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186 Association of American Geologists. 
toa large extent of ores of copper, and even of copper in a native state. 
This was observed only in close proximity to considerable veins. 
The veins, as well as different portions of the same vein, are very vati- 
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 unl 
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 Pro. 
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. 
r. Hodge and Mr. Trego, who had explored that portion of 
this basin which extends into Pennsylvania, also made some Te 
marks in which they differed from the views of Prof. Johnso0; 
particularly with regard to his opinion that some of the uppet 
strata of the carboniferous rocks near the Savage Mountain, rest 
unconformably upon the lower ones. 
r. Hodge placed on the table some clay concretions from 
Kennebec river. 
On motion of Dr. Beck, Resolved, That when this Associatio? 
terminates its present session, it adjourn to meet in Boston, on tb 
Monday in April next. 
Dr. Jackson, Prof. Hitchcock, and Mr. Moses B. Williams; 
were appointed a local committee, (pursuant to a resolution te 
