Table 2 Summary of metamorphic and deformational stages of the two Complexes and the Barmet Shear Zone
Internal complex | Barmet Shear zone | External complex |
|---|---|---|
1. Pre-Alpine HT | Â | 1. Pre-Alpine HT |
Minor, rare, pre-Alpine minerals relics | Â | Large undeformed volumes, pre-Alpine minerals relics |
2. Eclogite facies | Pre-stage 4 HP (Eclo-Bs) | 2. Epidote-blueschist facies |
Pervasive foliation (S2~NW/45), local stretching lineation (L2~NW/SE) | Mostly in fragments. Rare Gln in carbonate breccia matrix | Epidote blueschist foliation (S2) parallel to compositional bands, stretching lineation (L2) |
3. Retrograde blueschist to greenschist facies | Â | 3. Greenschist facies |
Tight to isoclinal folds (F3, PA~N-NE/30), amplitude from dm to km |  | Tight to isoclinal folds (F3), amplitude 1–10 m |
Local new axial planar foliation (S3) | Â | Composite foliation developed (S2Â +Â S3~SE/60) |
4. Greenschist facies | 4. Greenschist facies | 4. Greenschist facies |
Mylonitic foliation (S4~N-NW/70) | Mylonitic greenschist foliation | Mylonitic greenschist foliation (S4~SE/80) |
Close to contact with External Complex | (S4~SE/60), local stretching | Close to contact with Internal Complex |
Rare stretching lineation (L4~NW/30) | lineation (L4~W/E) | Local stretching lineation (L4~W/E) |
5. Greenschist facies | 5. Greenschist facies | 5. Greenschist facies |
Close to tight recumbent folds (F5, PA~NW/45), amplitude 1–20 m | Close to tight recumbent folds (F5), amplitude of 1–20 m | Close to tight recumbent folds (F5, PA~NE/45), amplitude 1–20 m |
Local weak and spaced axial planar (S5) | Â | Local and spaced foliation (S5) or fracture cleavage |
6. Lower greenschist facies | 6. Lower greenschist facies | 6. Lower greenschist facies |
Rare open to tight upright folds (F6), amplitude some metres, fracture cleavage in the hinge zone | Rare open to tight upright folds (F6), amplitude of some metres | Rare open to tight upright folds (F6), amplitude some metres |
7. | Â | 7. |
Emplacement of dykes | Â | Emplacement of dykes |
Rare dykes 0.5–1 m thick |  | Rare dykes reported by Lanza (1977), not found in mapped area |
8. | Â | 8. |
Brittle fracturing | Â | Brittle fracturing |
Rare brittle fractures (B8) with S-C features top to east sense of shear | Â | Rare brittle fractures (B8) |