Glacial polish is a characteristic of rock surfaces where glaciers have passed over bedrock, typically granite or other hard igneous or metamorphic rock. Moving ice will carry pebbles and sand grains removed from upper levels which in turn grind a smooth or grooved surface upon the underlying rock.[1] The presence of such polish indicates that the glaciation was relatively recent (in geologic time scale) or was subsequently protected by deposition, as such polish will be subsequently lost due to weathering processes (such as exfoliation).
Glacial polish at Devils Postpile National Monument, Madera County, California, USALow-angle sunlight illuminates glacial polish on granite. Emigrant Wilderness, Sierra Nevada, California, USA. Both flat and pockmarked polish surfaces are visible. The polish itself is a thin layer, some millimeters thick, that is being removed by weathering.
glacial, polish, characteristic, rock, surfaces, where, glaciers, have, passed, over, bedrock, typically, granite, other, hard, igneous, metamorphic, rock, moving, will, carry, pebbles, sand, grains, removed, from, upper, levels, which, turn, grind, smooth, gr. Glacial polish is a characteristic of rock surfaces where glaciers have passed over bedrock typically granite or other hard igneous or metamorphic rock Moving ice will carry pebbles and sand grains removed from upper levels which in turn grind a smooth or grooved surface upon the underlying rock 1 The presence of such polish indicates that the glaciation was relatively recent in geologic time scale or was subsequently protected by deposition as such polish will be subsequently lost due to weathering processes such as exfoliation Glacial polish at Devils Postpile National Monument Madera County California USA Low angle sunlight illuminates glacial polish on granite Emigrant Wilderness Sierra Nevada California USA Both flat and pockmarked polish surfaces are visible The polish itself is a thin layer some millimeters thick that is being removed by weathering See also editGlacial striationReferences edit Monroe James S Reed Wicander 2004 Changing Earth Thomson Brooks Cole p 395 ISBN 0 495 01020 0 nbsp This glaciology article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Glacial polish amp oldid 1146848732, wikipedia, wiki, book, books, library,
