GEOLOGICAL SURVEYS IN ALABAMA. 28/ 



existence, within the Coal Measures, of certain areas heretofore 

 untried, in which the mining of coal will undoubtedly be profit- 

 able ; it has pointed out a source of wealth in the phosphatic 

 marls of certain sections ; it has shown that gold may be mined 

 with profit at many points within our limits ; it has demonstrated 

 the fact that clays suitable for the manufacture of fine porcelain 

 ware, fire-brick, tiles, and other articles, occur in practically 

 limitless quantity in many sections ; it has pointed out the local- 

 ities where good marbles and building stones may be had for the 

 quarrying ; all these have as yet not been turned to account. 



Ufisolved problems. — Of the problems of geological interest, 

 developed in the course of the survey but not yet settled, I may 

 mention the following : The stratigraphic relations of some of 

 our Lower Cambrian formations are still uncertain ; the relations 

 between the formations of unquestioned Cambrian age, and the 

 gold-bearing semi-crystalline strata adjacent to them and in some 

 instances interlocking, are yet to be definitely fixed ; the correla- 

 tion of the seams of our three coal fields is still an unsolved 

 problem, at least 'in its details. 



Work yet to be done. — After the issue of the publications now 

 in hand, the most important items of work proposed, are i) The 

 accurate mapping of the outcrops of all the coal seams of eco- 

 nomic importance. The finishing of two or three of the sheets of 

 the U. S. topographical survey will render this comparatively 

 easy. 2) The preparation of county maps on the scale of half 

 an inch to the mile, with accurate locations of all mineral 

 deposits, mines, etc., as well as of the geological formations. 3) 

 A republication, or rather a new edition, of the Agricultural 

 report, with a map showing the distribution of the soil varieties. 

 4) An investigation of the water supply of the Coastal plain 

 region, with special reference to Artesian borings. Much of the 

 material for this is already in hand and in part published. 



Eugene Allen Smith. 



