海底堆積物中の粘土鉱物
分析電顕による研究その1
1988 年 28 巻 2 号 p. 1-10
詳細
1988 年 28 巻 2 号 p. 1-10
A piston core sample collected from off Boso Peninsula, Chiba Prefecture and a sample of late Oligocene calcareous mudstone collected from Daito Ridge have been examined for clay mineralogy by means of X-ray powder diffraction (XRD) and analytical transmission electron microscopy (ATEM). The<2 μm fractions of the subsamples from the piston core were composed principally of smectite, chlorite, illite and kaolinite. The smectite belonged to an iron-rich member, and the chlorite comprised iron-and iron-magnesium types. The proportion of smectite tended to decrease since the late Glacial period, while that of illite showed the opposite trend. The<2μm fractions from the calcareous mudstone was composed almost entirely of smectite low in iron content. The low iron content suggested that the smectite was of terrigenous origin sedimented during the late Oligocene.
