306 ASHLEY — GEOLOGY OF ARKANSAS. [May 13, 



relation, it may be said that there occur deposits of approximately 

 the same age and of the same character in Alabama, Mississippi, 

 Texas and Indian Territory.^ 



Age of the Gravel. — No fossils have been found in these gravels, 

 so that the only determination of their age possible is by their 

 stratigraphic position. They lie unconformably on the Paleozoic 

 and Cretaceous. Similar gravels overlie the Tertiary, and are 

 therefore of more recent origin, and on that account the age of the 

 gravels is given as Post-Tertiary.^ 



X. Economic Geology. 



Minerals and Stones. 



Minerals. — Many have been led by the disturbed condition of 

 the layers all over this area to think that mineral of some kind 

 must exist here in quantity. Much prospecting has been done and 

 many thousands of dollars expended in sinking shafts and prospect 

 holes, but all without results, except in a small belt in the northern 

 part of Sevier county. For convenience it may be well to consider 

 first this belt which is known as the antimony district. 



The Antimony District. 



The ores found in this district have been discussed in the Sur- 

 vey's report on Gold and Silver, to which the reader is referred,^ 

 As Prof. Comstock misinterpreted the structure in this district, it 

 may be well to state that more fully. 



Extent of the Antimony District. — As defined by localities in 

 which ore has has been found, the antimony district lies entirely in 



^Tuomey, Second Biennial Report on Geology of Alabama, 1858, p. 144. 

 Hilgard, Report on the Geology and Agriculture of the State of Mississippi, 

 i860, pp. 3-46. Hilgard, Anier. Jour, of Sci., May, 1866. Geo I. Surv. of 

 Ark., Rep. for 1888, VoL ii, pp. 43-47. 



2 Mr. Ashley's paper was written before the publication of the report on the 

 Tertiary of Arkansas by Professor Harris. The latter author has, in my opinion, 

 solved the problem of the age of these gravels. He regards them as shore de- 

 posits " laid down under similar conditions, though by no means in the same 

 geological epoch," and he thinks that their " rearrangement presumably took 

 place before the close of the epoch represented by the underlying stratified beds." 

 See An. Rep. Geo I. Surv. Ark. for 1892, Vol. ii, 7-9. The Tertiary Geology of 

 Southern Arkansas. By Gilbert D, Harris. — J. C. Branner. 



3 Geol. Surv. of Ark., Rep. for 1888, Vol. i, p. 136, et seq. See also Wait^ 

 Trans, of Am. Inst, of Mining Eng., Vol. viii, 1879-1880, pp. 42-52. 



