Just out | Strontium stratigraphy of the upper Miocene Lithothamnion Limestone in the Majella Mountain, central Italy, and its palaeoenvironmental implications @ Lethaia


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Strontium stratigraphy of the upper Miocene Lithothamnion Limestone in the Majella Mountain, central Italy, and its palaeoenvironmental implications


Author(s)

Irene Cornacchia, Per Andersson, Samuele Agostini, Marco Brandano, Letizia Di Bella


Abstract:

The 87Sr/86Sr isotope ratio has been widely used as a physical tool to date and correlate carbonate successions due to the long Sr residence time in comparison with the ocean mixing time. If this method works on oceanic successions, marginal basins may show different Sr isotope records in comparison with the coeval ocean one due to sea-level variations, continental run-off and restricted water exchanges. In this work, we present the 87Sr/86Sr isotope record of the upper Miocene carbonate ramp of the Lithothamnion Limestone (Majella Mountain, central Apennines), as an example of the onset of restricted water exchanges between a marginal basin and the ocean water masses. The overall latemost Tortonian–early Messinian Sr isotope record of the LithothamnionLimestone fits below the global reference line. This deviation has been interpreted as due to the strong control that freshwater input and enhanced continental run-off, linked to the migration of the Apennine accretionary wedge and foredeep system, have had on the central Adriatic water chemistry. These results imply that an accurate oceanographic and geodynamic framework along with diagenetic overprint investigation has to be taken into consideration prior to apply SIS on carbonate successions on marginal basins, even when facies analyses indicate fully marine conditions. This seems to be the case for the upper Miocene Central Mediterranean carbonate successions, but may have more general validity and be extended to other recent or past marginal basins.


READ IT HERE:

http://onlinelibrary.wiley.com/doi/10.1111/let.12213/abstract

Lurdes Fonseca

Assistant Professor and Researcher at University of Lisbon
Sociologist (PhD), Paleontologist (Researcher in Micropaleontology), Majors in Sociology and Biology, Minor in Geology. Main interests in Paleontology: Microfossils, Molecular fossils, Paleobiology and Paleoecology. (read more about me)