WYOMING ROCKIES 



3&3 



TETON RANGE 



Crancf Teton 

 El / 3,7*7 



WIND RIVER RANGE 

 Wmcf River Ph. 



f/- CO JS,O0O 



Fig. 24.2. Cross sections of the Teton and Wind River Ranges. The west slope of the Tetons is 

 after Horberg (1938), the Blacktail Butte and Gros Ventre geology after Foster (1946), and the 

 eastern slope of the Wind Rivers is after Branson and Branson (1941). Other parts are by the 

 author. Ob, Big Horn dolomite; Dd, Darby formation; Cbm, Brazer and Madison limestones; Cta, 



i Hills. Along their southwestern flank, however, steep upturning and over- 

 j thrusting is the rule. The Wind River Range is separated from the Gros 

 Ventre by a broad sag or saddle in which most of the Paleozoic and 

 jMesozoic formations are preserved and in which folds and faults of con- 

 siderable magnitude occur (Richmond, 1945). The Gros Ventre Range is 

 separated from the Tetons by a broad and picturesque valley, Jackson 

 Hole, which trends north and south. The depression is due mainly to late 

 Cenozoic block faulting, and the Laramide structural setting between the 

 two ranges is not known. The post-Laramide faulting has been discussed 

 in Chapter 22, and will be mentioned again in Chapter 30. 



A cross section into the Gros Ventre Range from the facing Hoback 

 Range has already been presented (Fig. 22.9), and the structural relations 

 of the two ranges discussed. Other sections of the Tetons, Gros Ventre, 



Tensleep and Amsden; Cp, Phosphoria formation; Tic, Chugwater formation; Jn, Nugget sand- 

 stone; Jtc, Gypsum Spring and Twin Creek formations; Tp, Pass Peak (middle Eocene); Tc, Camp 

 Davis (uppermost Miocene); Tea, andesites of Camp Davis formation. 



and Wind River ranges are given in Fig. 24.2, which bv inspection should 

 explain the broad features of each. 



The southwest flank of the Wind River uplift has been traversed seis- 

 mically by Berg and Wasson (1960), and they report a thrust that dips 

 as low as 18 degrees and carries under the range about 8 miles. The 

 amount of vertical uplift in the Wind River Mountains is in excess of 

 35,000 feet. 



BEARTOOTH RANGE 



The Beartooth Range extends from southern Montana into northern 

 Wyoming. Its northeast front is uplifted and generally overthrust north- 

 eastward, whereas the southwest front of the Wind River Range is ap- 

 parently overthrust southwestward. A number of porphyry intrusions are 



