Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 149-156). Also available via the Internet.

The western Piedmont of Pennsylvania is underlain by the Octoraro and Peters Creek Formations, and these formations were juxtaposed during Late Paleozoic dextral strike-slip shearing. North of the shear zone, the Octoraro Formation contains evidence for two metamorphisms and deformations prior to strike-slip shearing, whereas south of the shear zone the Peters Creek Formation contains evidence for only one. The discordance in metamorphic and deformational history across the shear zone suggests the now juxtaposed rocks originated in different parts of the orogen. A minimum of 150 km of orogen parallel dextral offset is proposed for the shear system based on palinspastic reconstruction of the Cambrian-Ordovician shelf edge between northern Maryland and southeastern New York. The Peters Creek Formation consists of three lithofacies: 1) graded metasandstone beds, 2) meta-quartz-pelite, and 3) massive metasandstone lenses within the graded bedded sequences. The occurrence of interlayered greenstone in lithofacies 1) suggests rift related deposition. These rift clastics consist of two submarine turbidite-fan systems defined by thick sequences of interlayered feldspathic metasandstone and schist, separated by a region underlain of quartz-schist. Comparison of the Peters Creek Formation with known Iapetan rift clastics in the central Appalachians of Virginia suggests the Peters Creek deposits are also related to Iapetan rifting. Transpressional structural models have been applied to oblique convergence tectonics, with the coeval development of contractional and transcurrent structures. Late Paleozoic post-Taconian deformation in the north-central Appalachian Piedmont of Pennsylvania and Maryland is characterized by two stages of dextral transpression. Stage one comprises a map-scale ductile conjugate shear zone pair (the Rosemont and Crum Creek shear zones) that developed at amphibolite facies. These conjugate shear zones were later overprinted, during stage two, by greenschist facies dextral shear zones that flank broad upright antiforms. Conjugate shear-pair criteria were applied to these structures to constrain the paleo-principal compressive stress orientations. During stage one σ1 and σ3 were shallowly plunging, with σ2 steeply plunging. During stage two σ1 and σ2 were shallowly plunging, with σ3 steeply plunging. The structural evolution and associated change in stress array suggests unroofing during transpression, consistent with the decrease in metamorphic grade. Post-transpressional deformation produced a pair of conjugate cleavages in the lower Susquehanna River region, and determined orientations of the principal compressive stresses suggest Late Paleozoic extension, possibly related to gravitational collapse. Previously published orthogonal collision and tectonic assembly models for the north-central Appalachian Piedmont are incompatible with the new data. Oblique collision tectonics resulted in complex dextral transpressional deformation and large orogen parallel displacement of crustal blocks. Tectonic models that do not include the transpressional orogen component of the tectonic history should be seriously reconsidered. / Ph. D.

Investigated in this research was the effect of different shoulder positions on different sleeve/bodice structures. Since a sleeve/bodice may have numerous variations and design details incorporated into the structure, this research concentrated on the set-in sleeve, kimono sleeve, raglan sleeve, and kimono sleeve with gusset. The variables used to determine the reaction of the different structures to different shoulder positions were garment slippage away from the wrist, the waist, the center back/waistline positions, and the angle formed by the center back/waistline intersection. A Factorial ANOVA was used to test for significant differences between the sleeve/bodice structures and shoulder positions. A Tukey's pairwise comparison was used to determined the difference between the slippage at each shoulder position and each sleeve/bodice structure compared with each of the others. Regression equations were fit as linear, quadratic and their interactions with each sleeve/bodice structure. Based on the theoretical framework, the amount and location of the slippage found in the statistical analyses was not necessarily those predicted. From the analyses, it was determined that when comparing the slippage at the wrist, waist, center back/waistline location and the center/back angle as a whole, general trends which occurred in the data were that the set-in sleeve consistently exhibited the greatest amount of slippage and the kimono sleeve exhibited the least. From the plots of the regression coefficients, the amount of slippage illustrated for the raglan sleeve was of similar slope to that of the set-in sleeve, whereas the kimono sleeve with gusset was more closely related to the slippage of the kimono sleeve. The results of this study provide information that other clothing designers may find useful when developing sleeve/bodice structures based on specific shoulder positions. From known shoulder positions, a designer may determine which sleeve/bodice structure would exhibit the least or most garment slippage, or be able to predict the amount of garment slippage for a specific structure. / Ph. D.