Geodatabase of the datasets used to represent the two subunits of the Pennsylvanian aquifer in the Lower Peninsula of Michigan

These data were released prior to the October 1, 2016 effective date for the USGS’s policy dictating the review, approval, and release of scientific data as referenced in USGS Survey Manual Chapter 502.8 Fundamental Science Practices: Review and Approval of Scientific Data for Release. This geodatabase includes spatial datasets that represent the Pennsylvanian aquifers in the Lower Peninsula of Michigan. Included are: (1) polygon extents; datasets that represent the entire aquifer extent in the States of Alabama, Georgia, Illinois, Indiana, Kentucky, Maryland, Michigan, Ohio, Pennsylvania, Tennessee, Virginia, and West Virginia; the entire extent subdivided into subareas or subunits where data exist (Lower Peninsula of Michigan only), [...]