The Soil Geochemistry in the Beardmore Glacier Region, Antarctica: Implications for Terrestrial Ecosystem History.

W B Lyons,G Michalski,K A Welch,S A Welch,B J Adams,U Nielsen,W W Walters,D H Wall,K Deuerling,I Hogg

doi:10.1038/srep26189

Abstract

Although most models suggest continental Antarctica was covered by ice during the Last Glacial Maximum (LGM) it has been speculated that endemic species of soil invertebrates could have survived the Pleistocene at high elevation habitats protruding above the ice sheets. We analyzed a series of soil samples from different elevations at three locations along the Beardmore Glacier in the Transantarctic Mountains (in order of increasing elevation): Ebony Ridge (ER), Cloudmaker (CM), and Meyer Desert (MD). Geochemical analyses show the MD soils, which were exposed during the LGM, were the least weathered compared to lower elevations, and also had the highest total dissolved solids (TDS). MD soils are dominated by nitrate salts (NO3/Cl ratios >10) that can be observed in SEM images. High δ17O and δ18O values of the nitrate indicate that its source is solely of atmospheric origin. It is suggested that nitrate concentrations in the soil may be utilized to determine a relative “wetting age” to better assess invertebrate habitat suitability. The highest elevation sites at MD have been exposed and accumulating salts for the longest times, and because of the salt accumulations, they were not suitable as invertebrate refugia during the LGM.

Highlights

Samples were collected from three locations: Ebony Ridge (ER) in the Mt. Kyffin region, the Cloudmaker (CM), and the Meyer Desert (MD) (Fig. 1; Table 1)
If we use the same NO3− flux for the Dominion range determined by Lyons et al.[17] for the CM and Ebony Ridge (ER) sites, the accumulated NO3− yields wetting ages between 20–23,000 years at CM and between 56 and 63 years for ER. These findings suggest that the lower ice-free locations along the Beardmore receive more precipitation and/or melt
Soil samples analyzed from the Beardmore Glacier area of the central Transantarctic Mountains (TAM) of Antarctica have very different geochemical characteristics

Summary

Introduction

Samples were collected from three locations: Ebony Ridge (ER) in the Mt. Kyffin region, the Cloudmaker (CM), and the Meyer Desert (MD) (Fig. 1; Table 1). The results are similar to what has been observed in other soil studies, both in the central TAM and other parts of Antarctica, in that the highest elevation soils have very high nitrate concentrations, and dominate the soluble The “wetting age” of our sample locations and their elevation during the LGM is important for determining their potential to serve as refugia.

Results

Conclusion