Letter. A simple inorganic process for formation of carbonates, magnetite, and sulfides in martian meteorite ALH84001

@article{Golden2001LetterAS,
  title={Letter. A simple inorganic process for formation of carbonates, magnetite, and sulfides in martian meteorite ALH84001},
  author={D. C. Golden and Doug W. Ming and Craig S. Schwandt and Howard V. Lauer and Richard A. Socki and Richard V. Morris and Gary E. Lofgren and Gordon Mckay},
  journal={American Mineralogist},
  year={2001},
  volume={86},
  pages={370 - 375}
}
Abstract We show experimental evidence that the zoned Mg-Fe-Ca carbonates, magnetite, and Fe sulfides in Martian meteorite ALH84001 may have formed by simple, inorganic processes. Chemically zoned carbonate globules and Fe sulfides were rapidly precipitated under low-temperature (150 °C), hydrothermal, and non-equilibrium conditions from multiple fluxes of Ca-Mg-Fe-CO2-S-H2O solutions that have different compositions. Chemically pure, single-domain, defect-free magnetite crystals were formed by… 

Figures and Tables from this paper

Submicron magnetite grains and carbon compounds in Martian meteorite ALH84001: inorganic, abiotic formation by shock and thermal metamorphism.
Purported biogenic features of the ALH84001 Martian meteorite (the carbonate globules, their submicron magnetite grains, and organic matter) have reasonable inorganic origins, and a comprehensive
Decreasing CO2 partial pressure triggered Mg–Fe–Ca carbonate formation in ancient Martian crust preserved in the ALH84001 Meteorite
We retrace hydrogeochemical processes leading to the formation of Mg–Fe–Ca carbonate concretions (first distinct carbonate population, FDCP) in Martian meteorite ALH84001 by generic hydrogeochemical
Origin of supposedly biogenic magnetite in the Martian meteorite Allan Hills 84001
  • D. J. Barber, E. Scott
  • Geology
    Proceedings of the National Academy of Sciences of the United States of America
  • 2002
TLDR
All occurrences of magnetite and periclase are entirely consistent with in situ growth by solid-state diffusion as a result of carbonate decomposition during impact heating.
Evidence for exclusively inorganic formation of magnetite in Martian meteorite ALH84001
Abstract Magnetite crystals produced by terrestrial magnetotactic bacterium MV-1 are elongated on a [111] crystallographic axis, in a so-called “truncated hexa-octahedral” shape. This morphology has
Magnetite in ALH 84001: An origin by shock‐induced thermal decomposition of iron carbonate
Abstract— In martian orthopyroxenite ALH 84001, pockets of feldspathic glass frequently contain carbonate masses that have been disrupted and dispersed within feldspathic shock melt as a result of
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 35 REFERENCES
An Evaporation Model for Formation of Carbonates in the ALH84001 Martian Meteorite
Small, discoid globules and networks of magnesium-iron-calcium carbonates occur within impact-produced fracture zones in the ALH84001 Martian meteorite. Because these carbonates contain or are
An experimental study on kinetically‐driven precipitation of calcium‐magnesium‐iron carbonates from solution: Implications for the low‐temperature formation of carbonates in martian meteorite Allan Hills 84001
Abstract— Spherical carbonate globules of similar composition, size, and radial Ca‐, Mg‐, and Fe‐zonation to those in martian meteorite Allan Hills (ALH) 84001 were precipitated from Mg‐rich,
A possible high-temperature origin for the carbonates in the martian meteorite ALH84001
TLDR
It is argued that the most likely explanation for the observed compositions, and for the absence of co-existing hydrous minerals, is that the carbonates were formed by reactions between hot (>650 °C), CO2-rich fluids and the ultramafic host rock during an impact event.
Experimental hydrothermal alteration of a martian analog basalt: Implications for martian meteorites
Abstract— A number of martian meteorite samples contain secondary alteration minerals such as Ca‐Mg‐Fe carbonates, Fe oxides, and clay minerals. These mineral assemblages hint at hydrothermal
Petrologic evidence for low-temperature, possibly flood evaporitic origin of carbonates in the ALH84001 meteorite.
TLDR
It is proposed that the carbonates formed as evaporite deposits from floodwaters that percolated through the fractures of ALH84001, but only briefly, as evaporation and groundwater flow caused the water table to quickly recede beneath the level of this rock during the later stages of the flood episode.
Low-Temperature Carbonate Concretions in the Martian Meteorite ALH84001: Evidence from Stable Isotopes and Mineralogy
TLDR
The isotopic variations and mineral compositions of the martian meteorite ALH84001 offer no evidence for high temperature (>650°C) carbonate precipitation and suggest non-equilibrium processes at low temperatures (<∼300°C).
Search for Past Life on Mars: Possible Relic Biogenic Activity in Martian Meteorite ALH84001
TLDR
High-resolution scanning and transmission electron microscopy study of surface textures and internal structures of selected carbonate globules show that the globules contain fine-grained, secondary phases of single-domain magnetite and iron sulfides.
Carbonates in fractures of Martian meteorite Allan Hills 84001: petrologic evidence for impact origin.
TLDR
The heterogeneous distribution of carbonates in fractures, tapered shapes of some disks, and the localized occurrence of Mg-rich microdisks appear to be incompatible with growth from an externally derived CO2-rich fluid that changed in composition over time.
...
1
2
3
4
...