Nya Fynd av Subglacialt Bildade Kalkstenar

Abstract

Deposits of limestone on the lee-sides of glaciated rocks have earlier been described from Norway and Sweden (Höeg 1929, 1931 a, 1931 b, 1932, 1934, Westergård 1934, Bohlin 1943, and Kers 1961). In 1962 and 1963 similar limestone were observed in the vicinity of Gothenburg, in front of the Austrian glacier Pasterzenkees, and at Nigardsbreen, Norway. The crusts consist of microcrystalline calcite with varying contents of other mineral grains. The limestone is laminated. Plates with a thickness of 1 cm are common but there are also ridges, furrows, and nodules. A prominent lee-side is covered with coarse, dark calcite in semispherical bodies. The contents of calcite range from 30 to 75 percent by weight. The origin is shown to be subglacial. According to the formation through precipitation, there must, at least occasionally, have been some water both beneath the inland ice and the glaciers. The new localities suggest that subglacially formed limestone can be expected where unweathered, glaciated rocks are exposed.