Abstract
We present new 87Sr/ 86Sr ratios in groundwater from Proterozoic and Cambrian sandstone aquifers of southeastern Minnesota (USA), emphasizing the Mt. Simon aquifer. In Mt. Simon waters, 87Sr/ 86Sr ranges from 0.7141 in the recharge area to 0.7085 at depth. Sampling of the overlying Franconia, Ironton, and Galesville aquifers similarly indicates 87Sr/ 86Sr from 0.7132 in shallow conditions to 0.7086 at depth. Proterozoic sandstone aquifers in shallow bedrock conditions exhibit 87Sr/ 86Sr of 0.7103-0.7119. Sr sources to the Mt. Simon include: (1) more radiogenic Sr derived from overlying Cretaceous rocks and/or Pleistocene glacial deposits that incorporate Precambrian crystalline rocks and Cretaceous sedimentary rocks; and (2) less radiogenic Sr associated with Na-bearing waters, possibly from plagioclase weathering. Overall, the observed 87Sr/ 86Sr and correlation with carbon-14 activity record the Sr system's sensitivity to groundwater evolution from the recharge area to deep, slow-circulating areas and contributions from multiple Sr sources associated with hydrogeologic setting.
| Original language | English |
|---|---|
| Title of host publication | Water-Rock Interaction: Proceedings of the 13th International Conference on Water-Rock Interaction, WRI-13 |
| Publisher | CRC Press |
| Pages | 111-114 |
| Number of pages | 4 |
| ISBN (Electronic) | 9781439862995 |
| ISBN (Print) | 9780415604260 |
| State | Published - 1 Dec 2010 |
| Externally published | Yes |
| Event | 13th International Conference on Water-Rock Interaction, WRI-13 - Guanajuato, Mexico Duration: 16 Aug 2010 → 20 Aug 2010 |
Conference
| Conference | 13th International Conference on Water-Rock Interaction, WRI-13 |
|---|---|
| Country/Territory | Mexico |
| City | Guanajuato |
| Period | 16/08/10 → 20/08/10 |
ASJC Scopus subject areas
- General Environmental Science
- General Earth and Planetary Sciences