Depth-shifting and orientation of core data using a core–log integration approach: A case study from ODP–IODP Hole 1256D

Studies of the evolution and architecture of the oceanic crust's basement are significantly hindered by the lack of sample orientation with respect to geographic coordinates. Generally, the length of cores recovered in oceans is not equal to the drilled length (recovery percentage < 100% or > 100%). Thus, data such as structural measurements are either lost or not suitable to reliably interpret many aspects of the geological environment. Core–log integration enables the correction of each core piece to the appropriate in situ depth position and reorientation of core structures with respect to magnetic North by correlating core measurements to downhole high-resolution resistivity images and acoustic images. This technique was tested on results from the shallowest section of ODP–IODP Hole 1256D that drilled through a complete in situ section of upper ocean crust formed at ultra-high spreading rate.

Research Highlights
► Cores recovered in oceans are not geographically oriented.
► The length of cores recovered in oceans is not equal to the drilled length.
► Downhole images obtained with FMS, BHTV, or UBI are geographically oriented.
► We matched log images with analogue core data.
► Core–log integration enables depth-shifting and reorientation of core data.