KXDucii.] WIND KIVER RANGE METAMORPIIIC ROCKS. 69 



at the extreme southern end of tlie Wind River Ranoe, wliere the transi- 

 tion into the Sweetwater Hills begins, we Avill find : That tlie f^ranite of 

 tlie subsidiary range lias disapjieared from tlie surface ; that steei)ly- 

 dipping- schists occupy the region where we might ex])ect to find the 

 former; that the granite of the main chain, the schistoid rocks of its 

 eastern slope, and the granites of the higher foot-hills have sunken out of 

 sight ; that the granites of the lower foot-hills occupy ])oints of higher 

 elevation than they do farther to the northwest, and that the relations 

 of the quartzite and unchanged sedimentary beds to the latter are not 

 afi'ected. AVe observe, fuithermore, that the character of the schists 

 here exhibited is not identical with that observed in the main chain, and 

 that their thickness is by far greater. From the relative positicms of these 

 various groui)s it follows that the schists in question cover the granite of 

 the subsidiary range. That of the main chain and of the higher por- 

 tions of the foot-hills has probably pinched out in part and lies' buried 

 beneath the yoimger masses elsewhere found near the base of the hills. 

 In the hills near Miner's Delight this granite shows a dip of about 25° 

 to the eastward and remains conformable mth the sedimentary beds 

 superincumbent. 



Within the area ux)on which the schists are ex]'0sed, we observe a 

 munber of varieties. IMicaceous and hornblendic are the two chief 

 varieties, but gneiss and chloritic schists are not "\\ anting. They dip 

 steeply, almost 90°, to the eastward. From the hills south of Camp 

 Stambaugh their strike, and in a measure their dip, c:m be beautifully 

 observed. Seen from the summit of some point, the harder strata, 

 which have resisted erosion, give the ground a regulaiiy funowed ap- 

 pearance. This extends frequently for some distance, aiid may be sud- 

 denly broken oft". So far as could be observed, the dip of the schists 

 decreased as we proceeded toward its junction wth the younger gran- 

 ites. A number of good exposures in small caBons furnish ample 

 information toward the southern end of the metamorphic area. 



Ee^^ewing in a few words the result sho^vTi by all these occiu-rences, we 

 have, following a line fi'om below South Pass to Miner's Delight, a sinking 

 of the oldest granites accompanied by the ax)pearance of younger schists, 

 an elimination of the rocks elsewhere composing the central portion of 

 the Wind River Range, and a rise of the youngest granites of the region. 

 It seeems that the enormous bulk of material irom which the rocks com- 

 posing the highest mass of the range w^as obtained was exhausted near 

 this line. The original products of deposition there accumulated had 

 come to an end, and only those now represented by the younger granites 

 existed at the locality. This condition of aflau's permitted the older, or 

 probably even oldest, sedimentary products to rise sufficiently high to 

 reach to the present siu^face. Their quantity was not sufiiciently great 

 to rise to the same elevation that the masses farther noi'thwest reached, 

 or we should to-day be without South Pass. From subsequent state- 

 ments it Mill be seen that farther eastward we have an analogous case 

 where still another member of this same group disai^pears. 



An important feature of this older metamorphic area is the existence 

 of metalliferous veins. The mines of South Pass, Atlantic City, and 

 Miner's Delight are located m the old dark-colored schists; all of them 

 contain gold. This distribution explains why as yet no remunerative 

 veius have been found in the metamoi-phics of the main chains. A number 

 of metalliferous veins have thpre been observed, but none of them carry 

 the precious metals in quantities greater than mere traces. A number 

 of lodes have been discovered, and some exaggerated reports thereabout 

 are current. So far as oiu- observations extend, the metal contained in 



