Abstract
Detailed studies of rocks from the Limpopo (South Africa) and Lapland (Kola-Fennoscandia) high-grade terrains were carried out in order to reveal similar geological and thermodynamic conditions in their formation. Both complexes (1) are situated between Archean greenstone belts, (2) are younger than the belts, (3) are bounded by crustal-scale shear zones, (4) have a similar intrusive-like (harpolith) geometry, and (5) show similar reaction textures that reflect both breakdown and growth of garnet in each high-grade terrain. Local mineral equilibria within the textures indicate their successive formation with cooling of the granulite facies rocks. Some of the textures in the metapelites must have resulted from the following reverse reactions: Grt + Qtz ⇌ Opx + Crd and/or Grt + Sil + Qtz ⇌ Crd. Based on these data, both the decompression cooling P-T path and the near-isobaric cooling P-T path were deduced for each HGT. However the near-isobaric cooling P-T path is not a characteristic of the central zones of both complexes studied. Similar structural framework of the high-grade terrains, similar morphologies (shapes of granulitic bodies), similar reaction textures developed in metapelites, and similar shapes of P-T paths suggest similarity in geodynamic history of both complexes.
Original language | English |
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Pages (from-to) | 69-107 |
Number of pages | 39 |
Journal | Mineralogy and Petrology |
Volume | 69 |
Issue number | 1-2 |
DOIs | |
Publication status | Published - 2000 |
ASJC Scopus subject areas
- Geophysics
- Geochemistry and Petrology