and Stucture of Mid-Ocean Ridges and Basins; Geochemical Evolution of the Oceanic Crust; 

 Fluxes, Transport and Deposition of Marine Sediments; and the Geologic and Climatic History of 

 the Oceans). The ODP field programs build on and complement the marine geology and geophysics 

 field efforts and provide the data required for U.S. scientists to translate their research goals to 

 specific drilling objectives. 



A number of different types of downhole studies are supported. These include the analysis and 

 interpretation of the data from the ODP shipboard logging program; development and operation of 

 instrumentation required for downhole experiments together with the analysis of the data; and 

 feasibility studies of new general use downhole instruments or techniques. The results of the 

 studies together with analyses of recovered geologic samples are crucial to converting the 

 drillhole work to solutions to the scientific questions and problems. 



II. Critical Needs of the Core Program 



Borehole geochemical and geophysical measurements permit extrapolation of drillhole results 

 well beyond the sides of the wellbore. Experiments such as oblique seismic reflection sounding, 

 using a geophone clamped in the wellbore, give a picture of the regional lithology and structure 

 for several tens of kilometers. Downhole sampling of formation water, especially in holes which 

 penetrate the plumbing systems of hydrothermal regions, allows the measurement of the 

 material balances within the oceanic crust. Downhole measurements of physical properties 

 show the natural state of stress in the ocean floor and indicate the modes of response to that 

 stress by fracture and flow. These measurements require the development of expensive 

 instruments and their deployment in the drillhole. Because of the peculiar requirements for 

 deployment in the drillhole (narrow diameter, high pressure, high temperature, etc.) these 

 instruments must be substantially modified from more conventional instruments used in other 

 studies. The costs of this enhancement are expected to be $1 .5M in FY 1989 increasing to 

 $2.1MbyFY1996. 



Regional geological and geophysical field studies provide the fundamental information base for 

 the formulation of drilling proposals. The U.S. effort in regional studies supplies the bare 

 minimum of well-surveyed regions. The appropriate level is considerably higher. There should 

 be two well-studied regional drilling targets for each drilling leg to insure that the drillship is 

 used on the most important and interesting targets. The costs of these efforts are expected to be 

 $2M in FY 1 989 with a 1 0% annual growth for the remaining life of the Ocean Drilling 

 Program. Approximately half of these funds will be expended on ship time and half on scientific 

 operations. 



Critical needs and initiatives in other ocean science programs are important to ODP. In order to 

 ensure that samples are effectively used, ODP has a collaborating interest in the Marine Geology 

 and Geophysics Program (MGG) enhancement for ODP sample analyses. Similarly MGG efforts 

 in the Ocean Lithosphere Studies are important to ocean drilling objectives and represent 

 opportunities to collaborate with nondrilling investigators. The Open Ocean Fluxes program is 

 also important to ODP as it will demonstrate the relationship between the sedimentary record of 

 the environment and environmental parameters which paleoceanographers are attempting to 

 understand using ODP cores. These programs provide new insights into geological processes and 

 problems which will develop into new drilling targets for ODP. Exchange of ideas between 

 nondrilling and drilling science operates in both directions and benefits both. 



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