7427 W-12-Corzel Creek Approx measurement foss zone base Lakota (more down) 2.0+ Massive ss ledgy 7.0+ Tan to gray clstn becoming shelly at base. 2.0+ Avgill limestone - Fossilit, snails ostreocods, chavophytes. 1.6 Clzystone, gray with greenish cast, becoming calc downward + grading into ls below 0.8 Limestone, argilaceous, grading to limy clstn at top -Sample W-57-1- 0.8 is and lower 0.6 of claystone above. 2.0 Silty, blocky gray claystone; upper 1.0+ weathers to OB silt. May be calc. Sample W-57-2.-Most of it from somewhat shelly-breaking base? 0.6. 2.3 Blocky calc? gray clzystone with thin 0.1-0.5 lenses avgill limestone Sample W-57-3 3