That s a good sign Any mesa like mountains are likely to be sills i e Rabbit Mountain Mount McKay While checking some references on the Mount McKay article I found Pie Island Isle Royale and Flatland Island which appear to be sills as well along with others at Lake Nipigon which appears to be a failed arm of the main rift called the Nipigon Embayment The other sills can be found here I m wanting to take some pictures of pillow lava formations around my area but I don t have a camera lol So I ll have to wait until I have one