-142- Section 7 contd. Thickness (feet) 21. Calcirudite, with chert cobbles near base, grades upwards into calcarenite in up- per 6 inches, planar siliceous upper surface, A coll. 7-21. 7 1/2 20. Sandstone, unit 15 4 1/2 19. Limestone, gray weathering, biothermal with brown chert pebbles, upper 2 feet cal- carenite with planar upper surface, siliceous brown cap, coll. 7-19 6 18. Calcarenite, like 16 2 17. Sandstone, brown weathering, upper surface irregular and apparently eroded before deposition of unit 18 1/2 16. Calcarenite, brown weathering, organic fragmental particles up to 2 inches in diameter 1 15. Sandstone, light brown, 1/16 to 1/2 inch beds. 7 14. Calcirudite, gray weathering, grading upward into a calcarenite of algal, sponge, and fusulinid fragments, 6 13. Covered, probably brown siltstones and sand- stones 6 12. Calcarenite, medium gray weathering, organic fragmental, 2 foot beds, coll. 7-12 6