In Situ Petrophysical Measurements in the Caribbean

Measurements of Porosity in Sediments of the Lower Continental Margin, Deep-Sea Fans, the Aleutian Trench, and the Alaskan Abyssal Plain

“…Hamilton's (1964) measurements are strengthened by the acceptable data of Gealy and Gerard (1970) and by the consolidation graph of Site 181, Core 12, made by Lee and others (this volume). With these data, a generally valid correction factor for laboratory measurements is estimated.…”

“…4 During the first six Challenger legs, a downhole logging system was aboard but many difficulties accompanied its operation and the measurements often appeared uninterpretable. On Leg 4, however, a comparison between downhole gamma ray-neutron and laboratory GRAPE measurements was made by Gealy and Gerard (1970). They report differences in the two types of porosity measurements as great as 21 percent (at 150 m depth).…”

Natural Gamma Radiation of Sediments from the Western Equatorial Pacific: Leg 7, Glomar Challenger

“…On Leg 4 at Site 29 (Gealy and Gerard, 1970), in-situ gamma radiation was measured with a calibrated logging tool. When the values so obtained were 312 274 273 274 270 265 305 296 288 297 336 310 318 333 302 293 314 268 275 310 314 318 318 269 352 Mean Water Control 1493 1516 1490 1490 1490 1490 1490 1505 1478 1478 1478 1478 1478 1520 1520 1520 1520 1520 1520 1520 1517 1491 1491 1491 1491 Mean Air Control 1455 1449 1486 1486 1486 1486 1486 1446 1439 1439 1439 1439 1439 1453 1453 1453 1453 1453 1453 1453 1409 1460 1460 1460 The uncertain reliability of the controls run in connection with gamma radiation measurements made aboard the D /V Glomar Challenger poses a problem in the selection of a background count by which raw measurements should be reduced.…”

Saturated Bulk Density, Grain Density and Porosity of Sediment Cores from the Western Equatorial Pacific: Leg 7, Glomar Challenger

“…A study of cores from the caribbian by Gealy and Gerard (1970), showed that the effects of thermal expansion on marine sediments recovered are smaller than errors in measurement, and can be ignored. However, the study showed that the effect of the release of the sediments from in situ confining pressure on the volume and porosity of the sediments recovered may be substantial.…”