View source for Mazon Creek Fossil Flora

__NOTOC__{{DISPLAYTITLE:Mazon Creek Fossil Flora}}[[File:Fern.gif|frameless|right|104px|Illustration by Mary Parrish]]
==Mazon Creek Fossils==
===Introduction===
The Mazon  Creek fossil deposit extends over a wide area of northeastern Illinois. The fossils are best known from concretions  or nodules of siderite, an iron carbonate mineral, which generally must be fractured to expose a plant or animal fossil within. These nodules occur in a geological unit  known as the [[ilstrat:3000|Francis Creek shale]], a wedge-shaped body of gray shale that lies  immediately above the [[ilstrat:3020|Colchester (No. 2)]] coal bed in northeastern Illinois. The [[ilstrat:3000|Francis Creek shale]] is of Middle [[ilstrat:1520|Pennsylvanian]] age, approximately 309 million  years old, which is part of the late Moscovian Stage in the latest international terminology for the [[ilstrat:Carboniferous_System|Carboniferous System]] (ICS), or the [[ilstrat:Desmoinesian_Series|Desmoinesian]] Stage in regional North American terminology. At the time of [[ilstrat:Francis_Creek_Shale_Member|Francis Creek shale]] deposition, the Mazon Creek area was near the equator and  the present day continents formed one large land mass, Pangaea.

The  [[ilstrat:1520|Pennsylvanian Subperiod]] of the [[ilstrat:Carboniferous_System|Carboniferous]] was a time of intense polar glaciations, particularly in the southern hemisphere, known as Gondwana. These glaciations resulted in a series of  glacial-interglacial cycles much like those the Earth has experienced over the  past million years or so. The Francis Creek shale appears to have been  deposited as the Earth transitioned from one of these glacial intervals to an  interglacial. This transition was accompanied by rising sea-level, which flooded the surface of the vast coastal peat-forming swamp that became the [[ilstrat:3020|Colchester coal]]. During this time, climate also was in  transition from very wet when the peat/coal bed formed, during glacial times,  to increasingly seasonally dry during the interglacial. The plants that were deposited in the Francis Creek shale were part of the waning wet climate that accompanied drowning and  flooding of the tropical lowlands.

Plant and animal fossils have been excavated from  the banks of Mazon Creek (River) since the 1840s. About 1855, papers describing  the plant and animal fossils found in these concretions began to appear in  scientific journals. Preservation of the land animals, insects, and other  arthropods equaled or exceeded anything known at that time. This association of  fauna and flora (the Mazon Creek biota) became world famous. Concretions and  their contents became paleontological prizes, subjects of intensive research.  At the turn of the century, shaft mines and then strip mines, permitted the  collecting of fossils from Will to LaSalle counties, roughly paralleling the Illinois River for over 50 miles. Concretion collecting developed into a popular hobby and tens of millions of these fossiliferous rocks have been  rescued from weathering and/or reburial by collectors.
            
Large collections of Mazon  Creek plants and animals are held by many major museums around the United  States and in many foreign countries. The largest U.S. collection is housed in the Field Museum of Natural  History in Chicago. The plant fossils from that collection have recently been re-examined and a catalogue of the flora has been published by Jack Wittry<ref>Wittry, J. 2006. The Mazon Creek Fossil Flora. ESCONI Associates, Downers Grove, Illinois. 154 p.</ref>. The Smithsonian has a modest sized, but  excellent collection of Mazon Creek plants and animals, many acquired by  donations made by private collectors. Especially fine and noteworthy are the Langford and McLuckie collections, which account for many of the specimens illustrated here.

===Follow these links to  explore our Mazon Creek flora fossils:===
{| class="wikitable"
|-
| <gallery mode="packed-overlay" heights=150px>
File:Paleo_link.jpg|link=[[Mazon_Creek_Fossil_Flora/Paleontology]]
</gallery> || '''The [[Mazon_Creek_Fossil_Flora/Paleontology|Paleontology]] of the Mazon Creek flora.'''
|-
| <gallery mode="packed-overlay" heights=175px>
File:Group_link.jpg|link=[[Mazon_Creek_Fossil_Flora/Groups]]
</gallery> || '''An index page of the [[Mazon_Creek_Fossil_Flora/Groups|Groups]] with descriptions, photographs, and artists' reconstructions of each of our 200 featured specimens.'''
|}
<!--* ??<a href="mazonGlossary.html">Glossary</a> and <a href="mazonPronunciation.html">Pronunciation Key -->

===Some Mazon Creek websites at other museums and universities===
* [http://fieldmuseum.org/explore/our-collections/mazon-creek-flora Field Museum of Natural History]. Go also [http://fieldmuseum.org/explore/multimedia/mazon-creek-fossil-invertebrates here], and [http://fieldmuseum.org/mazon-creek-paleobotany-references here].				
* [http://www.museum.state.il.us/exhibits/mazon_creek/ Illinois State Museum].  Go also [http://www.museum.state.il.us/databases/geology/mazoncreek/graphical/index.php here], and [http://www.museum.state.il.us/exhibits/mazon_creek/about_mazon_creek.html here].			
* [http://www.ucmp.berkeley.edu/carboniferous/mazon.html University of California Museum of Paleontology]
* [http://www.isgs.illinois.edu/outreach/geology-resources/illinois-state-fossil-tullimonstrum-gregarium Tully Monster at the Illinois State Geological Survey]
* [http://www.uhaul.com/supergraphics/states/illinois/tully/introduction.html Tully Monster] (U-Haul Supergraphics)
[[Category:Mazon Creek]]
{{#set:mazoncreek= Mazon Creek}}
==References==
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