HuwG, you described the position well from the Geology standpoint. Your observation of However, members of any "establishment" can lapse into an exclusive, know-it-all attitude. . . is a the point at which paradeigm shifts happen, when the older ideas in science become overburdoned with their own importance and not responsive to the newer research. They get left behind. There is a role there where the "skeptic" becomes the new mainstream practitioner. Skeptic is too general a term to consistently apply to one particular type of position (i.e., conservative vs. liberal, though after enough repetition, who knows--other words have lost their original or primary meanings through repeated popular usage).

I actually didn't associate daylia with snake oil salesman. I merely illustrated the positions occupied on a sliding scale that runs from scholarship to annecdote in the field of topical discourse. There will always be some overlap, but there are points where it is a higher density of one or the other. "Sales pitch" should of course not be taken literally--many people "sell" ideas in encounters in which no $$$$ will ever be exchanged. That doesn't make it any less of a "selling" situation.

HuwG, you might enjoy visiting a page that links to the work of Chris Scotese at the U. of Texas Arlington, who is doing some interesting work in illustrating the motion of plate tectonics.

SRS