DGS Publications
| Title | Authors | Publication Date |
|---|---|---|
| RI55 Geology of the Milford and Mispillion River Quadrangles | Ramsey, K.W., Groot, J.J. | |
| RI53 Geology of the Seaford Area, Delaware | Andres, A.S., Ramsey, K.W., Groot, J.J. | |
| OFR25 Saturated Thickness of the Columbia Formation in Southern New Castle County, Delaware | Groot, J.J., Demicco, P.M., Cherry, P.J. | |
| B2 Geology and Ground-Water Resources of the Newark Area, Delaware with a Section on the Surface Water Resources | Groot, J.J., Rasmussen, W.C., Hulme, A.E. |