File:USGS Decorah crater.jpg

Summary

The Iowa and Minnesota airborne geophysical surveys are targeting an igneous intrusion, known as the Northeast Iowa Igneous Intrusive complex, that may be similar to the Duluth layered igneous complex exposed in the Lake Superior region of northern Minnesota. Known copper, nickel, and platinum group metal resources were deposited during the formation of the Duluth complex. Both of these complexes are associated with a large structural feature known as the Midcontinent Rift, which is exposed in the Lake Superior Region but is covered by younger rocks as it extends to the south through Iowa, Nebraska, Kansas, and Missouri.

Licensing

This image is in the public domain in the United States because it only contains materials that originally came from the United States Geological Survey, an agency of the United States Department of the Interior. For more information, see the official USGS copyright policy. Bahasa Indonesia ∙ català ∙ čeština ∙ Deutsch ∙ eesti ∙ English ∙ español ∙ français ∙ galego ∙ italiano ∙ Nederlands ∙ português ∙ polski ∙ sicilianu ∙ suomi ∙ Tiếng Việt ∙ Türkçe ∙ български ∙ македонски ∙ русский ∙ മലയാളം ∙ 한국어 ∙ 日本語 ∙ 中文 ∙ 中文（简体） ∙ 中文（繁體） ∙ العربية ∙ فارسی ∙ +/−

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