D. R. Gregg’s research while affiliated with Canterbury Museum and other places

The bones reported from the Triassic of Mount Potts last century are indeterminable Ichthyosauria. No bones preserved in collections or seen on recent visits approach the large sizes reported by Hector. The names proposed for them by Hector, Lydekker and Chapman are either nomina nuda or were based on almost certainly non-diagnostic material which has subsequently been lost.Indeterminable ichthyosaurian centra from the Motuan Stage (Upper Albian) of Wairarapa district are the first Cretaceous ichthyosaurs to be reported from New Zealand.

When I wrote an historical account of the Tongariro volcanoes (Gregg, 1960, 1961) I felt confident that I had included all important references to the literature. Recently, when pursuing the history of the discovery of fossil reptiles in New Zealand, I discovered that I had made an important omission.

Deposits of Lower Eocene low-grade swelling bentonite of marine origin are widespread in North Canterbury.Large deposits of non-swelling bentonite, of Miocene age and probably formed by the alteration of glassy basalt ash deposited in a freshwater lake, occur in the Harper Hills, 40 miles west of Christchurch. The essential mineral is an iron-rich montmorillonite containing a minor, interlay er ed, non-expanding component and having about 100meq/100g cation exchange capacity saturated with calcium and magnesium ions. The bentonite can be converted to a high-grade swelling form by treatment with sodium carbonate.