I rather think the Penn. Quarry did not make out the structure and therefore got their thicknesses to guess. The structure is as follows: Along Penn. Railway Oreida Lower Oreidian Shales. White Oreidian Qs. Upper Oreidian Shales Schuelker Rim. Delvin Red Cl. The Oreida - Hawangunk contact is as follows: H.R. Shales and SS. H.R. Sh. H.R. Oreids H.R. SS. Oreida. Spruce fault Pine Point Fault Oreida - Hawangunk. A white to grey leavy bedded quartzite, even bedded and with axes through, in the lower 418 feet, where the pellets are of to 3/16 inch; higher up we see them only on the bedding planes. The Penn. Quarry gives the thickness as 205 feet and this is correct as may be seen on the Penn. A.R. cuts.