New Zealand Geological Timescale 2024 project passes the halfway milestone
The New Zealand Geological Timescale (NZGT) 2024 project is a collaboration between GNS Science and New Zealand Universities
The project is intended to run through the current calendar year, recently reaching the halfway point milestone.
20 years since landmark timescale
It has been just about twenty years since the release of the landmark timescale monograph(external link) edited by the late Roger Cooper that provided absolute age calibrations for all the local New Zealand age units. In that time, the international community has diligently released updated versions of the Gradstein volumes, with the most recent in 2020.
On our own continent, New Zealand geologists have been continuing their studies of our own fossil biodiversity, garnering new radiometric dates, and generally expanding our understanding of its history. During that time, two initiatives to update the New Zealand timescale from Cooper were undertaken and published; the first was led by Chris Hollis in 2010 and the second by Ian Raine in 2015.
The NZGT 2024 project aims to provide the next update to the current timescale, however it is not seeking to produce another Cooper-style monograph. Instead, this update aims to go beyond simply tweaking the numbers presented in the most recent update, Raine et al 2015, but aims to strike a balance between building on previous work and introducing something new. Keep an eye out for updates as the project continues.
Geological Timescales
Used to work out rates of geological processes and events, such as earthquakes, eruptions, submergence, uplift, erosion, sea-level change, climate history, biodiversity change and organic evolution, geological timescales assign ages to rocks, fossils and minerals.
The age of New Zealand’s oldest rocks ranges from about 500 million years ago, to the most recent period known as the Quaternary, which spans from 2.6 million years ago to the present.
Dating of rocks is determined through a combination of analysing the fossils contained within rock units and the process of radiometric dating that measures the proportions of particular isotopes of elements in the rocks.
