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Reading: Scott and Rajan (1981)
1. Create a table that summarizes for the four chondrites
examined by the authors the following features: overall petrography of
clasts and host, whether the meteorite is gas-rich or contains solar-flare
tracks, metallographic cooling rates, and inferred origin. You can
use the following as a template:
|meteorite||petrographic description||gas-rich or solar flare tracks?||metallographic cooling rates||inference|
|Weston||H3 to "7" clasts set in H4 host; latter actually a mixture of equilibrated & unequilibrated material||yes, both||10-1000 K/Ma at 800-600 K||cooled at different depths before compaction|
2. What do the presence of solar-flare tracks or high
gas contents imply about where in the parent body some of these chondrites
3. How do the data of the authors and that shown
in Fig. 10 argue against a simple onion skin model for the parent bodies
of the ordinary chondrites?
4. There are two models consistent with the data presented
by the authors, and both involve collisions after the petrographic types
of chondrites were established. (a) What are these two models?
(b) Can you think of any way to discriminate between these two models?