Quelltext der Seite Benutzer:Shi Annan/Mazon Creek fossil beds

{{Importartikel}}

{{short description|Conservation lagerstätte in Illinois on the National Register of Historic Places}}
{{redirect|Mazon Creek|the river|Mazon River}}
{{infobox rockunit
| period = Moscovian
| age = ~{{fossil range|309|307|refs=<ref>McCoy VE, Asael D, Planavsky N. Benthic iron cycling in a high-oxygen environment: Implications for interpreting the Archean sedimentary iron isotope record. ''Geobiology''. 2017;15:619–627. https://doi.org/10.1111/gbi.12247</ref>}}
}}
{{Infobox NRHP | name =Mazon Creek Fossil Beds
 | nrhp_type =nhl
 | image = 
 | caption = 
 | nearest_city= Benson Road, [[Morris, Illinois]]
 | locmapin = Illinois#USA
 | area =
| designated_nrhp_type= September 25, 1997<ref name="nhlsum">{{cite web|url=http://tps.cr.nps.gov/nhl/detail.cfm?ResourceId=-1975645062&ResourceType=Site|title=Mazon Creek Fossil Beds|accessdate=2007-10-11|work=National Historic Landmark summary listing|publisher=National Park Service|url-status=dead|archiveurl=https://web.archive.org/web/20080103060206/http://tps.cr.nps.gov/nhl/detail.cfm?ResourceId=-1975645062&ResourceType=Site|archivedate=2008-01-03}}</ref>
 | added = September 25, 1997<ref name="nris">{{NRISref|2007a}}</ref>
 | governing_body = Private
 | refnum=97001272
}}
[[File:Tullimonstrum.jpg|thumb|''[[Tullimonstrum|Tullimonstrum gregarium]]'' in a concretion from the Mazon Creek [[lagerstätten]].]]

The '''Mazon Creek fossil beds''' are a conservation ''{{lang|de|[[lagerstätte]]}}'' found near [[Morris, Illinois|Morris]], in [[Grundy County, Illinois]]. The fossils are preserved in [[ironstone]] [[concretion]]s, formed approximately {{Ma|309}} in the mid-[[Pennsylvanian (geology)|Pennsylvanian]] epoch of the [[Carboniferous]] period. These concretions frequently preserve both hard and soft [[Biological tissue|tissues]] of animal and plant materials, as well as many soft-bodied organisms that do not normally fossilize. The quality, quantity and diversity of fossils in the area, known since the mid-nineteenth century, make the Mazon Creek ''{{lang|de|lagerstätte}}'' important to [[paleontologist]]s, in attempting to reconstruct the [[paleoecology]] of the sites.<ref>[http://www.museum.state.il.us/exhibits/mazon_creek/MazonCreekSite.html Illinois State Museum-Mazon Creek Fossil Exhibit]</ref> The locality was declared a [[National Historic Landmark]] in 1997.<ref name="nhlsum"/><ref name="nrhpinv2">{{citation|title=National Historic Landmark Nomination: Mazon Creek Fossil Beds |url={{NHLS url|id=97001272}} |format=pdf|date=March 30, 1995 |author=Joanne Klussendorf |publisher=National Park Service}}. {{NHLS url|id=97001272|title=Accompanying  photos, from 1912 and 1991.|photos=y}}&nbsp;{{small|(497&nbsp;KB)}}</ref>

==Geology==
The Mazon Creek fossils are found in the Upper Carboniferous '''Francis Creek Shale''';<ref name=Allison1987>{{cite journal |author=P. A. Allison |year=1987 |title=A new cephalopod with soft parts from the Upper Carboniferous Francis Creek Shale of Illinois, USA |journal=[[Lethaia]] |volume=20 |issue=78 |pages=117–121 |doi=10.1111/j.1502-3931.1987.tb02028.x}}</ref> the [[Type locality (geology)|type locality]] is the [[Mazon River]] (or Mazon Creek), a tributary of the [[Illinois River]] near [[Morris, Illinois|Morris]], [[Grundy County, Illinois]]. The 25 to 30 meters of [[shale]] were formed approximately {{Ma|309}}, during the [[Pennsylvanian (geology)|Pennsylvanian]] period. The fossiliferous [[concretions]] are usually found within the thickest deposits of Francis Creek. The concretions occur in localized deposits within the silty to sandy [[mudstone]]s, in the lower four metres of the formation. The paleoecosystem is believed to be a large [[river delta]] system, deposited by at least one major [[river system]] flowing from the northeast. The sediments are believed to derive from the [[Appalachian orogeny]] events. The delta had a [[tropical]] climate, a result of the area being within 10° north [[latitude]] of the [[equator]] during the [[Pennsylvanian (geology)|Pennsylvanian]].

