%0 Journal Article
%A Fernández López, Sixto Rafael
%A Chong, G.
%A Quinzio, L.A.
%A Wilke, H.G.
%T The Upper Bajocian and Bathonian inthe Cordillera de Domeyko, North-Chilean Precordillera : sedimentological and biostratigraphical results.
%D 1994
%@ 0016-6995
%U https://hdl.handle.net/20.500.14352/58492
%X The Jurassic ammonites of the Cordillera de Domeyko have been studied in several monographies. The classicmemoirs of Steinmann (1881), Tornquist (1898), Burckhardt (1903) and Stehn (1923) are particularly relevant.However, the biostratigraphic problems concerning stage boundaries arisen only in recent dates. New sedimentologicaland biostratigraphical data have been obtained in relation to the Bajocian/Bathonian of this region. Severalsections have been studied in two separate areas : Caracoles and Sierra de Varas. More than one thousandammonites were collected in situ from these localities. Facies analysis shows that sedimentation during LateBajocian and Bathonian occurs in a marine environment on a carbonate platform with abundant siliciclasticsupply. Facies distribution was controlled by structural segmentation of the platform and processes of differentialsubsidence. The stratigraphical-sedimentological results together with taphonomical-palaeoecological observationsare a diagnostic tool for sequence analysis. The successive ammonite assemblages which were found have allowedthe establishment of four biostratigraphic units, spanning the interval from Upper Bajocian to Upper Bathonian.The sedimentological and biostratigraphical results indicate the existence of a regional discontinuity at the base ofthe Bathonian.
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