+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Collisional facilitation of aqueous alteration of CM and CV carbonaceous chondrites

, : Collisional facilitation of aqueous alteration of CM and CV carbonaceous chondrites. Geochimica et Cosmochimica Acta 90(none)

CM chondrites exhibit a strong correlation between the degree of alteration and the extent of particle alignment (i.e., the strength of the petrofabric). It seems likely that the S1 shock stage of essentially every CM and the high matrix abundance (?7vol.%) of these samples ensured that the shock waves that produced CM petrofabrics (by collapsing matrix pores and squeezing chondrules into pore spaces) were significantly attenuated and were too weak to damage olivine crystal lattices. Random collisions on the CM body produced petrofabrics and created fractures in the target rocks. Subsequent impact-mobilization of water caused hydrated phases to form preferentially in the more-fractured regions (those with the strongest petrofabrics); the less-deformed, less-fractured CM regions experienced lower degrees of aqueous alteration. Many CV3 chondrites also have petrofabrics: roughly half are from the oxidized Bali-like subgroup (CV3 OxB ), roughly half are from the reduced subgroup (CV3 R ) and none is from the oxidized Allende-like subgroup (CV3 OxA ) (which is less altered than CV3 OxB ). Nearly all CVs with petrofabrics are S3 S4 and nearly all CVs that lack petrofabrics are SOxidized CVs have much higher porosities (typically 2 28%) than reduced CVs (.6 8%), facilitating more-extensive aqueous alteration. The CV3 R chondrites formed from low-porosity material that inhibited oxidation during alteration. The oxidized CV subgroups formed from higher-porosity materials. The CV3 OxB samples were shocked, became extensively fractured and developed petrofabrics; the CV3 OxA samples were not shocked and never developed petrofabrics. When water was mobilized, both sets of porous CV chondrites became oxidized; the more-fractured CV3 OxB subgroup was more severely altered.


DOI: 10.1016/j.gca.2012.05.016

Other references

Zehm, S., 1969: Surgical intervention in the external area of the middle cranial fossa. Archiv für Klinische und Experimentelle Ohren- Nasen- und Kehlkopfheilkunde 194(2): 297-302

Curtis, T.B., 1956: The Social Security Bill, H.R. 7225. Missouri Medicine 53(1): 36-39

Nepomuceno V.A.; Foster K.N.; Allen D.J.; Zacharias A.; Renno W., 1986: Morphological changes in the gastro intestinal tract of cyclosporine fed dog heart allograft recipients. Anatomical Record 214(3): 91A

Ward, Jl, 1989: Family ties: family meetings. American nurseryman, 169(11): 79

Birnbaum, H.G.; Leong, S.A.; Oster, E.F.; Kinchen, K.; Sun, P., 2004: Cost of stress urinary incontinence: a claims data analysis. The primary objectives of this research were to: (i) identify and present methodologies for estimating three types of 'cost-of-illness' measures using healthcare and disability claims data -- specifically 'cost of treatment', &...

Baudry, J.L., 1994: The dis-positive: metapsychological observations of the reality impression. In the author's view, Plato's myth of the cave is an exact description of the movie theatre. In both there is a constraint to immobility, repetition and a return to a former state--a primary-process throwback to the immobility of the new...

Leonard, R.E.; Federer, C.A., 1973: Estimated and measured roughness parameters for a Pine forest. A map of the upper surface of the canopy of a 35-year-old stand of Pinus resinosa in the Charles Lathrop Pack Forest, New York, was drawn from 275 canopy heights measured on a grid of 0.9 X 1.5 m. The methods of measurement are described. Estimate...

Paulzen, M.; Haen, E.; Stegmann, B.; Hiemke, C.; Gründer, G.; Lammertz, S.E.; Schoretsanitis, G., 2016: Body mass index (BMI) but not body weight is associated with changes in the metabolism of risperidone; A pharmacokinetics-based hypothesis. We sought to unravel the influence of body weight and body mass index (BMI), both consistently reported as pharmacokinetic relevant parameters, on metabolism of risperidone in a naturalistic sample. Conducting non parametrical tests we sought for...

Champlin, R., 2011: Now everyone has a donor for HSCT. Blood 118(2): 218-218

Smith, S.A.F.; Faulkner, D.R., 2010: Laboratory measurements of the frictional properties of the Zuccale low-angle normal fault, Elba Island, Italy. Using a case study from the island of Elba, Italy, we seek to test the hypothesis that the presence of minerals with low frictional strengths can explain prolonged slip on low-angle normal faults. The central core of the Zuccale low-angle normal f...