| Within the Grenville basement these are represented by alkalic to tholeiitic mafic dykes and alkalic to peralkaline granite plutons. |
| The authorities began working frantically up the river, using whatever materials and means available to construct dykes, dams and levees. |
| A stockwork of dykes of mainly jotunitic composition crosscuts the anorthosite bodies and the lopolith. |
| Columnar joints are best developed in sills and dykes, volcanic vents, and former lava lakes. |
| The deformation bands found in sandstone dykes and sills are true cataclastic deformation bands. |
| To explore this possibility both the anisotropy of susceptibility and the anisotropy of magnetic remanence of the dykes were measured. |
