ODP Leg 174A: Mid-Atlantic Sea-Level Transect


Figure 2


Wireline (color, Hole 1072B) and LWD (black, Hole 1072D) logs at Site 1072.

Small vertical mismatches between the logs, particularly across surface pp4(s), are associated with local variability in bedding and small scale topography at this sequence boundary (holes are about 30 m apart). Differences in resistivity between the LWD and wireline runs occur primarily in the unconsolidated sand-rich intervals and is interpreted to result from borehole fluid invasion in these intervals (wireline measurements were made several hours after drilling compared to a few minutes for the LWD resistivity).

Major bedding trends derived from the gamma-ray and resistivity logs and are indicated as: fu=fining-upward, cu=coarsening-upward, tu=thinning-upward, thu=thicknening-upward.