Passaic Formation

<h2 id="description">Description</h2>
<p>The Passaic is defined as a reddish-brown <a href="/facts/Shale/bsIhqY5F">shale</a>, <a href="/facts/Siltstone/sI119qT3">siltstone</a> and <a href="/facts/Mudstone/KWLvUash">mudstone</a> with a few green and brown shale interbeds; red and dark-gray interbedded <a href="/facts/Argillite/xG8FWJAH">argillites</a> near the base.<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a> In New Jersey, there are <a href="/facts/Conglomerate_(geology)/llpnLX76">conglomerate</a> and <a href="/facts/Sandstone/RP8B6fqL">sandstone</a> beds within the formation.
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<h3>Depositional environment</h3>
<p>The Passaic is mostly shallow lakes, playa, and alluvial fan deposits resulting from the rifting of <a href="/facts/Pangea/VGruHKJj">Pangea</a>. The red color is often evidence that the sediments were deposited in arid conditions.<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a> The Passaic Formation overlies the <a href="/facts/Lockatong_Formation/YIzhuNsl">Lockatong Formation</a> deep lake sediment cycles, which were deposited during wetter climatic cycles during the Late Triassic.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a> These sediments came from the northwest and contain clasts from Appalachian formations.
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<h3>Fossils</h3>
<ul><li><i><a href="/facts/Clepsysaurus/b53lGIxn">Clepsysaurus</a></i></li>
<li><i><a href="/facts/Hypsognathus/8b6SjPnf">Hypsognathus fenneri</a></i> <a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a></li></ul>
<h2 id="age">Age</h2>
<p>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 <a href="/facts/Lockatong_Formation/YIzhuNsl">Lockatong Formation</a> (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 <a href="/facts/Diabase/7XK2Sf8g">diabase</a> intrusions into the Passaic with local <a href="/facts/Metamorphic_rock/JRp6dsCm">contact metamorphic</a> rocks.<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a>
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<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/Geology_of_Pennsylvania/QKJLNIqm">Geology of Pennsylvania</a></li>
<li><a href="/facts/Geology_of_New_Jersey/4VXyvbcy">Geology of New Jersey</a></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>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. <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>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. <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
<li id="fn:3"><p>Faill, R.T., (2004). The Birdsboro Basin. Pennsylvania Geology V. 34 n. 4. <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li>
<li id="fn:4"><p>Faill, R.T., (2004). The Birdsboro Basin. Pennsylvania Geology V. 34 n. 4. <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li>
<li id="fn:5"><p>Sues, Hans-Dieter; Olsen, Paul E.; Scott, Diane M.; Spencer, Patrick S. (2000-06-27). "Cranial osteology of Hypsognathus fenneri, a latest Triassic procolophonid reptile from the Newark Supergroup of eastern North America". Journal of Vertebrate Paleontology. 20 (2): 275–284. doi:10.1671/0272-4634(2000)020[0275:COOHFA]2.0.CO;2. ISSN 0272-4634. S2CID 17669446. <a href="http://www.tandfonline.com/doi/abs/10.1671/0272-4634%282000%29020%5B0275%3ACOOHFA%5D2.0.CO%3B2" target="_blank">http://www.tandfonline.com/doi/abs/10.1671/0272-4634%282000%29020%5B0275%3ACOOHFA%5D2.0.CO%3B2</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li>
<li id="fn:6"><p>Berg, T.M., et al., (1983). Stratigraphic Correlation Chart of Pennsylvania: G75, Pennsylvania Geologic Survey, Harrisburg, Pennsylvania. <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li>
</ol>

Passaic Formation open-in-new

Passaic Formation