PRESIDENT’S ADDRESS. 
THE WORK OP THE IOWA GEOLOGICAL SURVEY. 
BY SAMUEL CALVIN. 
The present Geological Survey was organized in 1892. Before that time Iowa 
had had the honor and the distinction of being served in the office of State 
Geologist by that Nestor of American Geology and Paleontology, James Hall, 
and by his worthy successor. Dr. Charles A. White. It was Iowa’s great mis- 
fortune that neither of these distinguished geologists was permitted to do more 
than the merest reconnoissahce work. Official geological work in Iowa may 
indeed claim three distinguished names, for geological investigation began in 
this state under the direction of David Dale Owen, United States Geoolgist, in 
the autumn of 1839. Considering the limitations under which the earlier ge- 
ologists labored, the extent and accuracy of their observations are matters of 
constant surprise to their successors. 
All that was done, however, and all that could be done by the earlier geolo- 
gists, was to determine in a general way the age and characteristics of the 
geological formations which occurred within the state, and something of their 
surface distribution. Nothing like detailed work was possible. There was 
neither time nor opportunity to ascertain the limits of the minor divisions of 
the formations, nor could the zonal distribution of faunas be worked out; the 
geological resources of the state could be but dimly appreciated; approxima- 
tion only could be made to the boundary lines of the formational areas. 
The first great aim of the present Geological Survey was to make maps show- 
ing as accurately as conditions would permit the exact areas in which the 
several formations are exposed at the surface. In a country which, like Iowa, 
is deeply covered with glacial drift, the work of geological mapping is one of 
extreme difficulty. Even now, over large areas, it is impossible to do more 
than to draw lines where the few scattered outcrops indicate the boundaries 
should be found if the drift mantle were removed. The work has been pur- 
sued with the purpose of getting the nearest possible approximation to accuracy. 
The surface has been studied county by county, and the first studies were so 
distributed as to cover areas of strategic importance, areas in which contact 
lines, special formational characteristics, or geological products of commercial 
value were expected to occur. In the matter of the determination of forma- 
tional boundaries the results have been such as to make it possible to publish 
the large-scale geological map which was issued as part of Professor Wilder’s 
Report for 1905. A comparison of this with the geological maps of Iowa 
previously published will show what has been done in the direction of detailed 
mapping of Iowa’s geological formations. For seventy-five of the ninety-nine 
counties of the state geological maps have been published on a scale of half an 
inch to the mile, and the geological structure of these counties has been set 
out in detailed reports. County reports embrace all the information which may 
be collected by careful study of topography, drainage, building materials and 
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