| Basis for focus area |
Distribution of a thick, extensive layers of manganiferous carbonate nodules in clays of the Pierre Shale where exposed along the banks of the Missouri River and tributaries. Polygon shows outcrop extent. |
| Identified resources |
Identified resources for manganese. |
| Production |
No current production. |
| Status |
No known production. |
| Estimated resources |
Force and Cannon (1988) estimate that the zone of Mn nodules in the DeGrey Member of the Pierre Shale, which constitutes the Chamberlain deposit, is about 15 m thick with 4 to 10% nodules, averaging about 15 to 17% Mn. Exposures have an areal extent of at least 300 by 40 km, which suggests that the deposit may contain as much as 15 billion metric tons of contained Mn. Low grades, however, make this a huge, but currently subeconomic source. |
| Geologic maps |
Martin and others (2004), scale 1:500,000. |
| Geophysical data |
Inadequate aeromagnetic and aeroradiometric coverage. |
| Favorable rocks and structures |
Shale of the DeGrey Member of the Pierre Shale contains abundant Fe-Mn concretions. |
| Deposits |
No data. |
| Evidence from mineral occurrences |
Force and Cannon (1988). |
| Geochemical evidence |
No data. |
| Geophysical evidence |
No data. |
| Evidence from other sources |
No data. |
| Comments |
Force and Cannon (1988) describe the Chamberlain district as a manganese depocenter rivaling the world's largest. |
| Cover thickness and description |
Exposed where the Missouri River and other waterways cut through the generally flat-lying Pierre Shale. |
| Authors |
Laurel G Woodruff. |
| New data needs |
Geophysical data. |
| Geologic mapping and modeling needs |
No large scale geologic mapping. |
| Geophysical survey and modeling needs |
Airborne EM and radiometrics would be important methods, but not aeromagnetics or gravity. |
| Digital elevation data needs |
Lidar adequate. |
