Tully Formation
{{Short description|Geologic Unit found in the Appalachian Basin}}
{{Infobox rockunit
| name = Tully Formation
| image =File:Tully Formation at Taughannock Falls State Park.jpg
| caption ={{Center|Tully Formation at Taughannock Falls State Park}}
| type = Formation
| age = Devonian
| prilithology =Limestone
| otherlithology =Shale, Siltstone, and Sandstone
| namedfor =Tully, NY
| namedby =Vanuxem (1839)
| region = Maryland, New York, Pennsylvania, West Virginia
| country = United States, Canada
| coordinates =
| unitof =
| subunits = ;New York:
- New Lisbon Member
- Laurens Member
- West Brook Member
;Pennsylvania:
- Weissport Member
- Brodhead Creek Member
- Lehighton Member
| underlies =Harrell Shale/Genesee Group
| overlies =Hamilton Group
| thickness =
| extent =
| area =
| map =
| map_caption =
}}
The Tully Formation is a geologic unit in the Appalachian Basin. The Tully was deposited as a carbonate rich mud, in a shallow sea at the end of the Middle Devonian.{{Cite journal |last=Philip H. Heckel |date=1963 |title=Depositional Environment of the Devonian Tully Limestone of Central New York: ABSTRACT |url=http://dx.doi.org/10.1306/bc7439df-16be-11d7-8645000102c1865d |journal=AAPG Bulletin |volume=47 |doi=10.1306/bc7439df-16be-11d7-8645000102c1865d |issn=0149-1423|url-access=subscription }} Outcrops for the Tully are found in New York State and Pennsylvania.{{Cite journal |last1=Stevenson |first1=R. E |last2=Skinner |first2=W. S. |date=1949 |title=The Tully Clastics of New York and Pennsylvania |url=https://www.jstor.org/stable/44109398 |journal=Pennsylvania Academy of Science |volume=23 |pages=28–33|jstor=44109398 }} It is also found subsurface in western Maryland and northern West Virginia. A number of fossil remains from marine organisms may be found in Tully outcrops.
Description
The Tully is primary made up of limestone. There there are also layers with much higher clay contend resulting in a calcareous shale. To the east the Tully becomes siliciclastic. This is due to sediments being washed in from the Acadian Mountains to the east. By the time the Tully was being deposited the Appalachian Basin had been nearly filled in that the Tully was deposited on a broad planform of rock.{{Cite journal |last1=Baird |first1=G.C. |last2=Zambito |first2=J.J. |last3=Brett |first3=C.E. |date=2012 |title=Genesis of unusual lithologies associated with the Late Middle Devonian Taghanic biocrisis in the type Taghanic succession of New York State and Pennsylvania |url=http://dx.doi.org/10.1016/j.palaeo.2011.11.010 |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |volume=367-368 |pages=121–136 |doi=10.1016/j.palaeo.2011.11.010 |bibcode=2012PPP...367..121B |issn=0031-0182|url-access=subscription }} The Tully ranges in thickness to less than 1' in western New York to 70'+ thick in central Pennsylvania and 90'+ thick in southwestern Pennsylvania and northern West Virginia.
Fossils
= Brachiopods =
Tullypothyridina, Camarotoechia Mesocostale, Rhyssochonetes, Emanuella, Pseudoatrypa, Spinatrypa, Tylothyris, Mucrospirifer tulliensis, Cyrtina, Tullypothyridina, Echinocoelia, Strophodonta
References
{{reflist|refs=
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{{Chronostratigraphy of Maryland}}
{{Chronostratigraphy of New York}}
{{Chronostratigraphy of Pennsylvania}}
{{Chronostratigraphy of West Virginia}}
{{Portal bar|Geology|Paleontology|New York (state)|Pennsylvania|Devonian}}
Category:Devonian United States
Category:Devonian geology of New York (state)
Category:Devonian Pennsylvania
Category:Devonian West Virginia
Category:Limestone formations of the United States
Category:Shale formations of the United States