Kevin Forbes wrote:
Hi list, has anyone ever seen orbicular granite?
yes it is a popular dimension stone for construction
Is the formation of this material related to the formation of chondritic meteorites in any way?
NOPE--can't even stretch a connection as to similar formation. Chondrules apparently formed molecule by molecule out of primordial, proto-solar-disk "soup" flash melted by really huge lightening bolts
Orbicular granite is a partial remelt of older granitoid material -- rarely country rock of other igneous or metamorphic origin. The loosely spherical objects seen are referred to as zenoliths. If the orbicular granite hadn't been suddenly chilled -- had the process ran to completion, the zenos would have been reintegrated into the average/existing composition of the surrounding material. The result would have been regular texture granite. Perhaps the rain of zenoliths into the melt took away too much of the available heat and the activity came to a fast halt in mid-process.
Elton ______________________________________________ Meteorite-list mailing list [email protected] http://six.pairlist.net/mailman/listinfo/meteorite-list