The remains of plants and animals were rapidly buried by the [[sediment]] deposited in the deltaic system. Bacterial [[decomposition]] of the remains produced [[carbon dioxide]] that combined with dissolved iron from the [[groundwater]]. This process formed [[siderite]] in the sediments surrounding the remains, forming detailed casts of their structure. [[Lithification]] of the sediments formed protective nodules of ironstone around the now fossilized remains.  This mode of preservation is known as [[Fossil#Authigenic mineralisation|authigenic mineralisation]].

==Location==
The fossiliferous concretions are found in the Mazon River area of [[Grundy County, Illinois|Grundy]], [[Will County, Illinois|Will]], [[Kankakee County, Illinois|Kankakee]], and [[Livingston County, Illinois|Livingston]] counties. Additional fossils are found in [[LaSalle County, Illinois]]; between the [[Vermilion River (Illinois River tributary)|Vermilion River]] and [[Marseilles, Illinois]]. The ironstone concretions are recovered from exposures along streams, roadcuts and in active or abandoned [[coal mine]] areas.

While professional geologists commonly mispronounced it MAY-zon, the correct local pronunciation is Muh-ZOHN.  ({{IPAc-en|m|ə|ˈ|z|ɒ|n}}){{citation needed|date=January 2019}}

Most concretions are found among the shale and sandstone that was piled up in either a [[spoil tip]] of an older underground mine, or ridges of the later [[surface mining]]. The [[Peabody Energy]] company operated several large strip mines in Grundy County that are now abandoned. They were named Pit 1 through Pit 11. The northern pits 1-8 are known for the [[Mazon Creek fossil beds#Fauna|Braidwood Biota]] with mostly terrestrial fauna and flora. Pit 11, which was located southwest of the town of Braidwood, Illinois, is known for its [[Mazon Creek fossil beds#Fauna|Essex Biota]] with a greater abundance of marine species.<ref name="evofos">{{cite book | first1=Paul | last1=Selden | chapter-url=https://books.google.com/books?id=LgdL9ZP2ftgC&pg=PA94 | title=Evolution of Fossil Ecosystems | publisher=Manson Publishing Ltd | last2=Nudds | first2=John | year=2012 | edition=second | pages=94–96 | isbn=978-1-84076-623-3 | chapter=Mazon Creek}}</ref> Pit 11 is now [[Braidwood State Fish and Wildlife Area]], an [[List of Illinois state parks|Illinois state park]]. Fossil collecting is allowed at the park with a permit.<ref>http://dnr.state.il.us/Lands/Landmgt/PARKS/R2/MAZONIA.HTM#Fossil {{webarchive|url=https://web.archive.org/web/20070605232303/http://dnr.state.il.us/lands/landmgt/PARKS/R2/MAZONIA.HTM |date=2007-06-05 }}</ref>

The site's importance was realized in the mid-nineteenth century: "the nodules of Mazon Creek, where fragments of plants, even of the softest texture, have been preserved in  their integrity".<ref>A.H.W. in ''Geological Survey of Illinois'', 1866, p 489</ref>

==Flora==
The Mazon Creek flora comprises over 400 species from at least 130 genera. However, the true number of species is difficult to determine. [[Paleobotanist]]s name separate plant structures with different names by convention, inflating the number of fossil plant taxa. Paleobotanists are currently determining which taxa are valid.

