Tuesday, February 07, 2006
Research on Rapid Metamorphism
Andrew Snelling just posted an impact article reviewing research (both secular and YEC) on rapid metamorphism.
It's an interesting article, but geology is one of my weakest subjects, so there's not much I can comment on in it.
Biotite was not in the precursor granulites, so it had to form as a result of both their metamorphism to eclogite and the fluid flows. Of course, these radiohalos could only have been produced in the biotite grains after they formed. Furthermore, because there was no source of either parent uranium-238 or its radioactive decay products within either the eclogites or the precursor granulites, the large quantities of polonium-210 required to generate these radiohalos had to have been transported from external sources into the biotite flakes within these rocks by the hot fluids. But the polonium-210 only has a half-life of 138 days, and the radiohalos would only have formed and survived after the temperature in the rocks fell below 150°C. So this drastically restricts the duration of the earthquake-triggered hot fluid flows and associated eclogite metamorphism even more, perhaps to only a few weeks or months! And because the heat flow into the granulites to metamorphose them would have been primarily by convection associated with the fluid flows, rather than just by conduction, such a drastically short timescale of only weeks for this eclogite metamorphism is entirely feasible.
It's an interesting article, but geology is one of my weakest subjects, so there's not much I can comment on in it.
Permanent Link posted by crevo @ 11:18 AM 
