COAL MEASURES. 



139 



mouth of Six-Mile Creek, 6 miles north of Owosso. In the bluffs of 

 the Shiawassee River we observe the lower part formed of blue 

 shales, with seams of sand rock and abundant concretions of kid- 

 ney ore ; the top is drift with a considerable intermixture of 

 angular debris from the underlying strata. Under the shale, emerg- 

 ing a few feet above the water and partly submerged, are layers 

 of a black, shaly lime rock, visible in a thickness of 4 or 5 feet, 

 containing numerous fossils, partly in calcified, partly in pyritous 

 condition ; particularly observable is a large nodose Nautilus, de- 

 scribed by Meek and Worthen under two different names, N. latus 

 and N. Winslowi. A large Orthoceras is quite common, and other 

 forms are Spirifer cumeratus, Productus nanus, a Spirigera, Cho- 

 netes, Myalina, Platyceras, Bellerophon, Crinoid stems, and com- 

 pressed specimens of a Zaphrentis. 



The same limestone is seen a quarter of a mile off in the 

 bed of Six-Mile Creek ; its ledges are there more even-bedded flag- 

 stones, less shaly than those seen in the Shiawassee River. Close 

 under the lime rock is a 15-inch bed of coal, quantities of which 

 have been taken from the river bed when the water is very low. 

 The coal reposes on a soft, plastic clay of greenish-white color, which 

 incloses stems of Stigmaria and large, calcareous, nodular masses of 

 cone-in-cone structure. Stems of Stigmaria are also found in the 

 upper shales of the bluffs and in the geodes, when split open fronds 

 of ferns are sometimes found, but their occurrence is rare. A few 

 steps from the mouth of Six-Mile Creek, some parties made an 

 experimental shaft about 30 feet deep, and from that point drilled 

 to 100 feet below the surface. From the material thrown out of the 

 shaft, I see that shales of various color, with seams of sand rock 

 and conglomerate, besides an abundance of kidney ore, compose 

 the surface layers as far as the shaft went. Mr. Ott, the owner of 

 the land, informed me that four beds of coal, amounting in all to 

 1 1 feet, were found in the boring. He gave the same account 

 to Prof. Winchell, who has described in his report for 1861 the de- 

 tails communicated to him, to which record I refer the reader. 

 The record in itself is somewhat doubtful, and the hesitation to 

 take it as a true representation of facts is increased by the subse- 

 quent acts of the discoverers of so rich coal deposits (11 feet 

 within a vertical thickness of 20 feet of strata). Mr. Ott ends his 



