WILCOX CLAYS. 61 
Ilolly Springs clay. — The clay deposit at Holly Springs is in a large branch on the west 
side of the Illinois Central Railroad, about one-fourth mile north of the depot. The clay is 
a bluish gray with yellow horizontal streaks through it, giving it a laminated appearance. 
A small amount of gray sand is embedded in the clay. The deposit is not continuous for 
more than 25 feet and is A\ feet thick. It is overlain by 10 feet of deep Indian-red Lafayette. 
An interesting feature of this deposit is the large number of small lenses of highly plastic 
clay in the sand around the large deposit. Some of these small bodies are 2 feet long and 
from 1 to 2 inches thick. They are not very far distant from the larger mass and are 
entirely wanting in the Lafayette. The following is an analysis of this clay: 
Analysis of Holly Springs day, Marshall County. 
[By W. F. Hand, State chemist.] 
Silica (Si0 2 ) 67. 02 
Alumina ( A1 2 3 ) 20. 89 
Ferric oxide (Fe 2 3 ) 2. 9.3 
Lime (CaO) 67 
Magnesia (MgO) 55 
Sulphur trioxide (S0 3 ) 49 
Moisture 96 
Loss on ignition 6. 70 
100.21 
Dunlap clay.— A clay deposit occurs on Joe Dunlap's land in the cut where the Ilolly 
Springs and Pontotoc road crosses the Frisco Railroad. The clay is horizontally bedded 
and is exposed for a distance of 350 feet along the cut, with a thickness of 2 feet showing 
above the surface. It is a tough, white, siliceous clay, flecked with small particles of mica 
and burns to a cream-white. It is overlain by 6 to 7 feet of micaceous clayey sand. The 
top of the hill is covered with 6 to 7 feet of yellow loam. The following analysis has been 
made of the Dunlap clay : 
Analysis of Dunlap clay, Marshall County. 
[By W. F. Hand, State Chemist.] 
Silica (Si0 2 ) 62. 41 
Alumina ( A1 2 3 ) 24. 02 
Ferric oxide (Fe 2 3 ) 2. 80 
Lime (CaO) 57 
Magnesia (MgO) 50 
Sulphur trioxide (S0 3 ) : 56 
Moisture. 66 
Loss on ignition 7. 25 
98.77 
Holly Springs stoneware clay. — One and one-half miles east of the Holly Springs depot is a 
small area comprising 20 or 30 acres from which the Holly Springs Stoneware Company 
gets the clay for making its ware. The clay occurs in large lenticular masses with a maxi- 
mum length of 80 feet. Perhaps 25 yards from the point where one of these lenses cuts out, 
another large lens, or "mountain," as the clay digger calls it, will begin. The greatest 
thickness of the clay so far penetrated is 18 feet, and the bottom was not then reached. 
One pit is used until it gets too deep to throw the clay out with a shovel or until a rain 
fills it with water, and it is then abandoned and another opened. Small deposits of pure 
sand, from 1 inch to 1 foot thick and 2 to 3 feet long, often occur in the center of the clay 
lenses. The digger reports that numerous leaf impressions are found at a depth of 10 to 12 
feet. Clay coming from a depth of 10 feet works better than that near the surface. This 
clay is very plastic, free from sand, and has to be mixed with a more sandy clay before it 
is made into stoneware. It burns to a cream color under high heat. The following is an 
analysis of this clay: 
