摘要
Between 1850 and 1900, state geological surveys in the Midwest underwent an ideological shift by transforming from institutions based on applied science to those based on pure science. Three factors influenced this process： the acquisition of permanent status from state governments, the establishment of the USGS （United States Geological Survey）, and the increase in regional professional scientific societies and publications in the Midwest. These factors aided in the transformation of research projects by state geologists. These projects grew more focused, of higher quality, and increased in number during this time-period. State governments still expected Midwestern geological surveys to meet the practical needs of their respective states as this transformation continued, but surveys complemented these goals with projects more closely related to pure science. This shift encouraged the research goals of surveys to investigate projects more closely related to pure scientific pursuits, and significantly aided in the growth of the earth sciences in the nineteenth Century and early twentieth Century.
