396 EEPOET UNITED STATES GEOLOGICAL SUEVEY. 



77. Gray spar-seamed sandstone^ obscure exposure 5 dip northeast- 

 ward. 



78. Chocolate-red shales, exposed space 180 feet. 



79. Chocolate-gray, thin-bedded sandstone; dip steeply northeastward. 



80. Chocolate-red shales, exposed space 120 feet. 



81. Gray, thin-bedded, spar-seamed sandstone 5 dip 38°, K. 55° E. 



82. Red shales, exposed space 90 feet. 



83. Chocolate-gray sandstone, 10 feet exposed. 



84. Gray, thin-bedded, spar-seamed sandstone, exposed 20 feet, thrown 

 up into a sharp arch, on the one hand dipping 35°, '^. 20° E., and on 

 the opposite flank 50° to 60°, W. 15° S. Exposed space 75 yards. 



85. IJnexposed 20 yards. 



86. Gray, spar-seamed sandstone, exposed 10 feet; dip very steep south- 

 westward ; almost vertical. 



87. Imperfectly exposed space, with red, chocolate-colored shales, 180 

 yards. 



88. Gray, thin-bedded sandstone, obscure exposure; dip 72°, S. 

 65° W. 



89. Eed and chocolate-colored shales and thin bands of sandstone ; ex- 

 posed space 300 yards. 



90. Gray, chocolate-mottled, thin-bedded sandstone ; obscure exposure. 



91. Chocolate-red shales ; exposed space 100 yards. 



92. Softish, gray, thin-bedded sandstone, 20 feet exposed ; dip 46°, S. 

 55° W. 



93. Blue indurated clay shales, exposed space 100 yards. 



94. Gray, reddish- weathered, thin-bedded sandstone. 



95. Eed shales, exposed space 120 yards. 



96. Gray, spar-seamed sandstone, obscure exposure. 



97. Eed shales, exposed sx)ace 100 yards. 



98. Brownish-gray, coarse-grained sandstone, exposed 15 feet ; dip 45°! 

 S. 65° W. 



99. Eed arenaceous shales, exposed space 70 yards, 



100. Gray, thin-bedded sandstone, obscure exposure ; dip 35°, S. 60° W. 



101. Drab and red shales, with drab indurated shales, alternating, 

 imperfectly exposed over a space of 500 to 800 yards, up to wooded point 

 of spur on the northwest of Anderson's Gulch. 



The section thence was carried from a point on Iowa Gulch near the 

 lower placer mines, where antichnal fold G again appears, up the great 

 spur between Anderson's Gulch and Bilk's Gulch to the crest of Station 

 XXVIII (Mount Caribou). In this ridge the same series of gray sand- 

 stones outcrop as shown above, and which incline southwestward. At 

 a higher point, where the ascent steepens, a heavy ledge of eruptive 

 material makes its appearance, with which the section is continued, as fol- 

 lows : 



102. Unexposed space lying between the last above-mentioned depos- 

 its, No. 101, and the following : 



103. Gray, hornblendic trachyte, with debris of similar rock in slope 

 above. 



104. Hard, gray sandstone debris, not seen in situ. 



105. Hard, gray sandstone, obscure exposure. 



106. Space with red earth and gray sandstone below, red shales 

 above. 



107. Gray, thin-bedded sandstone; dip 50° to 60°, S. 65° W. 



108. Eed earth, indicating subjacent red shales. 



109. Gray sandstone ; dij) steei) southwestward. 



