90 THE CLAYS OF ARKANSAS. 
manufacture of good fire bricks. It is probable that other Tertiary 
clays that underlie Drew County might, by washing, be made avail- 
able for the manufacture of pottery. 
At Cornish Ferry, on Saline River, a section of the Tertiary beds 
is exposed, having at the base a dark lignitic clay that resembles 
some of the pottery clays of Saline County. 
4 CLAY INDUSTRY. 
In the town of Monticello the Drew Brick Company and a plant 
operated by J. H. Blythe are engaged in the manufacture of com- 
mon building bricks. 
FAULKNER COUNTY. 
GENERAL GEOLOGY. 
The geology of Faulkner County is merely a repetition on a some- 
what larger scale of that of the western part of White County. The 
rocks have been thrown into great folds and then worn away, but 
the folding has been, on the whole, so simple and the alternation of 
the sandstones and shales has been so regular, that the geologic 
structure of the county is easily interpreted. When this structure 
is understood the distribution of the clays and clay shales in the 
county will be readily comprehended. 
The rocks of this region belong to what are commonly known as 
the "Barren Coal Measures." They are sandstones and shales, 
across which run occasional veins of quartz, and on the upturned 
edges of which there are patches of bog iron deposited by chalybeate 
springs. Locally the sandstones and shales are somewhat calcareous, 
but these calcareous places are only thin bands or small patches 
and are of little or no importance except that some of them contain 
fossils. 
The rocks of the county are all sedimentary, having been depos- 
ited originally in horizontal layers in water. After their deposition 
these sediments were consolidated by the pressure of thick beds that 
were deposited on top of them. In the course of time they were sub- 
jected to horizontal pressure from the south and thrown into a series 
of parallel folds, and, rising above the water, they formed dry land. 
After this elevation they were acted upon by weathering and eroding 
agencies, the former breaking up the rocks (for these sediments, 
originally sand and mud, were already hardened by long pressure to 
sandstone and shale) and the latter washing the fine material away. 
But as rocks are not all equally soluble or equally acted upon by 
decomposing and weathering agencies, and as they are not all trans- 
ported with the same facility after disintegration, some of these rocks 
in Faulkner County have been removed much more rapidly than 
others. Thus rocks which long resist decay and removal — that is, 
