Cedric J. Hagen*
College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, Oregon 97331, USA,
and Geological Sciences Department, University of Colorado Boulder, Boulder, Colorado 80309, USA
Jessica R. Creveling
College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, Oregon 97331, USA
Peter Huybers
Dept. of Earth & Planetary Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
Abstract
Stratigraphic correlation underpins all understanding of Earth’s history, yet few geoscientists have access
to, or expertise in, numerical codes that can generate reproducible, optimal (in a least-squares framework)
alignments between two stratigraphic time-series data sets. Here we introduce Align, a
user-friendly computer app that makes accessible a published dynamic time warping (DTW) algorithm that, in a
minute or less, catalogs a library of alignments between two time-series data sets by systematically
exploring assumptions about the temporal overlap and relative sedimentation rates between the two
stratigraphic sections. The Align app, written in the free, open-source R programming language,
utilizes a graphical user interface (e.g., drop-down menus for data upload and sliding bars for parameter
exploration) such that no coding is required. In addition to generating alignment libraries, a user can
employ Align to visualize, explore, and cull each alignment library according to thresholds on
Pearson’s correlation coefficient and/or temporal overlap. Here we demonstrate Align with
time-series records of carbonate stable carbon isotope composition, though Align can, in principle,
align any two quantitative stratigraphic time-series data sets.
*Cedric.Hagen@Colorado.edu
CITATION: Hagen, C.J., Creveling, J.R., and Huybers, P., 2024, Align: A User-Friendly App for
Numerical Stratigraphic Correlation: GSA Today, v. 34, p. 4–9, https://doi.org/10.1130/GSATG575A.1 © 2024 The Authors. Gold
Open Access: This paper is published under the terms of the CC-BY-NC license. Printed in USA.
Manuscript received 23 June 2023. Revised manuscript received 4 Oct. 2023.
Manuscript accepted 11 Dec. 2023. Posted 16 Jan. 2024.
© The Geological Society of America, 2024. CC-BY-NC.
https://doi.org/10.1130/GSATG575A.1