X The 27th, July 27 '99. Black Shale 681. About half way between Indian Creek and Long Bottom Island, a little near to Indian Creek a short distance from reaching the strung bed in the right, the fol- dowing section is shown. 36 ft. Black Shale D, 6ft of binnish rock in face of B.E.D. 48 1/2, Madison beds. More thin C, lodded below and some layers more in massive layers 3-12 in. thick near top, 16 1/2 ft. soft shales with about-B, dunt fossils at base. 91 32 3/4 ft. of massive clay stone with limestone in irregularly defined horizontal patches (early madison?) 74 3/4 A 42 1/2 ft. of bedded limestone with clay partings, the latter then still hard forming a clay rock in which the limestone occurs as layers. Rich mud A. Portelno, Caliprato, A. occidentalis Lamellibranchia, Murchisonia, Bucania. B. Section above face not exposed. C. This is the appearance the Madr- sion bed should have of this bed turned to a gentle plane limestone. The lime- stone is very dense, very fine grained of medium then rather light blue color, when weathered it shows that it is made up of very thin bedded layers. X Thursday hanging together, it is practically impossible to see but I found in it one specimen of Lingula? sps. Does this indicate Lower Upper Silurian age. at trip = The occurrence of quite typical Mad- ison beds on the clayey beds with few regular limestone layers, which I have suspected to be Madison further up the river at a number of points is very interesting. Does this mean that the Madison does not become fossiliferous when folded horizontally in an exposure or exposure? at face of Black Shale is a brown- ish sandy appearing rock which when freshly fractured appears as though it might be the base of the Black Shale here, corresponding to the greenish mure clayey beds seen in the range of the Black shale in the section half way between Greasy Creek + Belk Island. See 8th page preceding this. The very thin bedding shown by this binnish rock is especially characteristic, and suggests relationship to a shaly rock, and as I suppose from previous sections, to the base of the Black Shale. See 4th page following. 7