Geology Reference
In-Depth Information
EH chondrite impact melt
313.50 g
Found December 14, 2002
7.0 × 7.0 × 3.5 cm
Weathering = B
were likely formed during impact. These rare samples offer a glimpse of
the pressure and temperature conditions existing during impact of the EH
parent body, as well as an opportunity to study mineral transformations
for these unusual reduced meteorite groups.
LAP 02225,0
LAP 02225 EH impact (met S)
χ
FWHM
(610)
Plate 33
MiNERALogy
SigNiFiCANCE
LAP 02225 consists of a matrix of small (~0.2 mm long)
pyroxene laths with interstitial plagioclase, nickel-iron
metal, troilite, daubreelite, Mg,Mn,Fe-sulfides, and per-
ryite. The latter is often exsolved on the {111} axes of the
metal. Also present are ~10 vol.% large enstatite laths that
can exceed 3 mm in long dimension. Enstatite is
Fs0-1
; pla-
gioclase is An
0
or
2-3
; and metal contains 3 wt.% Si.
LAP 02225 is one of only a few EH impact melts,
recording the conditions and effects of severe impacts on
the EH parent body. its fine-grained matrix has been
characterized using micro x-ray diffraction (lower right,
[223]), which has revealed plagioclase and enstatite
together with FeNi metal, troilite, daubreelite, keilite, and
perryite.
References [223]
