Alameda - Rt. 40 Hogback. AIN-58-19 Recheck on clays - numbers on photo in red. 1 Pit, abandoned, surface-mined, in split of main bed. Main bed is cut out or nearly so. About 1' with basal bentonite. 2 Solution continues as at 1 with lower split in as very siltstn - and pass above 2 ss legde then thin split piece main clay bed. Then Dakota ss 12 -odd(black) numbers. Here the air hole is in the lower split. main bed air shaft Dak. < split 1st Glen. SS Under lower split is typical 1st Glen. ss., with silty zones locally making "claybed-like swales. 3 3 Dakota caps ridge. Main bed? still very thin no bentonite. Split thick but usual silty silt Blish (Main bed) ss < platy ss. silty sh+ siltstn- ( lower split.. 1st Glen.ss Just to S. 1st Glenn, thickens split pinched out, Dakota comes down on top 1st ss. All clay beds out - solid ss to base 1st Glen. Dak - 1st Glen ss contact discernible because of diff. lith's. Dak massive X bed. 19.