An understanding of the Earth's magnetic field and the causal core dynamo processes remains on of the outstanding problems in solid earth geophysics. Paelosecular variation provides a detailed record of field behavior. This project will extend that the record back in time by studying a group of seven long piston cores recently recovered from the western North Atlantic. All of the cored sediments are less than 120,000 years old and have sedimentation rates of at least 10 cm/kyr during the Holocene and 30 cm/kyr or higher during the Pleistocene. The results will provide new information about the long term behavior of the earth's magnetic field and an improved relative chronostratigraphy for related paleoceanographic studies that are also being done on these cores. The proposed work will include detailed rock magnetic studies of these cores to estimate grain size changes, diagenetic influences, and magnetic fabric variations that may have paleoceanographic implications.
