UNIVERSITY OF IOWA LIBRARIES

摘要

Iowa Geological Survey Annual Report These annual reports contain information on the topography and geological formations of all of Iowa's counties, assessments of Iowa's mineral resources, and reports on Iowa's water resources. Whether being used to grow crops in the field, livestock in the pasture, or to harvest minerals from the ground, the physical environment of Iowa has been the lifeblood of Iowa's economy. These reports were the first detailed, organized reports on the geology and natural history of Iowa and sometimes included other information like the plant species of the time.