b. mi Association of American Geologists. 183 
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* overspread with diluvium, still that the deposits have been going on ever 
since. Specimens were shown from, and some remarks made, concern- 
ing the gold and copper ores of Davidson and Guilford counties, N. C. 
Veins originally worked for the former, gradually passed into lodes of 
sulphuret of copper and iron, though these formed a very small part of 
the veins at the surface. Rich specimens of the double sulphurets from 
the Harlan mine, Guilford county, were exhibited, in which mine the lode 
is over ten feet thick, or the depth of one hundred and five feet, and con- 
sists almost entirely of these ores. 
Some account of King’s silver mine, Davidson county, was given, and 
specimens of the varieties of the silver ore shown. The mine was origin- 
ally worked for lead, the ore being a carbonate, very rich, and in beauti- 
ful crystals. Native silver was discovered, and the pig lead already made, 
found to contain a considerable amount of that metal. Phosphate of lead, 
copper, zinc and sulphuret of iron, were also mentioned as occurring in 
the lode, which was twelve feet thick. Some of the ore was of a soft 
light magnesian character, and though its specific gravity could not be 
twice that of water, yet it was considered a rich silver ore. 
The lode lies between granite and a magnesian rock above. All the 
metalliferous veins, it is believed, are found at the point of contact of these 
two rocks, 
Peter A. Browne, E'sq. presented to the Association a section 
of the rock strata on the Schuylkill above Philadelphia, drawn 
about the year 1825, being the first geological section made in 
the state of Pennsylvania. ; 
Dr. Houghton then made some remarks upon the subject 
of the metalliferous veins of the northern peninsula of Mich- 
igan, 
He began by remarking, that that portion of Michigan lying between 
Lakes Huron and Michigan on the south, and Lake Superior on the 
north, is known as the upper or northern peninsula, while that portion 
of the state lying south of the Straits of Mackinac, is more usually known 
as the southern or lower peninsula. f ; 
The rocks of the easterly portion of the upper peninsula, for . distance 
of one hundred and fifty miles, consist of a series of fossiliferous limestones 
and shales, resting upon sandstones, the whole dipping a few degrees east 
of south. ‘The limestones appear only on the southerly portion of the pe- 
ninsula, while the underlying sand-rocks form the immediate coast of 
Lake Superior. 
At a point very nearly one hundred and fifty miles west from the east- 
erly extremity of the peninsula, and near to the immediate coast of Lake 
Superior, several low ranges of granitic hills make their appearance, 
which hills are flanked on the south, by quartz rock, alternating with 
