1921] FricJc: Faunas of Bautista Creek and San Timoteo Canon 335 



LOWER SAN TIMOTEO DEPOSITION, THE EDEN BEDS 



Throughout a considerable area, in the southwest quarter of the 

 Badlands', deposits characterized by greater induration and the preva- 

 lence of calcareous bluish and greenish shales appear unconformably 

 underlying the San Timoteo beds. They are here designated as the 

 Eden Formation (see fig. Ic ; pi. 43, fig. 2 ; and pi. 44, figs. 3 and 4) . 



In its most northwesterly extension the Eden occurs in two low 

 outcroppings of north-dipping, blue shales at the base of the west 

 wall, a half mile above the mouth of Outlaw Canon. At the opposite 

 side of the same canon the formation may be seen in north-and-south- 

 dipping series in the cut for the new Rabbit Grade. The sharply 

 north-dipping beds occupy a two hundred yard section along the 

 road in the upper part of the first mile, the south-trending series being 

 exposed for a quarter of a mile to the south. Southeastward the 

 outcroppings of the Eden Formation may be followed for some five 

 miles, across Eden Mountain, Laborda Canon, and Lamb Canon to 

 the vicinity of the coarse underlying arkosics of the San Jacinto foot- 

 hills and Lamb Mountain. The largest and finest exposures are to 

 the immediate east of the Rabbit Grade, in the region about the 

 western base and upon the higher northwestern corner of the moun- 

 tain whose name has been given to the formation. There faulted 

 ledges of indurated Eden sands and shales intermixed in lower planes 

 with limestone breccia rest against the metamorphic limestone of the 

 basement complex. These ledges have yielded much of the best 

 material. They extend a fifth of a mile along the mountain face, and 

 are capped by bluish shale slopes, thickly grown with brush. To the 

 immediate east they disappear in the neighborhood of an overreaching 

 arm of the San Timoteo formation. To the north and west they 

 tumble canon-ward and pass beneath the later deposits of the opposite 

 hill-land. 



The Eden beds in the Rabbit Cut lie in a sharp northeast- and 

 southwest-dipping anticline unconformably overlain by similarly 

 dipping beds of the San Timoteo deposit. The section is believed to 

 represent the more general structure of the region. In the vicinity 

 of the mountain itself the strata are much disturbed, the dips tending 

 away from the schists. Immediately east of the Rabbit Cut the 

 northeast dip is replaced by a northwestern. A particularly well 

 marked break occurs in a 150-foot cliff in the hillside opposite the 

 northwest corner of Eden, a forty foot ledge of dark indurated 



