Mechanical stratification and decollement fold kinematics:an example from the Sierra Madre Oriental, northern Mexico

Presenter: Shu-Jui Fan

Date: 2015/12/31

Abstract

Regional-to outcrop-scale stratigraphywithin Mesozoic formations at the Sierra del Fraile anticlinorium in northern Mexico playsan important role incontrolling the deformation distribution and fold kinematics.To explore thisrelationship between stratigraphyand deformation features, lithologies and structures withineachformationwere investigated through field survey. Moreover,the measurement of anisotropy of magnetic susceptibility (AMS) fabricshelpsprovide constraintson kinematics during folding.The abovementioned structural analyses from all stratigraphic and structural positions allow for the delineation of five regional-scale mechanical unitswhich display different deformationbehaviorswith different lithologies. Based onthedelineation of mechanical units and AMS data, four stages of fold kinematics were shown to explain the mechanisms during folding processes, including compaction, layer-parallel shortening, layer rotation and late flattening.

Reference

Latta and Anastasio, 2007. Multiple scales of mechanical stratification and decollement fold kinematics, Sierra Madre Oriental foreland, northern Mexico. Journal of Structural Geology29, 1241-1255.Pages 125-150, June 1996.

Fischer and Jackson, 1999. Stratigraphic controls on deformation patterns in fault-related folds: a detachment fold example from the Sierra Madre Oriental, northern Mexico. Journal of Structural Geology21, 613-633.