OCEAN DRILLING PROGRAM: RESULTS FROM NINTH YEAR OF DRILLING OPERATIONS

The Ocean Drilling Program (ODP) has completed 61 internationally staffed expeditions and ten years of scientific ocean drilling in search of answers relating to the tectonic evolution of passive and active continental margins, origin and evolution of oceanic crust, origin and evolution of marine sedimentary sequences, and paleoceanography. To address these problems, ODP has made numerous advances in technology for retrieval of continuous undisturbed cores under hostile environmental conditions. ODP curates over 198 km of cored material and associated scientific data bases and publishes results of the scientific expeditions in a continuous series of Proceedings volumes. During its tenth year, ODP continued its pioneering exploration in the Atlantic Ocean. This paper reviews the drilling activities associated with the Atlantic Leg of the project. It focuses on volcanic rifted margins and magma emplacement; the chemical composition and evolution of the lower crust and mantle; depth transect reconstruction for a variety of temporal resolutions; research on the Amazon deep-sea fan and associated paleoclimatology; temporal and spatial scales of fluid flow, the role of faults in fluid transport, and the relationships between mechanical state and seismicity in the northern Barbados accretionary prism; and the history of volcanic activity in the Canary Hotspot, themore » detailed evolution of large volcanic oceanic islands, the growth of volcanic aprons and the filling of the distal Madeira Abyssal Plain. Finally, Leg 158 investigated fluid flow, alteration and mineralization and associated geochemical fluxes, microbiological processes and the subsurface mixture of an active hydrothermal system on a slow spreading, sediment-free mid-ocean ridge (TAG area -- Mid Atlantic Ridge).« less