A newly developed logging-while-coring system was deployed during Ocean Drilling Program legs 204 and 209 off the coast of Oregon and near the Mid-Atlantic Ridge. The system consists of two existing devices modified to be used together--a Schlumberger Resistivity-at-the-Bit (super *) tool, and a Texas A&M University wireline-retrieved core barrel and latching tool. The combination allows for precise core-log depth calibration and core orientation within a single borehole, and without a pipe trip. These tests, conducted in clay-bearing sediments (Leg 204) and in crustal peridotite and gabbroic rocks (Leg 209), mark the first simultaneous use of coring and logging-while-drilling technologies. Sediment cores were recovered with 33% recovery, on average, and as high as 68% to 75 m depth below the sea floor. Core recovery in crustal rocks was only 1-2%, however, penetrating to 21 m depth below sea floor, which is attributed to a problem with the core catcher. High-resolution logs were recorded in the downhole tool memory over the entire drilled intervals at both test sites. It is anticipated that logging-while-coring systems will be utilized more routinely where rig time constraints may otherwise preclude coring in difficult drilling environments.

West: -125.0900 East: -125.0400 North: 44.3500 South: 44.3400

Expedition: 204

Site: 204-1249

Provider: SEDIS Publication Catalogue

Data set link: http://sedis.iodp.org/pub-catalogue/index.php?id=2007-038750 (c.f. for more detailed metadata)

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