IOWA ACADEMY OF SCIENCE 
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marshalled the arguments and the facts in favor of the eolian origin of loess 
so convincingly that his views are now generally accepted by leading geologists 
everywhere. Professor Shimek was attracted to the loess by his interest in 
the life, habits and distribution of land snails which he had studied more 
patiently and exhaustively than probably any other living naturalist. The loess 
is very generally fossiliferous, and practically all of its fossils are shells of 
terristrial mollusks. These fossils bear conclusive evidence of having been 
buried where the creatures lived and died. Professor Shimek has driven home 
the argument that no theory of loess origin is tenable that does not satisfac- 
torily account for the presence and distribution of its fossil land snails. The 
loess fossils throw light on the humidity and temperature of the atmosphere 
and on the distribution of plants at the time the loess was forming. The loess 
and its fauna and all the economic, geologic, meteorologic and botanic problems 
connected with it will be the subject of a monograph, now in preparation by 
Shimek, which will soon appear as one of the volumes of the Iowa Geological 
Reports. 
Among the more distinctive contributions made by the Survey to pure science 
attention may be called to the discovery of the great Devonian fish bed in the 
State Quarry limestone near North Liberty. The fishes from the State Qdarry 
bed, together with other Devonian fishes from Iowa, have been studied by the 
scholarly master of this branch of Paleontology, Dr. Charles R. Eastman of 
Harvard, and his report has been recently published as volume XVIII of our 
current series. As shown by this report, the new fish bed has furnished a 
number of genera and 'species at present unknown elsewhere in the world. 
Some of these new forms illuminate in interesting ways the history of fish 
development and bring to our knowledge ancestral phases of certain groups 
which have long been known to students of science. 
Among other contributions to pure science we may note that the Survey has 
brought order out of the apparently hopeless confusion which previously existed 
relative to the limits, distribution and characteristics of the Galena and so- 
called Trenton limestones; it has shown that no representatives of the lower 
Devonian occur in our geological column, only late Middle, and part of the 
Upper Devonian being present; it has proved the great overlap and unconform- 
ity in the northern part of the state whereby comparatively late Devonian 
has been brought to rest on eroded Ordovician, with the consequent apparent 
thinning and complete disappearance of the Niagara in that direction; the 
definite life zones of the various rock systems from Cambrian to Carboniferous 
have been worked out with a fair degree of thoroughness; the true correlation 
of the Iowa Cretaceous has been ascertained; and the characteristics, thickness 
and distribution of the earlier beds underneath younger formations have been 
studied, and mapped in connection with Norton’s work on deep wells. 
Precise and definite knowledge of every sort and kind has a value that it is 
difficult to express in the standard units making up the currency of commerce. 
It has been the aim of the Survey to collect and furnish trustworthy informa- 
tion, the fullest possible, relative to the geologic structure and geologic re- 
sources of Iowa; but while the purely economic side of the subject has neces- 
sarily been emphasized more or less in all the work so far done, any facts that 
could make knowledge clearer, broader, more definite, have not been neglected. 
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