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While it remains uncertain whether excursions in the stable carbon isotopic composition of Ediacaran marine carbonate (δ13Ccarb) represent globally synchronous events (or a direct measure of ocean carbon cycling), the absence of widely distributed and readily preservable fauna, and the presence of several iconic carbon isotope excursions (CIEs), has sustained δ13Ccarb correlation as the primary means to establish relative time relationships for Ediacaran successions. Here we present an Ediacaran global δ13Ccarb composite built with a dynamic time warping (DTW) time-normalization algorithm that generates libraries of least-squares alignments between chemostratigraphic records of unequal length and distinct sediment accumulation rates. When developing a δ13Ccarb composite for each of 16 globally distributed Ediacaran paleo-depositional regions, we selected high Pearson r alignments that conformed with published geological guidance about the correlation of constituent sections. When applying DTW to align these regional algorithmic composites into one global δ13Ccarb stack, we selected alignments that allied the excursions that field workers have established (or speculated) are the Marinoan cap carbonate excursion, the Shuram excursion, and/or the basal Cambrian excursion. There are strengths and weaknesses to making explicit the temporal relationships (point-to-point correspondences) often left implicit in visual correlation. One strength is to extrapolate depositional ages by means of isotopic correlation, and here we explored this with a Bayesian Markov chain Monte Carlo age model that predicts a median age, and uncertainty, for every carbonate stratum in the global Ediacaran δ13Ccarb composite. Yet, one must caution against a false accuracy that can arise from selecting one alignment among many possibilities––the likelihood that time-uncertain time series can be stretched and squeezed into one unequivocal alignment is low. Thus, while these alignments are grounded in the expert assessment of the field worker, this global Ediacaran δ13Ccarb–Bayesian age model should be viewed as a working hypothesis to enrich, but not arbitrate, discussions of the correlation, synchrony, and completeness of Ediacaran successions. 

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.