Abstract
Drift prospecting surveys in New Brunswick have previously had limited success in recognizing dispersal plumes through geochemical or mineralogical analyses of tills. This study was undertaken in the Todd Mountain - Trout Lake area of central New Brunswick to define possible constraints on glacial dispersal and assist in related prospecting activities. Dispersal patterns for specific heavy minerals in the silt to fine sand (0. 1 25 mm - 0.250 mm) fraction of 63 till samples were investigated over a 12 km x 25 km area. Twelve minerals, confirmed by Scanning Electron Microscopy, were selected for study on the basis of local geology and ease of recognition.
In this area of New Brunswick, eastward-trending dispersal plumes can be distinguished over short distances (<5 km) only for rare indicator minerals that characterize specific sources (e.g., coticules or zircon grains). When sampled at intervals of 100 m the mineral dispersal patterns more clearly reflect the nature and trend of units in the bedrock. Correlations between mineral content and geochemistry are poor because of glacial mixing of variable source materials. Some poor chemical correlations may also be due to weathering and hydromorphic dispersion. In this area of central New Brunswick, prospecting programs utilizing the fine-grained till fraction require close sample spacing and accurate identification of till facies.
| Translated title of the contribution | Glacial dispersion of heavy minerals in Late Wisconsinan till from southeastern New Brunswick |
|---|---|
| Original language | English |
| Pages (from-to) | 199 - 208 |
| Number of pages | 10 |
| Journal | Atlantic Geology |
| Volume | 27(3) |
| Publication status | Published - 1991 |