270 ASHLEY — GEOLOGY OF ARKi^XSAS. [May 13, 



the thin bed of novaculite and siliceous shale being exposed along 

 the axis. In 5 S., 23 W., the axis strikes S., 20° W., across section 

 2S to ^6, being readily traced by the fragments of novaculite over 

 the surface. Passing into 6 S., 23 W., it follows the same course, 

 the novaculite being exposed on both sides of the axis. In 6 S., 

 24 W., it crosses the north fork of Antoine creek just north of the 

 crossing of the Alpine-Kirby road, where the anticline is no 

 longer overturned. 



Big Bear Mountain Overturn. — The Big Bear mountain over- 

 turn is almost .in the strike of the last-mentioned one, but at the 

 eastern end it seems to be deflected to the south. This anticline 

 starts in 6 S., 24 W., section 11, southeast quarter, runs a little 

 north of west for half a mile, then turns and runs S., 70° W., into 

 6 S., 25 W., on the western sheet, the southeast quarter of section 

 14 at the crossing of the Kirby-Murfreesboro road. 



The Little Bear mountain, to be described later, is in this same 

 strike, but its eastern end is deflected south, much as the eastern 

 end of the Big Bear mountain is ; otherwise the Bear mountains 

 and the preceding anticline might be considered as a single anti- 

 cline from the Caddo to the Little Missouri. 



The Big Bear mountain anticline produces a high, sharp, irregu- 

 lar ridge. This ridge, which is about three hundred feet high, rises 

 from a low, flat country and so makes a conspicuous landmark. It 

 is the best example of an overturned anticlinal ridge in the region. 

 The crest is sometimes as sharp as the roof of a house, the hard 

 layer which makes this crest in many places forming the south 

 flank of the mountain for a score or two of feet from the top with 

 a dip of 67°. In several places where there is an exposed dip on 

 the crest of ten or fifteen feet in length, springs start out from the 

 very top of the ridge. In 6 S., 24 W., between sections 16 and 17, 

 it is cut square in two by Gap creek. 



While this may be due to the same causes that have allowed the 

 main streams to run south across the strike of the beds, in this 

 case the explanation seems to be that it 'is due to a backward cut- 

 ting stream, an excellent example of which is a small stream on 

 top of the ridge farther east. One of the little channels starting 

 from a depression in the crest, as shown in Figs. 23 and 24, has cut 

 its way along the top but on the side of the crest opposite to that 

 down which it flows. This has continued until the channel extends 

 for some distance along the top and has made a deep gap of the 



