IOWA ACADEMY OP SCIENCE 
65 
HISTORY OF GEOLOGY IN IOWA FOR THE LAST TWENTY-FIVE YEARS. 
BY MELVIN F. AREY. 
This is so broad and full a subject that the necessary limitation of time and 
space will compel its treatment in a somewhat bald and meager manner. It is 
fitting that there should be given at the outset a brief statement of what had 
been accomplished previous to 1886-7. In 1839 Dr. D. D. Owen organized a 
corps of observers with whom he made a reconnaissance of portions of low^a, 
Wisconsin and Illinois, the results of which were published in 1840 as a part 
of the senate documents. Several years later he revisited the state and the 
fruits of his survey were published by authority of Congress in 1852 under the 
title of a Report of a Geological Suryey of Wisconsin, Iowa and Minnesota. 
These pioneer reports, so far as they pertained to Iowa, have been of marked 
value from a scientific standpoint, because they called attention to the things 
and places of special interest in a state where geology was in the main some- 
what tame and obscure and apparently unimportant in an economic sense. The 
difficulties that had to be overcome at the time were extreme and one wonders 
that results of such extent and value w^ere achieved under the attendant trying 
circumstances. 
In 1855, 1856 and 1857 Professor James Hall w^as employed as State Geologist. 
His report was published in two parts and contained chapters on Physical 
Geography by J. D. Whitney, General Geology and Geology of Iowa by Hall. 
Geology of the Des Moines Valley and Certain Counties of Southeastern Iowa 
by A. H. Worthen, Central and Northern Counties of the Eastern Half of the 
State, and Chemistry and Economical Geology by J. D. Whitney, constituting 
Part I, and Chapter VIII ,on Palaeontology by Hall which formed Part II. The 
impetus given to the interest in the geology of Iowa by this report resulted in 
the inauguration of a new survey in 1866, which however was discontinued 
with the publication of two volumes in 1870. Prof. C. A. White was the State 
Geologist and O. H. St. John was the. assistant. The work was necessarily 
preliminary to a large extent, but covered the entire state as never before. 
In 1886, just on the threshold of the quarter century, the geological history 
of which we are to review briefly, T. C. Chamberlin and R. D. Salisbury made 
a report on the Driftless Area of the Upper Mississippi which appeared in 
the Sixth Annual Report of the U. S. Geological Survey. This area is located 
largely in Wisconsin, but a relatively small portion of it extends across the 
Mississippi into Minnesota and Iowa and therefore Iowa geology shares amply 
in the. benefits of this most interesting and able report. 
In 1890 the Eleventh Annual Report of the Director of the U. S. Geological 
Survey contained a paper on the Pleistocene History of Northeastern Iowa 
by W. J. McGee. Undoubtedly this was the most extensive and important con- 
tribution pertaining wholly to Iowa geology that had been made since the 
publication of White’s Reports. Considering the area covered it was very 
complete and thorough- in its details. Its philosophical method of treatment 
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