ODP Leg 176: Return to Hole 735B

Figure 10

 

Comparison of raw and dynamic processed FMS images of gabbros from the lower oceanic crust section drilled at Hole 735B. 

The poor quality of the raw data monitored during acquisition was apparently due to tool sticking and specially the high resistivity of the formation (> 10,000 ohm-m) which caused the electrical current to travel along the borehole fluid and saturate the tool receivers. An alternative solution to avoid this problem would be to fill the borehole with fresh water mud in order to reduce the contrast between the conductivity of the fluid and the formation.