This repository contains data representations of various geological timescales (GTS) for use with the Generic Mapping Tools (GMT) and GPlates.

The color palettes use RGB colours, follow the GMT formattting and are based on the specifications published by the International Commission for Stratigraphy (ICS) . They are available for geomagnetic and legacy geological time scales, with the formatting allowing easy conversion and comparison of stratigraphic and absolute ages.

Currently, the following incarnations of the geological time scale are covered (some only partly):

  1. ICS GTS2012 time scale (link to PDF)
  2. ICS GTS2004 (Gradstein, 2004)
  3. Exxon88: The old Exxon/Haq timescale from 1988. (Haq et al., 1988)

Using the GeoTime CPTs

Clone or download the repository (see "Usage" below). In GMT or GPlates you can then simply load the GeoTimeCPTs as color palettes.

Check my TectonicWaters blog for examples of how these color scales can be used with GPlates and GMT:

The cpts are also accessible through cpt-city with the direct link to the cpts being the "Heine collection" here.

Contributions to extend the coverage of timescales and to the repository are welcome.

This repository

The GeoTimeCPTs repository, wiki and forum are hosted using the Fossil source code management software.

A GIT Mirror exists on my Sourcehut account here: **If you are accessing this repository on Sourcehut under the following URL: note that this is a downstream mirror of the original Fossil repository**. Please use the original repository for documentation, issues, and a forum. I have deleted my git clones on GitHub and BitBucket in favour of hosting privately and on Sourcehut.


This repository is hosted using the self-contained Fossil distributed version control software which has some minor differences to the popular GIT repositories:

Tickets and forum can be used anonymously, however, users can also create an account.

To clone the repository, you have to install Fossil first. The workflow is similar to git, yet you will also have access to the wiki, documentation, and tickets in one go:

  • fossil clone geotimecpts
  • cd/mkdir to the directory which you want to be the root of your directory tree for this repository, then
  • fossil open <path>/<to>/<gptools clone>/geotimecpts.fossil

For detailed instructions, please see the Fossil Quick Start guide.


The GeoTimeCPTs (cpt files, scripts, images) are licensed under a GNU Public License v3. See LICENSE.txt.

The following files are covered by separate licenses/copyright and are explicitly excluded from the above license:

(c) [Christian Heine](, 2012-2023