Waxaa jira qaar ka mid ah dhagaxyada ugu da'da weyn ee dhulka, gneisses oo qiyaastii ah 3.6 bilyan oo sano (80% sida jirka adduunka). Qiyaastii 2.7 bilyan oo sano ka hor, lava basaltic ayaa ka soo baxday dillaacyada ku yaal salka badda asalka ah; haraadiga dhagaxan volcanic wuxuu sameeyay Canadian Shield ee waqooyi-bari Minnesota.
waqooyi bari Minnesota