Mineral Resources On-Line Spatial Data
Mineral Resources > Online Spatial Data > Geology > by state > North Carolina Geology
Geologic units in Robeson county, North Carolina
- Yorktown Formation and Duplin Formation, Undivided (Tertiary) at surface, covers 28 % of this area
Yorktown Formation and Duplin Formation, Undivided - Yorktown Formation: fossiliferous clay with varying amounts of fine-grained sand, bluish gray, shell material commonly concentrated in lenses; mainly in area north of Neuse River. Duplin Formation: shelly, medium- to coarse-grained sand, sandy marl, and limestone, bluish gray; mainly in area south of Neuse River.
- Black Creek Formation (Cretaceous) at surface, covers 69 % of this area
Black Creek Formation - clay, gray to black, lignitic; contains thin beds and laminae of fine-grained micaceous sand and thick lenses of cross-bedded sand. Glauconitic, fossiliferous clayey sand lenses in upper part.
- Middendorf Formation (Cretaceous) at surface, covers 3 % of this area
Middendorf Formation - sand, sandstone, and mudstone, gray to pale gray with an orange cast, mottled; clay balls and iron-cemented concretions common, beds laterally discontinuous, cross-bedding common.
- Cape Fear Formation (Cretaceous) at surface, covers < 0.1 % of this area
Cape Fear Formation - sandstone and sandy mudstone, yellowish gray to bluish gray, mottled red to yellowish orange, indurated, graded and laterally continuos bedding, blocky clay, faint cross-bedding, feldspar and mica common.