Strontium Isotope Stratigraphy: LOWESS Version 3: Best Fit to the Marine Sr‐Isotope Curve for 0–509 Ma and Accompanying Look‐up Table for Deriving Numerical Age

TLDR

The marine 87Sr/86Sr record for the Triassic and Paleozoic (0–509 Ma) was previously omitted due to sparse data. The study compares the new LOWESS fit and look‑up table to earlier versions and examines geological implications of the 87Sr/86Sr record. The updated LOWESS fit and look‑up table (V3) provide accurate age–isotope conversions with 95 % confidence intervals and have been demonstrated to be useful in strontium isotope stratigraphy.

Abstract

An improved and updated version of the statistical LOWESS fit to the marine 87Sr/86Sr record and a revised look‐up table (V3:10/99; available from [e-mail]) based upon it enables straightforward conversion of 87Sr/86Sr to numerical age, and vice versa, for use in strontium isotope stratigraphy (SIS). The table includes 95% confidence intervals on predictions of numerical age from 87Sr/86Sr. This version includes the Triassic and Paleozoic record (0–509 Ma) omitted from previous versions because of the paucity of adequate data at the time of preparation. We highlight differences between the previous versions of the table and the current version and discuss some aspects of the 87Sr/86Sr record that may have geological significance. We give examples of how the table can be used and where it has proven useful.