Portland Formation

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Portland Formation
Stratigraphic range: Hettangian-Sinemurian
~199–195  Ma
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Type Geological formation
Unit of Agawam Group, Newark Supergroup
Sub-units Turners Falls Sandstone & Mount Toby Formation
Overlies East Berlin Formation
Lithology
Primary Sandstone
Other Mudstone, siltstone, limestone
Location
Coordinates 42°18′N72°30′W / 42.3°N 72.5°W / 42.3; -72.5
Approximate paleocoordinates 24°00′N18°36′W / 24.0°N 18.6°W / 24.0; -18.6
Region Connecticut, Massachusetts
CountryFlag of the United States.svg  USA
Extent Deerfield & Hartford Basins
Usa edcp relief location map.png
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Portland Formation (the United States)
Relief map of USA Massachusetts.png
Blue pog.svg
Portland Formation (Massachusetts)

The Portland Formation is a geological formation in Connecticut and Massachusetts in the northeastern United States. [1] It dates back to the Early Jurassic period. [2] The formation consists mainly of sandstone laid down by a series of lakes (in the older half of the formation) and the floodplain of a river (in the younger half). The sedimentary rock layers representing the entire Portland Formation are over 4 kilometres (2.5 mi) thick and were formed over about 4 million years of time, from the Hettangian age (lower half) to the late Hettangian and Sinemurian ages (upper half). [3]

Contents

In 2016, the paleontologist Robert E. Weems and colleagues suggested the Portland Formation should be elevated to a geological group within the Newark Supergroup (as the Portland Group), and thereby replacing the former name "Agawam Group". They also reinstated the Longmeadow Sandstone as a formation (within the uppermost Portland Group); it had earlier been considered identical to the Portland Formation. [4]

Vertebrate paleofauna

Dinosaur coprolites are known from the formation. [2] This formation and the underlying East Berlin Formation are well-known for its numerous well-preserved dinosaur tracks, which represent ornithischians, theropods, and sauropodomorphs, which are preserved at sites such as Dinosaur Footprints Reservation. [2] [5] Other tracks are also known representing animals such as pseudosuchians, turtles, and temnospondyls. [6]

Dinosaurs
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
Anchisaurus [2] A. polyzelus [2]
  • Connecticut [2]
  • Massachusetts [2]
Anchisaurus NT.jpg
Podokesaurus [2] P. holyokensisMassachusettsPartial postcranial skeleton. [7] All known remains of this species have been destroyed.[ citation needed ]
Podokesaurus restoration.jpg
Neotheropoda sp. [8] MassachusettsPartial humerus.Estimated to have been 9 meters long, and possibly a semiaquatic piscivore.
Non-Dinosaur Archosaurs
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
Stegomosuchus [9] S. longipesHine's Quarry, LongmeadowPartial postcranial skeleton.Originally Stegomus. A small armored "protosuchian" crocodyliform.
The American journal of science (1904) (18125938496).jpg
Pterosauria sp. [10] South Hadley, MassachusettsPartial Wrist and tooth.Non-pterodactyloid pterosaur estimated to have a wingspan of 40 cm.
Fish
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
Redfieldius [11] R. gracilisThe last surviving redfieldiiform fish. Redfieldius gracilis.jpg
Semionotus [11] S. sp.A semionotid fish. Semionotus bergeri.jpg

Invertebrate paleofauna

Insects
GenusSpeciesLocationStratigraphic positionMaterialNotesImages
Holcoptera H. schlotheimi [12] A coptoclavid beetle. Holcoptera schlotheimi elytron NHMUK I.6653.jpg
H. giebeli [13]
Orthoptera sp. [13] An indeterminate orthopteran
Blattaria sp. [13] An indeterminate cockroach

See also

Related Research Articles

<i>Anchisaurus</i> Extinct genus of dinosaurs

Anchisaurus is a genus of basal sauropodomorph dinosaur. It lived during the Early Jurassic Period, and its fossils have been found in the red sandstone of the Upper Portland Formation, Northeastern United States, which was deposited from the Hettangian age into the Sinemurian age, between about 200 and 192 million years ago. Until recently it was classed as a member of Prosauropoda. The genus name Anchisaurus comes from the Greek αγχιanchi-; "near, close" + Greek σαυρος ; "lizard". Anchisaurus was coined as a replacement name for "Amphisaurus", which was itself a replacement name for Hitchcock's "Megadactylus", both of which had already been used for other animals.

