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ABSTRACT: The environmental conditions, mechanisms, and processes that resulted in the deposition of organic-matter-rich sediments during the early Toarcian oceanic anoxic event are still a matter of discussion. A petrographic and geochemical study was carried out using Posidonia Shale Formation (lower Toarcian) black shale samples from two wells located offshore The Netherlands in the Dutch Central Graben. This formation is a lateral equivalent of Toarcian black shale successions in northern Europe. The lower Toarcian black shales in the Dutch Central Graben exhibit a variety of depositional fabrics, sedimentary structures, and textures that indicate dynamic energetic conditions at the time of their deposition and appear to have been deposited mostly by bottom currents rather than settling from pelagic suspension. The Posidonia Shale Formation black shales are characterized by normally graded thin beds (, 10 mm thick) with erosional bases wherein cross-lamination is very common. The tops of these thin beds are commonly bioturbated. These observations are in contrast with the traditional interpretation of the deposition of lower Toarcian black shales as having taken place under a stagnant, anoxic water column vi