Also check out vanden berg forum
Vanderburg is a variant spelling of the original surname van den Berg.
I have also come across the following variants (either as oneword or three word)--
van der Berg
van der Bergh
van den Burg
van den Burgh
My previous attempts to post this message appeared to fail. If they did get through, please ignore the variants vanamburg which is actually van Amburg.
Sam van den Berg