Abstract

Gordon Creek, Farnham Dome and Woodside fields are closed anticlines that have tested and/or produced large volumes of inert gas (primarily carbon dioxide and nitrogen).

Gordon Creek field tested carbon dioxide from the Permian Coconino and Triassic Moenkopi formations. Flammable gas has been recovered from the Ferron Sandstone and Blue Gate Shale Members of the Mancos Shale.

Farnham Dome field produced 4.76 BCF of carbon dioxide from the Navajo Sandstone. Carbon dioxide has been tested, but not produced, from the Triassic Moenkopi Formation. The field has been shut in since 1979. The Woodside field tested nitrogen, carbon dioxide, and up to 1.51 percent helium from the Permian Kaibab Formation. Flammable gas and oil were tested from the Pennsylvanian Hermosa Group which may still have some exploration potential along the east flank of the anticline. The Woodside field was established as U.S. Helium Reserve No. 1 in 1924.

It is unlikely that one source rock could be responsible for the variety and quantity of inert gases found in these fields. Metamorphism of carbonates may be the source for the carbon dioxide but can not have generated the volumes of nitrogen and helium found. The likely source for the nitrogen and helium is degassing of the Precambrian granitic basement.