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HR: 0800h
AN: B31B-0998
TI: Fluorescent signatures of 2 Ma old
travertine deposits in Death Valley, CA
AU: * Adachi, T
B31B-0998
AF: Catholic University of America, Department of
Physics, 200 hannan hall, Washington, DC 20064 United States
AU: * Adachi, T
B31B-0998
AF: NASA-GSFC, Solar System Exploration -
Astrochemitry, Code 691, Greenbelt, MD 20771 United States
AU: Kletetschka, G
EM: gunther.kletetschka@gsfc.nasa.gov
AF: Catholic University of America,
Department of Physics, 200 hannan hall, Washington, DC 20064 United
States
AU: Kletetschka, G
EM: gunther.kletetschka@gsfc.nasa.gov
AF: NASA-GSFC, Solar System Exploration
- Astrochemitry, Code 691, Greenbelt, MD 20771 United States
AU: Kletetschka, G
EM: gunther.kletetschka@gsfc.nasa.gov
AF: Acad. Sci., Institute of Geology,
Rozvojova 6, Prague, 20063 Czech Republic
AB:
Epifluorescence petrography clearly images information that cannot be
seen in a standard petrographic microscope with regular transmitted
polarized light. Epifluorescence examination reveals hidden structures
located in less transparent areas of the
thin section from Pliocene-Pleistocene spring travertine deposits in
Funeral Formation in Death Valley, CA. Thin section
material absorbs and reradiates light (autofluorescence). This can be
caused by an extremely small number of fluorescent
molecules (50 molecules per cubic micron). Fluorescent material in our
thin section can be both of organic and inorganic
nature. We cannot rule out micropore space filled with organic matters
(aminoacids with ring structures autofluoresce).
Fabric-specific isotope and textural analysis on the spring travertine
deposits indicate that these deposits closely resemble modern
hot-spring travertine in Yellowstone National Park. Modern deposits are
known to contain abundant microbial life
forms. These microbial communities live in the hot-spring and entrapped
by rapidly precipitating calcite or aragonite.
Epifluorescence examination of thin sections of the spring travertine
calcite revealed presence of autofluorescence material
in less transparent areas of thin section where the hidden distinctive
structure was not otherwise seen by regular
transmitting polarized light. These structures may be organic
signatures trapped in between the inorganic precipitates and
may be the hall mark for future approach of biosignature detection in
ancient hydrothermal deposits on terrestrial and
extraterrestrial environment.
DE: 0419 Biomineralization
DE: 0420 Biomolecular and chemical
tracers
DE: 0424 Biosignatures and proxies
DE: 0444 Evolutionary geobiology
DE: 0463 Microbe/mineral interactions
SC: Biogeosciences [B]
MN: Fall Meeting 2005
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