Mazon Creek flora includes: [[lycopsid]]s, related to modern club moss, with arborescent forms named ''[[Lepidophloios]]'', ''[[Sigillaria]]'' and ''[[Lepidodendron]]'', and herbaceous forms called ''[[Lycopodites]]'' and ''[[Cormophyton]]''; [[sphenopsida|sphenopsids]] like ''[[Calamites]]'' a tree-like [[horsetail]] relative, with common foliage names of ''[[Annularia]]'' and ''[[Asterophyllites]]'', and a vine-like form called ''[[Sphenophyllum]]''; Pteridophyta as marattitalean tree ferns and Filicales and Zygopteridales understory ferns, with common foliage names of ''[[Pecopteris]]'', ''[[Acitheca]]'' and ''[[Lobatopteris]]''; [[pteridosperm]]s, also known as seed ferns, an extinct group of plants that grew both as trees and smaller shrubs, with features like pinnated leaves similar to true ferns, but reproduced by seeds instead of spores; they had common foliage names ''[[Mariopteris]]'', ''[[Alethopteris]]'', ''[[Odontopteris]]'', ''[[Neuropteris]]'', ''[[Laveineopteris]]'' and ''[[Macroneuropteris]]''; extinct [[gymnosperm]] ''[[Cordaites]]'', believed to be closely related to and sharing many features with modern [[conifer]]s.

==Fauna==
[[File:Bandringa rayi fossil shark, Mazon Creek Lagerstatte.jpg|thumb|upright=1.4|''[[Bandringa rayi]]'' [[fossil]] [[shark]], Mazon Creek Lagerstatte. This  is the [[holotype]] specimen of the species. Its size and lack of developed [[Cartilage|cartilaginous]] skeletal structures indicate that this is a juvenile shark.]]
The Mazon Creek fauna has over 320 species of animals that have been identified. The fauna is divided into two components: the  [[ocean|marine]] '''Essex fauna''' and the land and [[freshwater]] '''Braidwood fauna''', that were washed into the deltaic sediments.

===Essex biota===
The Essex fauna includes jellyfish, sea [[worm]]s, [[snail]]s, saltwater [[clam]]s, [[shrimp]], [[Eurypterida|sea scorpions]], cephalopods<ref name=Allison1987/> and [[fish]].
The most common species found is the ''[[Essexella]]'' jellyfish. It consists of 42% of all fossil finds in the Essex biota.<ref name="evofos"/> The Essex area also includes the most famous faunal member of the Illinois' state fossil ''[[Tullimonstrum]]'', known popularly as the "Tully Monster". Other well-documented organisms include the [[crustacean]] ''[[Belotelson]]'' and the possible [[hemichordate]] ''[[Etacystis]]''.

===Braidwood biota===
The Braidwood fauna includes [[insect]]s, [[millipede]]s, [[centipede]]s, [[scorpion]]s, [[spider]]s, other [[arachnid]]s, [[amphibian]]s, freshwater fish, freshwater shrimps, freshwater [[horseshoe crab]]s and [[ostracod]]s. The oldest known [[beetle]] has been described from the Braidwood fauna.<ref>{{cite journal |author=Oliver Bethoux |year=2009 |title=The earliest beetle identified |journal=[[Journal of Paleontology]] |volume=83 |issue=6 |pages=931–937 |doi=10.1666/08-158.1|s2cid=85796546 }}</ref>

Three species of centipede have been described from Mazon Creek. They are known from around 60 specimens in total, and belong to three species:<ref name="Shear">{{cite book |editor=Alessandro Minelli |year=1990 |title=Proceedings of the 7th International Congress of Myriapodology |publisher=[[Brill Publishers]] |isbn=978-90-04-08972-3 |author1=William A. Shear  |author2=Patricia M. Bonamo  |name-list-style=amp |chapter=Fossil centipeds from the Devonian of New York State, U.S.A. |pages=89–96 |chapter-url=https://books.google.com/books?id=BJzFnCunVxsC&pg=PA89}}</ref>
*''[[Latzelia|Latzelia primordialis]]'' <small>[[Samuel Hubbard Scudder|Scudder]], 1890</small> ([[Scutigeromorpha]])
*''Mazoscolopendra richardsoni'' <small>Mundel, 1979</small> ([[Scolopendromorpha]])
*''Palenarthrus impressus'' <small>Scudder, 1890</small> (Scolopendromorpha)
Fossil centipedes are very rare, and ''Mazoscolopendra'' and ''Palenarthrus'' are the only known [[Paleozoic]] scolopendromorphs.<ref>{{cite journal |author=Heather M. Wilson |year=2003 |title=A new scolopendromorph centipede (Myriapoda: Chilopoda) from the Lower Cretaceous (Aptian) of Brazil |journal=[[Journal of Paleontology]] |volume=77 |issue=1 |pages=73–77 |jstor=4094718 |doi=10.1666/0022-3360(2003)077<0073:ANSCMC>2.0.CO;2}}</ref>

