Stress Field Evolution of the Southernmost Andean Cordillera From Paleostress Analysis (Argentine Tierra del Fuego)

Abstract

The Argentine Tierra del Fuego comprises part of the roughly east-west trending southern end of the Andean Cordillera intensely deformed since the Mesozoic. Mesostructures have been measured in Late Jurassic to Miocene rocks. Taking into account statistical criteria to provide a representative stress tensor from a fault population, this study defines 28 paleostress tensors pertaining to 22 sites. The orientation of σ 1 shows two main modes trending E-W to ESE-WNW and NE-SW. In addition, extensional sites reveal N-S, NE-SW, ESE-WNW, and NW-SE horizontal σ 3 and vertical σ 1 . The stress fields obtained are congruous with a regional NE-SW compressive stress direction active in the study zone since the Late Cretaceous. Shortening was coeval with a 30°counterclockwise rotation of the Patagonian orogenic curve and the indentation of the orogenic wedge against a basement high, the Río Chico Arch, up to the early Miocene. The indentation caused a modification in the orientation of the compressive stress trajectories, showing NE-SW direction in Sorondo Range sector and NW-SE in Mitre Peninsula area. Since the late Miocene, left-lateral activity along the Magallanes-Fagnano Fault System produced local deviations of the NE-SW compressive stress toward an E-W direction. The present-day stress field is also characterized by NE-SW subhorizontal P axis derived from earthquake focal mechanisms and geodetic studies.

The Fuegian thrust-fold belt: From arc-continent collision to thrust-related deformation in the southernmost Andes

“…Several fracture sets, analyzed for paleostress directions, indicate compression perpendicular to most of the structures during the Paleogene (Maestro et al, 2019). In Península Mitre, on the other hand, the curvature of the thrust-fold belt forms a recess (Península Mitre recess).…”

Quantitatively Deciphering Paleostrain From Digital Outcrops Model and its Application in the Eastern Tian Shan, China

“…Paleostress analysis is a branch of structural geology whose target is characterizing stress systems acting in the past from their record in deformation structures, singularly from fault slip data (Simón, 2019), based on the principle that past tectonic stress should have left traces in the rocks (Hancock, 1985). Since the first introduction of the paleostress inversion methods by Wallace (1951) and Bott (1959), it has been developed worldwide during the last decades (e.g., Angelier, 1979Angelier, , 1984Angelier, , 1989Angelier, , 1990Angelier et al, 1982;Delvaux et al, 1997;Kaven et al, 2011;Shimizu, 2008;Stipp & Tullis, 2003;Twiss & Unruh, 1998), and several thousands of paleostress reconstructions have been carried out in all tectonic settings (e.g., Amrouch et al, 2010Amrouch et al, , 2011Arboit et al, 2015;Hashimoto et al, 2019;Homberg et al, 1999Homberg et al, , 2002Lacombe et al, 2006;Maestro et al, 2019;Radaideh & Melichar, 2015;Riller et al, 2017). In the opinion of Simón (2019), "perhaps no other branch of structural analysis offers such a high number of methods and is submitted to such an intense conceptual discussion."…”

Quantitatively deciphering paleostrain from digital outcrops model and its application in the eastern Tian Shan, China

“…Paleostress analysis is a branch of structural geology whose target is characterizing stress systems acting in the past from their record in deformation structures, singularly from faultslip data (Simón, 2019), based on the principle that past tectonic stress should have left traces in the rocks (Hancock, 1985). Since the first introduction of the paleostress inversion methods by Wallace (1951) and Bott (1959), it has been developed worldwide during the last decades (e.g., Angelier, 1979;Angelier et al, 1982;Angelier, 1984Angelier, , 1989Angelier, , 1990Delvaux et al, 1997;Twiss and Unruh, 1998;Kaven et al, 2011;Stipp and Tullis, 2003;Shimizu, 2008), and several thousands of paleostress reconstructions have been carried out in all tectonic settings (e.g., Homberg et al, 1999Homberg et al, , 2002Lacombe et al, 2006;Amrouch et al, 2010Amrouch et al, , 2011Arboit et al, 2015;Radaideh and Melichar, 2015;Riller et al, 2017;Hashimoto et al, 2019;Maestro et al, 2019). In the opinion of Simón (2019), "perhaps no other branch of structural analysis offers such a high number of methods and is submitted to such an intense conceptual discussion".…”