44 THE GEOLOGIST'S TRAVELING HAND-BOOK. 



regards this coal-formation as transitional, or Lower Eocene 19. Tertiary, and in 

 the within Guide for Colorado it is called the Lignitic Group, lying between the 

 Cretaceous and Tertiary. Mr. Lesquereux is of the same opinion as to its Tertiary 

 age, but nearly all other geologists regard it as Cretaceous. 



In the annexed Guide for Wyoming and Utah, the formation is given at points 

 where the coal is mined Carbon, Separation, Black Buttes, Point of Rocks, Rock 

 Springs, and Evanston. All the coal now mined in Wyoming is, according to the 

 Guide, in the 18 d. Laramie Cretaceous, which corresponds with Hayden's Lignitic 

 beds. Every division of the Cretaceous is said to be lignitic or coal-bearing, and 

 may some day produce good coal. The Evanston beds are in the Laramie, but the 

 Coalsville beds are probably in the 18 b. Colorado Cretaceous. The Rock Creek 

 coal may be 18 c. Fox Hill. A. Hague. There is no Carboniferous coal in the far 

 west. The difference of opinion as to the age of the Lignitic or coal-bearing group, 

 arises from the fact of its lying at the transition point from the Cretaceous to the 

 Tertiary, where, as is not unusual, the fossils of both are mingled ; and the con- 

 troversy is as to precisely where the Cretaceous ends, and the Tertiary begins. 



19-20. CENOZOIC. 



19. Tertiary. The Tertiary formation of the Atlantic coast is wholly of an 

 earthy character, without solid rocks, consisting of sands and sandy blue clays, and 

 above these yellow and brown ferruginous sand ; also clays and sands imbedding 

 extensive layers of uncemented fossil shells. But as we trace them south and 

 southwest through the Southern cotton-growing states, it becomes more calcareous, 

 consisting of lead-colored sandy clays, and whitish and bluish friable limestone in 

 North and South Carolina and Eastern Georgia. West of that, the upper member 

 consists of two limestone strata, the middle of sand and sandy marl, and the lower 

 part of limestone and marl. H. D. Rogers suggests that on the Atlantic slope, 

 opposite the Appalachian Mountains, the older rocks furnished only sandy and 

 clayey sediments, and the Tertiary deposits composed of the ruins of the former, 

 are of that character ; while farther west a wide expanse of limestones fills the 

 upper valley of the Mississippi, and hence the Tertiary deposits bordering the 

 Gulf of Mexico, and extending up the Mississippi River, are of a greatly more 

 calcareous or lime-bearing character. The cotton-growing lands of the Southern 

 States are chiefly Tertiary. In the central part of the continent, the Tertiary beds 

 are lake sediments, or fresh- water deposits ; while on the west coast they are marine. 

 The Tertiary, in the southern part of New Jersey, furnishes great quantities of bog 

 iron-ore, but bog iron-ore is not peculiar to the Tertiary formation. The upper bed 

 of the green-sand of New Jersey is Tertiary. In the far-west the Tertiary strata 

 are in a greatly more indurated or rocky condition than those of the eastern coast. 

 The 19 a. Eocene consists of beds of clay and sand, with round ferruginous con- 

 cretions and numerous seams and local deposits of lignite, according to Mr. Les- 

 quereux. Also gray and ash-colored sandstone, with more or less argillaceous 

 layers. The 19 b. Miocene consists of white and light drab clays, with some beds 

 of sandstone and local layers of limestone. The 19 c. Pliocene is composed of fine, 

 loose sand, with some layers of limestone, and contains fossil bones of animals, 

 which are scarcely distinguishable from living species. 



