Theme I - Field Investigations

The RPL team will unravel feedbacks between hydrological, geochemical and biological processes that give rise to habitability during low-temperature W/R interactions by conducting studies in serpentinizing systems.

Low-temperature serpentinizing systems field sites

There are 3 sites that the RPL team have identified as excellent Astrobiological targets for investigation of ecosystems supported by water-rock interactions, the Coast Range Ophiolite CROMO in California, the Samail Ophiolite in Oman, and the Atlantis Massif, 15 km from the Mid-Atlantic Ridge. These 3 sites are focused around the theme of low-temperature “Serpentinizationâ€. RPL NAI members are also conducting fieldwork in other complementary water/rock hosted ecosystems such as Yellowstone National Park, Great Salt Lake, Robertson Glacier, Edgar Mine Classroom.

The RPL team is using these sites as collaborative test-beds for efforts in life-detection and biosignature formation for the entire NAI community.

CROMO

Continental tectonic mélange including peridotite

Peridotite Environment to be accessed: Shallow cores and wells (20m) accessing pH 7 to pH 12.7 water. Temperature 13-18°C

Water/Rock ratio: High water fluxes: large inputs & high permeability

Gas Characteristics: Comparatively low (nM) H2 concentrations, high (mM) CH4

Oman

Continental intact peridotite (km deep)

Peridotite Environment to be accessed: Deep (300m) cores and wells accessing pH 8 to 12.5 waters along a reaction path. Temperature ~40-50°C

Water/Rock ratio: Low water fluxes: low inputs and high storativity

Gas Characteristics: Moderate (µM) H2 and (µM) CH4 concentrations;  low flux of oxidants such as HCO3- and SO42-

Atlantis Massif

Submarine, slow spreading mid ocean ridge

Peridotite Environment to be accessed: Core recovery from 10-12 sites. Temperature ~40-90°C

Water/Rock ratio: High water fluxes: channelized fluid flow?

Gas Characteristics: High (mM) H2 and greater flux of oxidants such as HCO3- and SO42-