Artículo
Quaternary deformation around the Palo Negro area, Pampa Norte, Argentina
Brunetto, Ernesto
; Iriondo, Martin Horacio
; Zamboni Galliusi, Luis Victorio; Gottardi, Maria Griselda
Fecha de publicación:
04/2010
Editorial:
Pergamon-Elsevier Science Ltd
Revista:
Journal of South American Earth Sciences
ISSN:
0895-9811
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
The Pampa Norte region is a great plain characterized by low slopes and accumulation of hundreds of meters of thick loose sediments. A high morphostructure denominated San Guillermo block stands out in the central plain, the Tostado-Selva scarp forming its western boundary. It is located in an intraplate setting characterized by low tectonic activity. However recent uplift can be inferred by means of terrain analysis and the sedimentology of the Palo Negro Fm. Pond deposits (Palo Negro Fm.) observed in the scarp suggest topographic inversion during the Late Quaternary in the Palo Negro area. The morphology indicates that the deformation was widely distributed, forming a gentle (ca. 5 m amplitude and 13 km wavelength) asymmetric fold. Low sinuosity lineaments located in the base of the scarp, coincident with knick points in the topographic profile, can be interpreted as the projection of tip-lines by high-angle fault-propagation. This geometry is compatible with reverse kinematics on blind faults.A deformation style with reactivation of pre-existing faults is consistent with structural observations. Seismic reflectors suggest the presence of Cretaceous high-angle normal faults, and the orientation of lineaments is similar to the orientation of the graben systems and transverse accommodation zones originated during the opening of the South Atlantic Ocean.One OSL dating of 67.4 ± 5.1 kyr B.P (from Palo Negro Fm. supposed as deposited on a flat plain floor) and a height difference of 9.5 m measured in the Tostado-Selva scarp account for an averaged uplift rate of 0.14 mm/year.
Palabras clave:
Late Quaternary Deposits
,
Neotectonics
,
Pampa Plain
,
Terrain Analysis
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Articulos(CICYTTP)
Articulos de CENTRO DE INV.CIENT.Y TRANSFERENCIA TEC A LA PROD
Articulos de CENTRO DE INV.CIENT.Y TRANSFERENCIA TEC A LA PROD
Citación
Brunetto, Ernesto; Iriondo, Martin Horacio; Zamboni Galliusi, Luis Victorio; Gottardi, Maria Griselda; Quaternary deformation around the Palo Negro area, Pampa Norte, Argentina; Pergamon-Elsevier Science Ltd; Journal of South American Earth Sciences; 29; 3; 4-2010; 627-641
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