A volcanic chronosequence as a time-resolved paleo-detector array to study the cosmic-ray flux in the Late Pleistocene and Holocene

TL;DR

This study explores using volcanic olivine xenoliths as natural, time-resolved detectors to measure cosmic-ray flux variations over the last 40,000 years, revealing potential insights into historical astrophysical events.

Contribution

It introduces a novel application of paleo-detectors using volcanic samples to reconstruct cosmic-ray flux history over millennia.

Findings

Detectable nuclear recoil tracks in olivine indicate cosmic-ray flux variations.

Method can identify flux enhancements during geomagnetic excursions.

Potential to detect contributions from nearby supernovae.

Abstract

We present a phenomenological study demonstrating the feasibility of using olivine xenoliths from the Cha\^ine des Puys as a time-resolved paleo-detector array to probe the cosmic-ray flux over the last 40,000 years. This volcanic region provides a unique chronosequence of samples brought to the surface by well-dated eruptions. By modeling the expected density of nuclear recoil tracks induced by cosmic-ray muons in olivine, we show that the signal is detectable and above backgrounds from natural radioactivity. We demonstrate that by analyzing samples with different exposure ages, it is possible to construct a time-differential measurement of the cosmic-ray flux. This method shows sensitivity to historical variations, such as the enhanced flux expected during the Laschamp geomagnetic excursion ($\sim$41~kyr) and the potential contribution from nearby supernovae, for which we use the Antlia supernova remnant precursor as a benchmark. This work establishes a new application of the paleo-detector technique for long-scale time-domain high-energy astrophysics and provides the direct scientific motivation for experimental efforts to measure these track records.