Pleistocene sediment offloading and the global sulfur cycle

[摘要] Quaternary sea level fluctuations have greatly affected the sediment budgetsof the continental shelves. Previous studies suggested that this caused aconsiderable increase in the net loss of shelf sediments. Since sedimentaccumulation and erosion are closely tied to the formation and re-oxidationof pyrite, we use a high-resolution record of sulfur isotope ratios(³⁴S / ³²S) of marine sulfate to evaluate the implications of theso-called "shelf sediment offloading" on the global sulfur cycle. Modeling ofour δ³⁴S record suggests that erosion during sea levellowstands was only partly compensated by increased sedimentation duringtimes of rising sea level and sea level highstands. Furthermore, our datasuggests that shelf systems reached a new equilibrium state about700 ka, which considerably slowed or terminated shelf sediment offloading.

[学科分类] 地球化学与岩石