New answers tagged mineralogy
2
There are two ways (at least two I will discuss here) to date a metamorphic rock.
The first is using an isochron. During a heating event, isotope ratios between different minerals (most often used are Rb-Sr and Sm-Nd) equilibrate, and the clock resets among the different minerals. You get a Rb-Sr value for several different minerals and plot them up. Ideally,...
1
The main objection with regard to sedimentary rock is that you can date the individual mineral grains with isotopic techniques but not when they were laid down together. All metamorphic rocks show some degree of new crystal growth whether through melting of the existing rock or additional material being deposited by transiting geothermal fluids, often both, ...
5
Skarn is metamorphosed sedimentary rock, it's iron deposits are in the form of sulfides. This means two things;
There almost certainly will be iron oxide contamination throughout the unit, at least I have never seen a sedimentary rock that didn't have staining from iron oxides. In my Earth Science classes we were always told that copper, and particularly ...
Top 50 recent answers are included