Paleoecology and Sedimentation in Part of the Arctic Basin


  • David L. Clark



Magnetic surveys


In a basin with an ~10 million sq km area, the number of sediment cores taken is of the magnitude of 1/10,000 sq km, and most cores are <4 m long, providing little more than a 1 or 1-1/2 MY record. Progress in study of >300 cores from the T-3 drift is outlined; procedures are noted, as is the good record of the most recent major reversal of the earth's magnetic field left in 2-1/2 m (or longer) cores and of more magnetic events in cores longer than 3 m; this provides a basis for magnetic stratigraphic correlations with other parts of the world and determination of sedimentation rates. Progress in moisture content measurements, gross mineralogy, carbonate content and texture of the sediments and study of foraminifera and ice-rafted debris in sediments are still tenuous; the only sustained trend noted was toward less sinistral coiling specimens at the tops of cores which has been interpreted as indicating an ice-covered Arctic during most of the Pleistocene.