Analogs for Planetary Exploration
Travertine and tufa from Dalhousie Springs (Australia)—Implications for recognizing Martian springs
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Published:December 01, 2011
Thermal spring deposits are features of considerable interest to Mars scientists because of their potential as astrobiological oases and as records of the paleohydrology of the planet. Terrestrial counterparts can assist in recognizing such features on Mars and in developing technologies for their study and sampling. In this paper, we describe one such analog, the Dalhousie Springs complex in central Australia. The Dalhousie Springs complex is one of largest groundwater discharge landforms known on Earth. It is a carbonate-limited precipitation system due to the non-supersaturated ascending water. Spring carbonates are deposited as discrete mounds and outflow channels resting unconformably on older units. Although subject to postformation geomorphic modification, the spring deposits persist in the landscape and are recognizable long after the parental spring has shut down. We identify 14 specific microfacies belonging to seven facies, which form three environmental associations related to specific depositional environments. Diagenesis has occurred in several stages, as evidenced by distinctive textures on the deposits. Spring deposits on Mars would potentially be recognized by similar textures (although compositions may be quite different) and similar geomorphic relationships. However, in satellite images, spring deposits may be difficult to differentiate from deposits resulting from other processes that produce similar geomorphic features, including mud volcanoes, pingos, and rootless cones. Mineralogical data may assist, but ultimately ground truth will be required.
- astrobiology
- Australasia
- Australia
- carbonate rocks
- chemically precipitated rocks
- depositional environment
- diagenesis
- discharge
- geomorphology
- Great Artesian Basin
- ground water
- hot springs
- landforms
- limestone
- Mars
- microbialite
- microfacies
- outflow channels
- paleohydrology
- petrography
- planets
- sedimentary rocks
- springs
- terrestrial analogs
- terrestrial planets
- thermal waters
- travertine
- tufa
- Dalhousie Springs