Compositional and spectroscopic investigation of reactive gossans on Axel Heiberg Island, NU, Canada, as iron-rich Mars analog environments of astrobiological interest

Context:

Gossans are superficial geological formations that result from the oxidation of sulfide ore deposits by fluids, such as meteoric water or hydrothermal solutions. Gossans occur in all climatic zones, but gossans located in the permafrost undergo seasonal chemical weathering after their initial formation and are thus called “reactive” gossans. The seasonal chemical weathering occurring at reactive gossans should provide a sustained energy source for microbial activity living in such neutral to acidic environments. Gossans are thought to have formed on Mars as well, as sulfide-bearing magmas, meteoric water and hydrothermal solutions were present in the planet’s past. The present-day permafrost present on Mars could have led to the formation of reactive gossans, providing a potential environment for sustained microbial activity. Reactive gossans could thus be prime targets for future missions looking for signs of past life on Mars.

However, while hundreds of gossans have been identified in the Arctic, few have been studied in detail and even fewer have been studied using rover-compatible remote sensing instruments. Thus, their formation and evolution processes, the microbial activity they host, as well as their potential characterization using remote sensing instruments are poorly understood. In 2022 and 2023, the T-MARS (Terrestrial Mineral Analysis by Remote Sensing) team conducted field work at Expedition Fiord, on Axel Heiberg Island, Nunavut, to locate gossans and acquired samples to be further studied in laboratories. Some of these samples have not yet been analyzed.

Main goal and work:

The goal of this internship is to analyze gossan samples that have not yet been analyzed by the T-MARS team and compare the results with samples that the team previously characterized. Analyses will focus on determining the geochemistry, mineralogy, and the organic carbon content in the samples using X-ray fluorescence, X-ray diffraction, visible to thermal infrared reflectance and Raman spectroscopy. This internship will introduce the student/trainee to research in geology, astrobiology and planetary sciences, focusing on sample characterization with rover-compatible remote sensing instruments.

Deliverables:

Laboratory results in a usable format (.xls, .csv or equivalent).

Internship report.

Applying:

Send a CV, academic transcripts and a motivation letter to Prof. Myriam Lemelin (Myriam.Lemelin@USherbrooke.ca). Deadline to apply: August 30th, 2025.