%0 Journal Article
%A Casquet Martín, César
%A Galindo Francisco, María Del Carmen
%A González Casado, José Manuel
%A Alonso Millán, Ángela
%T El metamorfismo en la Cuenca de los Cameros.Geocronología e implicaciones tectónicas
%D 1992
%@ 0213-683X
%U https://hdl.handle.net/20.500.14352/56924
%X A case of hydrothermal metamorphism is described from the Cameros Basin along the rio Cidacostransect. The highest grade is reached at the base of the Urbión Group, a fluvial sequence UpperJurassic to Lower Cretaceous in age (Weald facies). Physical conditions at the thermal peak areestimated at abo 1 Kb (PL) and 326± 13°C (i.e. very low grade metamorphism). Fluids were largelywater brines with minor amounts of gases, CO2 and CH4• f02 and f52 were close to the graphiteand Po-Py buffers respectively. This metamorphism is spatially associated with a deformation band(5-6 km. ín wídth) wíth schístosíty ín the pelitíc beds and promínent tensíonal, quartz ínfílled veínsin the more samítíc ones. K-Ar dating on authígeníc illites has gíven ages from 108 to 86 M.a., i.e.Míddle Cretaceous, and thus younger than the basín fílling (Urbíón Group+Enciso F.+Olívan F.).Metamorphism migth be related wíth the circulatíon of hot mígratory fluíds (i.e. tectoníc brínes),along the deformation bando The tectonic sígníficance of this deformation band is slill uncertain.
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