606 REPORT UNITED STATES GEOLOGICAL SURVEY. 



of this butte is one similar to it south of Weston Creek. Weston Creek 

 rises on the west side of the northern portion of the Malade Range, in 

 Pliocene rocks, and cuts through the Silurian rocks to come out into 

 Cache Valley, where it again cuts its way through the Pliocene (?) deposits. 

 jS"ear this point is a synclinal of these Pliocene beds, coarse conglomer- 

 ates outcropping. They appear to rest in a synclinal in the older rocks, 

 which are dark limestones, beneath which dark-green chloritic and met- 

 amorphosed argillaceous slates outcrop. .The Pliocene beds appear to 

 reach high up on the mountains, and seem to dip with the older rocks, 

 although there is little doubt as to their unconform ability. The soft- 

 ness of these more modern beds causes them to break down readily 

 under atmospheric influences, and their junctions with the older rocks 

 are thereby much obscured. 



At the north end of the valley, on the southern slopes of the Portneuf 

 Bange, these Tertiary beds appear to be present in considerable areas. 

 They were not visited but seen from the valley. As we approach Bed 

 Bock Pass, a conglomerate is seen resting on the quartzites, which out- 

 crop irregularly, as though they had formed an uneven floor upon which 

 the conglomerates were deposited. It is probable that a large portion 

 of the lake deposits has been carried away from this part of the valley. 

 Whether there are any of the soft sands and marls near the pass, I 

 could not determine, but I think not. If they ever did exist here they 

 have been carried away by the draining of one of the lakes that existed 

 in the valley. 



MALADE RANGE. 



Under this head I shall describe the two ranges that separate Cache 

 Valley from Malade Valley. The northern portion ends at Weston 

 Creek, having a length of about 20 miles. It ends just southwest of 

 Eed Eock Gap. The southern range begins about 4 miles north of the 

 " Gates" of Bear Biver, and extends a little west of north for about 25 

 miles, overlapping the south end of the northern portion, which is 6 miles 

 farther east. The country between is filled with the Pliocene (?) lime- 

 stones and sandstones which are here continuous from Cache Valley to 

 the Malade Valley. 



Northern range. — This range, as I have already said, is some 20 miles 

 in length. Its highest peaks rise 4,000-5,000 feet above the valley at 

 the east base. It is really composed of two groups which are separated 

 by a comparatively low saddle. The view from Station 132, looking 

 down on this saddle, appeared to show the whitish Tertiary beds reach- 

 ing well up on it from the west. The station (132) is the highest point in 

 the northern mass. A very abrupt face is presented toward the east. 

 On the ridge extending south limestones outcrop with shaly beds (lime- 

 stones'?) above them. They dip slightly north of east, and appear to 

 rest on the green chloritic rocks that outcrop on the slopes lower down. 

 On the summit the following is the section, which corresponds with the 

 accompanying diagram, which shows how the eastern face of the mount- 

 ain is eroded : 



Section Kb. 32. 

 Top. Thickness in feet. 



1. Red quartzite 



2. Red sandstone shales 



3. Red quartzites, conglomeritic at base i 



4. Very dark red conglomeritic quartzites 



5. Space in which limestones probably outcrop (the connection with the fol- 



lowing portion of the section is somewhat obscure) 



