• Distribution of Lower Devonian Strata (GIS data, line features)
• Distribution of Lower Middle Devonian Sub-Headless Strata (GIS data, line features)
• Distribution of Lower Middle Devonian Sub-Headless Strata (GIS data, polygon features)
• Distribution of Lower Givetian Strata (GIS data, polygon features)
• Distribution of Lower Givetian Strata (GIS data, line features)