Recent mapping in the Navajo Mountain region of southern Utah revealed the presence of a small syenite porphyry intrusion on the southwest part of Navajo Mountain. The presence of euhedral hematite crystals which appear to have crystallized directly from the magma suggests a means of estimating the crystallization Po2, At 500-600°C a Po2 equal to or greater than 10-13 to 10-17 atms would be necessary for hematite to be the equilibrium iron oxide phase. It is suggested that intrusion at a shallow depth may be partly responsible for the oxidizing environment that existed during crystallization.
|Number of pages||4|
|Journal||Bulletin of the Geological Society of America|
|Publication status||Published - 1964|