Climate and rock weathering: a study of terrestrial age dated ordinary chondritic meteorites from hot desert regions

Bland, P. A.; Sexton, A. S.; Jull, A. J. T.; Bevan, A. W. R.; Berry, Frank J.; Thornley, D. M.; Astin, T. R.; Britt, D. T.; Pillinger, C. T.

doi:10.1016/s0016-7037(98)00199-9

Cited by 123 publications

(179 citation statements)

References 42 publications

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“…2). The decrease in primary phases with increasing oxidation suggest that all iron-containing minerals within the meteorite are affected by weathering to some degree, as previously reported for OCs from other hot deserts [6].…”

Section: Resultssupporting

confidence: 78%

57 Fe Mössbauer spectroscopy studies of chondritic meteorites from the Atacama Desert, Chile: Implications for weathering processes

Munayco¹,

Munayco²,

Valenzuela

et al. 2013

Hyperfine Interact

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Some terrestrial areas have climatic and geomorphologic features that favor the preservation, and therefore, accumulation of meteorites. The Atacama Desert in Chile is among the most important of such areas, known as dense collection areas. This desert is the driest on Earth, one of the most arid, uninhabitable locals with semi-arid, arid and hyper-arid conditions. The meteorites studied here were collected from within the dense collection area of San Juan at the Central Depression and Coastal Range of Atacama Desert.57 Fe Mössbauer spectroscopy was used for quantitative analysis of the degree of weathering of the meteorites, through the determination of the proportions of the various Fe-bearing phases and in particular the amount of oxidized iron in the terrestrial alteration products. The abundance of ferric ions in weathered chondrites can be related to specific precursor compositions and to the level of terrestrial weathering. The aim of the study was the identification, quantification and differentiation of the weathering products in the ordinary chondrites found in the San Juan area of Atacama Desert.

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Section: Resultssupporting

confidence: 78%

57 Fe Mössbauer spectroscopy studies of chondritic meteorites from the Atacama Desert, Chile: Implications for weathering processes

Munayco¹,

Munayco²,

Valenzuela

et al. 2013

Hyperfine Interact

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“…7a) A number of studies of hot desert ordinary chondrite finds have demonstrated that there is a systematic decrease in Mg (and Si) with increasing degrees of weathering (Gibson and Bogard 1978;Bland et al 1998;Al-Kathiri et al 2005). Increased levels of Ca in CKs from hot desert environments have been documented by Huber et al (2006), which they ascribe to the formation of calcite-like weathering products.…”

Section: Bulk Compositional Resultsmentioning

confidence: 99%

The relationship between CK and CV chondrites

Greenwood¹,

Franchi²,

Kearsley³

et al. 2010

Geochimica et Cosmochimica Acta

195

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CK chondrites are highly oxidized meteorites containing abundant magnetite and trace amounts of Fe,Ni-metal. Although the group is predominately composed of equilibrated meteorites (types 4 to 6), in recent years a significant number of new samples have been classified as being either CK3 or CK3-anomalous. These unequilibrated CKs often display a close affinity with members of the CV oxidized subgroup. CKs and CVs (oxidized subgroup) may therefore form a continuum and by implication could be derived from a single common parent body. To investigate the relationship between these two groups a detailed study of the oxygen isotope composition, opaque mineralogy and major and trace element geochemistry of a suite of CV and CK chondrites has been undertaken. The results of oxygen isotope analysis confirm the close affinity between CV and CK chondrites, while excluding the possibility of a linkage between the CO and CK groups. Magnetites in both CV and CK chondrites show significant compositional similarities, but high Ti contents are a diagnostic feature of the latter group. The results of major and trace element analysis demonstrate that both CV and CK chondrites show overlapping variation. Supporting evidence for a single common source for both groups comes from their similar cosmic-ray exposure age distributions. Recent reflectance spectral analysis is consistent with both the CVs and CKs being derived from Eos family asteroids, which are believed to have formed by the catastrophic disruption of a single large asteroid. Thus, a range of evidence appears to be consistent with CV and CK chondrites representing samples from a single thermally stratified parent body. In view of the close similarity between CV and CK chondrites some modification of the present classification scheme may be warranted, possibly involving integration of the two groups. One means of achieving this would be to reassigned CK chondrites to a subgroup of the oxidized CVs. It is recognized that a full evaluation of this proposal may require further study of the still poorly understood CK3 chondrites. ACCEPTED MANUSCRIPT3

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“…We can show an example of the case of the Western Australian meteorites. (Jull et al , 1995bBland et al 1998). …”

Section: Desert Meteoritesmentioning

confidence: 99%

“…In a new approach to the question of meteorite survival and weathering, Bland et al (1998) compared the terrestrial ages of many meteorites with the degrees of weathering observed. Previous studies (e.g.…”

Section: Desert Meteoritesmentioning

confidence: 99%

“…Previous studies (e.g. Wlotzka et al 1995) had used a petrographic weathering estimate, however, Bland et al (1998) introduced the idea of using Mössbauer spectroscopy, where the relative amounts of Fe in different valence states could be measured. Bland et al (1996) further showed that meteorites of different composition weather at different rates, a fact known qualitatively to many meteoriticists, but difficult to quantify.…”

Section: Desert Meteoritesmentioning

confidence: 99%

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Radiocarbon Beyond this World

et al. 2000

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ABSTRACT. In this paper, we review the production of radiocarbon and other radionuclides in extraterrestrial materials. This radioactivity can be produced by the effects of solar and galactic cosmic rays on solid material in space. In addition, direct implantation at the lunar surface of 14 C and other radionuclides can occur. The level of 14 C and other radionuclides in a meteorite can be used to determine its residence time on the Earth's surface, or "terrestrial age". 14 C provides the best tool for estimating terrestrial ages of meteorites collected in desert environments. Age control allows us to understand the time constraints on processes by which meteorites are weathered, as well as mean storage times. Third, we discuss the use of the difference in 14 C/ 12 C ratio of organic material and carbonates produced on other planetary objects and terrestrial material. These differences can be used to assess the importance of distinguishing primary material formed on the parent body from secondary alteration of meteoritic material after it lands on the earth.

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Climate and rock weathering: a study of terrestrial age dated ordinary chondritic meteorites from hot desert regions

Cited by 123 publications

References 42 publications

57 Fe Mössbauer spectroscopy studies of chondritic meteorites from the Atacama Desert, Chile: Implications for weathering processes

57 Fe Mössbauer spectroscopy studies of chondritic meteorites from the Atacama Desert, Chile: Implications for weathering processes

The relationship between CK and CV chondrites

Radiocarbon Beyond this World

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