Preferred chondrule orientations in meteorites

Martin, Philip; Mills, Angela

doi:10.1016/0012-821x(80)90252-6

Cited by 44 publications

(30 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previously in the literature, AMS has only been studied on ordinary, E, and C chondrites and a few achondrites with oblate fabrics observed in most cases (e.g., Martin and Mills 1980;Hamano and Yomogida 1982;Sugiura and Strangway 1983;Sneyd et al 1988;Morden and Collinson 1992). Furthermore, Gattacceca et al (2005) is the only study with a substantial AMS database using L chondrites.…”

Section: Discussionmentioning

confidence: 99%

“…Anisotropy development was originally attributed to lithostatic pressure due to overburden material, i.e., load compaction during crystallization during the accretionary phase (Stacey et al 1961;Martin and Mills 1980). Compaction would cause flattening and reorientation of the Fe-Ni metal grains, and was used to explain the observed negative correlation between anisotropy and porosity.…”

Section: Discussionmentioning

confidence: 99%

“…In addition, 145 of these 321 specimens, covering 14 classes of chondrites, primitive achondrites and achondrites, have also been measured for AMS at a frequency of 19,000 Hz yielding parameters (3) and (4) (Smith et al 2004). Until very recently, only a handful of published studies has been done involving AMS measurements on several dozen meteorites; they all focused, however on LL, L, H, E and C chondrites, and involved no other classes (e.g., Hamano and Yomogida 1981;Martin and Mills 1980;Sugiura and Strangway 1983;Sneyd et al 1988;Morden and Collinson 1992). Recently, Gattacceca et al (2005) investigated the AMS of LL, L, C, and R chondrites and HED and SNC achondrites.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Stony meteorite characterization by non‐destructive measurement of magnetic properties

Smith

Ernst

Samson

et al. 2006

Meteorit & Planetary Scien

View full text Add to dashboard Cite

All appendix tables for this article are available online at http://meteoritics.org.Abstract-Four parameters of low-field magnetic susceptibility (bulk value, frequency dependence, degree of anisotropy, and ellipsoid shape) have been determined for 321 stony meteorites from the National Collection of Canada. These parameters provide a basis for rapid, non-destructive, and accurate meteorite classification as each meteorite class tends to have a distinct range of values.Chondrites show a clear trend of increasing bulk susceptibility from LL to L to H to E within the 3.6 to 5.6 logχ (in 10 −9 m 3 /kg) range, reflecting increasing Fe-Ni metal and Fe-Ni sulfide content. Achondrite values range in logχ from 2.4 to 4.7 and primitive achondrites from 4.2 to 5.7. Frequency dependence is observed, using 19,000 Hz and 825 Hz, with variations in strength among meteorite classes and individual specimen dependence ranging from 1-25.6%. Degrees of anisotropy range from 1 to 53% with both oblate and prolate ellipsoids present. The aubrite class is marked by high degrees of anisotropy, low bulk magnetic susceptibility, and prolate fabric. Camel Donga is set apart from other eucrites, marked by higher bulk susceptibility, degree of anisotropy, and magnitude of oblate ellipsoid shape. The Shergotty, Nakhla, and Chassigny (SNC) meteorites show subclass distinction using frequency dependence and Chassigny is set apart with a relatively strong oblate fabric. The presence of both strong oblate and prolate fabrics among and within meteorite classes of chondritic and achondritic material points to a complex, multi-mechanism origin for anisotropy, more so than previously thought, and likely dominated by impact processes in the later stages of stony parent body formation.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Stony meteorite characterization by non‐destructive measurement of magnetic properties

Smith

Ernst

Samson

et al. 2006

Meteorit & Planetary Scien

View full text Add to dashboard Cite

show abstract

“…It is likely that, in general, chondrite petrofabrics are produced by impacts (Martin and Mills, 1980;Hamano and Yomogida, 1982;Sugiura and Strangway, 1983;Nakamura et al, 1992;Gattacceca et al, 2005;Rubin and Swindle, 2011). Among ordinary chondrites (OC) many rocks exhibit petrofabrics, commonly manifested as a strong foliation (a local planar structure) and a weaker lineation (a local linear structure) (Dodd, 1965;Sneyd et al, 1988).…”

Section: Collisional Formation Of Petrofabrics In Chondritesmentioning

confidence: 99%

Collisional facilitation of aqueous alteration of CM and CV carbonaceous chondrites

Rubin

2012

Geochimica et Cosmochimica Acta

115

View full text Add to dashboard Cite

“…Petrofabrics in ordinary chondrites (Dodd, 1965;Martin and Mills, 1980) have been ascribed to impact-induced deformation of chondrite whole rocks (Sneyd et al, 1988). The petrofabrics in some CV (Cain et al, 1986) and CR (Weisberg et al, 1993) chondrites probably formed analogously.…”

Section: Matrix Lineationsmentioning

confidence: 99%

Non-nebular origin of dark mantles around chondrules and inclusions in CM chondrites

Trigo‐Rodríguez

Rubin

Wasson

2006

Geochimica et Cosmochimica Acta

117

120

View full text Add to dashboard Cite

Our examination of nine CM chondrites that span the aqueous alteration sequence leads us to conclude that compact dark fine mantles surrounding chondrules and inclusions in CM chondrites are not discrete fine-grained rims acquired in the solar nebula as modeled by Metzler et al. [Accretionary dust mantles in CM chondrites: evidence for solar nebula processes. Geochim. Cosmochim. Acta 56, 1992Acta 56, , 2873Acta 56, -2897. Nebular processes that lead to agglomeration produce materials with porosities far higher than those in the dark mantles. We infer that the mantles were produced from porous nebular materials on the CM parent asteroid by impact-compaction (a process that produces the lowest porosity adjacent to chondrules and inclusions). Compaction was followed by aqueous alteration that formed tochilinite, serpentine, Ni-bearing sulfide, and other secondary products in voids in the interchondrule regions. Metzler et al. reported a correlation between mantle thickness and the radius of the enclosed object. In Yamato 791198 we find no correlation when all sizes of central objects and dark lumps are included but a significant correlation (r 2 = 0.44) if we limit consideration to central objects with radii >35 lm; a moderate correlation is also found in QUE 97990. We suggest that impact-induced shear of a plum-pudding-like precursor produced the observed ''mantles''; these were shielded from comminution during impact events by the adjacent stronger chondrules and inclusions. Some mantles in CM chondrites with low degrees of alteration show distinct layers that may largely reflect differences in porosity. Typically, a gray, uniform inner layer is surrounded by an outer layer consisting of darker silicates with BSE-bright speckles. The CM-chondrite objects characterized as ''primary accretionary rocks'' by Metzler et al. did not form in the nebula, but rather on the parent body. The absence of solar-flare particle tracks and solar-wind-implanted rare gases in these clasts reflect their lithified nature and low surface/volume ratios during the period when they resided in the regolith and were subject to irradiation by solar particles. The clasts are analogous to the light-colored metamorphosed clasts in ordinary-chondrite regolith breccias (which also lack solar-flare particle tracks and solar-wind gas).

show abstract

Preferred chondrule orientations in meteorites

Cited by 44 publications

References 2 publications

Stony meteorite characterization by non‐destructive measurement of magnetic properties

Stony meteorite characterization by non‐destructive measurement of magnetic properties

Collisional facilitation of aqueous alteration of CM and CV carbonaceous chondrites

Non-nebular origin of dark mantles around chondrules and inclusions in CM chondrites

Contact Info

Product

Resources

About