188 Gould — Geology of Parts of the Seminole, 



ville, a few miles south of Okmulgee, extensive beds have been 

 located and are now being worked. 



From Okmulgee to Sapulpa, thirty-five miles north, the 

 same geological conditions obtain. Massive ledges of sandstone 

 continue to give tone to the erosion forms. Two isolated buttes 

 a few miles east of the " Frisco " railroad are so prominent as 

 to have received the name of " Twin Hills." In the vicinity 

 of these buttes the only ledge of limestone seen on the trip, 

 except that in the Osage nation, was observed. The ledge is 

 not to exceed two feet thick and is cut in a remarkable manner 

 by joints running nearly at right angles. These joints are from 

 twelve to twenty inches apart and in many cases extend the 

 entire thickness of the ledge. As a result the limestone is cut 

 into regular cubical blocks. In a number of places where the 

 ledge is exposed in the bed of a stream these blocks have been 

 pried out and used for foundations or stone walls. This rock 

 requires very little dressing and will doubtless prove a source 

 of considerable income. 



In the region around Sapulpa and between that place and 

 the Arkansas river at Tulsa, the sandstone ledges continue. 

 Buttes and narrow ridges bordered by high and steep bluffs 

 are frequent. Taneha mound, five miles east of Sapulpa, is 

 perhaps the most typical of these. It is situated on the high 

 prairie with its base 100 feet or more above the level of the 

 Arkansas river at Tulsa. The sides of the hill are grass-covered 

 and do not reveal the strata except the more prominent ledges 

 of sandstone. The following section taken along the east slope 

 illustrates the general rock structure of the country : 



Taneha Mound Section. 



No. Feet. 



10. Sandstone forming cap of mound 10 



9. Slope 15 



8. Sandstone forming prominent terraces 5 



1. Slope .._ __ 40 



6. Sandstone forming terraces. 10 



5. Slope _ 30 



4. Sandstone forming a broad terrace 5 



3. Slope 20 



2. Sandstone __ 10 



1. Slope from level of prairie 100 feet 



above the level of the Arkansas 50 



Total 195 



Of this 195 feet of strata 40 feet consist of sandstone. The 

 remainder, or 155 feet, is chiefly arenaceous shale. From the 

 top of the mound a magnificent view of the surrounding 

 country may be obtained. To the south especially is the scene 



