On the origin of low angle normal faulting in the southern rio grande rift

We reconstruct the stress regime in the East Potrillo and Franklin Mountains. Using modern numerical techniques the stress field and the tectonic history of this region is discussed and extensional veins were compared with the general stress field. The majority of faults were reactivated during the...

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Bibliographic Details
Authors: Carciumaru, Dana, Ortega, Roberto
Format: article
Status:Published version
Publication Date:2011
Country:México
Institution:UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO
Repository:Geofísica Internacional
Language:Spanish
English
OAI Identifier:oai:revistagi.geofisica.unam.mx:article/377
Online Access:http://revistagi.geofisica.unam.mx/index.php/RGI/article/view/377
Access Level:Open access
Keyword:inversión de esfuerzos
falla normal de bajo ángulo
correccion angular por basculamiento
rift del Rio Grande
stress inversion
low angle normal faults
back tilting
Rio Grande rift
Description
Summary:We reconstruct the stress regime in the East Potrillo and Franklin Mountains. Using modern numerical techniques the stress field and the tectonic history of this region is discussed and extensional veins were compared with the general stress field. The majority of faults were reactivated during the first Rio Grande rift extensional event and occurrence of extensive tilting and rotations occurred. In the East Potrillo Mountains, back tilting by W25°SE and W45°SE oriented along strikes of N30°W are required in order to obtain two homogeneous stress fields. The corrected fault plane shows a significant oblique component in both stress fields. The first stress field corresponds to a fault reactivation with σl and σ3 oriented N78°E and N69°E respectively, whereas the second stress field is related to the youngest fault oriented N64°W and N61°E respectively. In the Franklin Mountains, tilting is less significant; however two stress fields with similar orientations but different phi values are recognized. The post –Laramide stress history of the region is controlled by different extensional events that influenced the preexisting structures and generated other young fault systems.