| The basement is mainly composed of quartz biotite norite and minor serpentinite which belong to the Ordovician Boganclough intrusion. |
| Enstatite occurs in plutonic basic and ultrabasic rocks such as peridotite and norite, and also in some high-grade metamorphic rocks. |
| In New York the emery deposits are segregations of aluminum and iron oxides in norite. |
| In Canada great portions of the eastern portion of the Dominion are formed of gabbros, norite, anorthosite and allied rock types. |
| Near the ores there are likely to be granitic rocks, which, like the ores, seem to be segregations from the norite magma. |
| Most of these occur along with troctolites, norites, serpentine and peridotite. |
