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A crystallographic study of crystalline casts and pseudomorphs from the 3.5 Ga dresser formation, Pilbara Craton (Australia)
- Source :
- Digital.CSIC. Repositorio Institucional del CSIC, instname, Journal of Applied Crystallography, Journal of Applied Crystallography, International Union of Crystallography, 2018, 51 (4), pp.1050-1058. ⟨10.1107/S1600576718007343⟩
- Publication Year :
- 2018
- Publisher :
- Wiley-Blackwell, 2018.
-
Abstract
- Crystallographic methods are used to identify the primary mineral phase of pseudomorphs of crystals embedded in 3.48 Ga bedded carbonate-chert rocks from the Dresser Formation, Pilbara Craton, Australia. This identification provides valuable information on the chemical environments at the onset of life on Earth.<br />Crystallography has a long history of providing knowledge and methods for applications in other disciplines. The identification of minerals using X-ray diffraction is one of the most important contributions of crystallography to earth sciences. However, when the crystal itself has been dissolved, replaced or deeply modified during the geological history of the rocks, diffraction information is not available. Instead, the morphology of the crystal cast provides the only crystallographic information on the original mineral phase and the environment of crystal growth. This article reports an investigation of crystal pseudomorphs and crystal casts found in a carbonate-chert facies from the 3.48 Ga-old Dresser Formation (Pilbara Craton, Australia), considered to host some of the oldest remnants of life. A combination of X-ray microtomography, energy-dispersive X-ray spectroscopy and crystallographic methods has been used to reveal the original phases of these Archean pseudomorphs. It is found with a high degree of confidence that the original crystals forming in Archean times were hollow aragonite, the high-temperature polymorphs of calcium carbonate, rather than other possible alternatives such as gypsum (CaSO4·2H20) and nahcolite (NaHCO3). The methodology used is described in detail.
- Subjects :
- 010504 meteorology & atmospheric sciences
Pilbara Craton
Archean
engineering.material
010502 geochemistry & geophysics
01 natural sciences
General Biochemistry, Genetics and Molecular Biology
Crystal
Precambrian
chemistry.chemical_compound
Crystal morphology
[SDU.STU.AG]Sciences of the Universe [physics]/Earth Sciences/Applied geology
ComputingMilieux_MISCELLANEOUS
0105 earth and related environmental sciences
Mineral
Aragonite
Research Papers
Crystallography
Calcium carbonate
chemistry
precambrian
engineering
Pseudomorph
Pseudomorphs
X-ray tomography
Geology
Subjects
Details
- ISSN :
- 00218898 and 16005767
- Database :
- OpenAIRE
- Journal :
- Digital.CSIC. Repositorio Institucional del CSIC, instname, Journal of Applied Crystallography, Journal of Applied Crystallography, International Union of Crystallography, 2018, 51 (4), pp.1050-1058. ⟨10.1107/S1600576718007343⟩
- Accession number :
- edsair.doi.dedup.....02238585e7a4cd3cb8762ce0e744b00c