Podokesaurus is a genus of coelophysoid dinosaur that lived in what is now the eastern United States during the Early Jurassic Period. The first fossil was discovered by the geologist Mignon Talbot near Mount Holyoke, Massachusetts, in 1910. The specimen was fragmentary, preserving much of the body, limbs, and tail. In 1911, Talbot described and named the new genus and species Podokesaurus holyokensis based on it. The full name can be translated as "swift-footed lizard of Holyoke". This discovery made Talbot the first woman to find and describe a non-bird dinosaur. The holotype fossil was recognized as significant and was studied by other researchers, but was lost when the building it was kept in burned down in 1917; no unequivocal Podokesaurus specimens have since been discovered. It was made state dinosaur of Massachusetts in 2022.

<i>Grallator</i> Ichnogenus of dinosaur footprints

Grallator ["GRA-luh-tor"] is an ichnogenus which covers a common type of small, three-toed print made by a variety of bipedal theropod dinosaurs. Grallator-type footprints have been found in formations dating from the Early Triassic through to the early Cretaceous periods. They are found in the United States, Canada, Europe, Australia, Brazil and China, but are most abundant on the east coast of North America, especially the Triassic and Early Jurassic formations of the northern part of the Newark Supergroup. The name Grallator translates into "stilt walker", although the actual length and form of the trackmaking legs varied by species, usually unidentified. The related term "Grallae" is an ancient name for the presumed group of long-legged wading birds, such as storks and herons. These footprints were given this name by their discoverer, Edward Hitchcock, in 1858.

The Newark Supergroup, also known as the Newark Group, is an assemblage of Upper Triassic and Lower Jurassic sedimentary and volcanic rocks which outcrop intermittently along the east coast of North America. They were deposited in a series of Triassic basins, the Eastern North American rift basins, approximately 220–190 million years ago. The basins are characterized as aborted rifts, with half-graben geometry, developing parallel to the main rift of the Atlantic Ocean which formed as North America began to separate from Africa. Exposures of the Newark Supergroup extend from South Carolina north to Nova Scotia. Related basins are also found underwater in the Bay of Fundy. The group is named for the city of Newark, New Jersey.

<span class="mw-page-title-main">Forest Sandstone</span> Geologic formation in Southern Africa

The Forest Sandstone is a geological formation in southern Africa, dating to roughly between 200 and 190 million years ago and covering the Hettangian to Sinemurian stages of the Jurassic Period in the Mesozoic Era. As its name suggests, it consists mainly of sandstone.

<span class="mw-page-title-main">Dinosaur Footprints Reservation</span> Nature reserve

Dinosaur Footprints in Holyoke, Massachusetts, USA is an 8-acre (3 ha) wilderness reservation purchased for the public in 1935 by The Trustees of Reservations. The Reservation is currently being managed with the assistance from the Massachusetts Department of Conservation and Recreation (DCR). The fossil and plant resources on the adjacent Holyoke Gas and Electric (HG&E) riverfront property are being managed cooperatively by The Trustees, Mass DCR, and HG&E.

<span class="mw-page-title-main">Pekin Formation</span>

The Pekin Formation is a Late Triassic (Carnian) geological formation in North Carolina. The Pekin Formation is specific to the Sanford Sub-Basin of the Deep River Basin of North Carolina, although it may be equivalent to the Stockton Formation of Pennsylvania, New Jersey, and New York. The Pekin Formation was deposited in a rift basin along the Atlantic margin of North America during the breakup of the supercontinent Pangaea during the Late Triassic. The most common rocks in the Pekin Formation are red to brown sandstones, representing a terrestrial fluvial (riverine) and floodplain environment in a hot, humid climate. It has yielded both abundant plant and animal fossils, including some of the oldest potential dinosaur footprints in the world and the large predatory crocodylomorph Carnufex carolinensis.

<span class="mw-page-title-main">Moenave Formation</span> Geologic formation in Utah and Arizona

The Moenave Formation is a Mesozoic geologic formation, in the Glen Canyon Group. It is found in Utah and Arizona.

<span class="mw-page-title-main">Shuttle Meadow Formation</span> Geological Formation in Connecticut and Massachusetts

The Shuttle Meadow Formation is a Mesozoic geologic formation in the Hartford Basin in Connecticut and Massachusetts, USA. Insect fossils of Mormolucoides articulatus and dinosaur remains are among the fossils that have been recovered from the formation; Coelophysis sp.

