CENTRAL ARCTIC OCEAN SEDIMENTATION: MM/KA-SCALE OR CM/KA-SCALE RATES?

The Arctic Ocean is presently undergoing geoscientific investigations of the type that occurred during the late 1940's through 1960's in the Atlantic, Indian and Pacific oceans. Seismic reflection and refraction data are scarce in the Arctic Ocean and large areas are virtually unsampled with respect to piston or gravity coring. The vast majority of available cores are <10 m in length and largely lack biostratigraphically useful calcareous and siliceous microfossils. No drill cores exist from the ridges or deep basins in the central Arctic Ocean. Considering the limited geophysical and geological data available, it is not surprising that hypotheses concerning Arctic Ocean sedimentation rates are currently divergent. Yet, a review of both shorter-term, through analysis of available sediment core data, and longer-term, through estimates of total sediment thickness and bedrock age, sedimentation rates unequivocally suggests that the central Arctic Ocean has not been, on average, a sediment starved basin during either Plio-Pleistocene or pre-Pliocene times. Moreover, cm/ka-scale sedimentation rates appear to be the rule rather than the exception throughout this small, land-locked ocean basin. It follows that the seemingly consistent distribution of cores, in which cm/ka-scale rate cores chiefly occur in the Eurasian Basin and mm/ka-scale rate cores are concentrated in the Amerasian Basin, reflect a bias stemming from inadequate age models generating artificially low sedimentation rates for the Amerasian Basin.