392 BRUCE WADE 



Cypress, McNairy County. Clay is mined from the McNairy 

 sand at several localities in Carroll and Henry counties.^ Con- 

 spicuous large masses of quartzite or very hard, fine-grained, white 

 sandstone of irregular occurrence are found at several isolated 

 localities in Henderson, Carroll, and Henry counties in the lower 

 part of the McNairy sand member. The more important quartzite 

 localities are shown on the accompanying map and section. These 

 masses are exceedingly resistant to erosive agencies and are often 

 left lying bare on the surface after the softer sands and clays which 

 formerly inclosed these masses have been washed away. They occur 

 in irregular, cavernous, and often grotesque shapes that attract 

 the attention of travelers and the natives in these regions. The 

 well-known "hollow rock" at Hollow Rock Junction in Carroll 

 County has served as a landmark since early settlers first went into 

 that part of the state. The most extensive occurrences of this 

 quartzite are two miles south of Dollar in Carroll County where 

 masses as large as a two-story house may be observed in an area 

 of two or three square miles. The origin of these masses is due to 

 the cementation of local accumulations of very fine and pure quartz 

 sands deposited along with the other McNairy sediments. Large 

 masses of highly ferruginous hard sandstones are common in the 

 Ripley, but the quartzites under discussion are characterized by a 

 very low iron content. Similar occurrences of quartzites are known 

 in the Eocene of Tennessee, Arkansas, and Mississippi. 



Fossils are quite rare in the McNairy sand, and the few that 

 have been known until quite recently were about twelve species 

 of plants collected from near Selmer^ and Big Cut^ in McNairy 

 County and three species from the southeastern part of Henry 

 County.^ In 191 9 Schroeder noted the abundance of fossil leaf 

 impressions in the Cooper clay pit^ near Hollow Rock, Carroll 

 County, but made- no collection of these plants. During the latter 

 part of the summer of 1919 the writer made large collections of 



^ W. A. Nelson, Tmn. Geol. Sur. Bull. No. 5 (1911). 



= E. W. Berry, Torrey Bot. Club Bull. 43, pp. 283-304 (1916); U.S.G.S. Prof. 

 Paper 112, pp. 38, 39 (1919)- 



3R. A. Schroeder, "Res. of Tenn.," Tenn. Geol. Sur., Vol. IX, No. 2 (1919), 

 p. 154. 



