Submitted as: model description paper 12 Feb 2021

Submitted as: model description paper | 12 Feb 2021

Review status: a revised version of this preprint is currently under review for the journal GMD.

ShellChron 0.2.8: A new tool for constructing chronologies in accretionary carbonate archives from stable oxygen isotope profiles

Niels J. de Winter1,2 Niels J. de Winter
  • 1Department of Earth Sciences, Utrecht University, Utrecht, the Netherlands
  • 2AMGC research group, Vrije Universiteit Brussel, Brussels, Belgium

Abstract. This work presents ShellChron, a new model for generating accurate age-depth models for high-resolution paleoclimate archives, such as corals, mollusk shells and speleothems. Reliable sub-annual age models form the backbone of high-resolution paleoclimate studies. In absence of independent sub-annual growth markers in many of these archives, the most reliable method for determining the age of samples is through age modelling based on stable oxygen isotope or other seasonally controlled proxy records. ShellChron expands on previous solutions to the age model problem by modelling seasonal variability in the proxy record using a combination of growth rate and temperature sinusoids in sliding window approach. This new approach creates smoother, more precise age-depth relationships for multi-annual proxy records with the added benefit of allowing assessment of the uncertainty on the modelled age. The modular script of ShellChron allows the model to be tailored to specific archives, without being limited to δ18Oc proxy records or carbonate archives, with high flexibility in assigning the relationship between the input proxy and the seasonal cycle. The performance of ShellChron in terms of accuracy and computation time is tested on a set of virtual seasonality records and real coral, bivalve and speleothem archives. The result shows that several key improvements in comparison to previous age model routines enhance the accuracy of ShellChron on multi-annual records while limiting its processing time. The current full working version of ShellChron enables the user to model the age of a 10-year long high-resolution (16 samples/yr) carbonate records with monthly accuracy within one hour of computation time on a modern personal computer. The model is freely accessible on the CRAN database and GitHub. Members of the community are invited to contribute by adapting the model code to suit their research topics.

Niels J. de Winter

Status: final response (author comments only)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on gmd-2020-401', Anonymous Referee #1, 31 Mar 2021
  • RC2: 'Comment on gmd-2020-401', Anonymous Referee #2, 20 Apr 2021
  • AC1: 'Final author response to review comments', Niels de Winter, 13 May 2021
    • EC1: 'Reply on AC1', Olivier Marti, 02 Jun 2021

Niels J. de Winter

Data sets

Supplement to: "ShellChron: A new tool for constructing chronologies in accretionary carbonate archives from stable oxygen isotope profiles" by Niels J. de Winter Niels J. de Winter

Niels J. de Winter


Total article views: 456 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
326 118 12 456 29 2 3
  • HTML: 326
  • PDF: 118
  • XML: 12
  • Total: 456
  • Supplement: 29
  • BibTeX: 2
  • EndNote: 3
Views and downloads (calculated since 12 Feb 2021)
Cumulative views and downloads (calculated since 12 Feb 2021)

Viewed (geographical distribution)

Total article views: 370 (including HTML, PDF, and XML) Thereof 370 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
Latest update: 21 Sep 2021