Editing Gate, Oklahoma (section)

=== Silica mine ===
Volcanic ash is believed by geologists to have come from a volcano in north-central [[New Mexico]]. During the volcanic age, immense quantities of materials were thrown out of these volcanoes and the ash or dust was carried by the prevailing winds and collected in depressions or drifts in the same manner that snow does. There is evidence in the deposits that settled here that the ash settled into a lake, which accounts for the uniform quality of the main deposits, which became a hill. A canyon cut through the center of the deposit and exposed the deposit as cliffs. According to a certified analysis the Gate deposit is composed of 73% silica, 14% alumina and smaller amounts of iron, calcium, magnesium and alkalis.<ref name=":0" /><ref name=":1" />