NO. lO SMITHSONIAN EXPLORATIONS, I923 II 



tanooga black shale, all of the ui^per Ordovician, Silurian and Devon- 

 ian strata thus being absent. 



The Highland Rim in this j)art of Tennessee is dissected by many 

 streams which carve out narrow rocky valleys opening into the Central 

 Basin. This in turn gives rise to many rock outcrops and consequent 

 opportunities for collecting fossils. Such areas, although very rough 

 in nature, contain beautiful scenery, as shown in figure 13. The High- 

 land Rim is as a rule a monotonous |)lain, but interesting scenery upon 

 it is sometimes developed along the streams where erosion has been 

 sufTicient to cut through the hard silicious limestone into the softer 

 underlying black shale. In such cases, as shown in figure 14. waterfalls 

 of considerable size are developed. This particular outcrop is also of 

 archeological interest in that the blocks of black slate shown at the 

 base of the falls furnished part of the material with which the Indians 

 built extensive mounds along the river banks. A portion of these 

 mounds known as the Stone Fort is shown in figure 15. 



In company with State Geologist Nelson and the late Mr. W. E. 

 ]\Iyer. Dr. Bassler visited the Indian earthworks along the Harpeth 

 River west of Nashville in order to study a blue-clay stratum out- 

 cropping in the mounds. Elsewhere in Tennessee this blue clay con- 

 tains mammals of Pleistocene age but here it was underlaid by strata 

 holding human remains. Therefore at first glance it seemed that defi- 

 nite results as to the age of early man in America had been discovered 

 but upon a little investigation it became evident that the Indians had 

 transported this clay from some distance and packed it down into the 

 flat layers resembling geological strata. 



The geologic work in Kentucky was financed by ]Mr. Frank Springer 

 and consisted of quarrying operations in an area of crinoid-bearing 

 strata. Although some specimens were discovered this season, the 

 main object of the work was to uncover the fossiliferous strata so 

 that weathering during the coming year would reveal the crinoids now 

 hidden in the debris. 



In southwestern Ohio, in connection with the packing of the Austin 

 collection of fossil invertebrates for shipment to the Museum. 

 Dr. Bassler. through the courtesy of Dr. George M. Austin the donor 

 of this collection, was enabled to study the geology of the Niagaran 

 plain and surrounding areas from which Dr. Austin had secured his 

 specimens. In this way a first hand knowledge of the region was 

 obtained which is now proving very useful in the study and arrange- 

 ment of the specimens in final Museum form. 



