2 BULLETIN 141, U. S. DEPARTMENT OF AGRICULTURE. 
Another distinction which is of general but not quite universal 
application, is that the subsoils of the different types of the Clyde 
series, particularly the subsoils of the more extensive and heavier 
loam and clay soils, have been found to be calcareous. Many analyses 
of these subsoils have been made, which disclose from approximately 
1 per cent of lime carbonate to as much as 25 per cent of that mate- 
rial. Usually the more sandy members of the series are not so well 
supplied with lime carbonate as the heavier textured types. 
In their natural condition practically all the different soils of the 
Clyde series in all occurrences which have been encountered are 
rather poorly drained. They require artificial drainage to become 
of agricultural use but are then very productive soils for the growing 
of the staple farm crops of the region in which they occur and for 
the production of special crops where market facilities are favorable. 
GEOGRAPHICAL DISTRIBUTION. 
All of the known occurrences of the soils of the Clyde series are 
localized within the territory immediately to the south of the Great 
Lakes. The largest areas are to be found in the Maumee Valley in 
Ohio and Indiana; in the valley which stretches to the southwest 
from the shores of Saginaw Bay, in Michigan ; and along the shores 
of the St. Clair River. Lake St. Clair, and the Detroit River in south- 
ern Michigan. The latter region is a connecting strip between the 
two larger areas. In addition there are considerable areas of soils 
of the Clyde series in northern and western New York, associated 
with the glacial lake deposits of the St. Lawrence River Valley and 
the Lake Ontario Plain : in northern and central Indiana, associated 
with the great glacial river terraces of the Kankakee and other rivers; 
and in southeastern Wisconsin, in a glacial lake area which extends 
from the southern end of Green Bay to the vicinity of Fond du Lac. 
(See fig. 1.) These areas include all of the most extensive localities 
within which soils of this series have been encountered, and within 
which additional large areas may be expected to be mapped as the 
work of the Soil Survey progresses. 
There are, however, many smaller isolated areas of the soils of the 
Clyde series which are found in the smaller basins, drained lake 
areas, and swampy terraces of glacial out-wash material which occur 
throughout the upland portions of the States bordering the Great 
Lakes. Although such areas may be individually of limited extent, 
their aggregate area will ultimately be found to be very large. 
In addition many small disconnected areas of the soils of the 
Clyde series are found in low hollows and depressed level areas 
within the glaciated upland of the region immediately south of the 
Great Lakes, particularly in western Ohio and eastern and central 
Indiana. These areas represent tracts where the local drainage was 
