COMPARING ACOUSTIC PROPERTIES OF CLASTIC, MIXED CLASTIC-CARBONATE, AND NON-MARINE TO FULL-MARINE CARBONATE SEDIMENTARY SYSTEMS

Abstract

In this study a comparison is made of acoustic property measurements covering: (i) Continental deposits: Miocene, Spain and Pleistocene travertines, Turkey and Hungary; (ii) Marine mixed carbonate-siliciclastic sediments: Eocene, N-Spain; Jurassic, Spain, and Carboniferous-Permian, Norway; and (iii) Full marine sediments: Miocene, SE-Spain, and Urgonian carbonates, S-France. The dataset shows that rock fabric and mineralogy control the elastic properties of sediments with varying mineralogy and texture (carbonate, clay and quartz). High carbonate contents result in high velocities and low carbonate contents and/or highly mixed sediments demonstrate low velocities for a given amount of porosity. Deviations from aforementioned trends depend on the quantity, grain-size, and non-carbonates mineralogy. Porosity variations, related to the age and diagenetic history of the sediments, have a distinct impact on the P-wave velocity. The P-wave velocity values of marine and lacustrine carbonates overlap suggesting that pore structure and cementation in both systems determines acoustic properties. These P-wave velocities differ from travertines, which probably relates to pore type and pore distribution linked to sedimentary and diagenetic processes, and biology intrinsic of these depositional systems. In conclusion, the main parameters controlling the acoustic response are: porosity amount and pore type, mineralogical composition (including clay content), rock texture and fabric (frame).