Latest Breaking News On - Michigan formation - Page 1 : vimarsana.com

Here are photos - old and recent - of the gypsum mine of Grand Rapids, Michigan (recently, a sinkhole developed, revealing a portion of the gypsum mine).

United statesGrand havenGrand rapidsPlaster creekDouglass houghtonGrand rapidMississippian periodMichigan formationGypsum mineFirst mineJackson mineUnknown mine