Pre-test XCT data for sample BC3 (left image) and BC5 (right image). For BC3, (a) orthogonal 2D XCT image shows faint micro-cracks (dark lines); (b) XCT features in XY orientation; (c) XCT features in XZ orientation; (d) XCT features in YZ orientation; (e) XCT image of fractures in XZ orientation; (f) XCT image of fractures in YZ orientation. For sample BC5, (a) orthogonal 2D XCT image; (b) XCT features in XY orientation; (c) XCT features in XZ orientation; (d) XCT features in YZ orientation. Both samples were cut parallel to bedding but sample BC5 shows significantly less bioturbation and no initial micro fractures