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The first marine incursion of the incipient North Atlantic Ocean is recorded in the uppermost Triassic to Lower Jurassic sequence of DSDP Site 547 off central Morocco. A lithologic change from continental red beds below to slope breccias and hemipelagic carbonates above indicates that a carbonate ramp was probably established by Sinemurian time along the Moroccan continental margin and that subsidence in the adjacent basin was rapid in the early phases of continental rift. Foraminifers recovered from the Liassic (Sinemurian-Pliensbachian) basinal deposits are diverse and well preserved. The faunas are compositionally similar to contemporaneous neritic assemblages of Europe and the Grand Banks of Newfoundland. The Middle Jurassic in Hole 547B is characterized by regressive deposits that are poor in foraminifers. The major Late Jurassic "Atlantic" transgression is again represented by basinal deposits consisting of limestone breccias and pelagic carbonates. Foraminifers recovered from this interval are transitional between Late Jurassic assemblages reported from deep-sea deposits in the North Atlantic and typical Late Jurassic neritic assemblages of Europe. The Late Jurassic assemblages of Hole 547B are primarily dominated by nodosariids and spirillinids with moderate abundances of simple arenaceous forms. Nonreticulate epistominids occur very rarely in the Upper Jurassic of Hole 547B. It is tentatively suggested that these represent upper bathyal assemblages. INTRODUCTION An undeformed sequence of Jurassic carbonates and carbonate breccias with lesser amounts of interbedded shales was drilled at Site 547 from the area of the distal continental margin off Morocco (Fig. 1). The Jurassic section at Hole 547B is relatively thin (154 m) and contains stratigraphic gaps, particularly between the Lias (Lower Jurassic) and Dogger (Middle Jurassic). Although this part of the Northwest African continental margin was essentially sediment-starved during the Jurassic, the vertical lithologic changes compare favorably with deepwater Tethyan sections from around the Mediterranean (Bernoulli and Kàlin, this volume) and the central North Atlantic (Jansa et al., this volume). Transgressive/regressive phases inferred from the stratigraphic record of Site 547 generally parallel those interpreted from Moroccan epicontinental sections (Ager, 1974; Jansa and Wiedmann, 1982). The Jurassic carbonate section of Site 547 (Unit VI) overlies (?)Rhaetian-Hettangian (uppermost TriassicLower Jurassic) continental red beds (Fenton, this volume). This site records the first marine incursion of the incipient central North Atlantic Ocean. The underlying continental deposits change rapidly upward to hemipelagic and mass-flow deposits of the slope environment. The Lower Jurassic (Core 547B-24 to Section 547B-14-2) Hinz, K., Winterer, E. L., et al., Init. Repts. DSDP, 79: Washington (U.S. Govt. Printing Office). 2 Addresses: (Riegraf, Luterbacher) Institut und Museum für Geologie und Palàontologie, Universitàt Tubingen, Sigwartstrasse 10, D-7400 Tubingen 1, Federal Republic of Germany; (Leckie, present address) Department of Geology and Geography, University of Massachusetts, Amherst, MA 01003. consists of limestone breccias overlain by redeposited(?) nodular limestones with minor black shales (Fig. 2). By Sinemurian time a carbonate ramp was probably already established along the adjacent Moroccan margin and was a source of the redeposited sediment. Section 547B-14-2 through Sample 547B-11,CC contain limestone breccias. The core-catcher sample from Core 11 contains a rich foraminiferal fauna indicating a late Pliensbachian age, but a Middle Jurassic age is suggested from lithostratigraphic considerations (Steiger and Jansa, this volume; ?regressive Bajocian, Jansa et al., this volume). The Middle and Upper Jurassic section of Hole 547B consists of hardground cycles in Core 11 (Steiger and Jansa, this volume; Jansa et al., this volume) followed by limestone breccias and pelagic carbonates with intervals of turbidites in Core 547B-10 through Section 547B-6-2. For detailed lithologic descriptions and interpretations of the upper Triassic-Jurassic sequence, we refer the reader to the site chapter, to chapters by Jansa et al., Bernoulli and Kàlin, Steiger and Jansa, to the Leg 79 synthesis by Hinz and Winterer (this volume) and to Gradstein et al., 1975. In this contribution we describe Jurassic foraminifers and other associated microbiota found in washed residues from Hole 547B. Figure 3 summarizes the distribution of the various foraminiferal superfamilies through the section. Figure 4 shows the distribution of the foraminiferal species recorded at Site 547B and their relative abundances, and Figure 5 the distribution and relative abundances of other microbiota encountered. For detailed biostratigraphic discussions of other fossil groups, the reader is referred to chapters by Azéma and Jaffrezo

Jurassic Foraminifers from the Mazagan Plateau, Deep Sea Drilling Project Site 547, Leg 79, off Morocco