Here in the western end of Cimarron County, we have a history "book" with a lid some 50 to 60 feet thick, about 50 miles long, and from one-fourth to several miles in width. It is called Black Mesa (Mesa de Mayo). This book, at its eastern end, is about 650 feet thick, from the bottom of the Cimarron River to its basalt top. The very lid of the book has a history of its own dating back to the Pliocene Age of about one million years. Lava and basalt flow on Black Mesa originated ten miles west of the western end, where there are three spines of igneous rock known as the Bar Seven Ell Buttes or Piney Mountain.
The surface slopes away from these spines in all directions and at a distance it is plainly seen that they are the highest point of a great hill some five miles across at its base and roughly circular in outline. The rocks found on these slopes and in the spines are massive vesicular red and black basalt. This physiographic evidence points to the fact that these spines or vents are the source of the lava forming the cap of Mesa de Mayo. The present mesa top was once the lowest point of the area, as the hot lava followed such a depression.
This lava top thus covered the lower pages of history. The erosion, on the other hand, outside this protective cover, has laid bare in the perpendicular walls of the mesa in the lower or earlier formations which preceded the lava age. In order to arrange various ages protected by the lava cap we will start at the earliest age shown by erosion. Based on the Red Beds or Permian is the Morrison formation. Next up the scale is the Purgatoire, followed by the Dakota Formation. All three are classified as being within the Mesozoic age.
The Morrison structure is up to 50 feet thick and was laid down in a period starting 180 million years ago. During the build-up of this formation there were sluggish streams, swamps and lakes, all of which produced a vegetation of giant palms called cycads, conifers, and ferns. This lush growth of vegetation brought in giant dinosaurs and similar types of reptiles and animals. Under the supervision of the late Dr. J. Willis Stovall of the University of Oklahoma, more than 6000 bones of such a giant were excavated from a pit near Kenton and classified as members of a diplodacus. Also found in the formation were bones and tusks of giant elephants and massive jaws with broad rows of teeth running crosswise of the jaws, which indicated the vegetable-eating types of animals existing at that time.
Overlying the Morrison is the Purgatoire formation. The lower division is white to cream colored sandstone. At places where the overlying Dakota sandstone forms cliff, there is a covered slope from 30 to 60 feet, but where glimpses of the rock are possible it is found to be black shale and sometimes thin bedded sandstone or black sandy shale. Below this slope lies a thick bed of sandstone 20 to 50 feet thick. In most places this layer is white, the top of which is taken as the top of the sandstone member. This member comprises the lower 200 feet of the formation and is characterized by thick white beds of sandstone which are so prominent in the western part of the Cimarron Valley.
The Old Maid - This rock formation resembles a human profile.
There are actually a number of sandstone layers some white and some buff. The beds vary in thickness from 20 to 50 feet, but the white layers are more conspicuous. The layers appear massive from a distance, but on closer examination they appear to be extremely cross-bedded and there are scattered conglomerate lenses at rare intervals throughout. The sands are very poorly cemented and therefore yield readily to weathering, forming smooth round surfaces and making fantastic mushrooms and pillar forms.
About six miles east of Kenton, a group of these formations can be seen east of the 101 Ranch on the south side of the road. This group is known as "The Three Sisters" or "The Wedding Party". One mile further east on the north side of the road is the formation known as "The Old Maid".
Next in order lying above the Purgatoire is the Dakota formation, which is a solid sheet of sandstone measuring from 60 to 70 feet thick. The color is buff and most of the grains forming the stone are igneous in origin, as they contain inclusions of ratile and appatite needles. The Dakota sandstones are a basic part of the mesa, but also form the caps east and south of the mesa, where they did not have the protections of lava. So as one travels east from Kenton, all the points of any height are covered by the Dakotas.
The final formation between the Dakota and the basalt or lava cover, is the late Tertiary. Its greatest thickness is 110 feet, measured on the north side of the mesa. This formation has the greatest area of any of the various formation mentioned, spreading out and covering more than 60 percent of Cimarron County. The formation consists of a heterogeneous mixture of clay, sand and gravel, the last two in many places cemented by a lime deposit which is a very conspicuous part of the formation.
The origin of the formation is described as having been deposited by many streams flowing down the east side of the Rocky Mountains, on down over the Dakota and gradually off to become the Great Plains, east of the Rockies from Canada far down into Texas. The Upper Tertiary is found only in the Texas and Oklahoma Panhandles, and rests on rocks which date from the Permian and Cretaceous. The limestone cement, as mentioned previously, lies atop the formation and rests directly under the cap of the formation.
See Black Mesa State Park for more info