Publication Date:
2017-04-04
Description:
The Fortuna Basin is an example of a marginal Mediterranean basin with evaporitic sedimentation during the Late Tortonian and Messinian.
This basin shows an early restriction event before the main Messinian Salinity Crisis (MSC) that allows the Tortonian Salinity Crisis (TSC) to be
proposed as a tectonic uplift event isolating the eastern Betic basins. Four evaporitic events are present in the central part of the Fortuna Basin, from
bottom to top: Los Baños Marls Formation (composed by Fenazar Conglomerate Bed, Lower Gypsum Member [Mb] and Sanel Mb), Tale Gypsum
Formation (Fm), Chicamo Diatomites and Gypsum Cycles Fm, and Rambla Salada Gypsum Fm. The present work documents the first
biostratigraphic dating based on calcareous nannoplankton of these events. The lowest occurrence (LO) of Amaurolithus primus is registered at the
upper part of the Sanel Mb, below the Tale Gypsum Fm. The LOs of Amaurolithus delicatus and Reticulofenestra rotaria, which mark the base of
the Messinian, occur in the lower part of the Chicamo Cycles Fm, above the Tale Gypsum Fm, the Triquetrorhabdulus rugosus-Nicklithus
amplificus integrate form and the LO of Nicklithus cf. amplificus in the upper part of the Chicamo Cycles Fm. Taking into account these results, a
new calibration of the available magnetostratigraphic data is presented: the Chicamo Cycles Fm were formed during the reverse chron C3Ar and
the Tortonian-Messinian boundary should be found within the Tale Gypsum Fm or near the top of the Sanel Mb. The onset of the TSC, the first
restriction phase of the Fortuna Basin, is represented by the Fenazar Conglomerate Bed, bottom of the Los Baños Fm, and not by the Tale Gypsum
Fm, as previously considered.
Description:
Published
Description:
201-217
Description:
2.2. Laboratorio di paleomagnetismo
Description:
JCR Journal
Description:
restricted
Keywords:
Betic Cordillera
;
Tortonian Salinity Crisis
;
Calcareous nannoplankton
;
Messinian
;
Fortuna Basin
;
04. Solid Earth::04.04. Geology::04.04.08. Sediments: dating, processes, transport
;
04. Solid Earth::04.04. Geology::04.04.10. Stratigraphy
;
04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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