INTRODUCTION: CRETACEOUS-PALEOGENE CLIMATIC EVOLUTION OF THE WESTERN NORTH ATLANTIC, RESULTS FROM ODP LEG 171B, BLAKE NOSE 1

Since its inception in the Triassic, the Atlantic basins have become increasingly integrated with the global ocean. A key transition occurred during the Late Cretaceous and Paleogene from the narrow, silled basins that characterized the early North Atlantic to the deep marine connections of the modern Atlantic. The tectonic and oceanographic transition for the North Atlantic was accompanied by a suite of other remarkable events including some of the warmest global climates known for the past 100 m.y., several large body impact events (accompanied by one of the five largest mass extinctions of the past 500 m.y.), and profound changes in carbon cycling and greenhouse gas concentrations associated with mid-Cretaceous black shale deposition and the Paleocene/Eocene boundary. Ocean Drilling Program (ODP) Leg 171B was designed to recover expanded records of this transition period in North Atlantic evolution for examination of the oceanographic, climatologic, and evolutionary history of the Paleogene and Cretaceous ocean. This Scientific Results volume, in addition to a Special Publication of the Geological Society of London (Kroon et al., 2001) and other publications referenced here, reports the principle scientific results of drilling during ODP Leg 171B. 1Norris, R.D., Kroon, D., and Klaus, A., 200