The dikes seen here are basaltic in nature, and are one of the best inland exposures of igneous dikes in the Ò„amaru region and belong to the wider Waiareka Volcanic group.
These are located behind the village of Enfield in a disused quarry which has more recently been used as a landfill site. This site is fenced off to the public. You can however view the Geosite from behind the gates.
The quarry exposes several near-vertical dikes. Dikes are formed when volcanic activity pushes magma up through a crack or a weakness in the crust. This magma cuts across older material and cools in place as an igneous intrusion (i.e. it cools and ‘sets’ below the surface).