[Errant]

I don't accept a "earth-fart" as conclusive. The uniformity of the formation causes me to have some doubt with that hypothesis.

More study is needed, especially what the makeup of the geology underground is like.

[ApplegateRanch]

I agree; too much missing data that more investigation needs to discover, before a more definitive explanation can be derived. The ‘earth fart’ comment that was what I understood to be the gist of the quoted more less tentatively accepted hypothesis, as opposed to the other two mainline contenders.