View source for Middlesex Formation

{{Infobox rockunit
| name           = Middlesex Formation
| image          =
| caption        =
| type           = [[Formation (stratigraphy)|Formation]]
| age            =  [[Frasnian]]
| prilithology   =[[Black Shale]]
| otherlithology =
| namedfor       =Town of Middlesex, NY
| namedby        =
| region         = *{{Flag|Maryland}}
*{{Flag|New York}}
*{{Flag|Ohio}}
*{{Flag|Pennsylvania}}
*{{Flag|West Virginia}}
| country        = United States
| coordinates    =
| unitof         = [[Sonyea Group]]
| subunits       =
| underlies      = [[Cashaqua Shale]] or [[Pulteney shale]]
| overlies       =[[Genesee Group]]
| thickness      =6–{{convert|75|ft|m}}
| extent         =
| area           =
| map            =
| map_caption    =
}}

The '''Middlesex Formation''' is a carbon rich black shale [[Formation (stratigraphy)|geologic formation]] found in the  [[Appalachian Basin]]. It represents one of several transgressive events (rising sea levels) during the Late Devonian.<ref>{{Cite web |last1=KIRCHGASSER |first1=WILLIAM T. |last2=OVER |first2=D. JEFFREY |date=9 December 2023 |title=FRASNIAN (UPPER DEVONIAN) STRATA OF THE GENESEE RIVER VALLEY, WESTERN NEW YORK STATE |url=https://ottohmuller.com/nysga2ge/Files/1994/NYSGA%201994%20A5%20-%20Frasnian%20(Upper%20Devonian)%20Strata%20of%20the%20Genesee%20River%20Valley,.pdf |access-date=9 December 2023 |website=Otto's Website}}</ref>

== Description ==
The Middlesex is a laminated dark grey to black mudstones and siltstone. It developed in an [[Anoxic waters|Anoxic]] environment. Further evidence of this is the lack of [[bioturbation]]. There are also sparse sand and silt layers suggesting that they were single event deposits.<ref>{{Cite journal |last=Schieber |first=J. |date=1999-07-01 |title=Distribution and deposition of mudstone facies in the Upper Devonian Sonyea Group of New York |url=http://dx.doi.org/10.2110/jsr.69.909 |journal=Journal of Sedimentary Research |volume=69 |issue=4 |pages=909–925 |doi=10.2110/jsr.69.909 |issn=1527-1404|url-access=subscription }}</ref>{{Portal|Earth sciences|New York (state)|Paleontology}}

{{Chronostratigraphy of New York}}
{{Chronostratigraphy of Pennsylvania}}

==References==
{{Reflist}}

* {{cite web 
|url=http://mrdata.usgs.gov/geology/state/sgmc-unit.php?unit=NYDs%3B4
|title=Cashaqua and Middlesex Shales
|publisher=USGS 
|access-date=2015-09-17 
}}
* {{cite journal 
|last=Bergin
|first= M. J.
|date=1964
|title=Bedrock Geology of the Penn Yan and Keuka Park Quadrangles New York
|url=https://pubs.er.usgs.gov/publication/b1161G
|journal=Geological Survey Bulletin 
|publisher=USGS
|issue=1161-G
|access-date=22 September 2015}}
* {{cite web
 |url         = https://macrostrat.org/unit_info.php?name_id=4156
 |title       = Middlesex Shale Formation – Sonyea Group
 |publisher   = Shanan E. Peters & Noel A. Heim
 |access-date = 2015-09-17
 |url-status     = dead
 |archiveurl  = https://web.archive.org/web/20150923144159/https://macrostrat.org/unit_info.php?name_id=4156
 |archivedate = 2015-09-23
}}
* {{cite journal |last=Schieber |first=J. |date=1999 |title=Distribution and deposition of mudstone facies in the Upper Devonian Sonyea Group of New York |url=http://www.shale-mudstone-research-schieber.indiana.edu/sonyea-shales.htm |journal=Journal of Sedimentary Research |publisher=SEPM Society for Sedimentary Geology |volume=69 |issue=4 |pages=909–925 |access-date=22 September 2015 |doi=10.2110/jsr.69.909|url-access=subscription }}

[[Category:Devonian geology of New York (state)]]
[[Category:Devonian Pennsylvania]]


{{NewYork-geologic-formation-stub}}