle sizes of the samples. The interstratified chlorite-vermiculite alters to kaolinite with the relationship of syntaxy.