Passaic Formation

{{Infobox rockunit | name = Passaic Formation | period = Late Triassic | age = [[Late Triassic]], {{fossilrange|219|201.7}} | image = GoffleHill_SandstoneCliff.jpg | type = [[Geological formation]] | prilithology = [[Siltstone]], [[Mudstone]], [[Shale]] | otherlithology = [[Sandstone]], [[Conglomerate (geology)|Conglomerate]] | namedfor = [[Passaic, 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]], 1980<ref name=Olsen/> | region = [[Newark Basin]] of<br> [[Eastern North America Rift Basins]] | caption = Exposure of Passaic Formation sandstone on [[Goffle Hill]] in [[Hawthorne, New Jersey|Hawthorne]], [[New Jersey]]. | unitof = [[Newark Supergroup]] | underlies = Orange Mountain Basalt | overlies = [[Lockatong Formation]] | thickness = maximum of over {{convert|19,685|ft|m|-1}}<ref name=Olsen/> | extent = ~{{convert|200|mi|km}} in <br>[[New York (state)|New York]], [[New Jersey]], <br>and [[Pennsylvania]] }}

The '''Passaic Formation''' is a mapped bedrock unit in [[Pennsylvania]], [[New Jersey]], and [[New York (state)|New York]]. It was previously known as the Brunswick Formation since it was first described in the vicinity of [[New Brunswick, New Jersey]]. It is now named for the city of [[Passaic, New Jersey]], which is near where its type section was described by paleontologist [[Paul E. Olsen]].<ref name=Olsen/>

==Description== The Passaic is defined as a reddish-brown [[shale]], [[siltstone]] and [[mudstone]] with a few green and brown shale interbeds; red and dark-gray interbedded [[argillite]]s near the base.<ref>Berg, T.M., Edmunds, W.E., Geyer, A.R. and others, compilers, (1980). Geologic Map of Pennsylvania: Pennsylvania Geologic Survey, Map 1, scale 1:250,000.</ref> In New Jersey, there are [[Conglomerate (geology)|conglomerate]] and [[sandstone]] beds within the formation.

===Depositional environment=== The Passaic is mostly shallow lakes, playa, and alluvial fan deposits resulting from the rifting of [[Pangea]]. The red color 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> The Passaic Formation overlies the [[Lockatong Formation]] deep lake sediment cycles, which were deposited during wetter climatic cycles during the Late Triassic.<ref name="multiple"/> These sediments came from the northwest and contain clasts from Appalachian formations.

===Fossils=== *''[[Clepsysaurus]]'' *''[[Hypsognathus|Hypsognathus fenneri]]'' <ref>{{Cite journal |last1=Sues |first1=Hans-Dieter |last2=Olsen |first2=Paul E. |last3=Scott |first3=Diane M. |last4=Spencer |first4=Patrick S. |date=2000-06-27 |title=Cranial osteology of Hypsognathus fenneri, a latest Triassic procolophonid reptile from the Newark Supergroup of eastern North America |url=http://www.tandfonline.com/doi/abs/10.1671/0272-4634%282000%29020%5B0275%3ACOOHFA%5D2.0.CO%3B2 |journal=Journal of Vertebrate Paleontology |language=en |volume=20 |issue=2 |pages=275–284 |doi=10.1671/0272-4634(2000)020[0275:COOHFA]2.0.CO;2 |s2cid=17669446 |issn=0272-4634|url-access=subscription }}</ref>

==Age== The Passaic is Late Triassic with an astronomically calibrated age of 219 to 201.7 million years ago (Ma) and is about 13,000 ft (~4 km) thick in the basin depocenter. It conformably overlies the [[Lockatong Formation]] (darker, generally gray shales and mudrocks) and is overlain by the first Watching(Orange Mountain Formation) basalt. The Triassic/Jurassic boundary and correlated by pollen is located in the uppermost part of the formation, ~ 2 precessional cycles (~10–12 m) below the Orange Mountain Basalt. There are numerous [[diabase]] intrusions into the Passaic with local [[Metamorphic rock|contact metamorphic]] rocks.<ref>Berg, T.M., et al., (1983). Stratigraphic Correlation Chart of Pennsylvania: G75, Pennsylvania Geologic Survey, Harrisburg, Pennsylvania.</ref>

== References == {{reflist}}

== See also == * [[Geology of Pennsylvania]] * [[Geology of New Jersey]]

[[Category:Geologic formations of New Jersey]] [[Category:Geologic formations of New York (state)]] [[Category:Geologic formations of Pennsylvania]] [[Category:Shale formations of the United States]] [[Category:Mudstone formations of the United States]] [[Category:Siltstone formations of the United States]] [[Category:Paleontology in New Jersey]] [[Category:Paleontology in New York (state)]] [[Category:Paleontology in Pennsylvania]] [[Category:Triassic System of North America]] [[Category:Triassic geology of New Jersey]] [[Category:Triassic geology of New York (state)]] [[Category:Triassic geology of Pennsylvania]] [[Category:Conglomerate formations of the United States]] [[Category:Sandstone formations of the United States]]