Goodhue County Bedrock Geology relevance to silica sand mining Tony - PowerPoint PPT Presentation

Goodhue County Bedrock Geology – relevance to silica sand mining Tony Runkel Minnesota Geological Survey University of Minnesota

The Goodhue County Geologic Atlas describes and shows the distribution of bedrock, loose sediment on top of bedrock, and water within the rock and SAND, GRAVEL, CLAY sediment BEDROCK BEDROCK VERSUS QUATERNARY SEDIMENT (unconsolidated sand/gravel/clay) Tony Runkel Minnesota Geological Survey University of Minnesota

GOODHUE COUNTY BEDROCK MAP A’ A A’ A Tony Runkel Minnesota Geological Survey University of Minnesota

Quartz- rich sand grains from bedrock (“silica sand”) Typical “glacial” sand on top of bedrock Tony Runkel Minnesota Geological Survey University of Minnesota

A’ Quartz-rich bedrock layers generally near land surface Jordan Sandstone St Peter Sandstone Tony Runkel A Minnesota Geological Survey University of Minnesota A’ A Kenyon area White Rock area Red Wing area

Example: Jordan Sandstone ~500ft Red Wing area Kenyon area White Rock area Tony Runkel Minnesota Geological Survey University of Minnesota

Example: St Peter Sandstone ~500ft Kenyon area Red Wing area White Rock area Tony Runkel Minnesota Geological Survey University of Minnesota

Quartz-rich bedrock layers generally near land surface Jordan Sandstone St Peter Sandstone Tony Runkel Minnesota Geological Survey University of Minnesota

Thickness of unconsolidated (glacial” sediment in feet) = bedrock “cover” Tony Runkel Minnesota Geological Survey University of Minnesota

Quartz-rich bedrock layers Covered by less than 50 ft unconsolidated sediment Jordan Sandstone St Peter Sandstone Tony Runkel Minnesota Geological Survey University of Minnesota

Quartz-rich sandstone bedrock layers at or near (approx 50 ft) land surface St Peter at/near surface Jordan at/near surface Draft (unreviewed) Map by Minnesota Geological Survey Tony Runkel Tony Runkel Minnesota Geological Survey Minnesota Geological Survey University of Minnesota University of Minnesota

Tony Runkel Minnesota Geological Survey University of Minnesota

Tony Runkel Minnesota Geological Survey University of Minnesota