Digital database of structure contour and isopach maps of multiple subsurface units, Michigan and Illinois Basins, USA

This digital data release presents contour data from multiple subsurface geologic horizons as presented in previously published summaries of the regional subsurface...本数字化数据集发布包含多套地下地质层位（subsurface geologic horizons）的等值线数据，此类数据源自已发表的区域地下地质相关综述总结。