STATE GEOLOGIST. 77 



tor Of ■ black bituminous shale. In Mr. Cauwright's well, near 



Coldwater, the upper part is also bituminous, but soon pastel 



into a plastic dark blue clay, which he has worked very exten- 

 sively in the vicinity, in the manufacture of bricks. For this 

 the kidney iron day- rally well adapted 



\ 9 have beou detected in this group in the southern 



f the State, excepl a Tfetftno, a Solen andistinguishable 



ine in the Marshall Group, a Ghonetes and a Grammijsia. 

 The bituminona character of most oi' the shales of this group, 



and especially of that portion known as the "Black Bituminous 

 Shales," has given rise to numerous misapprehensions in regard 



to thei gical relations, and has been the occasion of the 



practice of a great amount of geological quackery The pop- 

 ular opinion is, that coal must exist somewhere in the vicinity 

 of the black shales. The opportunity has been very many 

 d for discouraging explorations contemplated or 

 undertaken, under the influence of this illusion. Large tracts 

 of land have been secretly taken up, with the view of securing 

 eligibly situated coal mines. The reports so rife among the 

 Indians and their missionaries, of the occurrence of coal in 

 the neighborhood of Grand Traverse Bay, are undoubtedly 

 ible to the same illusory shale. There is not the remotest 

 probability of the occurrence of coal witl^n a hundred miles of 

 Grand Traverse Bay. This statement is made in full recollec- 

 tion of the allegation of a learned judge, that he had seen 

 anthracite coal that was said to have been collected in that region. 

 One of the localities, of Indian notoriety, is at the southern 

 extremity of Ifucqua Lake, south of Little Traverse Bay. The 

 Indians report that they have often resorted there for fuel, and 

 that they have burned the C0<& in their camp fires — a statement 

 perfectly cr< dible if we substitute ehaU for codl. 



pcMiditures have been made in the same 

 !-., Ohio and other States. 



[uivalentfl of the Huron < Jroup 



itisfactorily Bettlcd, and 



for tl ': they 1: ived a provisional, local name. 



