While not Fennoscandia, there is the 3000 year old Kaali crater in Estonia, ie during the stone age, a thousand of year earlier than what this article is about.

While not Fennoscandia, there is the 3000 year old Kaali crater in Estonia, ie during the stone age, a thousand of year earlier than what this article is about. There would have been iron available from it, and there were settlements afterwards around the crater.