52 



the valuable bituminous coal of eastern Virginia, is of itself a task 

 in which much time and industry could be advantageously em- 

 ployed. To investigate minutely the relations and character of the 

 various rocks with which the auriferous quartz of the region adja- 

 cent to the western limits of the former, is associated, and to ascer- 

 tain the number, direction and relative value of these veins, so 

 productive in the precious metal, would also be a business requiring 

 much laborious and discriminating observation ; while, in the re- 

 mainder of the district of which we are now treating, multiplied and 

 accurate researches, directed to numerous lines across its surface, 

 would be indispensable to correct views of its geological details ; to 

 the removal of the many obscurities in which its structure in nu- 

 merous points is as yet involved, and to the really useful develope- 

 ment of its great mineral and agricultural resources. In the brief 

 period allotted to the reconnoissance, therefore, the attainment of 

 much minute knowledge regarding this region was not to be antici- 

 pated, although while aiming at the determination of interesting 

 points of general inquiry, it was always deemed an important object 

 to collect useful details, calculated to throw light upon the resources 

 as well as the structure of this region. 



Before entering upon the description of the strata of primary and 

 other rocks of a very ancient character, of which this region is in 

 the main composed, it will be most convenient to treat of" the inte- 

 resting formations, including the bituminous coal of eastern Virginia 

 as well as of the sandstones overlying the tide water borders of the 

 primary. 



GEOLOGY OF THE BITUMINOUS COAL FIELD INCLUDED IN THE PRIMARY REGION. 



Of the extent and exact geographical limits of this truly interest- ■ 

 ing coal formation of eastern Virginia, too little is yet known to 

 warrant more than a few words to designate its general position 

 and relations to the other strata. We shall dwell, however, upon 

 one or two points connected with its internal structure, of great 

 moment to all those who are interested in the further developement 

 and working of its coal seams. 



It will be apparent by a reference to the general profile or 

 geological section across the state, that the sandstones and their 

 associated coal seams, which make up the formation before us, 

 rest in a narrow trough in the primary strata. Whether the 



