202 Transactions of the Academy of Science of St. Louis 
Girardeau to a point north of St. Louis. It is characterized by 
a surface slope of four inches per mile, which is considerably 
less than that of the Mississippi River at the present time. It 
is stratified and is composed of thin layers of loess-like silt, fine 
sand, and some fine gravel. 
2. The Cuivre Terrace, whose upper surface is so remark- 
ably level over considerable distances as to make it appear to 
be a lake terrace. It is characterized by thick strata of loess- 
like silt and some sand. The terrace has wide expanses north, 
but not south, of St. Louis. 
3. The Boeuf Terrace, which is characterized by the pres- 
ence of glacial erratics in the midst of unstratified silt. It has 
been highly eroded. It can be traced along the Missouri River, 
from a point a short distance east of Labadie, westward; but 
not eastward, nor along the Mississippi River. It appears to be 
a terrace formed in a lake like the Cuivre Terrace, but at an 
earlier time. 
In addition, there is a group of terraces, of which the one 
on the Kaskaskia River may be considered a type. They are 
individual and independent terraces, found only on the Illinois 
side of the river and south of St. Louis. 
THE DRIFT 
GENERAL STATEMENT 
The drift in the Mississippi Basin has long been the subject 
of careful investigation by numerous geologists. It would appear 
that the first published reference to drift within the Middle 
Mississippi River Region was by Worthen®. He referred to a 
glacial, blue clay 12 feet thick found at the corner of West Pine 
Boulevard and Taylor Avenue and for several blocks westward in 
St. Louis. Among others who, during the nineteenth century, 
recognized glacial till in the Middle Mississippi River Region 
