Figure F20. Comparison of (A) core photograph and (B) computed tomography (CT) scan of a porphyroblastic mudrock created by thermal and hydrothermal effects of the intrusion of the upper diabase sill in lithologic Subunit 5C (interval 210-1276A-87R-6, 18–27 cm). The CT scan is a horizontal slice through a three-dimensional reconstructed image, viewed with IMAGEJ software. Note the apparent near-random orientation of the porphyroblasts.