Extrapolation of depositional geometries of the Menorcan Miocene carbonate ramp with ground-penetrating radar

Abstract

The Tortonian carbonate ramp of Menorca was previously studied on the basis of outcrops along sea-cliff outcrops. These sea cliffs, in combination with inland water wells, are the basis for a facies model for the reconstruction of the internal architecture and for characterizing the internal heterogeneities of this carbonate platform. However, any such three-dimensional reconstruction is generally limited by the given geometrical arrangement of the twodimensional outcrops and the uncertainties of correlation with the one-dimensional wells. Here, ground-penetrating radar (GPR) has been employed in order to test and refine the depositional model. Although GPR is well known for being an excellent tool for high-resolution underground studies of sedimentary systems, the application for studying carbonate rocks is still far from routine. The reason for this discrepancy is two-fold: the minor mineralogical contrast between lithologies in carbonate rocks results in subtle reflections, and, even more important, the porosity structure in carbonates is thoroughly and repeatedly changed during diagenesis, commonly across the different facies, leading to problems in predictability of the petrophysical properties. The study of the Menorcan carbonate ramp with large distance-deep penetration GPR sections demonstrates that in spite of these difficulties, GPR is a valuable tool for extrapolating information from outcrops and wells. It is useful for characterizing heterogeneities larger than outcrop scale.

A structural study of thermal tufas using ground-penetrating radar

“…The optimum velocity used for time-depth conversion was determined from modeling of diffraction hyperbolae to be 0.09 m/ns (corresponding to a dielectric constant of 10.4), which lies within the range of values reported for limestones in general (e.g., Al-fares et al, 2002;Asprion et al, 2009;Grasmueck and Weger, 2002;Sigurdsson and Overgaard, 1998). For example, Milsom (2003) gives a textbook value of 0.12 m/ns for limestones in general, whereas Sigurdsson and Overgaard (1998), Grasmueck and Weger (2002), and Neal et al (2008) give 0.07-0.08 m/ns.…”

Integration of sedimentology and ground‐penetrating radar for high‐resolution imaging of a carbonate platform

“…Recently, Asprion et al. (2009) proposed a new approach, which consists of using GPR sections for extrapolating facies information and geometries from outcrops and wells to refine and extend the resolution of the medium‐scale and small‐scale complexities in facies architecture on the Tortonian carbonate ramp of Menorca.…”

“…, 2004) are some of the studies using GPR in carbonates. To the knowledge of the present authors, only one study published by Asprion et al. (2009) integrates sedimentology and geophysics to characterize facies and geometry of a carbonate platform to interpret subsurface facies and geometry.…”

From ramp to platform: building a 3D model of depositional geometries and facies architectures in transitional carbonates in the Miocene, northern Sardinia

“…Reconstruction of geometries of carbonate depositional systems and their internal facies distribution is essential for a better understanding of lateral and vertical heterogeneity, complex stacking patterns, and stratal anatomy (Bosence et al 1998;Bosence 2005;Warlich et al 2005;Asprion et al 2008). The investigation of the type and loci of carbonate production, as well as of the factors controlling the depositional geometries and facies distribution (sea-level and paleoceanographic fluctuations or climate; Pomar and Kendall 2007;Pomar and Hallock 2008) are of wide interest.…”