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GENERAL GEOLOGY.

SEYMOUR BEDS.

There is an area of country extending from the Cretaceous hills south of the line of the Texas and Pacific Railroad northward entirely through the State. It is well presented. in a broad level plateau west of the town of Sweetwater, in Nolan county. It is bounded on the west by a high range of gypsum hills, and on the east by the edge of the limestone of the Clear Fork division of the Permian, which dips to the northwest against the slope of the surface, and seems to have formed a barrier against which the Seymour beds were deposited.

The formation, with its natural barriers, is well represented between the Brazos river and the Big Wichita river between Seymour, in Baylor county, and Benjamin, in Knox county, and I have named its beds Seymour beds, for the reason that I first saw them in that vicinity. They range in thickness from a few feet to fifty, the thickest being on the. west, and are composed of unstratified beds of sandy clay resting upon the red beds of the Permian. Very often at the base there are beds of pebbles cemented into solid masses by lime.

The formation has been cut across by the various rivers and streams flowing eastward from the Staked Plains, and are now only remnants of a once extensive plain. The Big Wichita and Brazos rivers are examples of this erosion. At one time the limestone which outcrops just east of the town of Seymour extended across the Brazos and Wichita rivets, and the whole country westward was covered with this inland lake. It is probable that a great rush of water came from the west and caused this lake to break over its eastern boundary, or at least to cause the rivers to cut their way back through the limestones, resulting in the drainage of the lake basin. When once the limestones were destroyed, the cutting back and the deepening of the river channels was comparatively rapid, until now they are not less than 150 feet below the top of the Seymour beds. There was once a great fall in the Brazos river just below the town of Seymour, the evidence of the old river deposits being well displayed on the farm of Mr. Jesse Cockrell, five miles southeast of Seymour, and it is probable that Table Top mountain, six miles north of Seymour, was above the water during the time of the deposition of the Seymour beds, as it is now higher than the surrounding country, with none of the material composing the beds above it.

These beds must not be confounded with the beds of gravel-and drift found in the river valleys at a much lower level.

The fossils in the Seymour beds are not very abundant, and those collected have not been definitely determined. At Mr. Green's place, fourteen