Fault-Zone Breccia
A cut-and-polished chunk of the Triassic New Oxford formation from Frederick, Maryland. This breccia is the product of faulting during the failed Triassic rift that created the down-dropped Frederick valley. It includes mostly angular Cambrian limestone and quartz fragments in a red mudstone matrix. This stuff was jokingly nick-named Rosie's Dinerite because at the time (before the area became completely built up and obliterated by progressive urbanization) there were some exceptional outcrops of it behind Rose's Diner on Route 40 just west of Frederick.
Fault-Zone Breccia
A cut-and-polished chunk of the Triassic New Oxford formation from Frederick, Maryland. This breccia is the product of faulting during the failed Triassic rift that created the down-dropped Frederick valley. It includes mostly angular Cambrian limestone and quartz fragments in a red mudstone matrix. This stuff was jokingly nick-named Rosie's Dinerite because at the time (before the area became completely built up and obliterated by progressive urbanization) there were some exceptional outcrops of it behind Rose's Diner on Route 40 just west of Frederick.