Los conglomerados sintectonicos de la Formacion Las Cumbres (Plio-Pleistoceno), Sierras Pampeanas de La Rioja y Catamarca, Argentina.
Syntectonic conglomerates of the Las Cumbres Formation (Plio-Pleistocene), Pampean Ranges from La Rioja and Catamarca, Argentina.
| dc.contributor | en-US | |
| dc.contributor | es-ES | |
| dc.creator | Bossi, Gerardo E. | |
| dc.creator | Georgieff, Sergio M. | |
| dc.creator | Muruaga, Claudia M. | |
| dc.creator | Ibanez, Lucia M. | |
| dc.creator | Sanagua, Javier G. | |
| dc.date | 2010-07-06 | |
| dc.identifier | http://www.andeangeology.cl/index.php/revista1/article/view/V36n2-a02 | |
| dc.identifier | 10.5027/andgeoV36n2-a02 | |
| dc.description | La Formacion Las Cumbres (Plio-Pleistoceno) aflora extensamente en el area comprendida entre las sierras de Velasco y Paiman al sur y las sierras de Vinquis y Zapata al norte (Provincias de Catamarca y La Rioja, NO Argentina) cubriendo concordantemente la Formacion Salicas (Mioceno tardio-Plioceno temprano). La Formacion Las Cumbres es una sucesion granocreciente de conglomerados y areniscas que desarrollan una gran bajada aluvial formada durante el pico del levantamiento de las Sierras Pampeanas. En el sector sureste del area estudiada (las Cumbres de los Pozuelos), la falla transpresiva Uscamayo creo cuatro alounidades locales separadas por discordancias angulares (progresivas), en el bloque hundido. Cada alounidad constituye un estadio de actividad tectonica intensa, mientras que las discordancias representan etapas intermedias de intensa erosion y pedimentacion. Se han distinguido dos facies sedimentarias principales: 1. conglomerados de milonitas angulosas y granitos deformados que dominan la parte sur del sistema de dispersion y 2. conglomerados polimicticos redondeados (granitos, esquistos, volcanitas, metavolcanitas y milonitas) que corresponden al sector norte. Las facies 1 provienen de las sierras de Velasco, cerro La Punta y Paiman, mientras que las facies 2 derivan del conjunto de sierras integradas por Vinquis, Zapata, Copaca-bana y Cerro Negro. Los dos sistemas convergen hacia el area de las Cumbres de los Pozuelos para hundirse alli en el 'Bolson de Pipanaco'. Estos sistemas de dispersion no son congruentes con la posicion actual de las sierras que han sufrido desplazamientos importantes en sentido norte-sur durante la etapa mas intensa de levantamiento, ocurrida en el Pleistoceno temprano y 'medio'. | es-ES |
| dc.description | The Las Cumbres Formation (Plio-Pleistocene) crops out extensively between the Zapata -Vinquis Ranges to the north and the Paimán-Velasco Ranges to the south (La Rioja and Catamarca Provinces, NW-Argentina) conformably overlying the Salicas Formation of late Miocene-early Pliocene age. The Las Cumbres Formation is a coarsening-upwards succession of conglomerates and sandstones related to a huge alluvial bajada. In the southeastern part of the mapped area, the Uscamayo transpressive fault created four local allounits separated by angular unconformities developed along the southern down-thrown block (the Cumbres de los Pozuelos). Each unconformity defines a stage of the Uscamayo fault activity followed by an intense reworking and pedimentation of the up-thrown northern block and sedimentation and differential subsidence of the southern block. At the western flank of the Velasco Range the Las Cumbres Formation dips gently to the west forming several faulted strips. It is organized in two facies: 1. fine-grained conglomerates composed of angular fragments of mylonites and deformed granites and 2. medium to fine-grained, polymictic conglomerates consisting of rounded fragments of pink and gray granitoids, deformed granitoids, schists, metavolcanics and milonites that predominate in the northern part. The facies define two dispersal systems: a southern system of angular pebbles and a northern, rounded pebble system. The outcrops of the two dispersal systems merge towards the east and southeast declining near the Uscamayo fault into the 'Bolsón de Pipanaco'. Several gravel composition maps with paleocurrent directions and maximum pebble sizes, show a dispersal system that, despite having its provenance in the surrounding ranges, is not adjusted with the present-day position of the ranges, suggesting that the system was emplaced in a north-south direction during the most intense phase of uplift in the early and middle Pleistocene. | en-US |
| dc.format | application/pdf | |
| dc.format | text/html | |
| dc.language | eng | |
| dc.publisher | Servicio Nacional de Geología y Minería | en-US |
| dc.relation | http://www.andeangeology.cl/index.php/revista1/article/view/V36n2-a02/971 | |
| dc.relation | http://www.andeangeology.cl/index.php/revista1/article/view/V36n2-a02/html | |
| dc.source | Andean Geology; Vol 36, No 2 (2009); 172-196 | es-ES |
| dc.source | Andean Geology; Vol 36, No 2 (2009); 172-196 | en-US |
| dc.source | 0718-7106 | |
| dc.source | 0718-7092 | |
| dc.title | Los conglomerados sintectonicos de la Formacion Las Cumbres (Plio-Pleistoceno), Sierras Pampeanas de La Rioja y Catamarca, Argentina. | es-ES |
| dc.title | Syntectonic conglomerates of the Las Cumbres Formation (Plio-Pleistocene), Pampean Ranges from La Rioja and Catamarca, Argentina. | en-US |
| dc.type | info:eu-repo/semantics/article | |
| dc.type | info:eu-repo/semantics/publishedVersion | |
| dc.type | es-ES | |
| dc.type | en-US |
This item appears in the following Collection(s)
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Andean Geology
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