Integrated stratigraphy of the St. Thomas section (Malta Island): A reference section for the lower Burdigalian of the Mediterranean Region

摘要: Abstract The 91.15 m thick St. Thomas section belongs to the Middle Globigerina Limestone, which is intermediate member of Limestone Formation, and crops out along eastern cliff Delimara Peninsula (the south-eastern part Malta Island). sedimentary record composed alternating calcareous marls marly limestones with subordinated prominent bioturbated indurated that are deposited in a pelagic environment. For first time paleomagnetic analyses Burdigalian succession have provided reliable data allow identification five magnetozones been correlated Astronomically Tuned Neogene Time Scale, spanning Early Miocene C6n–C5Dn interval. Calcareous plankton quantitative integrated analyses, allowed us identify date several bioevents great potential for Mediterranean extra-Mediterranean correlations interval between ~ 19.7 ~ 17.2 Ma. In particular, complete distributional range nannofossil Sphenolithus belemnos has recorded as follows: First Occurrence (FO) at 19.12 Ma, Common (FCO) 19.05 Ma, Last (LCO) 18.44 Ma, (LO) 18.02 Ma. addition, FO FCO heteromorphus documented 18.29 Ma 17.99 Ma, respectively. A new paracme lower this species described 17.56 17.31 Ma. Concerning planktonic Foraminifera, main Interval top Paragloborotalia siakensis 19.55 Ma, Globoquadrina dehiscens 19.34 18.48 Ma, Globigerinoides subquadratus 18.43 Ma, onset an acme acrostoma changes its coiling from random prevalently sinistral same time, 18.40 Ma. These biostratigraphic place standard zonal schemes make some amendments these schemes. S. was revealed more marker than base MNN3a Zone. With regard P. AB-r/s used subzonal G. / Catapsydrax dissimilis Zone, now comprises three subzones instead two. deep marine paleoenvironmental setting, excellent outcrops recognition continuous bio-magnetostratigraphic events suggest should be considered reference area future studies definition GSSP.