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We present an original anisotropic stress-dependent rock physics model for the organic rich shales of the Inoceramus formation, the main source rock and unconventional reservoir in the Austral Basin, Argentina. We implement a novel combination of anisotropic poroelastic theories which take into account organic matter content, lithologic description, fluid type, saturation and stress state. In this approach, we model the infill as a mixture of solid organic matter and interconnected pore fluids, using total organic carbon analysis and petrophysical data from two wells. The compliance of the matrix is considered to be stress-dependent following the porosity deformation approach (PDA). The elasticity and density of the multiminerallic saturated rock is obtained using the mineral fractions obtained from X-ray diffraction information, porosity analysis and fluid properties. This allows us to compute synthetic acoustic velocities. The calibration of the model also involved the inversion of several unknowns (the set of PDA parameters, clays and kerogen physical properties) by minimizing the misfit between modelled and ultrasonic measured velocities. Due to the lack of oblique velocity data, to complete the compliance tensor, a static-to-dynamic ratio was built for each sample, and constant anellipticity was assumed with increasing stress. The model calibrated with this innovative procedure demonstrated its usefulness to predict stiffness, compliance, and compressional and shear wave velocity variations under variable applied stress. It is also useful for the estimation of stress-related changes of porosity and Biot's effective stress coefficients, which can be difficult to measure in shales, and therefore there are few values reported in the literature. [ABSTRACT FROM AUTHOR]

• Age, stem slenderness and site index as key determinants of modulus of elasticity. • At each site, the most slender trees, will have a greater modulus of elasticity. • Simple variables (ABH, SI, S and RH) allow to predict modulus of elasticity. Using portable acoustic tools, measurements of dynamic modulus of elasticity (E d) were made in standing ponderosa pine (Pinus ponderosa (Dougl. ex Laws)) trees (n = 437) growing in 22 stands encompassing the range of environmental site conditions and ages of the plantations that have been established in NW Patagonia, Argentina. The objectives of this research were to (i) identify the stand and tree-level factors associated with the variation in E d and, with the most suitable variables (ii) develop a descriptive model to E d for ponderosa pine grown in NW Patagonia Argentina as the first step of a predictive model. Tree and stand variables showed a wide range of variation and E d ranged ten-fold, from 2.13 GPa to 22.1 GPa, with a mean value of 11.2 Gpa. The cross-correlations analysis performed among E d and independent tree and stand variables showed almost all variables to be significantly related to E d. The main positive and significant correlation was found for total tree height (H, r = 0.78, p < 0.001), top height of the stand (H100, r = 0.78, p < 0.001) and basal area of the stand (G, r = 0.68, p < 0.001). Nevertheless, the most suitable independent variables for modelling E d were two stand variables: age at breast height (ABH) and site index (SI 20) and two tree variables: stem slenderness (S , tree height/diameter at breast height) and social status or relative height (RH = H/H100). In combination, ABH, SI 20 , S and RH accounted for 68.4% of the variation in E d within the sample population. This model could be readily applied by managers to estimate stand-level E d , giving them greater understanding of how they can manipulate stands to achieve desired end product outcomes. [ABSTRACT FROM AUTHOR]