Aviary (birds birds)

I'm no geologist myself, but here's what I can tentatively tell you after lumbering about the internet. GNS tells me the island's rock is Jurassic era; I can't figure out the key exactly so can't get better details than that.

Tiritiri is an island not far off the coast, which sports Miocene origins (more recent than the outcropping island!) and the region as a whole is a volcanic field. Earthquakes might've pushed it out of the sea, but I'm not 100% on that.

I'm inclined to agree with Nopad - it does strongly resemble a sandstone of some description. The weird splintering and fractioning is a geological process, exacerbated by weathering (it's exposed at low tide and covered at high).

I need a better picture, but this isn't a "cliff". It's more like a low and tiny spit off an island. I'm uploading one now which might give a better idea.

E: Found one! The picture links to the image on flickr (caution: 2040 px wide)

The outcropping in question is right behind the wharf in this picture. This was taken earlier in the day and the tide was "low but on the way in again". The beach to the left of the outcropping was getting covered with water by the late afternoon when we made our way back round again.


Detailpic of the stuff when you're standing on top of it (bloody glad I took this now):