bckel.] ARKANSAS. 99 
Big and Little Buffaloes, and at many places along the north face of 
the Boston Mountains in Searcy, Stone, and Independence counties. 
It outcrops prominently on the mountain south of Jamestown, Inde- 
pendence County, as well as at many places on Salado Creek, in the 
same county, and it skirts the highlands southwest of the Oil Trough 
bottom. 
CRETACEOUS CHALK BEDS. < 
The Cretaceous rocks of Arkansas occur only in the southwestern 
portion of the State, reaching as far northeast as Arkadelphia (See 
PI. III. On the north they are bordered by Paleozoic sandstones and 
shales, while on the south and east they pass out of sight beneath a series 
)f sands, gravels, and clays of later age. 
In the present discussion the only part of this series to be consid- 
ered is the chalk formation of the upper Cretaceous. This is geolog- 
teally continuous with the Texas chalk (see pp. 308-309), but is cov- 
ered in many places by sands, gravels, and river bottoms, so that it 
)ccurs as a series of isolated outcrops. It outcrops near Rocky Comfort, 
n Little River County, and near White Cliffs, Saline Landing, Wash- 
ngton, and Okolona, and on Big and Little Deciper creeks. 
While the chalk of all these areas is of upper Cretaceous age, there 
s a considerable variation in stratigraphic position. The chalk beds at 
focky Comfort, White Cliffs, and Saline Landing become more sand}^ 
md clayey and less chalky as they are traced northeastward from 
he last-named area, and soon become worthless as cement materials. 
\.t the same time a series of limy clays, situated geologically about 
500 feet above this first chalk series, becomes more chalky as it is 
raced northeastward; and this second chalk bed is worth considering 
i a cement material in its outcrops near Washington and Okolona, and 
>n the Deciper creeks. 
The first or lower series of chalk beds has been called the White- 
liffs a formation and the second series the Saratoga formation, both 
)eing named from localities at which they are well exposed. 
The different areas of outcrop will be discussed separately in order 
rom southwest to northeast, after which a large series of analyses of 
he^chalk will be presented. 
" WHITECLIFFS (ANNONA & ) FORMATION. 
BOCKY COMFORT AREA. 
The chalk which outcrops in the vicinity of Rocky Comfort is 
emarkably uniform in physical appearance. It is massive, white, 
aThe description of the Cretaceous chalks is taken from a very detailed report, by Mr. J. A. Taflf, 
1 The chalk of southwestern Arkansas, with notes on its adaptability to the manufacture of 
ydraulic cements, in Twenty-second Ann. Rept. U. S. Geol. Survey, pt. 3, pp. 689-742. So far as 
ossible this matter is stated in Mr. Taff s own words. 
&As the term White Cliff had been applied in 1876 to a formation in the Uinta Mountains, the name 
.nnona, from Annona, Red River County, Tex., where the chalk is well exposed, has been adopted 
)r it by the U. S. Geological Survey. 
