ABSTRACT The Ocean Drilling Program (ODP) has completed 34 internationally staffed expeditions and six 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 150 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 sixth year, ODP has completed pioneering exploration in the western Pacific Ocean. Leg 130 recovered 4800 m of core, the most ever up to that point in time, in order to gain new insight into the evolution of global ocean dynamics and climate during the past 25 million years and the origin and tectonic history of the world's largest oceanic plateau -- the Ontong Java Plateau. Leg 131 studied the initial step in the process of mountain building and continental crustal growth by coring the toe of the Nankai Trough accretionary prism. Leg 132 was the second engineering cruise planned to test new drilling technology, in particular the diamond coring system, necessary to achieve the scientific objectives of ODP. Leg 133 broke the Leg 130 core recovery record by retrieving 5505 m of material over the platforms and basins of northeast Australia. Leg 134 drilled at seven sites in order to study collision of an aseismic ridge and a guyot with an island arc in the vicinity of the Vanuatu area. Future cruises include, amongst others, the Lau Basin on Leg 135, a hole for future Ocean Seismographic Network experiments off Hawaii on Leg 136, cleaning and continued coring of Hole 5048 off the Galapagos on Leg 137, an East Equatorial Pacific paleoceanographic transect on Leg 138, coring of sedimented ridges in the northern Juan de Fuca Ridge area on Leg 139 and, if possible, further efforts at the Hole 5048 (or Hess Deep) on Leg 140. This paper focuses on ODP's scientific and technical achievements during its sixth year of field operations and discusses areas of future study. Introduction The Ocean Drilling Program (ODP), an international basic research program of scientific ocean drilling, is the successor program to the Deep Sea Drilling Project (DSDP) with Texas A&M University as the science operator. ODP is funded by the U.S. National Science Foundation with major contributions from 18 non-U.S. countries. This international partnership is called the Joint Oceanographic Institutions for Deep Earth Sampling (JOIDES). To date, JOIDES Resolution (Figure I), the scientific drillship of ODP has retrieved sediment and hard rock samples from beneath the deep sea floor at 217 sites (Table 1) in search of answers to important scientific problems designated by JOIDES. These sites are located in the Atlantic, eastern and western Pacific, and Indian oceans, including high latitude zones bordering East and West Antarctica, and Baffin Bay, the Mediterranean, Caribbean, Norwegian, Sulu, Celebes, Philippine, Japan and Coral seas. Thus far, approximately 832 scientists from around the world(Figure 2) have participated in cruises and brought over 325,000 individual core samples home to their respective institutions for further study.

Abstract The Ocean Drilling Program (ODP) has now completed 29 internationally staffed expeditions and five years of scientific ocean drilling. JOIDES Resolution, the scientific drillship of ODP, has travelled in the Atlantic, eastern and northwest Pacific, and Indian oceans, including high latitude zones bordering East and West Antarctica, and the Mediterranean, Caribbean, Weddell, Sulu, Celebes, Philippine and Japan seas, in search of answers to important scientific problems designated by the Joint Oceanographic Institutions for Deep Earth Sampling (JOIDES). These scientific objectives relate to the tectonic evolution of passive and active continental margins, origin and evolution of oceanic crust, origin and evolution of marineedimentary sequences, and paleoceanography. In addition, ODP has continued modification and reliability of existing coring systems as well as made numerous advances in technology to improve the capture of scientific information. During its fifth year, the ODP has completed pioneering exploration in the Northwest Pacific Ocean and adjacent seas. Leg 124E, in the Philippine Sea, was our first cruise dedicated to engineering development. Legs 125 and 126 were a two cruise effort designed to study, amongst other important problems, the geological processes involved in thedevelopment of the Bonin and Marianas arcs. Legs 127 and 128 were dedicated to study the tectonics and sedimentation history of the Japan Sea. Leg 129 commenced after a dry dock period of JOIDESResolution, to study the oldest Pacific crust in Pigafetta and east Mariana basins in the Western Pacific. This paper focuses on ODP's scientific successes of five years of scientific ocean drilling and discusses areas of future study. Introduction The Ocean Drilling Program, an international basic research program of scientific ocean drilling, is the successor program to the Deep Sea Drilling Project (DSDP) with Texas A&M University as the science operator. The mission of ODP is to learn how Earth has evolved with time. To do this, sediment and hard rock samples are retrieved from beneath the deep-sea floor to study evolution of ocean basins, evolution of prehistoric life, evolution of past ocean current and paleoclimates. ODP is funded by the U.S. National Science Foundation with major contributions from 18 non-U.S. countries. This international partnership is called the Joint Oceanographic Institutions for Deep Earth Sampling (JOIDES) ODP commenced its field operations with a shakedown and sea trials cruise in January 1985 in the Gulf of Mexico1. About every two months since that time, an internationally staffed expedition of our drilling research vessel, the SEDCOIBP 471, better known to the scientific community as the JOIDES Resolution (Figure 1), has taken place in very remote but geologically important areas of the world's oceans. Each expedition carries a scientific and technical complement of 51 persons as well as a ship's crew and drilling complement of about 60 persons. The ship, as of cruise 129 (January 1990), has operated at 175 sites in the north Atlantic Ocean, in the eastern and northwest Pacific Ocean, in the Weddell Sea and Prydz Bay off Antarctica and in the Indian Ocean (Figure 2).