Scientific Objectives And Preliminary Results Of Deep Sea Drilling Project - International Phase Of Ocean Drilling

Abstract

ABSTRACT The goals of deep-sea drilling under the International Phase of Ocean Drilling (IPOD) include the further exploration of the ocean basins and their margins by drilling fewer, but deeper holes into the oceanic crust, the sedimentary wedges that border the rifted continents, and the areas where active subduction is occurring. The first part of IPOD has been devoted to deep penetration of the crust of the Mid-Atlantic Ridge, to determine how its properties vary geographically and with age, and to drilling of the continental margin of the eastern North Atlantic in order to reconstruct the earliest stages of rifting and continental separation. The preliminary results of these programs are summarized. INTRODUCTION For the past eight years the Deep Sea Drilling Project (DSDP) has used the drilling ship Glomar Challenger to recover more than 185,000 meters of sediment and rock cored from beneath most of the world's oceans. This collection has provided a priceless resource for study of the history of the ocean basins and the motion of lithospheric plates which interact to create and destroy them. The Project is funded by the National Science Foundation 'and scientific work aboard the ship is carried out by teams of scientists from many organizations and nations. Scientific guidance for the Project comes from a large group of volunteer scientists working through JOIDES (Joint Oceanographic Institutions for Deep Earth Sampling) panels. These groups advise on a wide range of subject from instrumentation to drilling targets and selection of shipboard staff. They have provided invaluable help and have contributed significantly to the success of deep-sea drillings. The international aspects of the Project have recently been formalized with the founding of the International Phase of Ocean Drilling or IPOD. This organization differs from earlier drilling phases not only in its formal multi-national character and financial support but in its basic goals, which are:to study the oceanic crust in terms of processes, structure and composition changes both in time and at different latitudes; andstudies of continental margins - their history and development - from initial rifting through final orogeny and destruction. These goals will be accomplished through fewer but deeper holes than in past drilling, a development that has involved technological problems and achievements. Direct application of the studies involve the origin and emplacement of petroleum resources and metalliferous deposits, but probably more important is the tremendous impact on geological thinking and planning in both exploration and research. Major scientific achievements in the past include verification of the youth of the major ocean basins, demonstration of the validity of sea-floor spreading and continental drift, discovery and quantification of great vertical motion of the earth's crust, delineation of the oceanographic and biological evolution of the oceans and refinement of fossil dating systems, as well as demonstrating more spectacular geologic events such as the late Miocene evaporation of the Mediterranean Sea and stagnation of the early.