RILLENKARREN ON GRANITE OUTCROPS, SW POLAND, AGE AND SIGNIFICANCE

Rillenkarren found in the Karkonosze granite massif in SW Poland are d escribed, and their origin, age and significance are discussed. They a re 35-350 cm long, 5-30 cm deep and 10-50 cm wide. The depth:width rat io varies from 1:1 to 1:5. Karren occur on slopes of bornhardts and on large tors, which are probably elements of pre-Pliocene relief. They have never been discovered on surfaces of Pleistocene age and therefor e are regarded as forms initiated in a greater past. Surficial weather ing controlled by local differences in moisture has been the main form ative process. Climatic interpretation of karren is difficult; it may only be said that they presumably have not formed in moderately humid temperate or periglacial climates. Karren are persistent landforms, th e persistence being related to diversified weathering between flutings and intervening ridges.