Aeolian Landform (10.Desert Varnish)

10.Desert Varnish                                                                                                                                  Back to Aeolian Landforms

• Desert varnish is dark coating on rocks.

• It compositeby clay minerals.

• Clay arrive by wind.

• These clays are;

                  -Black manganese oxide.(birnesite) 
                  -Red iron oxide.(hematite)

Desert varnish on Bishop Tuff

• Another terms are;

                    -Rock rust
                    -Desert patina
                    -Rock varnish

• Color range of rock varnish;

                   -Orange to Yellow -Black

• These rocks' high resistance to weathering process.

• Desert patina often identity of the underlying rock.

• But different rocks have varying abilities to accept and retain varnish.

                             ex:Limestones( too water soluble )

•  Shiny, dense & black varnishes forms on;

                              -Basalt.
                              -Quartzites.
                              -Metamorphosed shales.

Valley of Fire near Las Vegas, Nevada.

Desert varnish in Horseshoe Canyon, Canyonlands National Park, Uta