| The three mountainous areas consist of large cores of igneous rocks surrounded by larger areas of metamorphic rocks, mostly schists and gneiss. |
| The layering in these ultramafic rocks, and their position above mantle tectonites, is attributed to lower crustal igneous processes. |
| The basement of the Precordillera and Chilenia terranes are Grenville-age igneous and metamorphic rocks. |
| Most of these are on igneous and metamorphic rock to minimize groundwater losses. |
| They were primarily studying the igneous rocks in the region but still managed to bag a few good fossils. |
| It has also been found in silica-poor igneous rocks, such as syenite, nepheline syenite, serpentinite, and lamprophyre. |
