The Waipu Cove unconformity

East of Waipu Cove, Late Jurassic hardened sandstone and argillite (hardened clay) of the Waipapa Terrane are unconformably overlain by gently dipping Whangarei Limestone, of Oligocene age. The limestone is about 120 million years younger than the basement rocks it overlies. The Oligocene was a time when New Zealand (or Zealandia) was mostly submerged under the sea, and limestones of this age are widespread throughout New Zealand. The limestone accumulated on the continental shelf, from the remains of animals including bryozoa, echinoids, coralline red algae, molluscs and foraminifera.

Look for the actual unconformity contact between the limestone and the underlying basement rocks - it is marked by a thin band of breccia (fragmented pieces of rock) and yes, you can actually touch this surface which represents a gap in the record of 120 million years. The limestone is mainly fossil fragments but if you look hard you may find a complete fossil echinoid (sea urchin), or a fossil mollusc.