The isotopic composition of sedimentary sulfur through time

Our knowledge of the isotopic composition of sedimentary sulfur and its evolution through time is based on the studies of marine evaporitic sulfate deposits and sedimentary pyrite, the latter mostly formed as a result of bacterial sulfate reduction. Traditionally, their isotope records have been utilized to model and interpret the global sulfur cycle on Earth. The significance, potential and limitations of the presently available sulfur isotope data for the Phanerozoic and the Neoproterozoic with respect to modern concepts of high-resolution isotope stratigraphy are critically evaluated. In general, the sulfate and sulfide isotope records require further systematic research, particularly in order to improve the inadequate, irregular time spacing of results. The potential of sulfur isotopic investigations of sedimentary sulfides from time boundaries is rather limited. Frequently, local depositional and/or diagenetic effects appear to dominate over potentially present global signals. (C) 1997 Elsevier Science B.V.