Outcrops do not cover the majority of the Earth's land surface because in most places the bedrock or superficial deposits are covered by soil and vegetation and cannot be seen or examined closely. However, in places where the overlying cover is removed through erosion or tectonic uplift, the rock may be exposed, or crop out. Such exposure will happen most frequently in areas where erosion is rapid and exceeds the weathering rate such as on steep hillsides, mountain ridges and tops, river banks, and tectonically active areas. In Finland, glacial erosion during the last glacial maximum (ca. 11000 BC), followed by scouring by sea waves, followed by isostatic uplift has produced many smooth coastal and littoral outcrops.
Bedrock and superficial deposits may also be exposed at the Earth's surface due to human excavations such as quarrying and building of transport routes.
Study
Outcrops allow direct observation and sampling of the bedrockin situ for geologic analysis and creating geologic maps. In situ measurements are critical for proper analysis of geological history and outcrops are therefore extremely important for understanding the geologic time scale of earth history. Some of the types of information that cannot be obtained except from bedrock outcrops or by precise drilling and coring operations, are structural geology features orientations (e.g. bedding planes, fold axes, foliation), depositional features orientations (e.g. paleo-current directions, grading, facies changes), paleomagnetic orientations. Outcrops are also very important for understanding fossil assemblages, and paleo-environment, and evolution as they provide a record of relative changes within geologic strata.
^Howell, J. V., 1960, Glossary of Geology and Related Sciences. Washington, DC: American Geological Institute, pp. 207-208
^. Archived from the original on 2011-06-08. Retrieved 2010-05-24.
^. Archived from the original on 2012-09-20. Retrieved 2010-05-24.
External links
Media related to Outcrops at Wikimedia Commons
The dictionary definition of outcrop at Wiktionary
January 06, 2023
outcrop, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, september, 2011, l. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Outcrop news newspapers books scholar JSTOR September 2011 Learn how and when to remove this template message An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth 1 Outcrop of volcanic rock in Germany Contents 1 Features 2 Study 3 Examples 4 See also 5 References 6 External linksFeatures EditOutcrops do not cover the majority of the Earth s land surface because in most places the bedrock or superficial deposits are covered by soil and vegetation and cannot be seen or examined closely However in places where the overlying cover is removed through erosion or tectonic uplift the rock may be exposed or crop out Such exposure will happen most frequently in areas where erosion is rapid and exceeds the weathering rate such as on steep hillsides mountain ridges and tops river banks and tectonically active areas In Finland glacial erosion during the last glacial maximum ca 11000 BC followed by scouring by sea waves followed by isostatic uplift has produced many smooth coastal and littoral outcrops Bedrock and superficial deposits may also be exposed at the Earth s surface due to human excavations such as quarrying and building of transport routes Study EditOutcrops allow direct observation and sampling of the bedrock in situ for geologic analysis and creating geologic maps In situ measurements are critical for proper analysis of geological history and outcrops are therefore extremely important for understanding the geologic time scale of earth history Some of the types of information that cannot be obtained except from bedrock outcrops or by precise drilling and coring operations are structural geology features orientations e g bedding planes fold axes foliation depositional features orientations e g paleo current directions grading facies changes paleomagnetic orientations Outcrops are also very important for understanding fossil assemblages and paleo environment and evolution as they provide a record of relative changes within geologic strata Accurate description mapping and sampling for laboratory analysis of outcrops made possible all of the geologic sciences and the development of fundamental geologic laws such as the law of superposition the principle of original horizontality principle of lateral continuity and the principle of faunal succession Examples EditOn Ordnance Survey maps in Great Britain cliffs are distinguished from outcrops cliffs have a continuous line along the top edge with lines protruding down outcrops have a continuous line around each area of bare rock An outcrop example in California is the Vasquez Rocks familiar from location shooting use in many films composed of uplifted sandstone 2 3 Yana is another example of outcrops located in Uttara Kannada district in Karnataka India Serrote Branco outcrop in Caico Brazil Precambrian outcrop in Finland Granite outcrops at Silesian Stones Mountain in southwestern Poland Outcrop near Yana India Outcrop of the Roubidoux Formation in the Ozarks of southern Missouri Outcrop in the Vasquez Rocks Natural Area Park of southern CaliforniaSee also Edit Earth sciences portalDigital outcrop model Geological formation Geologic time scale List of rock formationsReferences Edit Howell J V 1960 Glossary of Geology and Related Sciences Washington DC American Geological Institute pp 207 208 oxy edu Vazquez Rocks access date 5 22 2010 Archived from the original on 2011 06 08 Retrieved 2010 05 24 parks lacounty gov Vazquez Rocks Natural Area and Nature Center access date 5 22 2010 Archived from the original on 2012 09 20 Retrieved 2010 05 24 External links Edit Media related to Outcrops at Wikimedia Commons The dictionary definition of outcrop at Wiktionary Retrieved from https en wikipedia org w index php title Outcrop amp oldid 1115373395, wikipedia, wiki, book, books, library,
