Analysis of chemical biosignatures in rock
EMSL Project ID
2057
Abstract
We are developing strategy and methods for non-Earthcentric life detection. We define biosignatures as measurable chemistry and structures found over several scales of observation. We are presently focusing on the chemical biosignatures present in rocks that distinguish life from past life or non-life. We propose to use EMSL facilities to study the distribution of chemical elements in rocks colonized by microbial communities. We have been using high res. ESEM with EDS spectroscopy first, then probing samples with other techniques that have higher spatial or spectral resolution. At EMSL, we'd like to use TOF-SIMS for study of four different samples with geobiological relevance:1. We have data obtained from a layered microbial community in an Antarctic sandstone rock. We collected data from the surfaces of quartz grains removed from each layer of the community and observed different abundances of elements associated with organisms than are found in parts of the rock with no organisms.2. Using ESEM and XPEEMS, we’ve studied ovoid clastic features in a manganese deposit from the Kalahari Desert. These features may be biogenic, and the high spatial and spectral resolution of TOF-SIMS could shed light on their origin. 3. The controversial SNC meteorite ALH84001 has never been chemically examined in a detailed way. This type of study would allow us to do a complete three-dimensional study of chemical elements associated with morphologies that some investigators are claiming to be evidence of life. Such a study will be crucial in either lending support or refuting these arguments. 4. Geologist Robert Folk has sent us samples of what he terms nano-bacteria. We can argue for or against structures this small being deemed life by studying the 3-D distribution of chemical elements associated with structures that look biological.The projects I’ve described are just a few of the possibilities we envision resulting from a collaboration between our group at JPL and EMSL.
Project Details
Project type
Exploratory Research
Start Date
2000-10-04
End Date
2001-04-01
Status
Closed
Released Data Link
Team
Principal Investigator