Ferricrete Formation at Base of Cement Creek

Ferricrete (surficial deposits cemented by iron oxides) formation at the base of Cement Creek north of Silverton, Colorado. Red color is due to iron oxides. Ferricrete forms when pyrite and other sulfide minerals weather to form acidic iron-rich water that cements surficial materials in place. Cement Creek was named due to the abundant ferricrete in this basin. Ferricrete in this area has been dated by radiocarbon methods between modern and 9,000 years before present. View to south with Kendall Mountain in background.