The rock is a quartzite, a metamorphosed sandstone, belonging to the Antietam Formation. This rock is Lower Cambrian in age and is believed to have formed as a barrier island or a beach deposit.

Soft rocks like limestone and shale underlie valleys and harder rocks such as quartzite (metamorphosed sandstone), igneous rocks and conglomerate make up the higher elevations. Limestone ...

Valley and colleagues have previously used uranium-lead radioactive dating to determine the age of a zircon crystal sample (named 01JH36-69), which was found 15 years ago in metamorphosed ...

Full size table Bedrock in the upper parts of the Franz Josef catchment is low-grade metamorphosed sandstone. The lower reaches of the Waiho Valley are dominated by outcrops of high-grade schist.