1. Lunar Pyroclastic Eruptions COSMOCHEMISTRY iLLUSTRATED Apollo 17 Orange Glass Pyroclastic Deposit Six Major Dark Mantle DepositsTaurus-Littrow Deposit at Apollo 17 Apollo 17 Site

2. Lunar Pyroclastic Eruptions COSMOCHEMISTRY iLLUSTRATED Apollo 17 Orange Glass It consists of orange glass spheres (average of 40 microns in diameter), black spheres (quench crystallized) and some mineral debris. The Apollo 17 orange glass deposit was sampled in place, though it was overturned by an impact event 30 My ago.

3. Lunar Pyroclastic Eruptions COSMOCHEMISTRY iLLUSTRATED Enrichments in Volatile Elements in Pyroclastic glass deposits Surfaces of pyroclastic glasses enriched in Zn, Cd, Hg, Pb, Cu, F, Cl compared to other lunar materials Probably were in gas phase associated with eruption Implies volatile reservoirs inside Moon Surface coatings enriched in volatile elements; largest crystals are NaCl, mounds enriched in Zn, S, etc. 1  m Image courtesy of David McKay

4. Lunar Pyroclastic Eruptions COSMOCHEMISTRY iLLUSTRATED H 2 O in Volcanic Glass Initial concentration estimated at 70-745 ppm. N-MORB glasses:~750-2000 ppm Saal et al. (2008) Ion microprobe measurements show that the orange and green glasses returned by Apollo contain H 2 O, along with other volatiles.