AIN -51-28 17. 3rd shale becoming shalyer, 2nd upper part - ?or lower part 2nd ss more platy - probable that platy top and base of 2nd ss = the 2 fossiliferous zones farther north N10W,43°E on base main chq. Main bed is 18 feet thick plus in this area. Trony zone about 10' from base, Basal bentonite and ripple marked ss. 19 Partial section of clay complex. Top 12't OF 2nd ss is thin bed x bedded resembling 1st ss. Section starts at top of this ss - surface locally rippled marked) grossly x bedded - 6