Feltville Formation

{{Infobox rockunit | name = Feltville Formation | period = Hettangian | age = Hettangian ~{{Geological range|199|196}} | image = 2ndWatchungMountain_FeltvilleFormation.jpg | type = Geological formation | prilithology = Sandstone, siltstone, mudstone | otherlithology = Limestone | namedfor = Deserted Village of Feltville, New Jersey<ref name="Olsen">Olsen, P.E., 1980. The Latest Triassic and Early Jurassic Formations of the Newark Basin (Eastern North America, Newark Supergroup): Stratigraphy, Structure, and Correlation. ''New Jersey Academy of Science Bulletin'', v. 25, no. 2, p. 25-51.</ref> | namedby = Paul E. Olsen<ref name=Olsen/> | year_ts = 1980 | region = Newark Basin of Eastern North America Rift Basins | caption = Exposure of Feltville Formation sandstone beneath a ledge of Preakness Basalt on Preakness Mountain in New Jersey. | unitof = Newark Supergroup  Meriden Group | underlies = Preakness Basalt | overlies = Orange Mountain Basalt | thickness = maximum of {{convert|1,968|ft|m|-1}}<ref name=Olsen/> | extent = continuous for ~{{convert|40|mi|km}} in New Jersey, with outliers present in New Jersey, New York & Pennsylvania | coordinates = {{coord|40.8|N|74.3|W|display=inline,title}} | paleocoordinates = {{coord|21.4|N|20.7|W|display=inline}} | map = {{Location map+ | United States#New Jersey | relief = 1 | width = 250 | float = center | places = {{Location map~ | United States#New Jersey | lat_deg = 40.8 | lon_deg = -74.3 | mark = Blue pog.svg | marksize = 12 }} }} }}

The '''Feltville Formation''' is a mapped bedrock unit primarily in New Jersey, with one known outlier in Pennsylvania and another one in New York. It is named for the Deserted Village of Feltville in Watchung Reservation, New Jersey, which is near where its type section was described by paleontologist Paul E. Olsen.<ref name=Olsen/>

== Description == The Feltville Formation is composed of red, gray, and white sandstone of varying grain thickness, as well as red, gray, and black siltstone and calcareous mudstone. Sandstone/siltstone layers tend to be alternatingly massive and cross-bedded. Black to white carbonaceous limestone layers exist near the base of the formation.<ref name=Olsen/><ref name="USGS Feltville">[https://mrdata.usgs.gov/geology/state/sgmc-unit.php?unit=NJJf%3B5 Mineral Resources Online Spatial Data – Feltville Formation, New Jersey]. U.S. Geological Survey. Accessed July 23, 2010.</ref> Additionally, pebbles and cobbles of quartz are embedded within layers of sandstone and siltstone that interfinger with the Feltville Formation near Oakland, New Jersey.<ref name="USGS Feltville"/>

=== Depositional environment === The Feltville Formation can be characterized as a continuation of the Passaic Formation, which is mostly playa and alluvial fan deposits resulting from the rifting of Pangea. The primarily red color of this formation is often evidence that the sediments were deposited in arid conditions.<ref name="multiple">Faill, R.T., (2004). The Birdsboro Basin. ''Pennsylvania Geology'' V. 34 n. 4.</ref> However, the Feltville Formation differs from the Passaic Formation in that it contains a more significant portion of non-red layers, which were laid down by deep lakes present during wetter periods.<ref name="Rutgers Newark Basin Geology">Schlische, Roy W. [http://geology.rutgers.edu/103web/Newarkbasin/NB_text.html Geology of the Newark Rift Basin] {{Webarchive|url=https://web.archive.org/web/20210604164004/https://geology.rutgers.edu/103web/Newarkbasin/NB_text.html |date=2021-06-04 }}. Department of Geological Sciences, Rutgers University, Piscataway, NJ. Accessed July 23, 2010.</ref>

=== Fossils === Fish fossils, commonly those of the ray-finned ''Semionotus'', can be found in limestone layers within the formation.<ref name=Olsen/> In other layers, indeterminate fossil ornithischian tracks have been noted,<ref name="dinosaurdistribution">Weishampel, et al. (2004). "Dinosaur distribution." Pp. 517-607.</ref> along with additional reptile and dinosaur prints. Fossil plant remains, as well as root structures and pollen, are also found in the formation.<ref name=Olsen/>

== Age == The Feltville Formation rests conformably above the Orange Mountain Basalt and below the Preakness Basalt, placing its deposition somewhere between approximately 199 and 196 million years ago during the early Jurassic stage known as the Hettangian.

== Economic geology == The Feltville Formation was once mined for freestone, as indicated by a historical work detailing quarrying operations at the base of Preakness Mountain in New Jersey.<ref name="1834 Description">Gordon, Thomas Francis. A Gazetteer of the State of New Jersey – Comprehending a General View of its Physical and Moral Condition, together with a Topographical and Statistical Account of its Counties, Towns, Villages, Canals, Railroads, &c. Published by D. Fenton, 1834. [https://books.google.com/books?id=BnIFAAAAQAAJ&pg=RA1-PA8 Available via Google Books]</ref>

== References == {{Reflist}}

=== Bibliography === * {{citation |last1=Weishampel |first1=David B. |author2-link=Peter Dodson |last2=Dodson |first2=Peter |author3-link=Halszka Osmólska |last3=Osmólska |first3=Halszka |year=2004 |title=The Dinosauria, 2nd edition |url=https://books.google.com/books?id=vtZFDb_iw40C |publisher=Berkeley: University of California Press |pages=1–880 |accessdate=2019-02-21 |isbn=0-520-24209-2 |author1-link=David B. Weishampel }}

Category:Geologic formations of New Jersey Category:Geologic formations of New York (state) Category:Geologic formations of Pennsylvania Category:Hettangian Stage Category:Jurassic geology of New Jersey Category:Sandstone formations of the United States Category:Siltstone formations of the United States Category:Mudstone formations of the United States Category:Alluvial deposits Category:Ichnofossiliferous formations Category:Paleontology in New Jersey Category:Paleontology in New York (state) Category:Paleontology in Pennsylvania Category:Limestone formations of the United States