Mountains
Intrusive Rocks
Volcanic Rocks
Sedimentary Rocks
Metamorphic Rocks
Structure
Geomorphology
Orthogneiss
Ptygmatic folds in gneiss
Orthogneiss
Paragneiss
Greenschist-grade meta-basalt
Andalusite porphyroblasts
Orthogneiss
Magnetite-apatite-actinolite replacing albitized metasediments
Magnetite-apatite-actinolite replacing albitized metasediments
Contact metamorphosed concretions
Acasta gneiss - world's oldest rocks - 4.0 Ga
Acasta gneiss - world's oldest rocks - 4.0 Ga
robert hildebrand photography