CARBONIFEROUS UNDIVIDED. 397 



The shaly members of the series are usually intensely crumpled, while the more massive beds 

 present broad, open folds complicated by frequent thrust faults, which make the stratigraphy 

 difficult to decipher. 



The coal-bearing formation, which is the lowest, * * * jg distinguished from the 

 overlying formation by the presence of coal beds and of fossil plants in some of the black shales 

 and clays. It is, therefore, essentially a fresh-water deposit. In one instance marine inver- 

 tebrates have been found in such position as to suggest a possible interbedding of marine sedi- 

 ments with the fresh-water deposits, but as this relation may be due to the infolding of some 

 of the overlying formations it can not be accepted as conclusive CAddence. The beds are usually 

 thin and the formation as a whole is softer than the overlying rocks. * * * 



The middle formation of the Carboniferous series * * * consists of thinly bedded 

 black slates, shales, cherts, and cherty limestones and is distinguished from the lower forma- 

 tion, which it resembles in general appearance, by the absence of coal beds or fossil flora of 

 any kind, and from the upper formation of the series, first by its lithologic character and 

 second by its fauna, which consists principally of brachiopods and moUusks, while that of the 

 upper consists principally of corals. * * * 



The upper member of this series [Lisburne formation] consists of massive thick-bedded 

 limestones, massive white cherts, and occasional thinner beds of black slate or shale and is 

 distinguished from the underlying Carboniferous formations by its lithologic character and its 

 fauna, which consists mainly of corals. The contact relation of the upper to the middle forma- 

 tion of the series is conformable in an exposure south of Cape Lewis, * * * \)^j^ j^ most 

 of the other places where the contact is exposed faulting has occurred. The thickness exposed 

 at Cape Lewis and also south at Cape Lisburne can not be regarded as less than 2,000 feet 

 and may be much greater. 



Girty "■ states regarding the age of the Lisburne formation : 



The Pennsylvanian probably occurs there, but the greater part of the beds appear to be 

 Mississippian. The Lisburne formation is in the main to be correlated, with httle doubt, with 

 the Mountain limestone of Europe and the upper Mississippian of the middle United States. 

 There appears to be an older series, however, which correlates with the lower Mississippian. 

 We have from it a few invertebrates suggesting this conclusion, among them Leptsena rhom- 

 loidalis, which is not known above the Burlington limestone, of the Mississippian. 



The section exposed along the coast south of Cape Thompson was examined 

 by Kindle,®"" who says: 



The lowest beds exposed at Cape Thompson outcrop along the beach immediately north 

 of the cliffs. The rocks exposed in these beach outcrops and the accessible or northern 

 portions of the cape cliffs are indicated by the following section: 



Section at Cape Thompson. 



Feet, 

 (d) Light-buff or cream-colored limestone with numerous fossils. Strike about north-south, 



dip variable, mostly E. 25° to 90°, complicated toward the south 500-|- 



(c) Black and buff thin-bedded limestone, the former predominating. Productus and large 



crinoid stems abundant 380 



(6) Bluish-gray to black fissile shale with abundant plant fragments. Dip E. 80° to 90°, 



strike N. 15° W '. 280 



(a) Very thin bedded lead-gray sandstone, with occasional bands of brown ferruginous chert 



and films of coal. Plant fragments abundant. Strike N. 15° W., dip E. 86° to 90° 140 



The lower 400 feet of the section appears to contain no invertebrate fossils. AH or nearly 

 all of these beds represent nonmarine sediments. Plant remains in various stages of macera- 

 tion occur through most of the shales and sandstones below the limestone. Plant fossils were 

 obtained from both a and h of the section and numbered respectively lots 5289 and 5290. These 

 were submitted to Dr. David White, whose report follows. 



o Letter of June 20, 1909, from the field. 



