https://ilstratwiki.web.illinois.edu/index.php?title=Hennepin_Member&feed=atom&action=historyHennepin Member - Revision history2024-03-29T05:57:38ZRevision history for this page on the wikiMediaWiki 1.38.4https://ilstratwiki.web.illinois.edu/index.php?title=Hennepin_Member&diff=15482&oldid=prevJennifer.Obrad: /* Name */2017-01-12T18:17:05Z<p><span dir="auto"><span class="autocomment">Name</span></span></p>
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{{Tree<br />
|category1=Paleozoic Erathem<br />
|category2=Ordovician System<br />
|category3=Blackriveran Stage<br />
|category4=Tippecanoe Sequence<br />
|category5=Ottawa Limestone Megagroup<br />
|category6=Platteville Group<br />
|category7=Champlainian Series<br />
|category8=Pecatonica Formation<br />
|tree1=Ottawa Limestone Megagroup<br />
|tree2=Platteville Group<br />
|tree3=Pecatonica Formation<br />
|tree4=Hennepin Member<br />
|tree21=Paleozoic Erathem<br />
|tree22=Ordovician System<br />
|tree23=Champlainian Series<br />
|tree24=Blackriveran Stage<br />
|tree31=Tippecanoe Sequence<br />
}}<br />
==Primary source==<br />
Willman, H. B., Elwood Atherton, T. C. Buschbach, Charles Collinson, John C. Frye, M. E. Hopkins, Jerry A. Lineback, and Jack A. Simon, 1975, Handbook of Illinois Stratigraphy: Illinois State Geological Survey Bulletin 95, 261 p.<br />
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==Contributing author&#40;s&#41;==<br />
H. B. Willman and T. C. Buschbach<br />
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==Name==<br />
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===Original description===<br />
The Hennepin Member of the Pecatonica Formation (Templeton and Willman, 1963, p. 75).<br />
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===Derivation===<br />
Named for Hennepin County, eastern Minnesota.<br />
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===Other names===<br />
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===History&#47;background===<br />
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==Type section==<br />
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===Type location===<br />
The type section of the Hennepin Member is in a bluff on the west side of the Mississippi River at Lock and Dam No. 1 in Minneapolis (NE SW NW 17, 28N-23W), where the member is 2.3 feet thick.<br />
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===Type author&#40;s&#41;===<br />
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===Type status===<br />
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==Reference section==<br />
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===Reference location===<br />
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==Stratigraphic relationships==<br />
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==Extent and thickness==<br />
The Hennepin Member is locally present in extreme northern Illinois, where it is a dolomitic sandstone containing phosphate pebbles and is commonly 2-4 feet thick.<br />
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==Lithology==<br />
The Hennepin Member varies from a dolomitic sandstone to a siltstone and to very sandy silty dolomite, which differentiates it from the relatively pure, although sandy, Chana Member above. It differs from the sandstone in the Glenwood Formation below in that it contains carbonates and its sands have a texture like that of the St. Peter. It appears in places to be a reworking of Glenwood sediments at the beginning of Platteville carbonate deposition.<br />
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==Core&#40;s&#41;==<br />
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==Photograph&#40;s&#41;==<br />
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==Contacts==<br />
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==Well log characteristics==<br />
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==Fossils==<br />
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==Age and correlation==<br />
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==Environments of deposition==<br />
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==Economic importance==<br />
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==Remarks==<br />
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==References==<br />
TEMPLETON, J. S., and H. B. WILLMAN, 1963, Champlainian Series (Middle Ordovician) in Illinois: Illinois State Geological Survey Bulletin 89, 260 p.<br />
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{{Codes<br />
|membercode=8150<br />
|geo_unit=--<br />
}}</div>Jennifer.Obrad