Dimensional Grain Orientation and Preliminary Radiographic Studies of the Sandstones from the Finger Lakes Stone Quarry

Abstract

<p> Interbedded turbidite sandstones and shales of the Sonyea Group are exposed in the Finger Lakes Stone Quarry near Ithaca, New York. In 28% of the samples studied the orientation of the grains was not significantly different from a uniform distribution. These distributions included some that were bimodal and some obtained from a bed showing cross-stratification. In 60% of the samples the grain orientations could be considered parallel to the flute marks. As the top of the massive interval was approached the grain orientation became increasingly aligned with the flute marks. A difference of 14° was found between the vector means of the flute and tool marks. </p> <p> Radiographs made of rock slabs cut from the samples used in grain orientation determinations frequently failed to show internal structures even though these were visible in the samples. A radiograph of one sample (02-08) showed cross-bedding, not visible in the sample or slab. The absence of internal structures in a radiograph do not exclude their being present. </p>