6 to 8 ft throught crop between AIN-50-21,9, and 13, but only exposed at intervals. To north of 9 it is thinner, to south of 13 it contains increasing#silty, ferruginous layers, the latter but no good exposures as it is covered. Kessler 1st Glencairn sandstone shows unusual variation. In N½ of hogback it is thinbedded and grossly crossbedded, featuring rapid lateral changes with channels coming in and out. These include 2 shaly and/or silty lenses (both in at AIN-50-19,17) near northend hogback, presence of which probably responsible for swale at 17 thru weakening of ridge crest. From just south of Alameda highway to AIN-50-21,2, it is crest forming sandstone south of AIN-50-21,2, it lies mostly below the crest and SS above 1st Glencairn clay carries crest; exception between 4 and 6 of AIN-50-21. Van Bippule 1st Glencairn shale.- horizon can be identified along most of hogback by bentonite-like layer near base and relative -stratigraphic position. "Bentonite" locally flinty to study, but persistent. In some places, especially in south end, the lower split of this bed is present and it not always possible to distinguish between the two. At no place is this clay of meetable thickness - or even as much as 4' thick. Shales above 1st Glencairn.- Some of the thin clays above main bed locally present. These are separated from mid-Dzhata 23