Ilo 
Some of these beds, as in St. Louis County, contain scarcely any 
pebbles from foreign rocks ; but nearly all are rounded portions of 
the underlying strata. 
The largest boulders observed in Missouri, are five or six feet in 
diameter. They are usually granite and Metamorphic sandstone. 
3d. Boulder Clay. In northern Missouri, the Boulder formation 
just described often rests upon a bed of bluish or brown sandy clay, 
through which pebbles of various sizes, are disseminated in greater 
or less abundance. In some localities this deposit becomes a pure 
white pipe-clay. 
Range and Thickness. The Altered Drift has been observed 
more frequently in the northwestern part of the State, and is often 
twenty-five or thirty feet thick. The Boulder formation abounds in 
all parts of the State north of the Missouri, and exists in small 
Its thickness 
Its development is 
quantities as far south as the Osage and Meramec. 
is very variable, from one to forty-five feet. 
greater, the boulders larger, and those of a foreign origin more 
numerous, towards the North. 
Its thickness varies from one to fifty feet. The Boulder clay is 
also most abundant in the northern part of the State, and is, in 
some places, more than one hundred feet thick. 
Organic Remains. Ihave seen no fossils in this deposit, save a 
few logs in the Altered Drift of the Missouri. Some of these are 
still sound, and burn quite well when dry, as we have proved by 
building our camp fires with them on several occasions. There are 
other deposits, particularly in the middle and southern parts of 
this State, which are not genuine drift ; and yet they bear a greater 
resemblance to that than to any other formation, and occupy pre- 
cisely he same stratigraphical position.; 
On the high lands beneath the Bluff formation there are angular 
fragments of the adjacent rocks, somewhat worn, and indiscrimin- 
ately commingled with sands and clays. 
Whether these deposits were formed by the same agencies which 
produced the drift, or by a part of them only, or by other causes, 
has scarcely been determined. 
SYSTEM I—TERTIARY. 
There is a formation made up of clays and sands, extending along 
the bluffs, and skirting the bottoms, from Commerce, in Scott 
County, westward to Stoddard, and thence south to the Chalk 
Bluffs in Arkansas. 
The following section, obtained in the neighborhood of Com- 
merce, will give a good idea of the character of those beds. The 
strata are numbered in their natural order, from the top, down: 
No.1, 9 feet. Pebbles, sand and clay intermingled. 
No. 2, 2 feet. Sand and iron ore, brown hematite. 
Brown and buff sand interstratified. ~ 
Buff and white sand interstratified, containing 
rounded masses of sandstone of the same character and color as 
No. 3, 10 feet. 
No. 4, 12 feet. 
the sand forming the strata. 
No. 5, 5 feet. 
No. 6, 1 foot. 
No. 7, 47 feet. 
rhomboidal masses. 
No. 8, 2 feet. Carbonate of iron ore. 
Clay and gravel, of a bright chrome yellow. 
Clay and hematite ore, nearly all iron. 
Blue shale, which separates on exposure into 
GEOLOGY - 
No. 9, 6 feet. 
No. 10, 1 foot. 
Blue shale, like No. 7. 
Iron ore like No. 8. 
Blue shale like No. 7. 
Carbonate of iron like No. 8. 
Blue shale like No. 7, with some thin bands 
and rodules of iron ore. 
No 11, 11 feet. 
No. 12, 114 feet. 
No. 12, ai feet. 
No. 14, 7 feet. Sandy clay, with thin strata, and globular 
masses of hematite ore. 
No. 15, 18 feet. White sand, interstratified with thin brown 
strata, containing some rounded masses of sandstone. 
No. 16, 5 feet. Sand, of a light peach-blossom color, interstrat- 
ified with brown beds. 
White sandstone, in thick beds. 
part is hard and vitreous; but the lower is soft and friable. 
No. £7, 12 feet. The upper 
This 
rock very much resembles the Saccharoidal sandstone of the Cal- 
cjferous series, and appears to have been much worn by running 
water. 
No. 18, 1 inch. 
and rings like pot-metal. 
Very hard, compact, oxide of iron. It is strong 
No. 19, 20 feet. Salmon-colored, white, purple and yellow 
sands; interstratified with clays of the same color. 
No. 20, 1 foot. Spathic iron ore. 
No. 21, 13 feet. Blue Potter’s clay. 
Total thickness, 214 feet. 
I have observed no fossils in these beds, except the impression of 
a leaf on the sandstone of No. 17. 
The zvon ore of these beds is very abundant, and exceedingly 
valuable. The Spathic ore has been found in no other locality in 
Southeastern Missouri, so that the large quantity and excellent 
quality of these beds will render them very valuable for the various 
purposes to which this ore is peculiarly adapted. 
The white sand of these beds will be very valuable for glass- 
Tne. 
clays are well adapted to the manufacture of pottery and stoneware. 
making, and for the composition of mortars and cements. 
SYSTEM III—CRETACEOUS. (?) 
Beneath the Tertiary beds above described in the bluffs of the 
Mississippi above Commerce, the following strata were observed : 
No. 1, 13 feet. Argillaceous sandstone, variegated with gray, 
brown and white. 
No. 2, 20 feet. Soft bluish-brown sandy slate, containing large 
quantities of iron pyrites. 
No. 3, 25 feet. Whitish-brown impure sandstone, banded with. 
purple and pink. 
Slate, like No. 2. 
Fine white silicious clay, interstratified with 
No. 4, 45 feet. 
No. 5, 45 feet. 
white flint more or less spotted, and banded with pink and purple, 
No. 6, 10 feet. 
The entire thickness is 158 feet. 
Purple, red and blue clays. 
These beds are very much disturbed, fractured, upheaved, and 
tilted, so as to form various faults and axes, anticlinal and syn- 
clinal; while the strata above described as Tertiary, are in their 
natural position, and rest nonformably upon these beds. 
These facts show the occurrence of great disturbances subsequent 
to the deposition of these beds, and anterior to the formation of 
the strata above. 
