Testing the utility of the porphyroclast hyperbolic distribution method of kinematic vorticity analysis

Bootstrapping statistics and a computational sieving process were used to analyze the PHD data set. Average standard deviations of the bootstrapped data sets yield a 1σ standard error of ±9% for a Wk-value measured as a % simple shear. Sieving results imply that back-rotated porphyroclasts may not orient parallel to the extensional eigenvector. The PHD method is useful for discerning between deformations that are pure shear dominated, general shear, or simple shear dominated, but is not accurate enough to report precise Wk-values. When performed on multiple sections the PHD method can identify zones of monoclinic versus triclinic shear.