ANISOTROPÍA DE SUSCEPTIBILIDAD MAGNÉTICA (ASM) COMO HERRAMIENTA PARA EL ESTUDIO DE ESTRATOS DE CRECIMIENTO

GUGLIOTTA M.E.; TOMEZZOLI, R.N.; CRISTALLINI, E.O.

Rio de Janeiro

Simposio; VII Reunión Bienal de la Asociación Latinoamericana de Paleomagnetismo; 2023

Latinmag

Growth strata are geological structures of significant economic importance because they can serve as petroleum traps. These growth strata are recognizable due to their cuneiform geometry, which results from sedimentary deposition over developing structures. However, high-quality outcrops of growth strata that can be easily identified and analyzed for studying structural kinematics are not common. We consider that the utilization of the Anisotropy of Magnetic Susceptibility (AMS) tool to identify and describe growth strata in locations could be useful to understand the geometry of these structures which is challenging. This is feasible because the orientation of the magnetic ellipsoid is coaxial with the deformation ellipsoid.The minimum axis (K3) of AMS in sedimentary rocks without tectonic deformation is typically vertical, owing to the anisotropy being controlled by lithostatic pressure (maximum principal stress σ1 in the vertical direction). Therefore, we expect to establish a relationship between the direction of the K3 axis and the bedding in sedimentary rocks. To validate this approach, we initiated the study of growth strata in Tertiary-age rocks with known geometry, located in the Bermejo basin, San Juan Province, Argentina (Fig. 1).