Trans. N. Y. Ac. Sct. ~ ‘20 Oct ae 
the mountains extends to the south and southeast. It is found as far 
west as the Haskell County copper bed, and as far east as the Archer 
County copper bed is known. The river channels of that section of the 
country have been formed since this drift period. The development of 
the Wichita Mountains seems to have marked the close of a period of 
uplift and simultaneous erosion. 
These mountains have the same general appearance as the Rocky 
Mountains, which pass through the western portion of Texas and the 
State of Coahuila, Mexico; and it has been a matter of much interest 
to observe that similar drifts of local origin are frequently met in the 
latter regions. The Wichita Mountains appear to be identical in origin 
with the Rocky Mountains, and constitute the most eastern spur of 
that system. In Northern Mexico short ranges are encountered, strik- 
ing east and west, and of these the Wichita Mountains appear to be a 
reproduction. ‘Che Wichita Mountains will be found to contain mineral 
deposits, possibly of some value; ve'ns of copper ores do exist 40 miles 
west of Fort Sill, near Otter Creek, in the mountains; but ‘I am con- 
vinced that the copper bed or stratum of Northern Texas will prove 
of no commercial importance. 
DISCUSSION. 
Prof. NEWBERRY remarked that the communication of Mr. Furman 
was of great interest, since no accurate description had before been 
given of the geological structure of the region where the copper occurs 
in Northern Texas and the Indian Territory. He had received speci- 
mens from that region long ago and recognized their similarity to the 
copper ores of New Mexico, where, in the upper portion of the Triassic 
formation, copper, forming concretions and replacing wood, occurs in 
many localities, and has been more or less mined for. In one locality 
near Abiquini very extensive galleries have been cut in the sandstone 
in search of copper, which there replaces branches and trunks of trees 
and forms concretions which are irregularly scattered through the rock. 
Here the work was done by the early Spanish explorers, perhaps 200 
years ago, and the remains of the furnaces in which the copper was 
smelted are still to be seen at the mouth of the mine. Still further 
west, in Southern Utah, the same formation carries copper and con- 
siderable silver, at Silver Reef enough to pay well for mining, but in 
no locality yet known are the deposits of copper ore sufficiently concen- 
trated and continuous to make mining for that material profitable: so it 
would doubtless be found in Texas and the Indian Territory. The 
copper was deposited, with the Triassic rocks, from a shallow sea in 
which an unusual quantity of copper was held in solution. This im- 
pregnated the sediments found at the bottom, replacing wood and 
