Carregant...
Fitxers
Tipus de document
ArticleData de publicació
Llicència de publicació
Si us plau utilitzeu sempre aquest identificador per citar o enllaçar aquest document: https://hdl.handle.net/2445/201987
New 40Ar/39Ar radiometric ages of lamproites indicate latest Tortonian marine restriction of the Fortuna Basin, Eastern Betics, southern Spain
Títol de la revista
Director/Tutor
ISSN de la revista
Títol del volum
Recurs relacionat
Resum
Exposures of lamproitic volcanic rocks have been used to constrain the age of the evaporitic basin-fill in the Fortuna Basin of southern Spain. K/Ar dates initially suggested a Messinian age assignment for these deposits; however, subsequent 40Ar/39Ar dates indicated a Tortonian age, implying the early onset of evaporite formation in the eastern Betic Cordillera, in an event termed the "Tortonian Salinity Crisis". In this paper, we critically review the published chronology of the key igneous outcrops and provide new 40Ar/39Ar ages, which show that the Cabezos Negros lamproites lie close to the Tortonian-Messinian boundary (c. 7.25 Ma). We also provide new paleomagnetic measurements from each of the three lamproitic outcrops (Cabezos Negros, Derramadores, and El Tale), which demonstrate normal magnetic polarity coincident with episodes of volcanic and subvolcanic activity. The presence of peperites and pillow structures indicate that volcanism at Cabezos Negros was coeval with deposition of the lower part of Rambla Salada Gypsum Member. Therefore, the normal polarity identified in this unit should be equivalent to the normal polarity on the Cabezos Negros lamproites. These results indicate that the initial marine restriction and evaporitic deposition of Fortuna Basin occurred more than a million years before the Messinian Salinity Crisis.
Matèries
Matèries (anglès)
Citació
Citació
GIBERT BEOTAS, Lluís, DEINO, Alan, CARRAZANA, Ariana, CRUSET SEGURA, David, PLAYÀ I POUS, Elisabet, IBAÑÑEZ-INSA, Jordi, GIMENO TORRENTE, Domingo, GARCIA-VEIGAS, Javier, LERÍA MORILLO, María, PINEDA, Victoriano. New 40Ar/39Ar radiometric ages of lamproites indicate latest Tortonian marine restriction of the Fortuna Basin, Eastern Betics, southern Spain. _Evolving Earth_. 2023. Vol. 1, núm. 1, pàgs. 100001. [consulta: 21 de gener de 2026]. ISSN: 2950-1172. [Disponible a: https://hdl.handle.net/2445/201987]