Looks like some kind of magnetic anomaly.....
I mixed it up last night and its settling again. I'll be there over the weekend and will keep an eye on it.
Sad git. 
I did have a thought for the rusty sediment. THERMITE!!!! all i need is a source of aluminium powder.

that souns like hard work, to which i'm alergic.A file and some aluminium.![]()



