Apparatus and method for cryogenic flash freezing of confined water in a rock formation with concomitant fracturing of the rock formation utilizes an anchoring device comprising gripping means actuatable responsive to release of pressurized gas effected by opening a valve responsive to the firing of an explosive charge in combination wih an elongated container for a cryogenic liquid so that the anchoring device may be positioned with said container depending therefrom in a hole in the rock formation and so that cryogenic liquid so held in position may be forcefully discharged from the container upon opening a valve responsive to the firing of an explosive charge for injection into water confined in the hole or in a cavity or crevice in the surrounding rock formation, the location of water to be flash frozen, if desired, being accomplished by a plug adapted to be fixed in place at different positions and to retain water thereon when fixed in place.
This is a division of application Ser. No. 523,887 filed Nov. 14, 1974, now U.S. Pat. No. 3,978,921, which is a continuation-in-part of my application Ser. No. 148,048 filed May 28, 1971, now U.S. Pat. No. 3,759,329, which in turn is a continuation-in-part of my application Ser. No. 823,306 filed May 9, 1969 which resulted in U.S. Pat. No. 3,581,821.
