Figure F19 (continued). CC. Damaged bit sub junk basket (BSJB) used for Run 17, probably caused by granoblastic basalt angular blocks falling down the borehole walls while milling at the bottom. DD. 9 inch flat-bottomed milling tool used for Run 18. Note the hard-facing structure of the bottom of the tool. EE. The BSJB used for Run 18 returned with a damaged pocket, probably due to rock(s) detached from the borehole wall (CC). FF. 9 inch flat-bottomed milling tool used for Run 18, after working 6 h at the bottom of the hole. The abrasive surface (note the difference with DD) was eroded away and some external junk damage noted on the side of the tool and the crossover sub directly above the milling tool. (Continued on next page.)
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