138 



II. F. BAIN — GEOLOGY OF THE WICHITA MOUNTAINS 



send off Btringers into the porphyry. It becomes, too, notably finer in 

 grain, while the porphyry is not changed in general character, though 



it is badly shattered near granite outcrops. In Blue Creek canyon the 

 porphyry platform upon which the Cambrian conglomerate was de- 

 posited has been sharply tilted by the granitic intrusion. The relations 

 of the granite to the limestone are clear from the three facts: (a) At an 

 actual contact observed on the west side of the Blue Creek canyon the 

 dark earthy limestone had been recrystallized into a white, coarse marble ; 

 (b) in the same vicinity the intrusion of the granite had tilted the por- 

 phyry and its covering of sedimentaries ; (c) the basal conglomerate con- 

 tains everywhere fragments of both porphyry and gabbro, but no granite, 

 though the latter could not have been more difficult of access, assuming 

 it to have been pre-Cambrian. 



It is only in the later conglomerates of the Geronimo series that granite 

 pebbles appear. 



LA TER ER UPTI VES 



At several points the granite is cut by greenstone dikes. At one point 

 in the Raggedy mountains three generations of the greenstone, including 

 the original gabbro, can be counted. Quartz veins, some of them gran- 

 ular and carrying mica, also cut the granite. The best known of these 

 veins is the one separating the easternmost from the middle porphyry 

 hill at Medicine bluff, in the Carrollton mountains. This vein is 12 feet 

 wide and shows plainly on both sides of Medicine Bluff creek. It is cut 

 by a small greenstone dike and was noted by Marcy. 



Sedimentaries 



BLUE CREEK SERIES AND RAINY MOUNTAIN LIMESTONE 



The character and relations of the sedimenta^ series can perhaps be 

 best made out from the exposures around Canyon Creek cam]), which 

 was located on the Fort Sill-Cheyenne trail about 7 miles north of mount 



Scott and in the canyon cut 

 by Blue creek. The trail 

 enters the limestone hills 

 from the south and runs for 

 some distance on granite, 

 believed to be a great dike 

 running off from the Mount 

 Scott mass. To the west is a great complex of highly contorted lime- 

 stone, changing into marble at the contact with the granite, and extend- 

 ing with many conflicting dips nearky to Rainy mountain. Figures 1 



Figure 5. 



•Crushed Anticline and Overthrust Fault in Lime- 

 stone, north of Mount Scott. 



