Abstract
Orientations of quartz optic axes and poles to deformation lamellae from each of five specimens from a single layer of Tuscarora Sandstone in a minor concentric fold exposed in the Delaware Water Gap define fabric axes a <sub>n</sub> , b <sub>n</sub> , and c <sub>n</sub> as described in Ingerson and Tuttle (1945) and Riley (1947). In all specimens, b <sub>n</sub> parallels the Sander fabric axis b, but all a <sub>n</sub> and c <sub>n</sub> axes do not parallel Sander axes a and c. For the lamellae to have formed late in the folding process, principal stress axes would have to have been refracted through inordinately large angles, hence the lamellae formed either before or early in the process of folding and were passively rotated into their present orientation. Fabric axis a <sub>n</sub> can parallel stress axes sigma <sub>1</sub> , or sigma <sub>3</sub> , and c <sub>n</sub> can parallel sigma <sub>1</sub> or sigma <sub>3</sub> ; in these specimens a <sub>n</sub> parallels sigma <sub>3</sub> and c <sub>n</sub> , sigma <sub>1</sub> .
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