Temperatures recorded by cosmogenic noble gases since the last glacial maximum in the Maritime Alps

This is a Preprint and has not been peer reviewed. The published version of this Preprint is available: https://doi.org/10.1017/qua.2018.109.

Downloads

Download Preprint

Supplementary Files
Authors

Marissa Marie Tremblay , David L. Shuster, Matteo Spagnolo, Hans Renssen, Adriano Ribolini

Abstract

While proxy records have been used to reconstruct late Quaternary climate parameters throughout the European Alps, our knowledge of deglacial climate conditions in the Maritime Alps is limited. Here, we report temperatures recorded by a new and independent geochemical technique—cosmogenic noble gas paleothermometry—in the Maritime Alps since the last glacial maximum. We measured cosmogenic 3He in quartz from boulders in nested moraines in the Gesso Valley, Italy. Paired with cosmogenic 10Be measurements and 3He diffusion experiments on quartz from the same boulders, the cosmogenic 3He abundances record the temperatures these boulders experienced during their exposure. We calculate effective diffusion temperatures (EDTs) over the last ∼22 ka ranging from 8°C to 25°C. These EDTs, which are functionally related to, but greater than, mean ambient temperatures, are consistent with temperatures inferred from other proxies in nearby Alpine regions and those predicted by a transient general circulation model. In detail, however, we also find different EDTs for boulders from the same moraines, thus limiting our ability to interpret these temperatures. We explore possible causes for these intra-moraine discrepancies, including variations in radiative heating, our treatment of complex helium diffusion, uncertainties in our grain size analyses, and unaccounted-for erosion or cosmogenic inheritance.

DOI

https://doi.org/10.31223/osf.io/aev5c

Subjects

Earth Sciences, Geochemistry, Geomorphology, Glaciology, Other Earth Sciences, Physical Sciences and Mathematics

Keywords

paleoclimatology, Quaternary, Europe, Cosmogenic isotopes

Dates

Published: 2017-11-24 08:23

Last Updated: 2018-12-13 11:04

Older Versions
License

CC BY Attribution 4.0 International

Add a Comment

You must log in to post a comment.


Comments

There are no comments or no comments have been made public for this article.