polonium halos

Out of curiosity, does Gentry have full lithologic descriptions and photos of all his samples? And if so, where might these be found?

Wrong.Fluids, gases, ions, etc. all can most certainly move through rocks and/or individual minerals. This fact has been known for quite some time.

You are already in discussion with posters who know far more than I on the subject of isotopes and isotopic dating. I was simply pointing out that your statement is incorrect.But to answer your question, yes, I have confidence in isotopic dating methods. I use those data quite often, in fact. However, that does not mean each date is accepted without question or scrutiny. It must make geologic sense.

I agree. AO's smugness is unwarranted considering his casual dismissal of the Putnis et al. paper. This is a clear indication that OA is incapable of recognizing potentially-significant lines of evidence -- probably because they do not support his position.In addition, not even the very best geologist in the world can confirm that the image AO linked to is granite. In fact, it looks more like the medium- to coarse-grained, clinopyroxene- and biotite-bearing syenite I have sitting on my desk. However, with a good petrographic description, most geologists CAN determine the presence and/or degree of metamorphism. And aren't those 'granites' from New Hampshire? I'm confused. Perhaps AO is referring to other photos...I'm not even sure what AO is attempting to convey with the picture of the apatite/fluorapatite(?). Is that from Silver Crater?