As glaciers advanced and retreated through minnesota, some of the ice was difficult to melt and stayed in one place for an extended period of time. the glaciers continued to deposit sediments around and sometimes on top of these isolated ice blocks. as glaciers advanced and retreated through minnesota, some of the ice that remained was more difficult to melt than other areas. the glaciers continued to deposit sediments around and sometimes on top of these lone ice blocks. as the ice blocks melted, they left behind