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BULLETIN 64, UNITED STATES NATIONAL MUSEUM. 



to execute it. In no place have I been received with more kindness than in Nash- 

 ville. Even soon after my arrival in your city the board of trustees of your University 

 established the professorship of mineralogy and geology which they conferred on me. 

 I have ever found amongst you my most cordial friends. 



This work treats of animals which innumerable ages ago inhabited this globe. Their 

 remains are found dispersed through the rocks of which you construct your dwellings. 

 No state or country of the same extent is as rich in these productions as the State of 

 Tennessee, and to spread the name of my adopted state amongst the scientific world 

 was my principal aim. 



With much consideration and gratitude, 



Your humble servant, G. Troost. 



INTRODUCTORY. 



When 25 years ago I entered for the first time the State of Tennessee, a country, 

 according to the map of Mr. W. Maclure, composed of recent strata from its most eastern 

 limit to its most western boundary, the Mississippi River, I was very much surprised 

 to find in the vicinity of Nashville, the centre of the State and about 300 miles from 

 the eastern limit, fossils which belonged to a formation which was then called Gray- 

 wacke or Transition formation, and my subsequent excursions towards the eastern 

 limit showed me at several places, as at the Roan Mountains in Carter County, that 

 even the Crystalline rocks, such as granite [gneiss] existed in this state, while the 

 Cretaceous and Green Sand strata, characterized by Exogyra costata, Gryphaea, Ham- 

 ites, extended towards the Mississippi, forming near Memphis the very bank of this 

 river. « I have therefore thought proper to commence this Monograph by a general 

 outline of the Geology of the state in which the Crinoids described were found. 



The fossiliferous strata west of the Appalachian Mountains, a ramification of which 

 separates the State of Tennessee from that of North Carolina, whilst several subordi- 

 nate branches of it traverse Tennessee from north east to south west, & are separated 

 from the Crystalline or primordial rocks by the principal or highest ridge of this Appa- 

 lachian chain. The highest elevation is the Smoky Mountain, which forms the 

 boundary between Tennessee and North Carolina, and is a continuation of the Appa- 

 lachian. It is granitic to about where the Tennessee river enters into Tennessee, in 

 the County of Monroe, c The western slope of the mountain in this county is com- 

 posed of psammite or slate, which forms here the highest ridge and assumes the name 

 of Unaka Mountain, continuing into McMinn County, where the primordial rocks 

 again enter the State of Tennessee, running to the Amoce River where they are again 

 replaced by psammitic rocks. The line of junction of these two formations is almost 

 the same as the boundary which separates South Carolina from the State of Tennessee. 



a The bluffs at Memphis are now known to be of Quaternary age, mainly Loess. 

 From the list of fossils given it is evidently the Selma clay to which Doctor Troost 

 refers, and outcrops of this formation are not reported west of McNairy and Henderson 

 counties in southern Tennessee. — E. W. 



& The Cumberland Mountains are a group which enters the State of Tennessee at the 

 Cumberland Gap, traverses Tennessee from northeast to southwest, and forms in this 

 state several ramifications which are called Walden's Ridge, Clinch Mountains, Stone 

 Mountain, Cumberland Mountains, Crab-orchard Mountains, and several other minor 

 ramifications which terminate partly in the State of Tennessee and partly in Alabama 

 where they form the Raccoon, Look-out, and several other mountains. — Troost. 



cThe greater part of the Smoky Mountain range is of slates and conglomerates 

 referred to the "Ocoee" series. The nearest exposures of the highly crystalline rocks, 

 constituting the Metamorphic Group of Safford, appear to the north in a small area 

 near the state line in Cocke County, and to the southwest in Monroe County where 

 the Tellico River crosses the range. — E. W. 



