Investigation on Late Domerian-Early Torcian Lagenina andGlomospirella assemblages in the Umbria-Marche Basin (Central Italy)》.pdfVIP

INVESTIGATION ON LATE DOMERIAN- EARLY TOARCIAN LAGENINA AND GLOMOSPIRELLA ASSEMBLAGES IN THE UMBRIA-MARCHE BASIN (CENTRAL ITALY) MARXSA N O C C I - H ANNACHIARA BARTOLINI NOCCHI M. BARTOLINI A. 1994. Investigation on Late Domerian-Early Toarcian Lagenina and Glomospirella assemblages in the Umbria-Marche Basin (Central Italy). [Recherches sur les associations de Lagenina et Glo- mospirella d~ge dom~rien sup4rieur-toarcien inf~rieur dans le Bassin de la r~gion Marche-Ombrie (Italie Cen- trale)] GEOBIOS, M.S. 17 : 689-699. ABSTRACT In the Umbria-Marche area, during the Sinemurian-Carixian, due to tectonic/eustatic events the carbonate platform (Calcare Massiccio Fm) was drowned, and a basin with a differentiated topography was established. The pelagic sedimentation was represented at first by a calcareous lithofacies (Corniola Fm) and later on by a clayey and marly lithofacies (Marne del Monte Serrone Formation =MS). The sediments here considered belong to the lower part of the MS, and they are Late Domerian-Early Toarcian in age. The micropaleontological assemblages show a progressive deepening of the sedimentary environment from middle shelf to outer shelf-upper bathyal conditions. This trend is compatible with a general sea-level rise in the European and North African domains during the Early Toarcian. In the clayey and/or marly s