442 GEOLOGICAL SURVEY OF THE TERRITORIES. 



appearing as if tliey really hold a higher horizon in the series than the 

 main coal (o) of the section. At this place these more fossiliferous beds 

 are seen in a ridge, abutting directly against the lighter-colored, more 

 massive sandstones of division 9, forming the first ridge. In following 

 this ridge along in a southwesterly direction we come suddenly to a 

 point where the more massive, lighter-colored sandstones of division 

 9 end, and we pass, almost by a single step, upon the thinner, more fos- 

 siliferous layers of division 3 ; the two divisions coming as abruptly 

 together as' if their strata had been sawed off. and placed end to end 

 against each other. Here the strike of the strata of these two divis- 

 ions is nearly the same, and the dip also of both is northwestward, but 

 those of division 3 dip at a somewhat higher angle than division 9. 



This lateral displacement of portions of these lower strata is very 

 puzzling, and had led to the conclusion that they belohg above the 

 horizon of the main coal. We were so fortunate, however, as to find 

 them cropping out at i)oints within a mile to the southeastward of the 

 coal-mine in the main bed, directly at Coalville, readily recognizable by 

 their characteristic fossils and lithological characters, and yet clearly 

 dipping under the division 4, which was, in the same way, traced along 

 the outcrops to where it is distinctly seen to dip under the main coal, 

 directly at Coalville. There can, therefore, be no question wiuitever in 

 regard' to these beds holding a position beneath the main coal-bed ; 

 that is, the lowest coal represented in the section here given. 



The determination of the position of these beds beneath this coal is 

 a matter of some little interest, because it shows that in viewing this 

 series in the ascending order, we start with a succession of highly fos- 

 siliferous beds, containing a group of forms, among which we recognize 

 the Cretaceous and older genus Inoceramus, represented by the well- 

 known Cretaceous »\){^cies ]. ijrohlcmaticus. The other fossils found in 

 these beds seem to be all new species, though several of them are uu- 

 distinguishable from forms found in the beds far above the main coal. 

 The TurriteUaixud Modiola., from thislocality, that I at onetime thought 

 probably identical with Cretaceous species from Calitornia and Texas, 

 came from these beds ; and although later comparisons have satisfied 

 me that they are new species, they are certainly very closely allied to 

 the Cretaceous forms with which I had compared them. 



Although nearly all the fossils from these beds are certainly marine 

 types, a few of them, such for instance as two or three species of Nere- 

 tina and one of Melanqnis, indicate that streams of fresh water proba- 

 bly flowed into the sea, bay, or inlet in which the marine forms lived, 

 from close-lying laud, during the deposition of these rocks. 



The local displacement of portions of the lower beds of the section at 

 Coalville, mentioned above, doubtless caused the impression at one time 

 entertained, that the dark-colored clay (division 7 of the section) con- 

 taining Inoceramus 2)rohlcmaticus, and perhai)S fragments of Ammonites, 

 seen in some of the excavations there, probably held a position beneath 

 the main coal, (division 5.) An inclined shalt, however, in course of 

 excavation directly at Coalville, during the past summer, demonstrates 

 in the clearest and most satisfactory manner that its position is above 

 the hori/.on of the sandstone forming the roof of this coal, as the shaft 

 passes first down through some 50 or more feet of this clay before it 

 strikes the sandstone immediately over this coal. Large quantities of 

 this clay were observed lying near the top of the shaft, when we were 

 at the locality, and numerous specimens of Inoceramus prohlematicus 

 were to be seen in it. 



Of course no attempt has been made to illustrate, in the accompany- 



