Volumetric extrusive rates of silicic supereruptions from the Afro-Arabian large igneous province

Abstract

The main phase of silicic volcanism from the Afro-Arabian large igneous province preserves some of the largest volcanic eruptions on Earth, with six units totaling >8,600 km3 dense rock equivalent (DRE). The large volumes of rapidly emplaced individual eruptions present a case study for examining the tempo of voluminous silicic magma generation and emplacement. Here were report high-precision 206Pb/238U zircon ages and show that the largest sequentially dated eruptions occurred within 48 ± 34 kyr (29.755 ± 0.023 Ma to 29.707 ± 0.025 Ma), yielding the highest known long-term volumetric extrusive rate of silicic volcanism on Earth. While these are the largest known sequential silicic supereruptions, they did not cause major global environmental change. We also provide a robust tie-point for calibration of the geomagnetic polarity timescale by integrating 40Ar/39Ar data with our 206Pb/238U ages to yield new constraints on the duration of the C11n.1r Subchron.

Diffuser: A user-friendly program for diffusion chronometry with robust uncertainty estimation

“…Radiometric dating is routinely used to determine timescales on the order of a few million years and, less frequently, tens to a few thousand years or shorter (e.g., Burgess et al, 2014;Li et al, 2017;Thines et al, 2021). For rapid geological events with shorter timescales (e.g., hours, days, months, and years), constraining their timescales via radiometric dating is very challenging (or even impossible) and requires ultra-high temporal resolution.…”