摘要
The Global Stratotype Section and Point(GSSP)for the base of Toarcian Stage,Lower Jurassic,is placed at the base of micritic limestone bed 15e at Ponta do Trovão(Peniche,Lusitanian Basin,Portugal;coordinates:39°22′15″N,9°23′07″W),80km north of Lisbon,and coincides with the mass occurrence of the ammonite Dactylioceras(Eodactylites).The Pliensbachian/Toarcian boundary(PLB/TOA)is contained in a continuous section forming over 450m of carbonate-rich sediments.Tectonics,syn-sedimentary disturbance,metamorphism or significant diagenesis do not significantly affect this area.At the PLB/TOA,no vertical facies changes,stratigraphical gaps or hiatuses have been recorded.The base of the Toarcian Stage is marked in the bed 15e by the first occurrence of D.(E.)simplex,co-occurring with D.(E.)pseudocommune and D.(E.)polymorphum.The ammonite association of D.(Eodactylites)ssp.and other species e.g.Protogrammoceras(Paltarpites)cf.
基金
supported by the BIOSCALES Project(POCTI/36438/PAL/2000)
coordinated by the Universidade NOVA de Lisboa
R.B.Rocha thanks the support of A.F.Soares,J.C.Kullberg,P.S.Caetano and P.H.Verdial
Financial support was provided to L.V.Duarte,S.Pinto and M.C.Cabral by Projects PDCTE/CTA/44907/2002 and PTDC/CTE-GIX/098968/2008.
