Gold's M&A rush

NovaGold Resources (TSX: NG) on Wednesday announced plans to buy the 40% stake it doesn't already own in Donlin Gold Holdings, creating a company valued at $4.2 billion. Why it matters: Mining M&A has hit the motherlode this year. There were $26.3 billion in deals in Q2. That's up 68% quarter over quarter, and is the second highest quarterly total since S&P began tracking the metric in 2013. Driving the news: NovaGold is acquiring the stake it does not own in the Alaskan gold miner from…