Quantifying Deformation of the Permian Halokinetic Cutler Group, Paradox Basin, Utah Using Rock Magnetic Methods: Implications for Salt Tectonics and Salt-Related Petroleum Systems

Abstract

Salt-related growth strata (halokinetic sequences) are critical to the understanding of salt-influenced petroleum systems, therefore these features are often studied to better comprehend the effects of diapirism on reservoir distribution, migration pathways, etc. Despite much work in recent years, deformation studies have been restricted to the analyses of mesoscale features in outcrops. This is why researchers have proposed the use of magnetic fabrics, determined using Anisotropy of Magnetic Susceptibility (AMS), as a way to study the deformation of halokinetic strata primarily because the technique’s high sensitivity allows it to give information even in the absence of strain markers. Soto et al. (2016) have previously demonstrated the use of AMS in order to analyze halokinetic structures, and this study uses similar methods on the Permian Cutler group in the Paradox Basin, Utah in order to further test the applicability of rock magnetic methods to study salt-related synkinematic strata. Oriented samples were collected from 20 sites along the Onion Creek salt diapir, which were later brought to the rock magnetic laboratory at the University of Texas at Dallas (UTD) where they were prepared into various specimens for rock magnetic analysis. All specimens display a magnetic foliation that is parallel to bedding, which suggests that it reflects depositional and compaction process. However, the magnetic lineations are all approximately oriented parallel to the diapir in a Northwest-Southeast direction, with some variation depending on proximity to diapir (i.e. sites farther from the diapir are less parallel and vice-versa). The orientation of the lineations are tentatively interpreted to represent deformation of the strata as a result of salt movement. This study shows the effectiveness of using magnetic fabric analysis to study salt-related growth strata, both in outcrop as well as a means to potentially study diapir related structures in the subsurface.

AAPG Datapages/Search and Discovery Article #90350 © 2019 AAPG Annual Convention and Exhibition, San Antonio, Texas, May 19-22, 2019