56 GEOLOGY AND MINERAL RESOURCES OF MISSISSIPPI. 
There is a great similarity in the clays from the Tennessee line to Calhoun County. Forty- 
five samples were collected from Benton, Marshall, and Lafayette counties. When made 
into small bricks and burned to the same temperature they show a striking similarity. In 
color they range from almost pure white to a lighl chocolate, with all of the intermediate 
shades. 
The clays of this formation may be divided into two distinct groups stratified and un- 
stratified clays. 
STRATIFIED CLAYS. 
The class of stratified clays includes the more arenaceous clays which occur in horizontal 
strata interbedded with the coarse, laminated sands of the Wilcox. In places the clays are 
remarkably free from impurities and could be used for various economic purposes. In some 
places they are being made into common stoneware, such as jugs, crockery, and churns. 
The greater part of the stratified clays contain loo much free sand for stoneware and pot- 
tery, but could be used advantageously for making a high grade of white to buff-colorec 
pressed brick, lire brick, lime-sand brick and pavers, terra cotta, and tiling. 
UNSTRATIPIED CLAYS. 
The high-class white pottery clays found particularly in the northern counties occur in 
large lens-shaped bodies. They are comparatively free from sand and other impurities. 
The potteries of Holly Springs obtain their clay from these unst rat died bodies. Fossil leaf 
impressions have been found throughout the (lays. 
The composition of these clays, as shown by the analyses below, is such that they can be 
used for making low-grade pottery and in some instances a finer grade of ware. They coul< 
also be used for making gas retorts, crucibles, and lire hrick. 
NOTES ON WILCOX CLAYS. 
Broum clay. — In sec. 25, T. 1, 1\. 2 E., near Laird, Benton County, clay occurs in lami- 
nated sands of the Wilcox, from which the Lafayette has been removed. It is plastic, free 
from sand, and hums to a cream-white color. Numerous other outcrops occur in the gullies- 
near by. An analysis of this clay is given below : 
Analysis of Broum clay, Benton County. 
[By w. F. Band, State chemist.] 
Silica (Si0 2 ) 55. 87 
Alumina ( A1 2 3 ) 30. 19 
Ferric oxide (Fe 2 3 ) 2. < 
Lime (CaO) . 53 
Magnesia (MgO) 
Sulphur trioxide (SO3) 23 
Moisture: 1. 12 
Loss on ignition <». 21, 
99.84 
Maclin clay. — In sec. 28, T. 1 S., R. 2 E., Benton County, on J. Maclin's land, clay occui 
in a deeply washed gully at the top of Wilcox sands. It is overlain by the Lafayette sands. 
The raw clay has a slightly bluish color, but burns to a cream-white. It is high in alumim 
and therefore very plastic. In almost every large gully where the overlying Lafayette ha? 
been removed the white "Wilcox clays are present. The thickness of the deposits is unde- 
termined. An analysis of the Maclin clay is given below: 
