sckbl.] ARKANSAS. 89 
Southeast of a line drawn through Pocahontas, Powhatan, Jackson- 
port, Searcy, Little Rock, Benton, Arkadelphia, Prescott, and Tex- 
arkana, Ark., is covered try clays and gravels, and so contains 
absolutely no materials for cement manufacture. All the limestones 
isted occur northwest of the above line. 
This distribution of cement materials is unfortunate, because plants 
working 1 the Arkansas limestones will be brought into direct competi- 
tion with Kansas plants using natural gas for fuel, and also because 
there is no good local market for cement in that part of Arkansas in 
which the cement materials occur. 
IZARD LIMESTONE. 
DISTRIBUTION. 
The Izard limestone occurs in Independence, Izard, Stone, Searcy, 
Marion, and Newton counties. It is found in quantity on all the main 
branches of Lafferty Creek, and ranging in thickness up to 200 feet. 
In a few places it occurs in almost perpendicular bluffs, but more 
commonly in steep, terraced slopes. The finest exposures are along 
the tributary flowing west from Cushman, known as Blowing Cave 
Creek; in the ravine in the north part of sec. 13, T. 14 N-, R. 8 W., 
ind on the lower part of West Lafferty Creek for 4 miles above its 
junction with East Lafferty. In sees. 3 and 10, T. 14 N., R. 8 W., are 
ireas especially noteworthy both for the quantity and quality of the 
Izard limestone exposed. 
At Penters Bluff on White River and in the adjoining region this 
imestone is in admirable position for quarrying. Penters Bluff is 
ilmost perpendicular and is more than 400 feet high, 285 feet of the 
base being Izard limestone. In the rear of the lower end of the bluff 
s a ravine from a fourth to half a mile in length, which penetrates 
the hill in a direction but slightly divergent from the course of the 
river, leaving a high narrow wall, which has an abrupt face riverward 
ind is so close to the river bank that there is scarcely room for the road 
ilong its base. The rear of this wall is a steep, terraced slope facing 
the ravine. The south end of the wall is tolerably abrupt for 60 to 70 
feet from the base, above which the slope is gentler, and one can with 
K little difficult climbing at the start ascend to the highest point of the 
luff by traversing it lengthwise. The rocks have a low dip to the 
southeast. The south end of the bluff for about a fourth of a mile 
onsists entirely of the Izard limestone. 
West of Penters Bluff, on the north side of White River, the lime- 
tone is covered in a few places by the chert debris, outcropping almost 
Continuously along the hills next to the river and on the lower course 
of all its tributaries as far, at least, as Mount Olive. 
The largest and most conspicuous outcrop of Izard limestone west 
f Penters Bluff is on Wilson Creek in the northwestern part of the 
