Tectonic map of Uruguay

The tectonic evolution of Uruguay is presented from the synthesis of the geological evolution. It will be show the evolution of different orogenic cycles including the evolution of magmatism, deformation and associated metamorphism, which affected these latitudes emphasizing the paleogeographic context. are recognized in the Uruguayan territory several orogenic cycles , shorter events associated with the movement of fluid reactivation fault zones, inter alia, that with isotope studies mainly those made in the past 15 years have improved the understanding and evaluating durations different tectonic events and associated phenomena. Structural provinces of the platform South America are characterized according to their origin in cratonic areas , orogenic belts and basins sedimentary . Cratons represent stable regions consisting of Precambrian rocks . During cycles orogenic these areas behaved as rigid regions, mobile belts that developed around him and were eroded and exhumed . South America was involved in events amalgamation and breakup of supercontinents during several consecutive orogenic cycles that occurred in the Paleoproterozoic (Atlantis or supercontinent Columbia), Mesoproterozoic (supercontinent Rodinia or paleopangea), Neoproterozoic (western Gondwana) and Carboniferous (Pangaea). Evidence attempt supercontinent Columbia suggests that existed between 1800 and 1500 Ma prior to the period of rapid growth mantle and cortical reorganization. In these latitudes the beam of mafic dikes (1700 Ma) granites with anorogenic (rapakivi) could represent the fragmentation of this supercontinent or episode tafrogénico Stateriano. The geodynamic evolution of the crust during the Late Proterozoic and Paleozoic less involved the formation of two great continents, Laurentia and Gondwana, from fragmentation Rodinia supercontinent that would have formed ca. 1100 Ma and would have dismembered into three fragments between 800 and 600 Ma during the Pan - African orogeny Brasiliana western Gondwana consisted several cratonic nuclei : Amazon , San Francisco, Sao Luis, Luis Alves Río de la Plata, in South America and West Africa, Congo, Kalahari in Africa, amalgamated between 750 and 510 Ma The orogenic cycles Registered in Uruguay are Transamazonian in OSO, Brasiliano - Pan-African E -NE , NNE cycle Gondwana (sedimentary cover) and NO extensional magmatism associated with the break and South America Africa . The objective is to present a synthesis of the different tectonic units for Uruguay . units older are represented by Craton of River Plate (CRP), Nico Pérez tectonostratigraphic Land (TTNP) , Dom Feliciano Belt (CDF), Basement inliers in the Dom Feliciano Belt ( BICDF) Systems Mesozoic extensional (SEM). The outcropping portion of CRP to the shear zone Sarandi del Yi (ZCSY) Land tectonostratigraphic Piedra Alta (Paleoproterozoic) consists of orogenic belts low and medium grade metamorphism (ca 2100 Ma) mafic layered complex , tardi - postorogenic magmatism (1900-2300 Ma), rapakivi A-type granites - (2078 Ma) and an extensional magmatism represented by a bundle of dikes (1700 Ma). These units were assigned to Transamazonian cycle as a time reference and not by its tectonic implication orogenic cycle. To the east is found the Nico Pérez tectonostratigraphic Land represented by orogenic land medium to high grade ( Blocks Pavas, Valentines, and Rivera ) and a anorogénico - Rapakivi 1700 Ma granite - La Brasiliana / Pan-African orogeny is represented by different tectonic units constituting the Dom Feliciano Belt (750-650 Ma). The units that make up this belt represent the evolution of back-arc basin in the southeast that evolves to a back-arc basin to the northeast. activity magma that characterizes this orogenic cycle is separated into arc magmatism and other post- orogenic (630-570 Ma). Similar basins are represented in the Kaoko belt (Namibia, Africa) , Ribeira belt (Brazil). Finally, associated with orogenic evolution of the Dom Feliciano belt linked basins developed to post- collisional extension and back-arc basins, foreland basin, as well as important events volcanic. These basins are formed by deposits Molásicos: Las Ventanas, Barriga Negra, San Carlos; Volcano- sedimentary sequences: Playa Hermosa, Sharpening Stones, Arroyo del Soldado and Sierra de Aguirre and magmatism (Sierra de Las Animas Complex and Fm. Sierra de Los Rios). Five litho-tectonic units are recognized in the basement inliers in the CDF, metamorphic sequences plataformales low to medium grade (≤ Fm Tiger Ditch 1.4Ga ?) Ringer Unit , Basement High degree (Cerro Olivo Complex - Paleoproterozoic - ) , low-grade orogenic belts (Rocha Training) foreland basin deposits (Paraná). Mesozoic units were formed in a tectonic framework dominated by the breakup of Gondwana. Magmatism and associated sedimentary basins are began during the Jurassic. These tectonic units are represented by an extensional magmatism (Paraná volcanic province , an extensional bimodal magmatism (Formations Puerto Gomez and Arequita Valle Chico complex) deposits Rift (Cuenca St. Lucia - Laguna Merin) and intracratonic basin (West Coast)