Stephanie Fones, “Geometries of Small-Scale Fold Structures Related to the Southern Iberian Shear Zone”
Mentor: Dyanna Czeck, Geosciences
Poster #94

The Southern Iberian Shear Zone (SISZ) is a ductile shear zone located in the Andalusia province of southwestern Spain. The Pulo do Lobo (PdL) formation is composed of quartzites and phyllites. The SISZ formed from collision of the PdL and a metabasite rock unit followed by continued shearing. The SISZ deformed both the PdL and adjacent metabasites, and the deformation is partitioned between and within each unit. Within the PdL, the deformation is expressed as foliation, folds, shear bands, boudinage, and other small structures. The central research question of this project is to observe and understand strain localization and kinematic partitioning within the PdL, which contains many cm-m scale structures associated with the SISZ including folds, shear bands, and boudinage. Folds form when layered bedding transforms into curved structures as a response to shortening. This research project aims to quantify deformation accommodated by folding within the PdL by analysis of orientation and fold tightness with respect to distance from the shear zone. Tightness can be measured tangential to the folded surface at the inflection line of each limb. It is expected that folds will be tighter near the Southern Iberian Shear Zone if they were solely produced during the latest stage of shear zone development. This research will determine how folding contributed to the overall deformation within the SISZ.