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This polygon feature class represents the spatial extent of surficial geology deposits, glacial and sub-glacial drainage, and historical glacial lake shoreline areas in Oakland County. These features were captured using a combination of a surface TIN derived from 10-foot contours and a detailed original map of Oakland County surficial geology by Twenter and Knutilla, 1972. Polygons were delineated on a hard-copy map by John Zawiskie, Cranbrook geologist. The map was then scanned and registered to Oakland County GIS data. The polygons were digitized on-screen. Data was collected at approximately 1:1200; however the original map was produced at a countywide scale. The key attribute is the geologic sediment type. |