9174 x 3866 px | 77,7 x 32,7 cm | 30,6 x 12,9 inches | 300dpi
Data acquisizione:
12 luglio 2013
Altre informazioni:
Red Rock State Park is located in a geologically unique area of north central Arizona near Sedona. The park encompasses between one and two river miles of perennial Oak Creek, giving the park a diversity of both riparian and upland plant and animal species. The park is also included in the Lower Oak Creek Important Bird Area, and is home to rare and unique avian species like the Common Black Hawk, Wood Duck, and Common Merganser. The deep red color for which Sedona is famous is due to the presence of hematite (iron oxide, otherwise known as rust) that stains the sandstone of the Schnebly Hill and Hermit Shale layers. The steepness of the terrain is due the fact that the top layers of the strata are composed of basalt and limestone, which are harder than the underlying sandstone. Water running off the edge of the escarpment eats away at the lower layers, creating the shear cliffs. Eventually enough soft material is weatherd away that it undercuts the cap layer, which subsequently breaks off in large slabs and falls into the canyons. This exposes new soft material and the process starts again, with the cliff face now twenty-odd feet further north than it was before.
