Shock Effects in Carbonates.
Interim rept. 1 Mar 76-28 Feb 77,
CALIFORNIA INST OF TECH PASADENA SEISMOLOGICAL LAB
Pagination or Media Count:
Permanent deformation of very small crystallites of carbonate minerals, such as those occurring in the Eniwetok core, has been examined using the following techniques a Peak broadening of X-ray powder diffractometer patterns due to decreasing effective grain size with increasing shock deformation is observed. This effect is clearly seen in the core material taken from directly under the Cactus explosion. b Angular strain in calcite single crystals has been observed in Debye-Scherrer patterns of laboratory shocked samples and single-crystallities from the Eniwetok core. Tentative peak shock pressures of approximately 8 kbar at a depth of approximately 15 m decaying the approximately 3 kbar at a depth of approximately 30 m are inferred on the basis of very preliminary data. c Shock-induced erasure of defect spectra, as examined by electron-spin resonance ESR techniques, is observed in carbonate materials, both shocked in the laboratory and by the Cactus explosion. This effect is yet uncalibrated. d Also using the ESR techniques, a systematic loss of fine structure of the resonance of Mn impurities in calcite is observed with increasing shock pressure, both in laboratory shocked samples and those in the Cactus core. Author
- Geology, Geochemistry and Mineralogy