HR: 11:35h
AN: P42B-06    [Abstracts]
TI: Pavilion Lake, British Columbia, Canada - An investigation of potentially unique freshwater microbialites, and their application to Mars exploration.
AU: * Lim, D S
EM: dlim@mail.arc.nasa.gov
AF: NASA Ames Research Center, MS 245-3, Moffett Field, CA 94025
AU: Laval, B
EM: blaval@civil.ubc.ca
AF: Civil Engineering, UBC, 2324 Main Mall, Vancouver, ON V6T 1Z4
AU: Slater, G
EM: gslater@mcmaster.ca
AF: McMaster University, 1280 Main Street W, Hamilton, ON L8S 4K1
AU: Andersen, D
EM: dandersen@seti.org
AF: SETI, 515 N Whisman Road, Mountain View, CA 94043
AU: Airo, A
EM: aairo@stanford.edu
AF: Stanford University, Building 320, Rm118, Stanford, CA 94305
AU: Mullins, G
EM: gkm@sfu.ca
AF: Simon Fraser Univ, 8888 University Dr., Burnaby, BC V5A 1S6
AU: Schulze-Makuch, D
EM: dirksm@wsu.edu
AF: Washington State University, #1148 PO Box 642812, Pullman, WA 99164
AU: Cady, S
EM: cadyl@pdx.edu
AF: Portland State Univ, 1721 SW Broadway, Portland, OR 97201
AU: McKay, C
EM: cmckay@mail.arc.nasa.gov
AF: NASA Ames Research Center, MS 245-3, Moffett Field, CA 94025
AB: Pavilion Lake, B. C., Canada has become the first target site of an on-going NASA effort to investigate the Mars analogue potential of terrestrial lacustrine carbonates. A combination of hypothesis and exploration driven research activities are underway to study the unusual freshwater microbialite structures found in this lake. These structures are of interest in terms of models of Precambrian reefs and may also be relevant to carbonate formation in ancient lakes on Mars. Laval et al. (2000) provides an overview of the morphological characteristics of the microbialites, and explores the physical limnology of Pavilion Lake. Several key hypotheses and questions related to the role of biology in the formation of the microbialites, and the effect of varying light levels on the microbialite morphologies have since resulted from Laval et al., but to date remain unanswered. In August 2004, the Pavilion Lake Research Project (PLRP) was established to commence a new round of investigations into Pavilion Lake, to test hypotheses concerning the factors controlling carbonate formation, and to collect further exploration data related to understanding the lake's limnology and development. Laval et al. classified the differing microbialite structures into four depth categories: shallow to intermediate (5-10m), intermediate (~20m), intermediate to deep (20-30m), and deep facies (30-35m). There is a variation of the morphology and mechanical strength of the structures with depth, which may reflect a change in the relative role of biotic and non-biotic precipitation with lowering light levels. Recent field investigations (August 2005) revealed carbonate structures at depths beyond what was reported in Laval et al. (2000). These new structures appear at 46-55m, and are morphologically distinct from the previously described microbialites. Here we present our current research activities at Pavilion Lake, along with recent data collection results. Excursions to the lake have included the use of SCUBA to sample collect and to install a variety of sensors including a thermistor chain and a Licor light meter. Seepage meters have also been placed in strategic regions of the lake to collect incoming lake groundwater for future chemical limnological analyses and hydrological mapping of the area. In addition, conventional Conductivity/Temperature/Depth (CTD) profiles and water sampling has been conducted during a winter and summer period, and will be presented here. Microbialite samples recovered from each of the discernible morphological depth transects have been investigated for relative variations in d13C isotopic signatures, and the results will presented here.
UR: http://supercritical.civil.ubc.ca/~pavilion/
DE: 5215 Origin of life
SC: Planetary Sciences [P]
MN: Fall Meeting 2005