Cook's Head Rock is a 24m high promontor consists of phonolite and consists of Miocene aged altered basalt rock that is surrounded by Halocene ocean beach deposits consisting of well sorted sand deposited predominantly by marine and lesser aeolian processes. just inland from it are Late Pleistocene ocean beach deposits consisting of slightly weathered gravel, sand, silt, and loess.
The lower faces of the rock are made up of numerous basalt colums suggesting that the rock is a vormer volcanic vent and it is regardes as an outlier of the Dunedin Volcano Complex.
Fresh basalt consists of plagioclase, titanomagneiti, titaniferous augite, and olivine, with some brown clay rimming the olivine. Taranakite and leucophite is found as veins crusts and alternation pools to 2 cm thick. The leucophospite forms darker patches 0.01 - 0.1 mms in diameter within the white taranakite.
Becaue this is a piece of volcanic rock surrounded by non volcanic rock there will be some flora that is isolated from other populations. Unfortunatly I was unable to source any information on the botantical life.
The usual approach is from Crystalls Beach Rserve Rd that runs parallel to the beach from the north east. There will be a short walk involved. when I placed the cache I walked across the bar that was blocking the Tokomairiro River to the south west but the blocking of the mouth is a rare event and it was still a 40 minute walk to the rock.
You do not need to climb the rock but go around to the west south west side of the rock and a tall person might be able to reach the cache with feet still planted on the beach. A rock has been placedslightly inland from the cache to make it easier for the more vertically challenged person but do take care if you have to scramble up. Placement is to ensure long term survival, hence it is not at the top where the muggles go, or at least try to go. You are looking for a 2 litre screw top container.