%0 Journal Article
%A Fernández López, Sixto Rafael
%A Henriques, María Helena Paiva
%A Mangold, Charles
%T Ammonite succession at the Bajocian/Bathonian boundaryin the Cabo Mondego region (Portugal)
%D 2006
%@ 0024-1164
%U https://hdl.handle.net/20.500.14352/50859
%X The Cabo Mondego outcrops exposed along the cliffs, on the western margin of theIberian Plate, show an expanded stratigraphic section of Lower Bathonian depositscontaining abundant ammonoids. Upper Bajocian deposits correspond to similar facies,of muddy limestones alternating with marlstones, although ammonoids are scarce.A detailed succession of ammonites across the Bajocian/Bathonian boundary has beenrecognized at Cabo Mondego, which can form a useful bio- and chronostratigraphicstandard for the Lusitanian Basin. The revision of previous collections from the classicalsection and new field samplings of two other separate sections allow the recognitionthrough up to twenty metres of thickness, the highest zone of Bajocian (ParkinsoniZone) and the lowest zone of Bathonian (Zigzag Zone). The Parkinsoni and the Zigzagzones established for NW European areas and belonging to the Northwest EuropeanProvince, can be identified in the Lusitanian Basin, although the ammonite fossilassemblages are composed of Submediterranean taxa. However, a subdivision of theParkinsoni Zone is not possible, due to the scarcity of well preserved ammonoids. TheZigzag Zone can be recognized and characterized as composed of two subunits (Parvumand Macrescens subzones) as represented in diverse European basins of the SubmediterraneanProvince. Ammonite fossil assemblages of the Parvum Subzone may begrouped into two successive horizons, which are biochronostratigraphically equivalent tothe subdivisions of the Convergens Subzone distinguished in the Digne-Barreˆme area(SE France). New biochronostratigraphic data on the Bigotitinae, youngest members ofLeptosphinctinae and oldest members of Zigzagiceratinae are relevant in understandingthe evolution and faunal turnover of the West Tethyan Perisphinctidae during earliestBathonian. The ammonite succession at the Bajocian/Bathonian boundary in the CaboMondego region (Portugal) represents one of the most complete biostratigraphic recordsso far recognized on the Iberian Plate.IAmmonoids, biostratigraphy, chronostratigraphy,Iberia, Lusitanian Basin, Middle Jurassic, palaeobiogeography.
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