Waxaa jira qaar ka mid ah dhagaxyada ugu da'da weyn dhulka, gneisses oo qiyaastii ah 3.6 bilyan oo sano (80% sida jir ah sida meeraha). Qiyaastii 2.7 bilyan oo sano ka hor, lava basaltic daadiyey baxay dillaacyada ku jira dabaqa ee badda asalka ah; haraadiga dhagax this volcanic sameeyay Canadian Shield ee waqooyi bari Minnesota. xididdada buuraha volcanic kuwan iyo ficilka ee badaha Precambrian sameeyay Range Iron ee waqooyiga Minnesota.
Minnesota