PT  - JOURNAL ARTICLE
AU  - Bucher, Walter H.
TI  - Cryptoexplosion structures caused from without or from within the earth? ("astroblemes" or "geoblemes?")
AID  - 10.2475/ajs.261.7.597
DP  - 1963 Sep 01
TA  - American Journal of Science
PG  - 597--649
VI  - 261
IP  - 7
4099  - http://www.ajsonline.org/content/261/7/597.short
4100  - http://www.ajsonline.org/content/261/7/597.full
SO  - Am J Sci1963 Sep 01; 261
AB  - The results of an analysis of cryptoexplosion structures in southern Germany, North American counterparts of these structures, and the Vredefort dome of South Africa are presented, on the basis of which a meteorite impact origin is rejected. "The writer suggests the release of vast quantities of water vapor through sudden crystallization of supercooled molten rock near the base of the crust as source of energy, carried rapidly into porous rocks near the earth's surface under an impervious cover. Rapid arrival of the vapor results in an explosion crater, with coesite, but without shatter cones. The energy required to form coesite may have been kinetic, transmitted as the pulverized material was forced through narrow and crooked passages toward the surface. The presence of shatter cones in cryptovolcanic structures suggests that the presence of vapor under high pressure in the pores of the rock favored their formation."