Periglacial Phenomena in Hou-Fuan Shan Massif, Taiwan

In the present paper the author gives the results of the investigations of periglacial landforms and deposits in the area of the Hou-Fuan Shan Massif, Central Range of Taiwan. The mountains of the massif consist of mainly sandstone, shale and slate with numerous bedding planes and joints. They are less resistive against the frost action and readily produce the rubble. There are various periglacial landforms and deposits on the east flankof the massif or windward side to the north-east winter monsoon. Active nonsorted steps covered with vegetation are found commonly on the upper part of the east flank. Fossil periglacial phenomena, such as cryoturbation deposits, patterned grounds and block fields are observed at the outcrops along the roadside of East-West Cross-island highway. It seems that the altitudes of the lower limits of nonsorted steps and fossil phenomena are 3, 100 m and 2, 500 m respectively. Stratified cryoturbation deposits are found in two sheets of bedding on the slope of more than 2, 700 m. The periods of development of the deposits seems to be the last glacial stage and the cold age in the Recent. Tors, frost riven cliffs and altiplanation terraces develop on the upper part of north-east-facing slope of Mt. East Hou-Fuan Shan. These forms were shaped by severe cryoplanation under the periglacial climatic condition during the last glacial stage and inactive at present. Cryoplanation acted on the former erosion surface and modified the surface to the step-like gentle convex slopes.