The colored maps in my slide show were generated by fly-overs in of an airplane equipped with a very sensitive machine able to detect very small changes in magnetic fields of bedrock 1000's of feet deep. Changes in color on the map indicate a change in the type of rock present deep below the surface. The near surface geology has largely been examined in Minnesota with state geologists taking core samples from both public and private water wells as they were drilled over the years. The deep geology of Minnesota has largely been unknown because of the expense of drilling deep wells for exploration. Until the Aeromagnetic maps were generated for the Midwest, the deep geology of the Midwest was far less certain. The red band that runs from Kansas through Iowa, Minnesota and Michigan is where the North American continent started to split apart 1.1 billion years ago. The red band running through the Aeromagnetic Map is what is left of a 1.1 billion year old mountain range. The Twin Cities area sits over the base of this mountain range that long ago weathered away to flat, and then as the Mid-continent drooped, it caused even more sediments from two addition inland seas at about 500 and 400 million years ago to deposit on top of the original sediments. A volcanic chain of islands ran through Minnesota at 1.1 billion years ago. These chain of volcanic islands were surrounded by water filled trough areas adjacent to their shorelines that served as collection basins for silt, mud and sand washing in from off the mountain range. The only life present at this point in time 1.1 billion years ago was Blue-Green Algae. Blue-Green Algae lived and died in these deep water basins that paralleled the Volcanic Island chains and the Blue-Algae decomposed into Oil and Gas as the sediments from the highlands covered them on the sea bottom. Most oil and gas is produced from decomposed Blue-Green Algae and not from dinosaurs. Coal beds are typically from near shore environments where trees were covered over by sediments. On the Aeromagnetic map there appears to be a bit of subduction going on too, meaning the two halves of the North American continent started coming back together, pushing the edges of the trough areas and volcanic inland chain back into the interior of the Earth. Some of these oil and gas deposits could be very deep, miles deep. As a simplification of the Aeromagnetic map, the best areas to drill for oil and gas would be the dark blue bands that run parallel to to the red band. These blue areas are likely the former water and algae filled trough areas that were filled with silt, mud and sand, causing the organics in the Blue-Green algae to turn to oil under heat and pressure caused by the depth of its burial in these sediments. My house in Arden Hills, Minnesota sits over one of these more promising areas for oil and gas production. In the process for mining copper in Michigan, a copper mine was dug under oil shale producing rock and it was noticed over the course of time the ceiling of this copper mine dripped oil, suggesting the rock strata above it had potentially commercial amounts of oil in it. This oil seep is labeled in slide three of my slide presentation. Since drilling exploratory wells is expensive and even with the best of geological maps, there is still luck involved in hitting commercial quantities of oil and gas, it isn't likely this area of potential oil and gas will be developed until exploratory wells suggest its worth the time and money to drill for it. Still, I think it is exciting Oil and Gas could be developed right here in the Twin Cities Area.
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How a Water Well is Drilledby TRUST1796214,100 views
I spent about 2 hours writing about oil and gas exploration in Minnesota only to have YouTube give me the punt. I lost everything. Now I will go back and compose my write-up again.
GregoryLog 3 years ago
Opps, I mis-spelled continental in the first slide
GregoryLog 3 years ago