Returned to Palo Duro Canyon otw back to NM to keep hiking the trails. Perfect weather for late summer, misting but not raining, which makes the trails impassable, but over cast and cool enough for a 5 mile round trip out and back hike up to the Fortress Cliff on the eastern rim. 700ft elevation gain, and a difficult trail but the geology is mindblowing!
A couple million years ago there was a rock slide. The Rock Garden trail on the eastern side of Palo Duro Canyon, through the rubble of this ancient event, exposes some of the most dramatic geology of the canyon.
Here's what the internet has to say:
.
The Quartermaster Formation is Permian in age, and forms the red, lower slopes of the Canyon. This layer was deposited in a near-shore shallow-marine environment consisting of siltstones and shales with ripple marks and cross bedding, that alternated with dry tidal flats indicated by satin spar gypsum and halite cast evaporite deposits. The red color indicates periods of oxidation. The Quartermaster Formation forms the lower wall and canyon floor, averaging 60 ft (20 m) in thickness where it outcrops. In particular, this alternating red and white formation forms the steep and gullied lower portion of the north flank of Timber Mesa, with the maroon and lavender smooth slopes of the Tecovas Shale above.
.
The Ogallala Formation is a late Miocene to early
Pliocene unit which forms the cliffs and ledges at the very top of the canyon. It is composed of sandstone, siltstone, and conglomerate eroded from a late Cenozoic uplift of the Rocky Mountains, and is separated from the lower Trujillo Formation by a disconformity, representing a long hiatus. The coarse, porous sedimentary units of the Ogallala Formation constitute the Ogallala Aquifer, which has historically functioned as a major source of drinking water for much of the High Plains.Fossils of saber-toothed cats (Smilodon), bone-crushing dogs (Borophagus), mastodons, horses, long-necked camels (Aepycamelus), rhinoceroses, and large tortoises up to 3 feet in length, are present in the Ogallala.The siltstone and sandstone have been cemented by silica, which gives rise to the occurrence of common opal and almost-chert pockets.The upper portion of the formation has thick deposits of caliche, very evident at the Coronado Lodge on the northwest rim of the canyon. Fortress Cliff, on the eastern rim of the canyon, has a spectacular exposure of the Ogallala Formation.
