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Big Sandy River, and those on the west to Ham's Fork. At Slate Creek, 

 further to the north twenty miles, a yellowish-brown sandstone rises into view, 

 and contiuues to increase in importance toward the north. At the mouth of 

 Fontanelle Creek, it rises on the east side of the river to a height of perhaps 

 250 feet, but sinks toward the north and east, from near the mouth of La- 

 barge Creek, fifteen miles up the river. North of Labarge, a similar bed of 

 sandstone rises again, and is immediately overlaid by white shales, resembling 

 those of the Green River epoch, which have here a great thickness. Oppo- 

 site the mouth of the Labarge, their lower strata are bright-red ; but, on the 

 west side of the river, the sandstone only is visible. All the beds rise to the 

 north ; the red beds forming the summits of the cliffs in that direction. 



In passing up Fontanelle Creek to the westward, the heavy beds of buff 

 sandstone gradually descend, and the white shales come into view. I exam- 

 ined the former for lignite and coal, but found none. There are several thin 

 beds of a tough, carbonaceous material in the white shales (which I take to 

 be of the Green River epoch). In the lower strata in this locality, as well as 

 on the east side of Green River above the mouth of Labarge Creek, are nu- 

 merous remains of fishes similar to those of Green River City, with insects 

 and their larvae, shells like Pupa and Cyrena, and millions of Cypris. The 

 larvae are dipterous, some nearly an inch long, and others minute and in pro- 

 digious numbers. With them are found stems of plants, but no leaves. 

 These beds rise with a very gentle dip, and, twenty miles from the mouth of 

 the creek, terminate against steeply-inclined strata of earlier age. At this 

 point the lower beds exhibit the bright-red colors that are so often seen in the 

 lower part of the formation at other points. The uplifted beds form a ridge 

 of high hills, having a north by east and south by west trend, across which 

 the Fontanelle cuts its way in a deep canon. This range is monoclinal; the 

 strata dipping 45° east, and their outcrop on the summit and western face. 

 The first bed which forms the surface of the incline is rather thin, and is 

 composed of a reddish quartzite without fossils, no doubt of Cretaceous age. 

 Below it is a stratum of highly fossiliferous bluish limestone of Jurassic age, 

 containing Pentacrinus asteriscus, M. and H. ; Trigonia, &c. Below this, a 

 reddish sandstone presented a similar thickness, which may represent the 

 Trias, which rests on a bluish-shale formation. We have now reached the 

 base of the western side of the hills ; from their summit, we have had a beau- 

 tiful and interesting view of geological structure. The valley, of three or four 



