18y7.] DRAKE^THE (lEOLOCrV OF INDIAN TERRITORY. 327 



and studied rather closely, partly because the coal beds of that area 

 are valuable economically, and partly because the folded structure 

 and the resulting topography are of special geologic interest. The 

 bordering areas of the Boone chert and limestones were studied 

 because these beds have a wide distribution, and a knowledge of 

 their relations to overlying beds was essential to an understanding 

 of the structure of the area and of the conditions of deposition. 



PART I. 

 Structural Geology. 



Af-ea of the Reconnaissance. — The area over which the reconnais- 

 sance was made includes the northern part or nearly half of the 

 Indian Territory, and a little of the adjoining part of Oklahoma. 

 It includes the Cherokee, Creek and Seminole Nations, all the 

 Indian Nations in the northeast corner of the Indian Territory, the 

 northern part or nearly one-third of the Choctaw Nation and a 

 little of Oklahoma adjoining the Creek and Cherokee Nations. 



The area is about 165 miles long and about 125 miles wide and 

 covers a little more than 20,000 square miles. 



Previous Investigators. — In 1819, Thomas NuttalP made several 

 excursions across this region to study its botany and geology. He 

 passed over the country southwest of Ft. Smith, Ark., between 

 Sugar Loaf and Cavaniol mountains' and across Winding Stair 

 mountains ; then he went up the Arkansas river to Verdigris river 

 and across the country in a southwesterly direction from Verdigris 

 river. He also went up Grand river to the Salt springs and made 

 short excursions in the vicinity of Salisaw and Lee's creeks. His 

 conclusions regarding this field were : that sandstones, shales and 

 coal-bearing rock extend over most of the area ; that limestones 

 and cherts all lie north of the Arkansas river; that the salt-bearing 

 strata of Grand river are different from the salt-bearing red beds in 

 the southwest, and that the mountain chains in central western 

 Arkansas and central Indian Territory have a southwest trend. ^ 



^A Joii7-nal of Travels into the Arkansa Territory y by Thomas Nuttall, 

 Philadelphia, i82l,pp. 146-177. 



"^Cavaniol, Caveniol and Kavanaugh are the different ways of spelling the 

 name applied to the mountain lying between the Sugar Loaf and the Sans Bois 

 mountains. Cavaniol is the oldest spelling of the name that has been found, 

 and is the one used in this report. 



^Jour. Acad. iVat. Sci., Vol. ii, p, 49. 



