Results from theoretical models, laboratory experiments, and full-waveform sonic log data converge toward a common interpretational model for Vp/Vs ratios in sedimentary rocks. Moreover, we show that Vp/Vs ratios obtained from sonic logs may be significantly different than those obtained from seismic reflection velocity analysis due to dispersion.

Abstract Recent advances in remote sensing technology and digital image analysis have been leveraged to significantly increase the level of complexity and precision that can be captured in maps of modern carbonate depositional settings. Satellite mapping efforts in a variety of modern carbonate environments have generated a spectrum of facies distribution characterizations that more accurately reflect the natural complexity of carbonate systems in terms of facies body size and shape. Predictive quantitative relationships are being harvested from this robust data set. Foremost among these is the globally observed power law scaling relationship between facies body size and frequency of occurrence. The scaling dimension, an attribute derived from the slope of the power law trend, describes the rate of change for the probability of encountering a facies body of a particular size. It also provides a robust measure for characterizing and comparing genetically distinct groups of facies. We propose here that the scaling dimension is a quantitative manifestation of the natural complexity inherent in carbonate depositional systems and can be used to test the fidelity of facies maps generated from outcrop, seismic, or other subsurface tools to natural facies patterning. For this study we compare modern carbonate facies trends observed in a series of global carbonate settings to evaluate the natural range of the scaling dimension and the sensitivity of the parameter to changing depositional controls. To demonstrate the persistence of the scaling relationship across widely varying settings, case studies from the Hawaiian Islands, Arabian Gulf, Caribbean Sea, Great Barrier Reef, the Flores Sea, and southern Indian Ocean are presented. Initial results suggest that the scaling dimension ranges between 0.6 and 1.6. Relatively higher scaling dimension values are associated with robust reef margin systems and lower values are associated with platform interior patch reef systems.