Corrigendum to: “Estimation of vorticity from fibrous calcite veins, central Maine, USA” [J Struct Geol 2006; 28(7):1167–1182

Abstract

We wish to correct Fig. 11 in Short and Johnson (2006), in which parameters M, N, T, Q and R, derived from the construction of Mohr circles are incorrect for two reasons and have resulted in slightly incorrect values for Rf, 1þDA, and g. First, incorrect values forM, N, T, Q and R below the Mohr circles were accidentally copied to the final figuree they were initial measurements from the Mohr circle before the scale of the circle was determined using equation (15) in Passchier (1990). Second, and more importantly, the scaled parameters M, N, T, Q and R were calculated erroneously because of the lead author’s omission of a minus sign on the left side of equation (15) in Passchier (1990), necessary for the calculation of parameters for the position gradient tensor of backward deformation (H). The necessity of this minus sign is somewhat unclear from Passchier (1990) as explained in Kuiper and Jiang (2010), who also give a more thorough review of the Mohr circle construction method and a set of accurate equations. The correct Mohr circles and deformation parameters, calculated using equation (8) in Kuiper and Jiang (2010) are given below. The backward (H) and forward (F 1⁄4 HL1) position gradient tensors are included. Kuiper and Jiang (2010) also present two alternative analyses for Short and Johnson’s (2006) data, using La(max). We consider it important to correct theMohr circle construction in Short and Johnson (2006) so that future constructions of this typewill be based on accurate equations presented in Kuiper and Jiang (2010). The recalculated values for Wks are however within error of those in Short and Johnson (2006). They are independent of the scale of the Mohr circle and because the position of the Mohr circle relative to the axes of the diagramwas correct in Short and Johnson (2006) their values for Wks were correct. The correct values for Rf, and g for the Mohr circles of Short and Johnson (2006) are only slightly different from the originally published values (þ0.26, and þ0.09, respectively, for the La(max) circle) and do not affect their conclusions.