Thesis Abstract and Dissertation Abstracts
Chemical and Microbiological study in the hyper-arid environment from Pampas de La Joya, Atacama Desert southern Peru, as a new analogue to Mars
Abstract Category: Science
Course / Degree: Philosophical Doctorate in Astrobiology/PhD
Institution / University: Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Mexico
Published in: 2009
The distribution of living organisms, organic matter, and chemical properties in Mars-like environments on Earth can be used as a model to guide the investigation of possible habitable environments on Mars.
This dissertation aims to demonstrate that Pampas de la Joya Desert, located along the Pacific coast of southern Peru between 15 and 17° S, is a possible analogue to Mars due to: 1) it is a hyper arid area comparable to Yungay in terms of its organic matter content, extreme environmental conditions, and presence of very low levels of microorganisms. 2) The mineralogical content of La Joya soils comes from Andean volcanic chains and exposed rocks from Precambrian gneisses and Cretaceous granitic batholiths surrounding the area. 3) Presence of microclimates and the “El Niño phenomena” effects allow the formation of an exotic and heterogeneous chemical composition in these soils, including iron oxides, sulphates and evaporatic minerals. 4) Thermal volatilization techniques applied to these soils, (similar to Viking and Phoenix spacecrafts), show high oxidant activity. 5) Great abundance of quartz and halite allow the growth of hypolithic and endolithic cyanobacteria communities similar to the Yungay region.
Environmental data showed a mean annual temperature of 28°C, precipitation of ~2 to 10 mm/y in the dryest areas with abrupt gradients within less than 100 km to values close to 100 mm/y, and an aridity index less than 0.05. Data from 485 soil samples showed that organic soil carbon ranged from 0.004 to 0.012% Carbon. Carbonate contents ranged from 0.017 to 0.14% Carbon. The dominant soil mineralogy shows three types of sources: volcanic, granitic and metamorphic, and the presence of sulfates was abundant. Thermal volatilization showed high organic decomposition to CO2 during the process, indicating oxidant activity. Microbiological studies show approximately ~104 -106 bacteria/g of soil. Colonies of cyanobacteria under the quartz and within halite rocks were also evident as described in other hyperarid regions. Altogether, the Pampas de la Joya in southern Peru is an interesting place for the astrobiologic study as an analogue to Mars.
Dissertation Keywords/Search Tags:
Analogues to Mars, Atacama Desert, hyperarid, extremophiles
This Dissertation Abstract may be cited as follows:
Valdivia-Silva, J.E., 2009. Chemical and Microbiological study in the hyper-arid environment from Pampas de Pampas de La Joya, Atacama Desert southern Peru, as a new analogue to Mars, PhD Thesis, Universidad Nacional Autonoma de Mexico, Mexico, 261 pp
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Pampas de La Joya southern Peru (click to enlarge) |
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Hypolitic cyanobacterias from Pampas de La Joya (click to enlarge) |
Submission Details: Dissertation Abstract submitted by Julio Valdivia-Silva from United States on 08-Dec-2010 23:42.
Abstract has been viewed 4642 times (since 7 Mar 2010).
Julio Valdivia-Silva Contact Details: Email: julvalsil@gmail.com Phone: +1-408-480-7533
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