Abstract
Ductile shear zones associated with the 2700 to 2650 Ma Limpopo Orogeny locally contain gold mineralization. Some of these shear zones contain zones of hydrothermal alteration that are of potential economic significance. Within the 2670 Ma Matok Complex, two examples of this shear zone controlled alteration are exposed, the Dwars River and Sand River alteration zones. They are, however, characterized by the absence of significant gold mineralization. The pattern of wall-rock alteration indicates that the hydrothermal processes were different from typical Archaean lode gold deposits because large ion lithophile elements were removed from the rocks. In addition, high salinities of fluids are unfavourable for major gold deposition. The high salinities and calculated oxygen isotopic compositions point to a magmatic source. The shear zone hosted alteration could have taken place anytime between emplacement of the Matok Complex and about 1315 Ma ago. -from Authors
| Original language | English |
|---|---|
| Pages (from-to) | 355-364 |
| Number of pages | 10 |
| Journal | South African Journal of Geology |
| Volume | 94 |
| Issue number | 5-6 |
| Publication status | Published - 1991 |
ASJC Scopus subject areas
- Geology
