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Deep Ocean Drill Bits-Deep Sea Drilling Project Operations Manager Valdemar F. (Swede) Larson inspecs some of the various types of core bits carried aboard D/V Glomar challenger. Bits on the left have roller cutters, while those on the right utilize industrial diamonds. The first two bits on the left have tungsten carbide inserts and were developed specifically for DSDP to improve penetration of hard chert layers. Extensive use of these bits began on Leg 11 and it was their use which was instrumental in recovery of the oldest sediment - Middle Jurassic 150 to 160 milliion years old. Two bits in the middle are the best performers in stiff clays or gumbo and saw extensive use in the Gulf of Mexico on Legs 1 and 10. Bits on right have proved excellent recoveries in the deep ocean oozes when extensive chert beds are missing. Development of better core bits has been a continuing joint effort between drilling industry and project personnel headed by Operations Manager Larson

Deep Ocean Drill Bits-Deep Sea Drilling Project Operations Manager Valdemar F. (Swede) Larson inspecs some of the various ...