In my opinion the groundwater chemistry can be a signature of the rock-water interaction.

I recommend to consult the drill and activity reports of the Continental Deep Drilling Project of the Federal Republic of Germany (KTB) where a drill hole for more than 12000 m was planned and ended around 9000m in crystalline basement rocks. There are all sorts of geoscientific analyses that have been conducted form the surface down to the final depth on the core sections and drill cuttings covering hydrogeology, geology, petrography, isotope analyses….etc. A pilot hole of 4000 m was sunken before the main hole was done. The drill reports providing information meter by meter should be available from the library of the Federal Institute for Geosciences and Natural Resources at Hannover, Germany. I was a staff member of the Project Management Group (responsible for mineralogy, geochemistry, economic geology).

In general, results answering your question should be found among a joint study of mineralogy, geochemistry, structural geology, petrophysics, and hydrogeology.

As far as the mineral assemblage is concerned have a look at uranyl-bearing minerals (phosphates, hydroxides, silicates, sulfates, arsenates) and K-Fe-Mn oxide-hydroxides both of them are amenable to radiometric age dating and enable you to correlate deep-seated supergene processes with landscape-sculpturing processes.

HGD