Newsletter |
25,2 |
Location |
Queen Alexandra Range |
Field Number |
12568 |
Dimensions (cm) |
2.0 x 1.5 x 1.25 |
Weight (g) |
3.95 |
Original Classification |
CK5 Chondrite |
Updated Classification |
CK4 Chondrite |
Pairing |
QUE 99675;
QUE 99676;
QUE 99677;
QUE 99678;
QUE 99679;
QUE 99680;
QUE 99681;
|
Fayalite (mol%): 29;Ferrosilite (mol%): 23 |
Ce |
C |
The exterior of 680 is covered with 50% brown/black fusion crust with polygonal fractures. The interior is a vuggy, weathered charcoal gray matrix with evaporites. The rock contains white and gray inclusions, ranging in size from 1-3 mm. 681 has 20% black fusion crust with polygonal fractures and evaporites. The interior is similar to 680 but has more evaporites and, an evaporite material that gives the rock the appearance of being smeared with toothpaste. White and gray inclusions are visible ranging in size from <1 - 2 mm. |
These two meteorites are so similar that a single description suffices. The sections consist of large (up to 2 mm), well-defined chondrules in a matrix of finer-grained silicates, sulfides and very abundant magnetite. The meteorites are little weathered, but extensively shock blackened. Silicates are homogeneous. Olivine is Fa29 and orthopyroxene is Fs21-23. The meteorites are CK5 chondrites. |
Olivine and pyroxene compositions show variation that is more consistent with CK4; see AMN 46, 2. |
This CK4 pairing group was originally QUE 99675, 99676, 99677, 99678, and 99679. QUE 99680 and 99681 were originally classified as CK5, but analyses of their olivine and feldspar (see AMN 46, 2) indicate similar compositional heterogeneity to the CK4 group. The combination of very close find proximity together with the mineral compositions indicates QUE 99680 and QUE 99681 are both part of the QUE 99675 pairing group. QUE 93007, was found 8 km away and has a distinct and homogeneous olivine and feldspar composition indicating it is an unpaired and unique sample. |