==See also==
{{Portal|Palaeontology|Illinois}}
* [[Burgess shale]]
* [[Hamilton Quarry]]
* ''[[Mazonova]]''

==References==
{{reflist|32em}}

==Further reading==
*{{cite book |author=Stephen A. Schellenberg |chapter=Mazon Creek: preservation in late Paleozoic deltaic and marginal marine environments |editor1=Walter Etter |editor2=James W. Hagadorn |editor3=Carol M. Tang |editor4=David J. Bottjer |title=Exceptional Fossil Preservation: A Unique View on the Evolution of Marine Life |publisher=[[Columbia University Press]] |year=2002 |isbn=978-0-231-10254-4 |pages=185–203}}
*{{cite book |editor1=Charles W. Shabica |editor2=Andrew A. Hay |title=Richardson's Guide to the Fossil Fauna of Mazon Creek |publisher=[[Northeastern Illinois University]] |isbn=978-0-925065-21-6|year=1997 }}
*{{cite book |author=Jack Wittry |title=The Mazon Creek Fossil Flora |publisher=[[Esconi]] |year=2006 |isbn=978-1-932433-71-5}}
*{{cite book |author=Jack Wittry |title=The Mazon Creek Fossil Fauna |publisher=[[Esconi]] |year=2012 |isbn=978-0578111483}}
*{{cite book |author=Jack Wittry |title=A Comprehensive Guide to the Fossil Flora of Mazon Creek |publisher=[[Esconi]] |year=2020 |isbn=978-0-578-22890-7}}
*{{cite news|author=Mike Sula|date=July 1, 2004|title=The Vanishing Mother Lode of Mazon Creek|work=[[Chicago Reader]]|url=http://www.chicagoreader.com/chicago/the-vanishing-mother-lode-of-mazon-creek/Content?oid=915941}}

==External links==
{{commons category|Mazon Creek fossil beds}}
* [http://www.museum.state.il.us/exhibits/mazon_creek/ Illinois State Museum: Mazon Creek Fossil Exhibit]
* [http://www.ucmp.berkeley.edu/carboniferous/mazon.html UC Berkeley: Mazon Creek fossil beds info]
*[https://web.archive.org/web/20050404073053/http://www.neiu.edu/~mcproj/frame.html Northeastern Illinois University: fossil fauna]
* [https://web.archive.org/web/20090207013955/http://www.fossilnews.com/2000/mazon/mazon.html Fossil News.com: General diagram of Mazon Creek Delta] — ''with photographs of fossils.''
* [https://web.archive.org/web/20090909173527/http://palaeo.gly.bris.ac.uk/palaeofiles/lagerstatten/mazon/index.html University of Bristol.uk: Mazon Creek flora and fauna] — ''species discussed, with photographs of fossils.''
* [https://www.flickr.com/photos/jsjgeology/sets/72157646416371744/ Flickr.com: Mazon Creek Lagerstätte photo gallery]

{{Portal bar|Paleontology|Prehistoric life|Illinois}}
{{Registered Historic Places|state=collapsed}}

{{coord|41.321|-88.346|type:landmark_region:US-IL|display=title}}

[[:Kategorie:Carboniferous paleontological sites]]
[[:Kategorie:Lagerstätten]]
[[:Kategorie:Paleozoic paleontological sites of North America]]
[[:Kategorie:Geography of Grundy County, Illinois]]
[[:Kategorie:Carboniferous Illinois]]
[[:Kategorie:Natural history of Illinois]]
[[:Kategorie:Paleontology in Illinois]]
[[:Kategorie:National Historic Landmarks in Illinois]]
[[:Kategorie:Natural features on the National Register of Historic Places]]
[[:Kategorie:National Register of Historic Places in Grundy County, Illinois]]
[[:Kategorie:Protected areas of Grundy County, Illinois]]
[[:Kategorie:1997 in paleontology]]