Measured By Condra and Upp, 1931, page 35; Schroyer limestone,Limestone, poorly exposed, cherty,Limestone, badly weathered, irregular,Limestone, dark gray, massive, uneven at top and bottom, grading into shaly lime,Limestone, shaly, slabby,Limestone, weathers slabby to shaly with Aviculopecten, etc.,Limestone, massive, irregular,Havensville shale,Shale, slabby,Shale, largely olive and gray and with some fossils,Four Mile limestone, cherty, massive, with thin shale partings,