Can certain rock types mess with signal?

[Billy Banana]

I was flying over a mountain and was getting terrible signal strength. The flight record shows how wacky it was. It kept losing signal and wanted to come home. The mountain was made of sandstone and limestone.
This was my first flight with my new argtek antennas. I calibrated the compass and took the usual precautions. The wind was blowing much harder than I knew.
I then flew it at home and had NO problems...
Any ideas?
Thanks

 

[Meta4]

I was flying over a mountain and was getting terrible signal strength. The flight record shows how wacky it was. It kept losing signal and wanted to come home. The mountain was made of sandstone and limestone.
This was my first flight with my new argtek antennas. I calibrated the compass and took the usual precautions. The wind was blowing much harder than I knew.

The only way geology can have an effect on your signal is if you fly behind it and it blocks your signal.
ps .. there's no need to be calibrating your compass before flying.