Mohole, Project, program proposed in 1957 to drill a hole down to the boundary between the crust and the mantle, known as the Mohorovičić discontinuity at about 4 to 43 mi (7 to 70 km) below the earth's surface. Initiated by the American Miscellaneous Society, a loose organization of scientists, the main purposes of the project were to determine the nature of this boundary and to attempt to fill gaps in the geologic record from samples of the rocks encountered. The technology of such a project, however, was beyond the state of drilling technology at that time. Groups such as the National Science Foundation and the National Academy of Science eventually backed phase 1, in which five holes were drilled off the coast of Mexico, the most successful entering 601 ft (183 m) into the ocean floor under 2.2 mi (3.5 km) of water. The project was abandoned by 1966, as funding to support the ever-increasing costs of the project failed to gain congressional approval. Nevertheless, ship positioning and design, along with deepwater drilling technology developed for Project Mohole, were employed in the Deep Sea Drilling Project and future drilling projects.
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