Abstract

The distribution, facies and plate tectonic position of Permian and Triassic phosphorites, which differ significantly from those of other Phanerozoic periods, are reviewed and compiled to investigate the driving factors for their exceptional distribution pattern. The interval is characterized by a small number of deposits and a shift of phosphorite sedimentation into high latitudes. There is only one occurrence of a “phosphorite giant”, it is of Permian age. The phosphogenic systems are sensitive to conspicuous changes in climate and resulting depositional environment in shelfal sea areas. The spatial and temporal distribution of phosphorites in Permian and Triassic are not the result of an anomalous ocean composition as earlier proposed, but the adaptation of phosphorite genesis to the exceptional and, for the Phanerozoic, unique paleogeographic and climatic pattern during supercontinent formation. The simple paleogeo-graphic configuration and the extreme climate pronounce the complex interplay of factors controlling global phosphorite genesis, which are primarily the availability of broad sea areas in suitable climatic belts and sea level changes, with further access to related major upwelling systems as a supporting factor. The temporal phosphorite distribution is not directly linked to proposed oceanic anoxic events. Freshwater phosphorites may be indicative of abundant lake stratification in higher latitudes.