st. JOHN.] MESOZOICS—BULL LAKE FORK. 247 
No. 20. Drab shales, 15 to 20 feet. 
No. 21. Dark gray fragmentary limestone, with obscure remains of 
fossils, 1 foot, +. 
No. 22. Drab clays with lamine of calcite or gypsum, 15 to 20 feet. 
No. 23. Dark gray fragmentary limestone, 4 feet, +. 
No. 24. Drab shales with thin beds of light-gray sandstone, 170 
feet, +. 
No. 25. Gray, buff weathered soft sandstone, in part thin-bedded, with 
soft flagging layers, forming mural exposures in crest of spur-ridge, 
showing a thickness of 20 to 30 feet, dip 19° to 239, N. 42° HK. Upper 
layers contain casts of several Lam llibranchiate shells, probably rep- 
resentatives of Jurassic forms. 
No. 26. a, red and drab shales, alternating; b, pale-red shales; ¢, 
chocolate-red shales and thin sandstone layers, alternating. This hor- 
izon presents a beautiful variegated belt in the steep slopes of spur- 
ridge, and probably attains a thickness of 300 feet, +. 
No. 27. Soft-white or light-buff sandstone, 10 to 15 feet. 
No. 28. Light and chocolate-drab shales, banded with thin indurated 
layers resting upon red shales, 250 feet, +. 
No. 29. Buff sandstone, forming a heavy ledge in crest of spur-ridge, 
25 feet, +. : 
No. 30. a, alternating layers buff sandstone and drab clays, with fu- 
coidal (?) impressions, 20 feet, + ; b, brownish-drab shales, with sel- 
enite ; ¢, banded brown, yellow, blue, and dark, gritty shales and thin 
sandstone layers, 200 feet, +. 
No. 31. Rather firm, light-gray, buff-weathered sandstone, 5 feet, + ; 
dip 18° N. 23° HB. 
No. 32. Dark-drab and bluish shales with selenite and thin bands of 
efflorescence, and in lower part a dark fragmentary calcareous layer 
perhaps 2 feet thick, 400 feet, +. 
No. 33. Shaly and concretionary, fragmentary, dark-blue limestone, 5 
to 10 feet. Contains fragmentary remains of Teliost fish-scales, &c., re- 
sembling and probably identical with forms elsewhere occurring in the 
Colorado group of the Cretaceous. 
No. 34. Drab clays and thin indurated layers, containing fish remains 
like those in No. 33, 110 feet, +. 
No. 35. Rusty weathered, gray sandstone with clay partings, 60 feet, 
+, exposed in bluffs about opposite the head of Bull Lake. Locally 
shows the following subdivisions: a, at base bluish-gray sandstone, 5 
feet exposed; b, space with drab shales, 15 feet; c, thin-bedded gray 
sandstone, 5 feet; d, space, 15 feet; e, bluish-gray sandstone, 5 feet, +; 
fp brown shales, 5 feet; g, gray sandstone with fucoid-like markings, 10 
eet, -. 
No. 36. Rusty-yellow sandstone, and sandy and brown gritty shales, 
dark flint nodules in upper layer, 30 to 40 feet. 
No. 37. White, very fine clays, 8 feet, +, forming a conspicuous 
band in the bluff exposures. 
No. 38. Drab shales with layers of rusty sandstone below, selenite 
and white efflorescence above, 30 feet, +. 
; a 0. om Yellow buff, soft sandstone, heavy bed, dip 15°, N. 42° H., 80 
eet, +. 
No. 40. Light-drab clays with white efflorescence, imperfectly exposed, 
40 feet, +. 
No. 41. Light-gray, thin-bedded sandstone, 6 feet, +. 
No. 42. a, Light-drab clay, with white efflorescence ; b, banded dark- 
drab clay, with brown carbonaceous, shaly bands; c, light-drab sandy 
clay. .175 feet, +. 
