NWA 4884 is a lunar mingled basalt-rich breccia. It has both mare and highland components. It is launch paired with Antarctic meteorites QUE 94281 and Yamato 793274. They were all blasted off the moon at the same time.
NWA 4884 contains spherules. The composition of the droplets in the Antarctic stones show that some are highland material and therefore the product of impact melting. Other beads are mare – each either the product of a mare basaltic fire fountain or impact melt splash.
Our sample weighed 0.34 grams. The original individual weighed 42 grams.
This is one of the three thin sections we had made.
That section in cross polarized light, XPL.
In plane polarized light, PPL. Spherules are sparse, scattered and small.
Only a couple were readily apparent at lower magnification so we searched at 250X. The arrow in the dark clast on the right points to a small swirl of translucent glass. PPL.
This spherule contrasts well with the matrix and is relatively large at 0.22 mm in diameter. PPL.
Spherule width = 0.18 mm. PPL.
Spherule width = 0.09 mm. PPL.
Length = 0.09 mm. PPL.
Diameter = 0.08 mm. PPL.
Less distinct. Field of view = 0.44 mm wide. PPL. In rotating XPL, optical extinction circulates in myriad minute sectors as in cryptocrystalline chondrules.
Diameter = 0.12 mm. PPL. This droplet contains crystal laths arrayed as in radial chondrules. In rotating XPL, bands of extinction sweep across this polished face, pivoting about a point in the area that is bright in this view.
A frozen swirl of translucent clear and brown melt glass within a dark clast. Field of view = 0.5 mm wide. PPL.
Spherule in a different NWA 4884 thin section. XPL.
That droplet in incident white light.
In XPL.
In PPL. We favor using PPL when searching for these objects.
