9730257 Moran This team of scientists from the Univbersity of Rhode Island and the University of Minnesota will test the hypothesis that horizontal advection plays a significant role in the transport of the radioisotopes 230Th and 231Pa in the water column of the North Atlantic. Studies will involve measurement of 230Th and 231Pa in North Atlantic Deep Water, the Labrador Sea, and other water masses of the North Atlantic as well as downcore measurements of the excess 231Pa/ 230Th isotopic ratio in high sedimentation rate cores from the Labrador Sea. Laboratory studies would be conducted to determine distribution coefficients of these isotopes between seawater and particulate surfaces. Such studies should prove important in interpreting the sedimentary record left by these isotopes inasmuch as that record provides insight into the paleoceanogrphy of the North Atlantic, especially the formation of North Atlantic Deep Water.