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Detrital Zircons Research

Posted on April 10th, 2020

IGS geologist, Ryan Clark, contributed to a recent publication, “Detrital zircons and sediment dispersal in the eastern Midcontinent of North America“ forthcoming in the June 2020 issue of Geosphere.  You can read it at

Clark collected samples which provided detrital zircon data from late Mississippian sandstones in SE Iowa.  The locations of these sandstones is also enigmatic because the thickest succession lies between two major sedimentary basins, the Illinois Basin and the Forest City Basin.

Zircons are durable minerals that form in magma chambers deep underground.  Various dating methods can be used to obtain the age of formation of zircons even billions of years after they formed.  When the host rock is uplifted and eroded away over millions of years, typically during mountain building, the zircon grains and other detritus is carried across the continent via complex river systems.  By collecting detrital zircons from various sandstone formations across the U.S. and analyzing their ages geologists can determine where the sediments originated and what paths they took to reach their final resting place.  Did sandstone in Iowa come from the eroding Appalachian Mountain range?