The non-marine Lower Cretaceous of El Montsec thrust sheet (South-Central Pyrenees)
Martín-Closas, Carles (Universitat de Barcelona)
Lozano-Fernández, Iván (Generalitat de Catalunya. Departament d'Educació)
Pérez Cano, Jordi (Institut Català de Paleontologia Miquel Crusafont)
Bover-Arnal, Telm (Universitat de Barcelona)

Date:	2025
Abstract:	The aim of this study is resolving uncertainties on the lithostratigraphy and chronostratigraphy of the non-marine Lower Cretaceous of El Montsec thrust sheet, which contains the most developed record of such facies in the central Pyrenees (Catalonia, Spain). The materials, traditionally known as "El Montsec Charophyte Limestones", overlie upper Berriasian marine limestones and belong in fact to two different stratigraphic units, separated by an angular unconformity, which is represented by an irregular karstic surface . The lower unit, newly defined as the Cova dels Lladres Intraclastic Limestone Formation, is composed by metric-scale fining-upward parasequences with black intraclast conglomerates at the base covered by charophyte limestones at the top. This first non-marine unit is attributed to the lower Barremian Eurasian charophyte biozone Atopochara trivolvis triquetra. The upper non-marine unit, (revisited El Montsec Charophyte Limestone), is made of metric-scale fining-upward parasequences of charophyte limestones. Ferruginous marls at the base of the upper unit have yielded charophytes of the Hemiclavator neimongolensis neimongolensis Eurasian charophyte biozone, corresponding to the early-late Barremian boundary. El Montsec Charophyte Limestone Formation transitions laterally to La Pedrera de Rúbies Lithographic Limestones Formation, which includes the two famous fossil Konservat Lagerstätten of La Pedrera de Meià and La Cabroa. In sum, the non-marine Lower Cretaceous succession of El Montsec thrust sheet shows at its base a stratigraphic gap ranging from the upper Berriasian to the early Barremian. Furthermore, the angular unconformity separating the Cova dels Lladres Formation and El Montsec Formation clearly reflects the strong tectonic activity associated with the Barremian Iberian rift, which has been linked with the opening of the Bay of Biscay.
Grants:	Agencia Estatal de Investigación PID2020-113912GB-I00 Agència de Gestió d'Ajuts Universitaris i de Recerca 2021/SGR-00349
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, sempre i quan aquestes es distribueixin sota la mateixa llicència que regula l'obra original i es reconegui l'autoria.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Early cretaceous ; Iberia ; Mesozoic rift ; Lacustrine ; Charales
Published in:	Geologica acta, Vol. 23 (2025) , p. 1-17 (Carbonate successions from Iberia and the Caribbean - Homage to Ramon Salas) , ISSN 1696-5728

Adreça original: https://revistes.ub.edu/index.php/GEOACTA/article/view/47987
Adreça alternativa: https://raco.cat/index.php/GeologicaActa/article/view/436713
DOI: 10.1344/GeologicaActa2025.23.7

17 p, 35.4 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Institut Català de Paleontologia Miquel Crusafont (ICP)
Articles > Published articles > Geologica acta
Articles > Research articles