SCIENCE. 



559 



here lies between the sandstone and gray bed, with the 

 red beds beneath. Eastward, between the Brazos and 

 Wichita rivers, the gravel drift is abundant, with many 

 stones of greater diameter. At the "Narrows," between 

 the Wichita and Brazos rivers, the width is only suffic- 

 ient to admit the passage of a single wagon. Continued 

 caving in of the bluffs of the two rivers has widened an 

 immense eroded area, rendering a large surface valueless, 

 and while the channels of the rivers are several miles 

 apart, their junction is only a question of time. In the 

 copper region of the little Wichita river, near the centre 

 of Archer county, the ore occurs under the same general 

 conditions, with "a different course, N. E. and S. W. and 

 copper nuggets, coal and cuprified wood are found. 



Embedded in the overlying sandstone, in some in- 

 stances several feet above the gray bed, the sandstone 

 frequently attains a thickness of more than fifteen feet. 

 The cuprified wood is altogether different from that of 

 Haskell county, and resembles the wood of the mesquie 

 tree, which I found scattered about. The gravel drift here 

 is identical in character with that of the region further west, 

 and pebbles occur in the gray copper-bearing bed be- 

 neath the sandstone. The extension of the gravel drift 

 of Haskell county, beyond the Brazos river system, its 

 absence west of the gypsum hills, the larger size of the 

 pebbles in Knox county, bordering the Wichita river, and 

 the occurrence of the drift only in the vicinity of the cop- 

 per-bearing lines mentioned, and in Archer county, sug- 

 gested to me a possible relationship of some kind between 

 the two, perhaps their origination in the same region. 



Between the Wichita and Pease Rivers I crossed sev- 

 eral copper-bearing beds, having a general northeast and 

 southwest direction. In Wilbarger County the gravel 

 drift is in great quantity, and boulders from three to 

 seven inches in diameter occur. In places, and having a 

 northeast and southwest bearing, heavy deposits or lines 

 of gravel and boulders attract attention, appe?ring as 

 though a great flow towards the southeast had met ob- 

 structions along its course, the great incline of this re- 

 gion being directed toward the southeast. Beyond Pease 

 River the gravel drift lessens, but the large boulders are 

 occasionally seen as far west as the gypsum hills. Not 

 far north from the centre of Hardeman County I again 

 found the Haskell County copper bed, the accompanying 

 sandstones being thin and much mixed with gypsum. 

 The copper bed reaches higher than the surrounding 

 country, except the gypsum hills to the west. From 

 this high locality of the copper, known as Prairie-dog 

 Mounds, the country inclines on one side northward to a 

 creek emptying into Red River, and on the other side 

 southward to the Pease River. 



South of these mounds, where only here and there 

 patches of the bed are preserved in the midst of a gen- 

 eral erosion, I found the largest mass of copper ore thus 

 far discovered, consisting of an aggregation of cuprified 

 wood, resembling the trunk of a tree, more than one foot 

 in diameter. Beyond Red River the bed continues to 

 the vicinity of the Salt Fork of Red River, distant but 

 little over 20 miles from the Wichita Mountains of the 

 Indian Territory. The bed probably continues nearly to 

 the western end of these mountains, and here must be 

 found the true centre of elevation and the origin of the 

 gravel drift. The Haskell County copper bed was also 

 traced south to the Wichita River, thus establishing its 

 continuity from the southern portion of Haskell County, 

 through Knox and Hardeman Counties, into the Indian 

 Territory, a length of more than 100 miles. Subsequent- 

 ly, the northern end of the bed was found a short distance 

 from the western end of the Wichita Mountains, on the 

 south side of the range. The copper formations of 

 Archer and Wichita Counties continue through Clay 

 County to the Red River boundary of the Indian Terri- 

 tory. The gravel drift does not extend to the north of 

 the Wichita Mountains, but a limestone district occurs 

 about 20 miles in width, that reaches probably as far out 



to the north, from the Wichita Range, the course of the 

 latter being east and west. This limestone area may be 

 called mountainous, is much disturbed and tilted, and is 

 similar in appearance to the metalliferous limestone for- 

 mation of Mexico. The Wichita Mountains are mainly 

 made up of porphyries, trachytes and basalt, and appear 

 to be two parallel ranges with transverse ranges and 

 small valleys between. About 12 miles west of Fort Sill 

 an extensive body of hornblende slate makes its appear- 

 ance between the two main ranges. The drift fiom the 

 mountains extends to the 5outh 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 lat- 

 ter regions. The Wichita Mountains appear to be 

 identical in origin with the Rocky Mountains, and con- 

 stitute the most eastern spur of that sysiem. In North- 

 ern Mexico short ranges are encountered, striking east 

 and west, and of these the Wichita Mountains appear to 

 be a reproduction. The Wichita Mountains will be 

 found to contain mineral deposits, possibly of some 

 value ; veins of copper ores do exist 40 miles west of 

 Fort Sill, near Otter Creek, in the mountains ; but I am 

 convinced that the copper bed or stratum of Northern 

 Texas will prove of no commercial importance. 



Scale — 52 Miles to i Inch. 



A. Archer County. 



B. Baylor County. 



C. Clay County. 

 HI. Haskell County. 

 Hn. Hardeman County. 

 Wa. Wichi'a County. 

 Wt. Wilbarger County. 

 c. c. c. Copper Bed. 



g. g. g. Gravel Drill. 

 11 ■ Narrows. 



Prof. Newbeny remarked that the communication of 

 Mr. Furman was of great interest, since no accurate 

 description had before been given of the geological 



