Volcanic "hailstones"
Location: Hailstone Trail - Chiricahua National Monument, near Wilcox, AZ
Year: 2007
Merckslides catalogue number: 25(06)-24001
Comments: These are a little geological oddity that have just become timely. Odd concretions (?) in rhyolitic tuff. The interesting thing is their close resemblance to the spherules weathering out of the bedrock at the Opportunity landing site in Meridiani Planum on Mars, that have planetary geologists so exercised. You heard it here first, the Meridiani bedrock is pyroclastic! (JM 2-28-04.) OK, it appears that I was wrong. The weight of evidence is that the Meridiani concretions are in-situ precipitates. Sue me. (JM 12-11-05)
