Contrasting palaeosol development in two different tectonic settings: the Upper Buntsandstein of the Western Iberian Ranges, Central Spain

Palaeosols may offer excellent evidence for the development of sedimentary basins but few studies have used diagenetically altered material: here we show that material of this sort can also reflect the sedimentary environment. The Lower to Middle Triassic red beds of the western Iberian Ranges were...

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Detalles Bibliográficos
Autores: Alonso Zarza, Ana María, Sopeña, Alfonso, Sánchez Moya, Yolanda
Tipo de recurso: artículo
Fecha de publicación:1999
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/59044
Acceso en línea:https://hdl.handle.net/20.500.14352/59044
Access Level:acceso abierto
Palabra clave:56:631.4(460)
551.3.051(460)
Buntsandstein
Palaeosol development
Western Iberian Ranges
Central Spain
Geología estratigráfica
Paleontología
2506.19 Estratigrafía
2416 Paleontología
Descripción
Sumario:Palaeosols may offer excellent evidence for the development of sedimentary basins but few studies have used diagenetically altered material: here we show that material of this sort can also reflect the sedimentary environment. The Lower to Middle Triassic red beds of the western Iberian Ranges were deposited in a tectonically active half-graben in which subsidence rates varied along the basin as a response to differential fault movements. During this period the basin was filled by a set of fluvial units with interbedded palaeosols. The palaeosols show typical pedogenic calcrete profiles, although extensive dolomitization has deleted part of their microstructure; however, macrostructure and morphology are preserved. Differences in the maturity stages of the palaeosols are related to the changes in subsidence and sedimentation rates along the basin. Thus, two different scenarios are recognized at: (i) the hanging wall, Riba de Santiuste area, where palaeosols reach stage III as the episodic tilting of the floodplain inhibited the development of more mature soils and (ii) the footwall, Cercadillo area, where palaeosols attain stage V maturity, favoured by prolonged periods of tectonic stability resulting in lower sedimentation rates over the floodplain areas.