Stevenson.] ^^^ [Oct. 7, 



haps the extreme, for the mass is not invariably a compact sandstone, but 

 often shows great beds of sandy shale, sometimes even clay shale, the 

 whole merging into the clay beds or beds of passage to the Fort Pierre 

 shales. 



JVeioland Greek. This is the next stream southward and makes a canon 

 across the whole of the field. But no detailed examinations were made 

 there. A distinct though gradual rise of the whole basin southward car- 

 ries out the highest members of the series before Newland creek is reached, 

 so that almost midway in the basin, the great sandstone with Halymenites is 

 at the top of the mesa. The measures above that sandstone are probably 

 not more than 150 feet thick and no exposures were found to yield a sec- 

 tion. Mr. BoAvie's observations along the eastern face of the field at and 

 beyond Newland creek show that the coal beds become thicker than they 

 are further north, as indeed is suggested by the section in Bailey's gulch. 

 A thick bed is worked on a tributary to Newland creek, which Mr. Bowie 

 thinks is equivalent to the Shaw coal. The section of the bed as given by 

 him is : 



Coal 1' 8" 



Clay 0/7" 



Coal 2' 



Shale V 2" 



Coal 1' 



Relations of this field. * 



Careful search was made everywhere for fossil remains, but nothing was 

 found aside from the fucoid, Halymenites major, and some palm leaves. 

 Halymenites occurs abundantly in the sandstone overlying Coal bed H, 

 and a few specimens were observed in the sandstone at the base of the 

 series, which was examined at but two localities. The palm leaves were 

 obtained in the Rockvale shaft, at fully one hundred feet below Coal bed 

 H. The thickness of measures included between the upper and lower 

 limits of the fucoid is more than four hundred feet. 



This distribution of the fucoid is of no little interest. The writer* has 

 shO/Wn that along the South Platte river, north from Denver, Halymenites 

 occurs throughout a great mass of sandstone, where it is associated with 

 forms proving the rock to belong to the Fox Hills group of the Upper 

 Cretaceous. Dicotyledonous leaves occur there in the same sandstone. 



In the Trinidad coal-field of southern Colorado and northern New 

 Mexico, the writerf recognized a persistent sandstone, 60 to 80 feet thick, 

 a. marking the base of Laramie group. This sandstone, which occasion- 

 ally holds a coal bed, contains Halymenites major in i^rofusion, while that 

 fossil occurs neither above nor below this horizon. At one locality, the 

 the sandstone contains a Cai-dium-Yike mollusk, but the specimens obtain- 

 ed are too indiff"erent for specific determination. 



* Am. Journ. of Science, 3rd Series, To], xvii, p. 370. 

 t Amer. Journ. of Science, 3rd Series, Vol. xviii, p. 132. 



