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Figure F19 (continued). OO. The C9 bit used for Run 24 (NN) returned to the rig floor in relatively good condition and nearly in gauge. It cored for ~2.5 h. PP. Worn outward faces of the cones, one missing tooth, and a small crack that started to propagate in the welding of the cone leg (see bottom right, close to the jet). QQ. Small marks on the outward facing structure of the Run 24 C9 bit, likely caused by hard, abrasive granoblastic basalt. Note the difference with the next picture. RR. For comparison with QQ, this picture shows the partly broken bit from Expedition 312 (missing cones), heavily damaged and cut by metal junk.

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