Late cretaceous history of eolian deposition in the mid-pacific mountains, central North Pacific Ocean

Abstract

Eolian dust preserved in deep-sea sediment can provide a direct historical record of global atmospheric circulation. Data from a reasonably complete Upper Cretaceous section of pelagic sediments recovered at DSDP Site 463 in the central North Pacific provides a good record of eolian activity during the time period between about 112 and 66 m.y. ago. We have isolated the eolian component from these sediments, determined its mass accumulation rate and combined these data with the mineralogy of the inorganic fraction determined by others to construct a record of eolian deposition. Volcanic input is significant during Aptian-Albian and Maastrichtian times, otherwise continentally derived minerals dominate. Mass accumulation rates of the continental eolian component range from over 500 mg/cm2/103yr during the late Albian to a low of 5 mg/cm2/103yr during Coniacian time. (For comparison, the upper Miocene to Pleistocene rate averages about 20 mg/cm2/103yr.) The temporal pattern of Late Cretaceous eolian accumulation of Site 463 generally matches known changes in sea level, suggesting that source availability is the dominant control of eolian sedimentation during that time.