In the Japan Alps, the main ridges with elevations of more than 2; 500m, have shown a marked modification by the climatic influences since the glacial ages. The origination of asymmetrical ridges may be explained from the following facts and assumptions; 1) As it has been said, snow accumulates on the more protected eastern slope on the lee side of the prevailing wind. 2) West wind is effective in promoting ablation of snow on the, windward side. 3) Less snowy western slope on the windward side of the prevailing wind has evidently been subjected to Solifluction. 4) On the eastern side, the occurrence of steep slopes produced by the past Glaciation or Nivation is distinguishable 5) Stone polygons and stripes are frequent on the flattened or cryo-planated rubbly surface oil the western remnant erosion surfaces. The above-mentioned facts and postulates are obviously capable of making appearance of the remarkable contrasts in the topographic and vegetational features between each side of ridges. Difference of opinion was proposed as to the interpretation that cirques are genetically composed of even and flat bottom surfaces. In empty-cirques in the Japan Alps, large amount of postglacial detritus under periglacial condition causes an illusion in which we are apt to believe that bottoms are originally flat and nearly horizontal. (Dept. Geol. Fac., Liberal Arts and Sci., Shinshu Univ., Japan)
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