6 ANNUAL EEPOET SMITHSONIAN INSTITUTION, 1915. 



STRATIGRAPHIC STUDIES IN CENTRAL TENNESSEE. 



Under the joint auspices of the United States Geological Survey 

 and the United States National Museum Dr. E. O. Ulrich and Dr. 

 R. S. Bassler, of the Museum, were engaged for several weeks dur- 

 ing the summer of 1914 in a study of debated points in the stratig- 

 raphy of the Central Basin of Tennessee with a view to determine 

 accurately the division line between the Chazyan and Black River 

 groups and to secure additional information on the black shale 

 problem. 



The well-laiown marble beds of east Tennessee and associated 

 shales and sandstones of Upper Chazyan age, with a thickness of 

 over 3,000 feet, have never been found in central Tennessee or, in 

 fact, in any area west of the Appalachian Valley. The first problem 

 was therefore to determine either the corresponding rocks in the 

 more western areas or, if such strata were wanting, to discover the 

 unconformity representing this great thiclaiess. It was found that 

 the Lower Chazyan or Stones River rocks of central Tennessee are 

 succeeded directly by the lowest Black River or Lowville formation, 

 and central Tennessee therefore was presumably a land area during 

 the time of deposition of the celebrated east Tennessee marbles. 



The second problem entailed further work on the determination of 

 the age of the widespread Chattanooga black shale, which previously 

 had been considered to be middle to late Devonian. In recent years 

 this determination had been questioned, and facts had accumulated 

 showing it to be of younger age. Two features of considerable sig- 

 nificance in this problem were the discoveries in northern Tennessee, 

 where the shale is well exposed, that (1) this black shale passes with- 

 out a discernible break into the overlying Mississippian (Kinder- 

 hook) shales, and (2) that the fossils of this overlying shale are of 

 late instead of early Kinderhook age. As a result of this work good 

 collections of several well-preserved faunas were added to the Mu- 

 seum collection. 



FOSSIL ECHIN0DERM8 IN WESTERN NEAV YORK. 



Field work carried on during the summer of 1914 under the super- 

 vision of Mr. Frank Springer, for the purpose of adding to the 

 Springer collection of fossil echinoderms in the Museum, was devoted 

 mainly to a careful examination of Silurian rocks exposed along the 

 new Erie Canal in western New York, especially the waste material 

 thrown out in excavations for the canal. The most valuable speci- 

 mens from this part of New York occur in the Rochester shales of 

 Niagaran age, which weather rapidly into mud upon exposure 

 to the elements, and it was therefore necessarj'^ that the new outcrops 

 be examined at once to secure the best results. Numerous specimens 



