Takatika Grit


The Takatika Grit is a geologic formation in Chatham Islands, New Zealand. It preserves fossils dating back to the Paleocene period, although it also preserves disturbed and re-worked Maastrichtian and Campanian microfossils and tetrapod fossils. A 2017 study found that it dated to late Early to Mid Paleocene on the basis of dinoflagellates. It has been subdivided into two informal units, a lower phosphatic unit containing bones and nodular phosphatic layers, and an upper unit with abundant sponge remains and siliceous microfossils.

Description

The two informal units are further subdivided into two units each, the lower is divided into the lower which consists of "poorly sorted, phosphatized grit with abundant phosphorite nodules and bones" and the upper which consists of "nodular bedded sandstone and grit". The upper biosiliceous unit is divided into the lower, which is heavily bioturbated, and the upper "characterized by parallel laminations and sinusoidal ripples".