1S97.] ASHLEY — GEOLOGY OF ARKANSAS. 289 



the Kirby-Murfreesboro road. Rising abruptly to a height of about 

 three hundred feet it runs at first northwest, then gradually swings 

 around until it runs a little south of west and ends abruptly in the 

 northwest corner of section 21. On the top of this ridge the 

 rocks, though not rising into a wall, present very much the same pe- 

 culiar structure as on the top of Antoine mountain. The sandstone 

 on top of this ridge, when not examined closely, bears a striking re- 

 semblance to novaculite in color, fracture and general appearance. 

 The structure is an overturn overthrown to the north. 



Chimney Rock Anticline. — In 6 S., 26 W., section 36, southwest 

 of northeast, a mass of rock juts out from the east bank of the Lit- 

 tle Missouri, forming a perpendicular cliff one hundred and forty 

 feet high and tapering from a broad base to a narrow top. It is 

 known throughout the region as the " Chimney Rock." The dips 

 along the river for a mile or two are within a few degrees of per- 

 pendicular, and so give no clue to the structure, but the most 

 probable explanation is that the '' Chimney Rock" is in the axis 

 of a closely pressed anticline. Several anticlines may be crossed 

 by the river in sections 25, 26 and 36 without their presence being 

 recognized. One case on the west bank in section 26, southeast of 

 northeast, where a mass of rocks having the same appearance as the 

 " Chimney Rock," but on a smaller scale, is thought to be an anti- 

 cline. The topography to the west strengthens this view. 



The Chimney rock anticline, or some anticline very close to it, 

 probably explains the structure of Jenkins' spring ridge, a high 

 ridge running a little south of west across the southern row of sec- 

 tions of this township, and is also responsible for the high ridge to 

 the east of the river. Evidences of an anticline appear in 6 S., 25 

 W., centre of section 27, on the Kirby-Murfreeeboro road. 



Siruciure in Townships 7 and 8 Soi/th. 



Silver Hill A fiticlinal Axis. — In 7 S., 30 W., section 6, south- 

 west quarter, the Cossatot crosses two anticlines, one at Antimony 

 Bluff, and one about three hundred feet further north. In 7 S., 31 

 W., the topography indicates that one or both of them passes 

 nearly due west, forming the high, flat-topped ridge upon which 

 Silver hill is situated. In 7 S., 32 W., an overturn with a north 

 dip is crossed by Robinson's Fork in section 8, northeast of the 

 northeast. The topography between the two prongs of the Roll- 

 ing Fork for several miles from their junction is extremely broken, 

 but it shows the strike of the rocks. 



