Onerahi chaos-breccia of Northland

Abstract

Ferrar's Onerahi and Otamatea formations have been shown recently to be olisto stromes, composed predominantly of a near-surface incompetent sheared chaotic breccii of rocks of Upper Cretaceous - Miocene age, with the following features: The lithologic term “chaos-breccia” is proposed for such beds, and as the type locality of the Onerahi Formation is typical the term “Onerahi” is retained. The formation is therefore renamed the “Onerahi Chaos-breccia”.