One more thing I did not know. From a reader:
Jonah;
The original mantle boring project was a victim of LBJ’s corruption
and the subject of my first ever letter to the editor. Global Marine
was a San Diego based company with lots of experience drilling in
deep ocean locations. The project was called “Operation Mo-hole” and
was to drill through the Mohorovic Discontinuity Layer, the thinnest
part of the crust which is found in very deep water. The Johnson
Administration diverted the project to Brown and Root (The
Halliburton of its day as it built all the bases in Vietnam), a big
contributer to Texan Johnson. The money was all spent but no hole was
ever completed.
Here is the NAS history:http://www.nas.edu/history/mohole/
The preliminary drilling they refer to was done by Global Marine. The
Brown-Root part was a fiasco as they had no experience with deep
water drilling. I’m still angry about it and that was 40 years ago.