late Pleistocene glaciation and periglacial processes in the high mountains of Taiwan

台灣有高於3,500 公尺的高山，有這 樣高度的山是東亞地區研究上次冰期山 岳冰川地形的好地方。由理論值推得台灣 上次冰期雪線為3,500 公尺（施雅風等， 1989 ）值得去實地探討。經由航照觀察玉 山、雪山與南湖大山頂，分辨主要由冰雪 營力侵蝕作用與主要由流水營力作用造 成的峰谷的地形及其在高度上的分界，以 得知上次冰期冰河覆蓋的範圍，若有冰坎 地形保留，則可借之推求上次冰期雪線位 置。由台灣中部低山地區頭社盆地上次冰 期時湖積物孢粉學研究，得知冰期早期（6 萬年前後）比晚期（2~3 萬年間）要冷溼， 冰期早期年均溫比現在降約9-10 ℃，因此 早期冰河規模必大於晚期。據(崔之久 等,2000)雪山冰河雪線可至3,400 公尺， 初步觀察、玉山可至3,300 公尺、南湖大 山可能更低。將來若能採到冰磧物定年， 則可確定各期地形形成年代。又研究中也 採了南湖大山2,300 到3,600 公尺的原始 林表土，以為日後研究基礎之用。High mountain island -Taiwan is a good place of Southeastern Asia for investigating alpine glacial during the last glacial. We try to discriminate the erosion forms of glacial from fluvial based on air photos, and check how low the glacial forms may extend. Snowline of Shueh Shan is 3400 m (Cui et al., 2000). Preliminary observation of the possible elevations are Yu Shan, 3300m; and Nanhuta Shan, even lower although the altitudes will be affected by topography and aspects of valleys. This appears reasonable if accessed by the max. lowering of 9-10 o C of temperature than recent during the last glacial based on pollen study in central Taiwan. Our mountain survey was limited due to two severe typhoons in this summer. Wealso ampled the surface soil of natural forests for pollen analysis by way of field survey. That will become a data base for future analytical work too