RT Journal Article T1 Datación de niveles condensados: Precisiones cronoestratigráficas utilizando estratigrafía de isótopos de Sr T1 Sr isotope stratigraphy elucidates the age of condensed levels A1 Nieto, L.M. A1 Ruiz-Ortiz, P.A. A1 Rey, J. A1 Benito Moreno, María Isabel AB The values of the ratio 87Sr / 86Sr in 16 belemnites samples from three sections of the upper part of the Gavilán Fm. of the Subbetic chain are analyzed. Elemental and C and O stable isotopes analysis were also made focused to test the preservation of primary marine calcite. The results of this study confirm the chronostratigraphy significance of Sr Isotope Stratigraphy from Pliensbachian belemnites. The interpretation of the results elucidates the age of the hardground or condensed level that supplies the belemnites rostra after adjusting the 87Sr / 86Sr ratio to pre-existing curves. PB Sociedad Geológica de España SN 0213-683X YR 2005 FD 2005 LK https://hdl.handle.net/20.500.14352/115250 UL https://hdl.handle.net/20.500.14352/115250 LA spa NO Ruiz Ortiz, P.A. et al. (2005) «Datación de niveles condensados: Precisiones cronoestratigráficas utilizando estratigrafía de isótopos de Sr», Geogaceta, 38, pp. 87-90. NO Ministerio de Ciencia y Tecnología (España) DS Docta Complutense RD 19 dic 2025