HR: 0800h
AN: P51D-0947 [Abstracts]
TI: Soil organic matter in the subsurface of the driest core of the Atacama Desert: Yungay,
Chile
AU: * de la Rosa, J
EM: delarosa@nucleares.unam.mx
AF: Laboratorio de QuĦmica de Plasmas y Estudios Planetarios, Instituto de Ciencias Nucleares, Universidad
Nacional Aut˘noma de Mxico, Circuito Exterior, Ciudad Universitaria, Mexico City, 04510
Mexico
AU: Molina, P
EM: paolam@nucleares.unam.mx
AF: Laboratorio de QuĦmica de Plasmas y Estudios Planetarios, Instituto de Ciencias Nucleares, Universidad
Nacional Aut˘noma de Mxico, Circuito Exterior, Ciudad Universitaria, Mexico City, 04510
Mexico
AU: Navarro-González, R
P51D-0947
AF: Laboratorio de QuĦmica de Plasmas y Estudios Planetarios, Instituto de Ciencias Nucleares, Universidad
Nacional Aut˘noma de Mxico, Circuito Exterior, Ciudad Universitaria, Mexico City, 04510
Mexico
AU: McKay, C
EM: cmckay@mail.arc.nasa.gov
AF: Space Science Division, NASA-Ames Research Center, NASA-Ames Research Center, Space Science Division,
Moffett Field, CA 94035
United States
AB:
The Atacama desert is one of the driest places on Earth. Geological studies indicate that the aridity in the region has
prevailed for more than 10-15 millions years ago making it one of the oldest deserts in the world. The arid core of the
Atacama Desert located in Yungay, Chile contains Mars-like soils that have undetectable bacterial populations, low organic
concentrations, and the presence of a non-chirally specific oxidant (Navarro-Gonz lez, et al., 2003, Science 302, 1018-1021).
Here we report a study of the organic content in the soil at various depths ranging from 10 to 140 cm in four soil pits in
Yungay. For comparison we have also studied the variation of organic matter with depth in other regions of the Atacama
Desert with more humidity (e.g., the Pacific Coast and about 200 km south of Yungay). The organic matter was determined by
pyr-GC-MS and oxidation with potassium permanganate in aqueous medium. The results show that the organic content in the soil
increases with the depth but there is variability within soil pits in the same region. We are currently characterizing the
chemical nature of this subsurface organic matter.
DE: 5200 PLANETARY SCIENCES: ASTROBIOLOGY
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: Fall Meeting 2005