Settings in geology when the term country rock is used include:
Igneous intrusionsEdit
When describing a pluton or dike, the igneous rock can be described as intruding the surrounding country rock, the rock into which the pluton has intruded.[3]
When country rock is intruded by a dike, perpendicular to the bedding plane, it is called discordant intrusion, while a parallel intrusion by a sill indicates a sub-parallel or concordant intrusion.[4][5][2][6]
Most intrusions into country rock are via magma. Usually, country rock is intruded by an igneous body of rock which formed when magma forced upward through fractures, or melted through overlying rock. Magma then cooled into solid rock, different from the surrounding country rock. Sometimes, a fragment of country rock will break off and become incorporated into the intrusion, and is called a xenolith, from Greek, ξένος, xenos, "strange,", and λίθος, lithos, the ancient Greek word for "stone."[7]
When describing recent alluvium, the material that has arrived through volcanic, glacial or fluvial action can be described as a veneer on the (older) country rock.
ReferencesEdit
^"Country rock - encyclopedia.com". encyclopedia.com. Retrieved 16 December 2018.
^Newfoundland and Labrador, Glossary of Geological Terms Accessed June 2018. Patricia L. Barnes-Svarney; Thomas E. Svarney (2004). The Handy Geology Answer Book. Visible Ink Press. pp. 113–. ISBN978-1-57859-156-5.
^"Hydraulic fracturing as a possible mechanism of dyke-sill transitions and horizontal discordant intrusions in trachytic tabular bodies of Arraial do Cabo, State of Rio de Janeiro, Brazil". Geofísica Internacional. 2008. Retrieved 18 December 2018.
^Granyia (June 6, 2017). "BATHOLITH…, LOPOLITH…, SILL OR DIKE? – INTRUSIONS (2)". Volcano Hotspot. Retrieved 18 December 2018.
^Khoso, Sultan Ahmed. "Intrusive Igneous Rock Structures" (PDF). miningstudents. Retrieved 22 December 2018.[permanent dead link]
^ ab"Country rock". encyclopedia.com. Retrieved 15 December 2018.
October 16, 2023
country, rock, geology, musical, genre, country, rock, geology, country, rock, rock, native, area, contrast, intrusion, viscous, geologic, material, commonly, magma, perhaps, rock, salt, salt, domes, unconsolidated, sediments, devonian, younger, silurian, ordo. For the musical genre see Country rock In geology country rock is the rock native to an area in contrast to any intrusion of viscous geologic material commonly magma or perhaps rock salt in salt domes or unconsolidated sediments 1 All of Devonian and younger Silurian and Ordovician are country rock The igneous intrusion leads to a volcanic eruption A dike dark intrudes into the country rock light Baranof Island Alaska United StatesMagma is typically less dense than the rock it intrudes widening and filling existing cracks sometimes melting the already existing country rock 2 The term country rock is similar to and in many cases interchangeable with the terms basement and wall rocks Country rock can denote the widespread lithology of a region in relation to the rock which is being discussed or observed Contents 1 Geologic settings 1 1 Igneous intrusions 1 2 Alluvial settings 2 ReferencesGeologic settings EditSettings in geology when the term country rock is used include Igneous intrusions Edit When describing a pluton or dike the igneous rock can be described as intruding the surrounding country rock the rock into which the pluton has intruded 3 When country rock is intruded by a dike perpendicular to the bedding plane it is called discordant intrusion while a parallel intrusion by a sill indicates a sub parallel or concordant intrusion 4 5 2 6 Most intrusions into country rock are via magma Usually country rock is intruded by an igneous body of rock which formed when magma forced upward through fractures or melted through overlying rock Magma then cooled into solid rock different from the surrounding country rock Sometimes a fragment of country rock will break off and become incorporated into the intrusion and is called a xenolith from Greek 3enos xenos strange and li8os lithos the ancient Greek word for stone 7 The heat of the intrusions usually changes the country rock often to contact metamorphic rock Commonly hornfels is produced or skarn 7 Alluvial settings Edit When describing recent alluvium the material that has arrived through volcanic glacial or fluvial action can be described as a veneer on the older country rock References Edit Country rock encyclopedia com encyclopedia com Retrieved 16 December 2018 a b Earle Steven 3 5 Intrusive Igneous Bodies 3 5 Intrusive Igneous Bodies Retrieved 16 December 2018 Newfoundland and Labrador Glossary of Geological Terms Accessed June 2018 Patricia L Barnes Svarney Thomas E Svarney 2004 The Handy Geology Answer Book Visible Ink Press pp 113 ISBN 978 1 57859 156 5 Hydraulic fracturing as a possible mechanism of dyke sill transitions and horizontal discordant intrusions in trachytic tabular bodies of Arraial do Cabo State of Rio de Janeiro Brazil Geofisica Internacional 2008 Retrieved 18 December 2018 Granyia June 6 2017 BATHOLITH LOPOLITH SILL OR DIKE INTRUSIONS 2 Volcano Hotspot Retrieved 18 December 2018 Khoso Sultan Ahmed Intrusive Igneous Rock Structures PDF miningstudents Retrieved 22 December 2018 permanent dead link a b Country rock encyclopedia com Retrieved 15 December 2018 Retrieved from https en wikipedia org w index php title Country rock geology amp oldid 1165594602, wikipedia, wiki, book, books, library,
