%0 Journal Article
%A Arribas Mocoroa, José
%A Arribas Mocoroa, María Eugenia
%T Petrographic evidence of different provenance in two alluvial fansystems (Palaeogene of the northern Tajo Basin, Spain)
%D 1991
%@ 0305-8719
%U https://hdl.handle.net/20.500.14352/57072
%X Palaeogene detrital deposits of the northern Tajo Basin are coalescent alluvial fansystems interfingering distally with lacustrine carbonates. Non-carbonate extrabasinal clastsincrease to the east while carbonate extrabasinal clasts decrease. Rock fragments increaseto the west, while the feldspar/quartz ratio remains constant. Rock fragments define twosedimentary domains: the Iberian, in the east, was derived from Mesozoic rocks of theIberian Range, and the Central System, to the west, was derived from Cretaceous cover andPalaeozoic metamorphic basement. Evolution of sandstone composition is related toerosion of the source areas and is different in the two domains. The tectonic setting isapparently "recycled orogen", providing calcareous rock fragments are included in the totallithic clasts.
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