Paleomagnetic Methods to Characterize Tectonic Systems in Active Basins

Abstract

In the last decades, the use of paleomagnetic and rock magnetic anisotropy studies together with structural geology and petrology, have proven to be efficient tools in increasing our knowledge about sedimentological, tectonic or volcanic processes on various scales. Paleomagnetic remanence provides unique geodynamic constraints that can be used to determine plate motions and configurations, characterize tectonic systems at the regional-scale, examine deformation associated with individual structures at the local-scale and resolve sedimentation dynamics in tectonically active basins. Magnetic methods are also important for assigning both absolute and relative time to geological sequences. Magnetostratigraphy and correlation to the Geological Polarity Time Scale (GPTS) constitute a standard dating tool in the Earth Sciences, applicable to a wide variety of sedimentary and volcanic rock types formed in different environments. Magnetic fabric analyses are now routinely employed in the quantification of petrofabric development at the micro- to macro-scales. Rock magnetic characterization provides insights into remanence acquisition during the formation and tectonic evolution of rock units, explored at the grain-scale. In the last few years, a regional paleomagnetic and magnetic susceptibility anisotropy study of the Tarija hydrocarbon basin in the Southern sub-Andean Sierras of Bolivia and Northern Argentina is being carried out. It will contribute with the stratigraphic, tectonic and kinematic reconstruction of the region to the time interval between the Upper Paleozoic - Early Mesozoic - Tertiary. The LA.TE.ANDES S.A. Company (GEOMAP - CONICET) is developing a new Argentine cryogenic magnetometer that will allow to increase the quantity and quality of the obtained data. This will allow delimiting the stratigraphic and tectonic evolution of the regional oil system with greater precision.

AAPG Datapages/Search and Discovery Article #90326 © 2018 AAPG Latin America & Caribbean Region, Optimizing Exploration and Development in Thrust Belts and Foreland Basins. Santa Cruz de la Sierra, Bolivia, June 6-8, 2018