POTD September 5, 2013: Crystal Peak, Millard County, Utah

Crystal Peak, Millard County, Utah
Photographer: Matt Affolter

Certain rock types weather into curious shapes and patterns by combinations of internal factors such as fractures and sediment grain size and external factors such as frost action and salt crystallization. Sandstone, granite, volcanic rocks, and limestone are all excellent mediums for creating bizarre rockscapes that can include smooth, rounded, and undulating forms (hoodoos or “goblins”), pinnacles, tafoni (holes and small alcoves), and honeycomb structures.

The Tunnel Spring Tuff exhibits remarkable tafoni (alcoves and pitting) covering the steep slope of Crystal Peak.