GeologyRocks

Hi Cirrus, welcome to GeologyRocks!

It is possible that a fossil might survive the metamorphic process. Given that the rock in question is a marble, which can form from heating of limestone it is possible. Does the marble show any other relict (or ghost) structures? Bedding, way-up structures and fossil can all survive metamorphism as gohst structures. Have you got any pictures?

Jon

Fossil may just survive low grade metamorphism. Good examples are the trillobites sp Angelina often found in Welsh slate. I believe that the amount of metamorphism can be measured by the the elongation of these fossils - but I have no idea of a formula or even where to find it! :?
John

I'd forgotten about the Welsh slates! Using the rather squished looking fossils you can calucate the strain the rock underwent by calculating the ratio of the normal "length" of the triobite to it's deformed length. You can do this in both the long and short axis to get two of the three directions of strain. I think this is right...anyone feel free to correct me!

Jon

Hi Jon,

That sounds about right. Not the sort of calculation I undertake on a daily basis!
I couldn't remember that much! :oops:

John