304 REPORT OF NATIONAL MUSEUM, 1904. 



Troost's fourth report appeared in ls:;7, in form of :i pamphlet of 

 37 pages. Of these the first 2<> were given up to a general exposition 

 of geology, as he understood it. This was followed by a description of 

 that part of the State lying south of the Hiwassee 

 Report s /837 rth River and east of the Tennessee, and known as the Ocoee 

 district. A map of this district and a colored geolog- 

 ical section were given, the latter extending in a general northeast 

 to southwest direction from the Tennessee River to a point near 

 Nicajack. The entire area to the point of the intersection of the Chatta- 

 nooga Creek was colored as occupied by "grauwacke," with outcrops 

 of primordial limestone coming to the surface near Coqua Creek. The 

 region to the west of Chattanooga Creek was represented as underlaid 

 by mountain limestone, with the Coal Measures forming Lookout 

 Mountain and Raccoon Mountain. These Carboniferous rocks, it 

 should be noted, were indicated as unconformable with all other rocks 

 of the region. 



The iifth annual report was made November, 1839, and comprised 

 all told 75 pages, including an appendix. This was accompanied by 

 a colored geological map of the State, the first which had thus far 

 appeared, and also a colored section across the entire 

 An n ua'i S Report. State from Roane Mountain, in Carter County, to 



Randolph, on the Mississippi. On this map the Roane 

 Mountain rock was colored as primordial, mostly granite. An area 

 from and including the Smoky Mountains to a point a little Avest of 

 Kingston, on the Clinch River, was colored as transition, composed 

 of graywacke, slate, limestone, and sandstone, all alternating with each 

 other, and in strata highly inclined and dipping toward the southeast. 

 From the last-named point to the Tennessee River the country was 

 stated to be underlaid by mountain limestone horizontally stratified, 

 upon which rested the Cumberland Mountains, composed of Coal- 

 Measure rocks, mostly horizontally stratified, and the Buffalo and 

 Harpeth hills, just east of the Tennessee River, which were put down 

 as formed of siliceous strata, assuming sometimes an earthy appear- 

 ance, sometimes that of chert, and horizontally stratified. 



The region west of the Tennessee was given as mostly occupied by 

 secondary strata composed of Cretaceous marl, greensand, and clay, 

 horizontally stratified. 



It should be noted that Troost, while seemingly recognizing the 

 importance of the fossils carried by the rocks of various ages, did not 

 attempt to utilize them systematically as means of correlation. On 

 page IS, however, he w T rote: 



The lowest pari of the stratum, where it is near the encrinital limestone, often 

 contains members of Encrinites, anil other fossils of thai stratum, and arc invariably 

 <>f a calcareous nature. This shows that the formation of those siliceous strata is 

 more or less contemporaneous with the encrinital strata. 



