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Sarn Complex
The Sarn Complex is a group of closely related igneous rocks that intrude and cut through other rock lithologies in the Cymru Terrane in Wales.P. J. Brenchley, P. F. Rawson ''The Geology of England and Wales'', 2006, 2nd Ed The complex outcrops on the Llyn Peninsula in a variety of places including Mynydd Cefnamlwch and the flanks of Pen y Gopa. Geological information The largest plutonic body in the terrane has limited outcrop and is Shear (geology), sheared by the Llyn Shear Zone in the west and covered by later (Arenig) sediments to the east. Altered to greenschist facies the pluton contains a bimodal suite of gabbro-diorite, monzogranite (Sarn Granite) and granodiorite. The Sarn Granite is leucocratic and covers an expanse of about 6 km2 in contrast to the gabbro and diorite that exist as small and scattered exposures. The dioritic component of the complex has been confirmed as having a Neoproterozoic age of 614 ±2 Ma using U-Pb zircon dating.P. J. Patchett ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Igneous Rock
Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main The three types of rocks, rock types, the others being Sedimentary rock, sedimentary and metamorphic rock, metamorphic. Igneous rock is formed through the cooling and solidification of magma or lava. The magma can be derived from Partial melting, partial melts of existing rocks in either a Terrestrial planet, planet's mantle (geology), mantle or crust (geology), crust. Typically, the melting is caused by one or more of three processes: an increase in temperature, a decrease in pressure, or a change in composition. Solidification into rock occurs either below the surface as intrusive rocks or on the surface as extrusive (geology), extrusive rocks. Igneous rock may form with crystallization to form granular, crystalline rocks, or without crystallization to form Volcanic glass, natural glasses. Igneous rocks occur in a wide range of geological settings: shields, platforms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
