HR: 0800h
AN: B51B-0373    [Abstracts]
TI: 2D Process-based Microbialite Growth Model
AU: * Airo, A
EM: aairo@stanford.edu
AF: Stanford University, Department of Geological and Environmental Sciences 450 Serra Mall Bldg 320, Rm 118 Stanford, CA 94305-2115, Stanford, CA 94305, United States
AU: Smith, A
EM: awsmith@stanford.edu
AF: Stanford University, Thermal Sciences Division of the Mechanical Engendering Department Bldg. 520, Rm. 521E, Stanford, CA 94305, United States
AB: A 2D process-based microbialite growth model (MGM) has been developed that integrates the coupled effects of the microbialite growth and sediment distribution within a two-dimensional cross-section of a subaqueous bedrock profile. Sediment transport is realized through particle erosion and deposition that are a function of local wave energy which is computed on the basis of linear wave theory. Surface-normal microbialite growth is directly correlated to light intensity, which is computed for every point of the microbialite surface by using a Henyey- Greenstein-type relation for scattering and the Beer's Law for absorption in the water column. Shadowing effects by surrounding obstacles and/or overlying sediment are also considered. Sediment particles can be incorporated into the microbialite framework if growth occurs in the presence of sediment. The resulting meter-size microbialite constructs develop morphologies that correspond well to natural microbialites. Furthermore, changes of environmental factors such as light intensity, wave energy, and bedrock profile result in morphological variations of the microbialites that would be expected on the basis of the current understanding of microbialite growth and development.
DE: 0406 Astrobiology and extraterrestrial materials
DE: 0408 Benthic processes (4804)
DE: 0456 Life in extreme environments
DE: 0466 Modeling
SC: Biogeosciences [B]
MN: 2007 Fall Meeting