I need help with this problem. I found this strange black deposit on the base of my mugo needle pines. I do not see any bugs but the bigger deposit ( last picture ) must be made/produced by something. It feels grainy/sandlike. I already lost one pine to this problem, searched all around but cant find what causes this, so i hope someone knows.

Sorry, I have never seen this on pines so I can't help much..
But it IS weird!

Looks a lot like sooty mould to me, usually result of infestation from scale insects.

Can you see any on the plant?