P- and S-wave velocities and densities in silicate and calcite rocks from the Peloritani Mountains, Sicily (Italy): The effect of pressure, temperature and the direction of wave propagation

A new calibration of seismic velocities, anisotropy, fabrics, and elastic moduli of amphibole‐rich rocks

“…These amphibole‐rich rocks display densities ranging from 2.81 to 3.20 g/cm 3 with a mean value of 3.01 g/cm 3 under ambient conditions (Table ), mainly reflecting the relative contents of amphibole, plagioclase, and other minerals such as garnet, clino‐ and orthopyroxenes, mica, chlorite, quartz, and magnetite. The density distribution for this set of 17 samples (Figure ) is comparable to that for the amphibole‐rich rocks reported in previous references [ Birch , ; Christensen , , ; Kern and Fakhimi , ; Fountain , ; McDonough and Fountain , ; Siegesmund et al ., ; Burke and Fountain , ; Fountain et al ., ; Miller and Christensen , ; Barruol and Kern , ; Fountain and Salisbury , ; Kern et al ., , , , , ; Khazanehdari et al ., ; Ji et al ., ; Punturo et al ., ; Zhao et al ., ; Zhou et al ., ]. Figure illustrates the histograms of the main chemical components of the studied samples, together with those of 28 amphibole‐rich rock samples from previous references [ Fountain , ; Burke and Fountain , ; Fountain et al ., ; Miller and Christensen , ; Kern et al ., , , , ; Zhao et al ., ; Zhou et al ., ].…”

Temperature dependence of seismic properties in geothermal rocks at reservoir conditions

“…In dry rocks, this decrease can be explained by the creation of new microfractures. If no thermally induced microfractures are created, heating does not change the dry moduli of rocks according to commonly used theoretical models (Garg, 1984;Kern et al, 2001;Punturo et al, 2005). This implies that the temperature dependence of velocity in fluid-saturated rocks is very likely due to the saturating pore fluid.…”

“…Laboratory measurements of temperature-dependent seismic velocities of rocks at high temperatures have been performed by Kern (1978), Kern et al (2001), Punturo et al (2005), and Scheu et al (2006). However, these laboratory experiments were done using dry samples under very high pressures (up to 6000 bar in 500 bar intervals) and temperatures (up to 1000 • C in 100 • C intervals).…”

Intraplate stress state from finite element modelling: The southern border of the Spanish Central System

“…In this case, the magnitudes of horizontal stresses in the upper 5 km of the central area of the model are greater than those of the vertical stress when ν = 0.25 (model B). Although Poisson's ratio is very high compared with experimental data (Turcotte and Schubert, 1982;Twiss and Moores, 1992;Chevrot and van der Hilst, 2000;Punturo et al, 2005), this value must be used to simulate lithostatic state by trade packages of finite elements, as a consequence of the theory of elasticity in-plane strain (1). The simplification of the behaviour of the upper crust from 3-D to 2-D implies that: a) the lithostatic loads outside the cross-section are not included in the modelling, and b) the component of the stress tensor which is perpendicular to the cross-section is solved from the two in-plane stress components.…”