Universidad Complutense de Madrid
E-Prints Complutense

Near surface geophysical analysis of the Navamuño depression (Sierra de Béjar, Iberian Central System): Geometry, sedimentary infill and genetic implications of tectonic and glacial footprint

Impacto

Descargas

Último año



Carrasco González, Rosa María y Turu, Valenti y Pedraza Gilsanz, Javier de y Muñoz Martín, Alfonso y Ros, Xavier y Sánchez Vizcaíno, Jesús y Ruiz Zapata, Blanca y Olaiz Campos, Antonio José y Herrero-Simon, Ramón (2018) Near surface geophysical analysis of the Navamuño depression (Sierra de Béjar, Iberian Central System): Geometry, sedimentary infill and genetic implications of tectonic and glacial footprint. Geomorphology . ISSN ISSN: 0169-555X

[img] PDF
Restringido a Sólo personal autorizado del repositorio hasta 4 Mayo 2020.

45MB

URL Oficial: https://www.journals.elsevier.com/geomorphology



Resumen

The geometric and genetic characterization of the Navamuño depression peatland system (Iberian Central System) is presented here using results from a geophysical survey. This depression is a ~30 ha pseudo-endorheic flat basin over granitic bedrock. Three geophysical techniques were used to map the subsurface geology, and identify and describe the infill sequence: shallow seismic refraction (SR), magnetic resonance sounding (MRS) and electrical resistivity measurements (VES and ERT). The three main geoelectrical layers (G1, G2, G3) identified in previous research, have also been identified in the present work. Using the data obtained in this new research we have been able to analyse these three geological layers in detail and reinterpret them. They can be grouped genetically into two sedimentary units: an ancient sedimentary body (G3), of unknown age and type, beneath an Upper Pleistocene (G2) and Holocene (G1) sedimentary infill. The facies distribution and geometry of the Upper Pleistocene was examined using the Sequence Stratigraphy method, revealing that the Navamuño depression was an ice-dammed in the last glacial cycle resulting in glaciolacustrine sedimentation. A highly permeable sedimentary layer or regolith exists beneath the glaciolacustrine deposits. Below 40 m depth, water content falls dramatically down to a depth of 80 m where unweathered bedrock may be present. The information obtained from geophysical, geological and geomorphological studies carried out in this research, enabled us to consider various hypotheses as to the origin of this depression. According to these data, the Navamuño depression may be explained as the result of a transtensional process from the Puerto de Navamuño strike-slip fault during the reactivation of the Iberian Central System (Paleogene-Lower Miocene, Alpine orogeny), and can be correlated with the pull-apart type basins described in these areas. The neotectonic activity of this fault and the icedammed processes in these areas during the Last Glacial Cycle (MIS2) were the main causes of recent sedimentary infill in this depression.


Tipo de documento:Artículo
Palabras clave:Near Surface Geophysics, Nuclear Magnetic Resonance, intermontain basin, distensive faulting, Late Glacial Period, Iberian Central System.
Materias:Ciencias > Física > Geofísica
Ciencias > Geología
Ciencias > Geología > Geodinámica
Código ID:47402
Depositado:07 May 2018 05:54
Última Modificación:07 May 2018 08:28

Descargas en el último año

Sólo personal del repositorio: página de control del artículo