Publication: The Upper Bajocian and Bathonian in
the Cordillera de Domeyko, North-Chilean Precordillera : sedimentological and biostratigraphical results.
Loading...
Official URL
Full text at PDC
Publication Date
1994
Authors
Advisors (or tutors)
Editors
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier B.V.
Citations
Exportar
Abstract
The Jurassic ammonites of the Cordillera de Domeyko have been studied in several monographies. The classic
memoirs 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 sedimentological
and biostratigraphical data have been obtained in relation to the Bajocian/Bathonian of this region. Several
sections have been studied in two separate areas : Caracoles and Sierra de Varas. More than one thousand
ammonites were collected in situ from these localities. Facies analysis shows that sedimentation during Late
Bajocian and Bathonian occurs in a marine environment on a carbonate platform with abundant siliciclastic
supply. Facies distribution was controlled by structural segmentation of the platform and processes of differential
subsidence. The stratigraphical-sedimentological results together with taphonomical-palaeoecological observations
are a diagnostic tool for sequence analysis. The successive ammonite assemblages which were found have allowed
the 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 of
the Bathonian.