golden spike

plural golden spikes

1. geographyA geologic marker created by a global event that leads to long lasting global changes recorded in the geologic record that can be used to indicate a change in a geologic time division such as an epoch, age, era.

   There was a further special problem when looking for a marker or definition of the Precambrian-Cambrian golden spike.

   2009, Susan Turner, David Oldroyd, chapter 13, in The Paleobiological Revolution: Essays on the Growth of Modern Paleontology, page 261

   1 more example

   The AWG is working backwards, Finney says: normally, geologists identify strata that should enter the geological timescale before considering a golden spike; in this case, they’re seeking out the lower boundary of an undefined set of geological layers.

   2022 December 13, McKenzie Prillaman, “Are we in the Anthropocene? Geologists could define new epoch for Earth”, in Nature, →DOI