An example on weathering of chlorite and sericite in the Sanbagawa green shist

Some of chlorite minerals in the Sanbagawa green shist have been converted to vermiculite-like mineral by weathering.Their mineralogical properties are clearly different from those of normal chlorite and vermiculite.The 001/002 intensity ratio of the minerals increases with the increase of weathering from 0.4 to 1.2.Normal chlorite found in the shist gives the ratio between 0.2 and 0.4, and vermiculite shows the ratio above 2.5.It is not sure that the minerals are interstratified chlorite and vermiculite, but they always occur with interstratified mica and expandable layer derived from sericite in the shist.1.