According to the article linked below geodes are another geologic problem.
http://www.isgs.illinois.edu/maps-data- ... bit3.shtml
They seem to occur in deposits of limestone and dolomite. According to NASA, this would work nicely with airborne comet dust.
http://ntrs.nasa.gov/archive/nasa/casi. ... 010014.pdf
Strangely the geodes sometimes contain oil under pressure.
[...]
Perhaps the most fascinating geodes are those that contain petroleum, which may be under enough pressure to squirt out when the geode is broken. The rock in which these unusual geodes are found north of Nauvoo, no longer contains any significant oil. So what is the source of oil in these geodes? What is the origin of the other minerals? We don't know for sure. Perhaps trace amounts of some of the elements that make up the rarer minerals were present in shale layers associated with the carbonate strata.
me again,
Because comets contain hydrocarbons according to NASA, an answer to this puzzle may be at hand.
http://www.nasa.gov/mission_pages/deepi ... 90705.html
If hydrocarbons were attracted to a Bennett Pinch while a plasmoid or enhanced aurora was in Earths atmosphere, the carbonates from a comet might have then been attracted to the oil, coating it in layers of compressed limestone and dolomite.
geode images below
http://www.firstcrackgeodes.com/geodetypes.html
http://www.google.com/search?hl=en&suge ... a=N&tab=wi
The hollow area in the center could be due to the filamentary pinch having a plasmoid at it's center, causing the material to form around it's exterior. Or it might be the double layer boundary of the pinch.
below is a response from a friend,
[...]
A plasmoid is just a glob of plasma that can be distinguished from whatever is around it. If T-eggs are formed in a pinch, I'd suspect the "shell" forms in (or inside) the DL that is the boundary of the pinch (like a balloon--outside force pinching in, inside force/pressure opposing). There could be other cell-like formations (plasmoids) inside the main one, I suppose. The T-eggs with horizontally striped filling probably (guessing) filled with mineral water after forming (maybe only seconds after) & solidified mechanically/chemically. The T-eggs found in the Missouri-Illinois-Iowa border area are filled with oil (sometimes under pressure--they spurt when a hole is drilled into them).
The pinch only has a "center" by abstraction--like a hula hoop. There's nothing there (as distinguished from gravity with mass at the center).
michael