Age and Paleoenvironment of the Maastrichtian to Paleocene of the Mahajanga Basin, Madagascar: a Multidisciplinary Approach
Marine Micropaleontology 47 (2002) 17^70 www.elsevier.com/locate/marmicro Age and paleoenvironment of the Maastrichtian to Paleocene of the Mahajanga Basin, Madagascar: a multidisciplinary approach S. Abramovich a;Ã, G. Keller a, T. Adatte b, W. Stinnesbeck c, L. Hottinger d, D. Stueben e, Z. Berner e, B. Ramanivosoa f , A. Randriamanantenasoa g a Department of Geosciences, Princeton University, Princeton, NJ 08544, USA b Geological Institute, University of Neucha“tel, CH-2007 Neucha“tel, Switzerland c Geological Institute, University of Karlsruhe, D-76128 Karlsruhe, Germany d Museum of Natural History, CH-4001 Basel, Switzerland e Petrography and Geochemistry Institute, University of Karlsruhe, D-76128 Karlsruhe, Germany f Muse¤e Akiba, PO Box 652, Mahajanga 401, Madagascar g De¤partment des Sciences de la Terre, Universite¤ de Mahajanga, Mahajanga, Madagascar Received 30 May 2001; received in revised form 1 May 2002; accepted 8 May 2002 Abstract Lithology, geochemistry, stable isotopes and integrated high-resolution biostratigraphy of the Berivotra and Amboanio sections provide new insights into the age, faunal turnovers, climate, sea level and environmental changes of the Maastrichtian to early Paleocene of the Mahajanga Basin of Madagascar. In the Berivotra type area, the dinosaur-rich fluvial lowland sediments of the Anembalemba Member prevailed into the earliest Maastrichtian. These are overlain by marginal marine and near-shore clastics that deepen upwards to hemipelagic middle neritic marls by 69.6 Ma, accompanied by arid to seasonally cool temperate climates through the early and late Maastrichtian. An unconformity between the Berivotra Formation and Betsiboka limestone marks the K^Tboundary, and juxtaposes early Danian (zone Plc? or Pld) and latest Maastrichtian (zones CF2^CF1, Micula prinsii) sediments.
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