Accession Number : AD0809011

Title :   DYNAMIC PROPERTIES OF ROCKS.

Descriptive Note : Final rept.,

Corporate Author : STANFORD RESEARCH INST MENLO PARK CA

Personal Author(s) : Ahrens, T. J. ; Rosenberg, J. T. ; Ruderman, M. H.

Report Date : 30 SEP 1966

Pagination or Media Count : 221

Abstract : Hugoniot equation of the state measurements using streak camera techniques have been performed for the following minerals which are constituents of common crustal rocks: polycrystalline and single crystal quartz (40-450 kbar), anorthosite (to 620 kbar), microcline (to 580 kbar) olivine (to 780 kbar), single crystal calcite (240-340 kbar), and augite and diopside (to 780 kbar). All these minerals, except calcite, exhibit Hugoniot elastic limits (HEL) (dynamic yield stresses) of the order of 50 kbar; the elastic limit for calcite is approximately 25 kbar. At pressures above the HEL, the Hugoniots of the minerals indicate, either by cusps or by anomalously high compression followed by a marked increase in incompressibility, that one or more shock-induced transitions to high pressure polymorphic forms occur. Release adiabats of polycrystalline quartz and anorthosite descending from various states on the two Hugoniot at pressures up to 380 and 420 kbar, respectively, were measured. The release adiabats of polycrystalline quartz and anorthosite descending from shock states above 120 kbar are quite steep, indicating irreversible transformation to denser materials believed to be high pressure polymorphs. At pressures above approximately 100 kbar the release adiabats centered at Hugoniot states above 300 kbar are steeper than the hugoniot. At the 100 kbar level a sudden change in slope marks the onset of anomalously high expansions to volumes somewhat greater than the initial volumes. (Author)

Descriptors :   (*ROCK, EQUATIONS OF STATE), DYNAMICS, MINERALS, ELASTIC PROPERTIES, MECHANICAL WAVES, PROPAGATION, DEFORMATION, COMPRESSIVE PROPERTIES, NUCLEAR EXPLOSIONS, ATTENUATION, LOADS(FORCES), RHEOLOGY, TEST METHODS, OPTICAL EQUIPMENT, PARTIAL DIFFERENTIAL EQUATIONS, CURVE FITTING.

Subject Categories : Geology, Geochemistry and Mineralogy
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE