I had a small research project on Rarotonga, on the only coastal outcrop of rock, called Black Rock. This research was presented at a later NZ Geological Society conference. Black Rock, is a poorly polygonally jointed rocky headland on the Rarotongan northwest coast and is a part of a phonolitic lava flow, dated at 2.80 ± 0.13 m.yrs. This research project is summarized in Part II of these images.

Part I of these images is a summary of the geology/geomorphology of the island of Rarotonga. The island is a highly eroded basaltic shield volcano, probably similar, although somewhat smaller, than modern Hawaii when it was last active, as Rarotonga too was a volcano on an Island Chain (hotspot). But since the activity ceased some 2.8 million years ago, the only process that has been active is erosion of the island, and the building of a coral reef.

The best way to explore Rarotonga is by walking or by hiring a motorscooter (available from most hotels). A motor scooter circum-navigation of the island takes no more than an hour. You will see the scooter I used is in some of these pictures (for scale).