Geological Papers. 113 



EXPEDITION TO THE LARAMIE BEDS OF CONVERSE 

 COUNTY, WYOMING. 



By Charles H. Sternberg, Lawrence. 



''F^HE beds consist of gray or yellowish sandstone, interlaid with 

 -*- redish and gray clays, and small beds of marl made up largely 

 of fresh- water shells. The sandstone is massive, or cross- bedded, 

 and scattered through it are concretions, usually shaped like small 

 marbles, up to the size of large cannon-balls, eight or more inches 

 in diameter. The most remarkable peculiarity of the sandstones 

 are the singular shaped masses of brown siliceous material, fiint- 

 like in structure, and of the same physical conditions as the soft 

 sandstone in which they are imbedded; either stratified or cross- 

 bedded. They assume every conceivable form, from flattened disks 

 to masses over a hundred feet long and less than a yard in width 

 and thickness. They often bridge a cjiasm, or roof a cave, and 

 where they are circular in form they protect the underlying strata, 

 which rises in columns. Often many stand up free and resemble a 

 colony of enormous mushrooms. 



Fantastic forms are everywhere visible, the sculpture different 

 than in any other formation of exposed rock I have explored. 

 Here is the head and bust of a woman wearing a* great " merry 

 widow" hat; there a laughing baby; yonder a huge bird, sitting on 

 a nest ; and every other form the mind can imagine. As the sand- 

 stone is only held together by cohesion it disintegrates readily, and 

 ravine after ravine is carved out of the surface of the country. 



The cross-bedded strata leave marks where sections are made 

 like the contour lines on a topographical map. In them are yellow 

 streaks of iron oxid, as well as seams of lignite, and iron concre- 

 tions; showing all that is left of some ancient bayou or marsh once 

 rich in swamp vegetation. The iron it collected now marks their 

 boundaries. Here, as would be imagined, are bone-beds, filled 

 with scales of ganoid fishes, teeth of dinosaurs and other reptiles, 

 and also teeth and bones of the rare mammal; for the Laramie of the 

 Upper Cretaceous here is indeed the border-land between the age of 

 reptiles and that of mammals. The great dinosaurs will appear no 

 more in* the earth's history, but a vast array of mammals hereafter 

 will dominate land and sea. We find here also the beautifully sculp- 

 tured bones of the fresh- water turtle Trionx, and others. I found 

 also numerous teeth of a ray, Myledaphus. I discovered the type 

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