portant practical inquiries appertaining to the reconnoissance, as 

 much local information of a useful nature has been obtained on each 

 excursion, as was consistent with the time which could be devoted 

 to investigations of a special character. The general nature of the 

 observations contemplated in the reconnoissance, and the necessity 

 of rapid movements when so great a breadth of formations was to 

 be traversed, rendered much delay in minute local observations in- 

 expedient, on which account many points of great practical interest 

 will be excluded from the report, which might otherwise have been 

 introduced. These would be among the proper subjects for inquiry 

 in a detailed survey. 



In regard to the tide water section of the state, it is proper to 

 remark, that through some previous attention to its geology, I am 

 enabled to present a somewhat minute account of its important 

 features, as observed in several large and interesting districts which 

 I have explored. Among which, I would specify the peninsula 

 bounded by the York and James rivers, and many of the counties 

 on either side. More recently, and in connexion with the recon- 

 noissance, I have examined the country on both sides of the Pamun- 

 key, from the junction of the North and South Anna to its mouth, 

 and have extended my inquiries with some success into similar 

 formations south and north as far as the James river and the Potomac. 

 The discovery of a material likely to prove valuable to the agricul- 

 ture of that section of the state, may, without impropriety, be re- 

 ferred to as an illustration of the utility to be expected from minute 

 geological inquiries, directed to every portion of our territory. 



But in addition to the duty of exploration performed according to 

 the plan which I have now described, I have devoted some time to 

 The chemical analysis of rocks, ores, earths, marls and mineral 

 waters. In relation to this department of my duties, however, it is 

 easy to perceive, that the tedious nature of such investigations, 

 would preclude the completion of many accurate analyses within the 

 period allotted to the reconnoissance ; but a variety of useful che- 

 mical results have been obtained, which as far as compatible with 

 the scope and objects of this report will be detailed in the following 

 pages. 



v-BNERAL GEOLOGICAL DIVISION OP THE STATE. 



For the sake of exhibiting under one view, each group of analo- 

 gous formations, the whole territory of the state may be conveniently 



