Petrological and mineralogical characterization of lutitic deposits in a fluvial dominated depositional system. Upper Oligocene - Lower Miocene, Loranca Basin (Central Spain)
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Universidad Complutense de Madrid
info
ISSN: 0214-2708
Année de publication: 1995
Volumen: 8
Número: 3
Pages: 149-160
Type: Article
D'autres publications dans: Revista de la Sociedad Geológica de España
Résumé
The study of the clay minerals in the Upper Unit (Upper Oligocene- Lower Miocene) in Loranca Basin shows a change from the bottom (subunit 1) to the top (subunit 2). Subunit 1 is characterized by the clay mineral association 1, when the great part of the clay minerals are detrital as illite and kaolinite. Subunit 2 is characterized by the clay mineral associations 2 and 3 which contain palygorskite. The great abundance in palygorskite along subunit 2 is related with a gradual diminution in the smectite content and with an important climate change. Clay mineral evolution reflects paleoenvironmental changes induced by tectonics and climate. Clay composition types cannot be associated to a clasification of flood-plain palaeoenvironments.