Rock Park
Almost all these specimens are from Cheapside Quarry, east Deerfield, with a few pillows from other loions in the same basalt formation. They are from the early Jurassic Deerfield Basalt, dated at 194,000,000 years ago by the potassium – argon method. #1 #1 Lava Flow Bottom — a complied mixture of basalt and hydrothermal altered material.