In article ,
says...

snip

The spherules found at the Apollo14 site, and at Opportunity are close to
the same size (no larger than a few milimeters). The spherules at the
Opportunity site are smaller than you must think they are. Note that rocks
at the Apollo 14 site were similar to the bulk composition that appears to
be seen at the Opportunity site: That is there is lots of olivine, which
indicates that there is a basaltic source rock somewhere in the vicinity.
The plagioclase at the Apollo 14 site no doubt originated from the basaltic
rocks in which the craters in the region were formed.

Well, there you are dead wrong. The plagioclase on the Moon was formed
when the early Moon, just after accretion, developed a "magma ocean" in
which plagioclase flotation resulted in an anorthositic crust.
(Anorthosite is a rock made up mostly of a single mineral, plagioclase.)
The plag at the Apollo 14 site was excavated from the highland materials
(i.e., the brecciated remnants of the original lunar crust) in the
target area of the Imbrium impact. The Fra Mauro formation on which
Apollo 14 landed is a huge splash sheet of ejecta from the Imbrium
impact -- very little (if any) rock from the original local surface
remains on the surface at the landing site. According to the experts
who have studied the Apollo 14 rock samples, not even Cone Crater was
deep enough to punch through the Imbrium ejecta. So everything at Fra
Mauro was originally located somewhere in what is now Mare Imbrium.

The interesting thing is that there seems to have been a fair amount of
mare basalt in the Imbrium target rock, since many of the clasts and
some of the matrices in the breccias collected by Shepard and Mitchell
are indeed basaltic, and analyze out at anywhere from 3.9 to 4.1 billion
years old, considerably older than the age of the Imbrium impact itself
(which is somewhere between 3.83 and 3.86 billion years). But the
impact melt itself, as collected at Fra Mauro, is predominately noritic
(anorthosite with some admixture of olivine).

I'd like to see a cite for these "spherules" from the Apollo 14
collection -- I've seen a lot of discussion of the breccias from the
site, and seen it noted that ALL of the Apollo 14 samples are indeed
breccias. Perhaps you're thinking of spherical clasts within the
breccias? I'd love to know which sample numbers you're speaking of...

Doug