Collecting penguins in the Kokoamu Greensand

The Kokoamu Greensand is the final resting place of many archaic penguins and dolphins.  Formed about 26 million years ago when much of present day New Zealand was covered by the Pacific Ocean, these deposits are exposed along modern day river valleys.  Coarse grains of greenish to orange sand record the layering of sands and the burrowings of invertebrates over millions years.  Some of the most common fossils are pectins (scallops) and brachiopods.  The later are sometimes known as lampshells because of their vague resemblance to Roman oil lamps, and are very rare today.

 

An exposure of Kokoamu Greensand, marine rocks now stranded far inland in a grassy hillside.

Our main target on this trip is a fossil penguin that Dr. Fordyce found exposed along a cliff face. With the bones visible in cross-section a meter up, the only way to get the fossils back to the lab is to cut them out of the rock.  Using a chainsaw, air scribes (aided by a gas powered compressor), picks and crowbars, we will slowly extract the fossil intact within the rock. In the montage below, you can see the start of the excavation.