Clay and silt fractions of A and BG horizons were separated into three fractions of 20-5, 5-1, and < 1μ. Fixation capacity of ammonium, chemical composition, base exchange capacity, dehydration curves, differential thermal curves, ethylene glycol retention, electron micrographs, and x-ray diffraction patterns were obtained for these separates. It was concluded piecing togethe r various properties observed that the clay was largely composed from minerals of illite-montmorillonoid series, and as the accessary minerals halloysite, R203-hydrates, and skeletons of diatoms were found in small amounts in the clay. The silt was illitic, but it had less potash and much hygroscopic water than the illite, and quartz was found in small amounts in the 1~5 and 5~20 μ fractions.