Midnight Volcano

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Midnight Volcano is believed to be a buried extinct volcano in southern Humphreys County, Mississippi. It is named after the nearby town of Midnight, Mississippi. During the time it was active, Midnight Volcano may have been a volcanic island in the Mississippi Embayment.{{Cite news|url=http://www.cdispatch.com/opinions/article.asp?aid=47721|title=Ask Rufus: Tombigbee sharks and Mississippi volcanoes|work=The Commercial Dispatch|access-date=June 11, 2018}}

The volcanic activity in the area is associated with the Monroe Uplift,{{Cite web|url=https://www.mdeq.ms.gov/wp-content/uploads/2017/06/Bulletin-85.pdf|title=Cretaceous Shelf Sediments of Mississippi, Mississippi State Geological Survey, Bulletin 85|last=Mellen|first=Frederic Francis|date=April 18, 1958|pages=23–24|access-date=June 11, 2018}}{{Cite web|url=http://www.newsouthernview.com/pages/nsv_wht_jacksons_volcano.html|title=NSV Whatever Happened To...?|last=Pitts|first=Bill|website=www.newsouthernview.com|access-date=June 11, 2018}} and igneous rocks in the region have been dated from 84 to 73 Ma.{{Cite journal|last=Cox|first=Randel Tom|date=September 2002|title=The Mississippi Embayment, North America: A first order continental structure generated by the Cretaceous superplume mantle event|url=https://www.researchgate.net/figure/Age-data-for-Cretaceous-igneous-rocks-in-the-Mississippi-Embayment-and-vicinity-Ages-are_fig2_248515758|journal=Journal of Geodynamics|volume=34|issue=2|pages=163–176|doi=10.1016/S0264-3707(02)00019-4|bibcode=2002JGeo...34..163C|via=ResearchGate}} A well drilled in Humphreys County found around 600 m (2000 ft) of volcanic rock, starting 1110 m (3641 ft) below the surface at the shallowest.{{Cite journal|last=Baksi|first=Ajoy|date=1997|title=The Timing of Late Cretaceous Alkalic Igneous Activity in the Northern Gulf of Mexico Basin, Southeastern USA|journal=The Journal of Geology|volume=105|issue=5|pages=629–643|doi=10.1086/515966|jstor=10.1086/515966|bibcode=1997JG....105..629B|s2cid=129911825}} The most recent measured volcanic rock was dated to 66 Ma,{{Cite journal|last=Merrill|first=Robert|date=1981|title=Genesis of bentonite in the Upper Cretaceous strata of Monroe County, Mississippi|url=http://umiss.lib.olemiss.edu/record=b1432684%7ES0|journal=Report of Student Investigations (Mississippi Mineral Resources Institute)|location=University of Mississippi Library, Special Collections|volume=820}} while older (and deeper) samples were dated at 81 and 94 Ma.{{Cite journal|last1=Sundeen|first1=Daniel A.|last2=Cook|first2=Philip L.|date=1977-08-01|title=K-Ar dates from Upper Cretaceous volcanic rocks in the subsurface of west-central Mississippi|url=https://pubs.geoscienceworld.org/gsabulletin/article-abstract/88/8/1144/202181/K-Ar-dates-from-Upper-Cretaceous-volcanic-rocks-in|journal=GSA Bulletin|language=en|volume=88|issue=8|pages=1144–1146|doi=10.1130/0016-7606(1977)88<1144:KDFUCV>2.0.CO;2|bibcode=1977GSAB...88.1144S|issn=0016-7606|url-access=subscription}}

These most recent deposits roughly coincide with the activity of Jackson Volcano, another buried volcano southeast of Midnight{{Cite web|url=https://digitalcommons.lsu.edu/cgi/viewcontent.cgi?article=5932&context=gradschool_disstheses|title=Petrogenesis and Provenance of Epiclastic Volcanic Cobbles From the Cretaceous Woodbine Formation, Southwest Arkansas.|last=Livesey|first=Christina Lee|date=1990|series=LSU Historical Dissertations and Theses 4933|access-date=11 November 2018}}

Volcanic debris from this volcanism was also found in the "Coffee sands", a Cretaceous sand layer to the north.