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REPORT OF GEOLOGIST FOR NORTHERN TEXAS.

Mr. E. T. Dumble, State Geologist, Austin, Texas:

DEAR SIR—In compliance with your request, I have the honor to submit a brief report of my geological observations in the northern part of the state, to which work I was assigned by yourself on the first day of last October.

I at once began preparations for the trip, and on the 15th of the same month was in the field at work. Since that time I have been continuously in the field, devoting all the time possible to making observations in the Carboniferous formation, except one week spent in going over the line of the Texas and Pacific Railroad on a tour of observation as far west as the Pecos River.

During the progress of the survey I have collected samples of the rocks, ores, and other minerals and soils, as well as the fossils occurring in the formation. I also collected from various sources such meteorological facts as it was possible to obtain, and noted the trees and plants and other indications of the agricultural resources of the region visited.

In making this general survey over so wide an area in so short a time it was impossible to trace out all the localities of rocks, ores, and coal, and to determine the exact areas occupied by them, or to estimate the amount of each in the space it occupied; yet these explorations, besides giving a general view of the country, have prepared the way for making a more detailed examination.

I have confined my observations to that part of the state north of the line of the Texas and Pacific Railroad, or very nearly so, and east of the Pecos River.

In this district there occurs the Quaternary, Tertiary, Jurassic, Triassic, Permian, and Carboniferous formations. Of these the Carboniferous is the only one of which I can speak at this time.

CARBONIFEROUS FORMATION.

The Carboniferous formation in this part of the state embraces only the Carboniferous and Permian periods. I am aware of the fact that the sub-Carboniferous period has been reported from Erath and Palo Pinto counties, but I have seen nothing to warrant such a conclusion; in fact, the evidences are all against it, and I do not believe it exists. Only the upper and lower Coal-measures, with the Permian above are found in this part of the state. As I intend to discuss the Permian at another time, and under a different caption, the following remarks refer only to the strata of the Carboniferous period, and I shall not in this report attempt to separate the strata into upper and lower Coal-measures or epochs.

This formation is situated between the Cretaceous on the east and the Permian on the west. The eastern boundary between the Carboniferous and Cretaceous formations begins at a point on Red River near the northeast corner of Montague County, running thence past Decatur, in Wise County, to Millsap, on the line of the Texas and Pacific Railroad, and thence in a southwestern direction to the Colorado River.

The line between the Carboniferous and Permian formations on the west begins at a point on Red River, near the northwest corner of Montague County; thence by a line passing Buffalo Springs, the southwest corner of Archer County, through Throckmorton County to Baird, and thence in a southwestern direction to the Colorado River.

The Carboniferous strata, as I have observed them, are about 2000 feet thick. The country is generally quite broken, consisting of high hills, with deep valleys of erosion between them. Some of these hills are 250 feet high, and the country has a rapid ascent to the northwest.

The country is generally overgrown with post oak, black jack, elm, pecan, hackberry, and mesquite, and in places there are groves of live oak. Along the creeks and rivers, in addition to the timber already mentioned, we find walnut and cottonwood.

DIP OF THE STRATA.

In some states the coal measures dip at various angles, forming what are sometimes called "coal basins," and both sides or edges of the strata are exposed. Such is not the case in this part of Texas. The lowest strata are seen on the southeast, from thence there is a gradual ascent to the westward, exposing one stratum after another up to the top of the series, where they pass under the Permian formation, and their western edge is therefore not exposed at all. The dip of the strata is to the northwestward, and it is therefore useless to expect to find such coal basins as I have mentioned above in the Carboniferous of this portion of Texas. The dip of the strata is about thirty feet to the mile, and the average ascent per mile from Millsap to Cisco is ten feet.