186 Association of American Geologists. 



to a large extent of ores of copper, and even of copper in a native state. 

 This vi^as observed only in close proximity to considerable veins. 



The veins, as well as different portions of the same vein, are very vari- 

 able in their metalliferous character, portions being apparently rich, while 

 others are completely barren. With the present knowledge upon the sub- 

 ject, we can scarcely arrive at safe conclusions as to the value of these 

 veins for the purposes of mining, but upon the whole they may be looked 

 upon favorably rather than otherwise. 



Adjourned to 4 o'clock this afternoon. 



Friday, 4 o'clock, P. M. — Prof. Silliman being absent, Dr. 

 Locke was called to the chair. 



Dr. Jackson gave his views in relation to the construction of 

 geological maps, suggesting the importance of concert and uni- 

 formity in design and execution, as regards scale, coloring, sym- 

 bols, &c. on the part of the various state geologists employed 

 throughout the Union. The subject was further discussed by 

 Dr. Locke and Prof. Johnson, who concurred in the views of Dr. 

 Jackson. 



On motion of Prof. Mather, the subject was referred to a 

 committee consisting of Dr. Jackson, Dr. Locke, and Prof. 

 Mather, who are to report at the next annual session of the As- 

 sociation. 



Prof Johnson exhibited a section drawn across the Frostburg 

 coal basin, extending between the Little Alleghany and Savage 

 Mountains, a distance of about four miles. He offered some ob- 

 servations concerning this coal-field, and enlarged upon its value 

 and importance as a coal and iron region. 



Mr. Hodge and Mr. Trego, who had explored that portion of 

 this basin which extends into Pennsylvania, also made some re- 

 marks in which they differed from the views of Prof. Johnson ; 

 particularly with regard to his opinion that some of the upper 

 strata of the carboniferous rocks near the Savage Mountain, rest 

 unconformahly upon the lower ones. 



Mr. Hodge placed on the table some clay concretions from 

 Kennebec river. 



On motion of Dr. Beck, Resolved, That when this Association 

 terminates its present session, it adjourn to meet in Boston, on the 

 last Monday in April next. 



Dr. Jackson, Prof. Hitchcock, and Mr. Moses B. Williams, 

 were appointed a local committee, (pursuant to a resolution re- 



