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2015 Annual Science Report

SETI Institute Reporting  |  JAN 2015 – DEC 2015

Characterization of Habitability and Biosignature Preservation in Cold Springs

Project Summary

In an increasingly colder Mars where permafrost was thickening, mineralizing cold springs could have provided extant subsurface habitats and a means to transport evidence of subsurface life to the surface. Depending on conditions and geochemistry, these precipitates could have encapsulated a record of past life, and the residual remnants of such spring mounds could still be exposed at the martian surface. On Earth, high latitude spring systems are rare due to the relatively impermeable permafrost. However, several groups of perennial springs are located at Axel Heiberg Island in the Canadian High Arctic (~80°N). With mean annual air temperatures of -17°C and permafrost depths ≥ 600 meters, these springs flow throughout the year despite minimum air temperatures reaching <-50°C during winter. Thick residual icing pastes form as a result of evaporation, sublimation and freeze fractionation, the mineralogy being dominated by halite, hydrohalite, calcite, gypsum, elemental sulfur, thenardite, and mirabilite. These springs provide an environment where prokaryotes thrive despite extreme conditions and their presence suggests that such systems could have been present throughout Mars history, and activated during cyclical climate changes.The primary goal of this investigation is to evaluate the potential of spring deposits in regions with thick, continuous permafrost and define their taphonomic window and biogeological context. Samples of icing pastes, travertine and other mineral precipitates have been sampled to understand the relationships between geochemistry, environment, presence of biosignatures and their potential preservation.

4 Institutions
3 Teams
0 Publications
1 Field Site
Field Sites

Project Progress

Initial field investigations for this project were carried out in July 2015 at three perennial springs sites and one paleo-spring site located at Axel Heiberg Island in the Canadian High Arctic.

Figure 1. Location Map
Figure 1. Location Map

Working from the McGill Arctic Research Station (M.A.R.S.) which has a long history of supporting science in this remote region (Pollard et al. 2009), Dale Andersen and Pablo Sobron had a goal of conducting in situ measurements using IR and Raman spectroscopy, collecting samples of sediments and mineral precipitates for additional laboratory-based studies and collecting environmental data for context. Studies were undertaken at Gypsum Hill springs, Colour Peak springs, Wolf Diapir springs and a paleo-spring deposit near the White Glacier. Concurrent with sampling, they deployed a Raman spectrometer and an IR reflectance spectrometer at all four locations, recording 100+ Raman spectra and 50+ IR reflectance spectra at each of the sites.

Figure 2. Colour Peak Springs - The Colour Peak Springs are located on the south- facing slope of Colour Peak at an approximate elevation of 100 m a.s.l., emerging from the top of the slope along a line nearly 400 m long. These springs are grouped into three distinct topographically controlled areas with 20 vents discharging directly into Expedition Fiord 300 m down slope. Interestingly, the springs on Axel Heiberg Island flow all year with little variation in their temperature and are not associated with volcanic activity.
Figure 3. Collecting IR Spectra at the paleospring site - Pablo Sobron using a field-portable IR Spectrometer in an area with chaotic limestone breccia with calcite infillings in pores and calcite veins with sulfides, mostly as pyrite (FeS2). In the background is the White Glacier. Their geomorphology, mineralogy and texture suggest that the veins represent the remnant roots of ancient (pre-glacial) set of perennial springs which have been exposed by erosion. Initial observations suggest that the ancient deposits intersect several of the same geologic units as the modern springs. Such chaotic breccias develop along the periphery of salt domes.

Figure 4. Wolf Diapir Springs - The Wolf Diapir site is characterized by a large mound of salt 3m in height and 3m in diameter that forms “fumarole- like” structure. A saltpan extends about 0.5 km to the west. Water is present as a pool in the central portion of the structure, and during the winter months as temperatures decrease, the water level builds up and flows out and over the top producing a series of small terraces and rim pools on the NNE side of the structure. Increasing air temperatures in the summer allow for the dissolution of the salts (such as hydrohalite), and the spring water breaks through the sides and is released at the base lowering the water level. Water flowing beneath and through the side of the structure is saline with a temperature of -3.5°C, pH of 6.4, and ORP of 60.0 (mV, NHE). Hydrogen sulfide is present in and around the discharge site.

They identified gypsum, iron sulfates, kerogens, elemental sulfur, organics, halite, hydrated, iron sulfates, and thenardite. We observed transformation during transport field-to-camp (dehydration/hydration, possible oxidation). We are currently refining the interpretation of the Raman and IR data, and exploring correlation of IR data with ASTER and Hyperion orbital data. In 2016 we will share samples with members of the NAI team who will perform additional lab characterizations (ESEM, XRD, XRD, LIBS).

Figure 5. Raman spectra at Gypsum Hill. The spectra show emission bands from gypsum, elemental sulfur, and organic compounds. These set of spectra show evidence of end- and intermediate-products of a sulfide-to-sulfate oxidation pathway; a pathway that may be biomediated.
Figure 6. IR reflectance spectra at Gypsum Hill. The IR spectra show vibrations typical of gympsum and other sulfates. The IR results confirm the mineral identification obtained through Raman spectroscopy (see Fig 5).

    Dale Andersen Dale Andersen
    Project Investigator
    Pablo Sobrón

    Wayne Pollard

    Objective 2.1
    Mars exploration.

    Objective 4.1
    Earth's early biosphere.

    Objective 7.1
    Biosignatures to be sought in Solar System materials