96 ANNUAL REPORT 
humus. But in Indiana and Michigan, large lakes are still in existence, 
though much shrunken in area, whose banks and bottom are covered 
with the marl. In some cases, extensive operations are undertaken to 
drain these lakes to get at the marl and in other cases the use of dredges 
is resorted to bring it up from the bottom. 
The origin of the marl has been discussed a great deal. It is now 
ascribed to the action of fresh water algz, which precipitate it or throw 
it down from solution. Whether this be the truth or not, its close and 
intimate connection with fresh water lakes is too patent to be denied. In 
searching for it, therefore, the obvious method is to observe the locality 
for flat meadows or marshes, which have the appearance of having been 
at one time the site of glacial lakes. The water sheds between the rivers 
flowing north to the lakes and south to the Ohio forms a promising 
territory for such explorations, but many of these marl covered lake-sites 
exist all through the drift covered area of the State, more abundantly in 
the northwestern third. 
The composition of the marl is eminently well suited to cement. It 
consists of the amorphous or organic form of calcium carbonate, mixed 
with varying amounts of soil, sand, humus, snail shells, etc. Frequently 
the percentage of calcium carbonate reaches 96 to 98 per cent., while mag- 
nesia, the bane of Portland cement, is practically absent. It is a soft, 
damp, gray earth somewhat like bulk sugar in appearance; it has little 
plasticity when worked up with water like a clay, and still less hardness 
or strength when dried. It dissolves in any acid, even vinegar, with 
much effervescence or foaming. Many farmers, owning land on which 
it occurs, do not know what it is, or of its possible uses ; others do not care 
to sell their land for cement purposes, as these old swamp beds are usually 
rich and productive for farming. 
Ohio’s known areas of marl are very limited compared to those of 
- Michigan and Indiana. It is not probable that any future discoveries will 
bring our deposits up to theirs in size or importance. But it is wholly 
probable that our resources can be greatly extended by systematic and 
intelligent search. Nothing of the sort has been yet undertaken. A two 
inch boring auger, with extensible handle, is about all the equipment that 
is needed, as these deposits are always superficial and under but slight 
cover of clay or soil. By driving over the country, studying its topog- 
raphy, searching out its old depressions, and drained marshes, it would 
be possible without doubt to bring many deposits to light. 
The marl beds of northwestern Logan county, lying between Harper 
and Rushsylvania, are typical deposits. These deposits support two 
Portland cement industries, the Buckeye and Alta plants. An analysis 
of the marls shows: 