<i>Stegomosuchus</i> Extinct genus of reptiles

Stegomosuchus is an extinct genus of small protosuchian crocodyliform. It is known from a single incomplete specimen discovered in the late 19th century in Lower Jurassic rocks of south-central Massachusetts, United States. It was originally thought to be a species of Stegomus, an aetosaur, but was eventually shown to be related to Protosuchus and thus closer to the ancestry of crocodilians. Stegomosuchus is also regarded as a candidate for the maker of at least some of the tracks named Batrachopus in the Connecticut River Valley.

<span class="mw-page-title-main">Zagaje Formation</span>

The Zagaje Formation is an Early Jurassic Epoch (Hettangian-Sinemurian) geologic formation located mostly in Poland with layers also exposed in north Germany. This unit is known for its diverse Ichnofossil assemblages, with traces of invertebrates along vertebrate footprints. Indeterminate fossil ornithischian tracks, of the Hettangian Stage, have been reported from the formation. The Zagaje Formation correlates with The lower part of the Höganäs Formation in Scania, as well the Munkerup Member and the Gassum Formation in Denmark.

<span class="mw-page-title-main">Towaco Formation</span>

The Towaco Formation is a mapped bedrock unit in New Jersey. It is named for the unincorporated village of Towaco, which is near the place its type section was described by paleontologist Paul E. Olsen.

<span class="mw-page-title-main">Feltville Formation</span>

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.

The East Berlin Formation is an Early Jurassic geological formation in New England, United States. Dinosaur footprints and trackways are abundant in this formation. These tracks include Eubrontes, Anchisauripus, and Anomoepus. Several museums, parks, and tourist attractions are based around the East Berlin Formation's dinosaur tracks, including Dinosaur State Park in Rocky Hill, Connecticut and Powder Hill Dinosaur Park in Middlefield, Connecticut.

<span class="mw-page-title-main">Boonton Formation</span> Lithostratigraphic unit

The Boonton Formation is a mapped bedrock unit in New Jersey, formerly divided between the Boonton and Whitehall beds of the defunct Brunswick Formation. It is named for the town of Boonton, New Jersey, which is near where its type section was described by paleontologist Paul E. Olsen.

<span class="mw-page-title-main">Precipice Sandstone</span>

The Precipice Sandstone an Early Jurassic geologic formation of the Surat Basin in New South Wales and Queensland, eastern Australia, know due to the presence of abundant vertebrate remains & tracks. This unit includes the previously described Razorback beds. This unit represents a major, almost primary, source of hydrocarbons in the region, with a Potential CO2 reservoir of up to 70m. It was deposited on top of older sediments, like Bowen Basin units, in an unconformable manner, resting along the eastern basin margin and the Back Creek Group in the southern Comet Platform, while in other areas it directly overlies the Triassic Moolayember Formation & Callide Coal Measures, being deposited in a comparatively stable basin. Isopach maps of the Precipice Sandstone indicate two distinct areas of sediment accumulation, suggesting two separate depocentres filled from different source regions during the Sinemurian, with the Thomson orogeny and New England Orogen hinterlands as possible ones. This unit represented a fluvial-palustrine-lacustrine braided channel north-flowing succession, that seem to have debouch into a shallow restricted tidal/wave influenced marine embayment, marked at areas like Woleebee Creek. Paleoenvironment-wise, it represents a hinterland rich in vegetation, hinting at wet environments like swamps, where agglutinated foraminifera suggests marine flooding and drier conditions or the encroachment of seawater onto coastal areas.

The Baños del Flaco Formation is a Late Jurassic to Early Cretaceous (Tithonian to Berriasian geologic formation in central Chile. The formation comprises limestones and sandstones deposited in a shallow marine to fluvial environment. Fossil ornithopod tracks have been reported from the formation.

The Bull Run Formation is a Late Triassic (Norian) stratigraphic unit in the eastern United States. Fossil fish bones and scales have been found in outcrops of the formation's Groveton Member in Manassas National Battlefield Park. Indeterminate fossil ornithischian tracks have been reported from the formation.

The Midland Formation is a Mesozoic geological formation in the Culpeper Basin of Virginia. It is a sedimentary unit which formed in a short period of time between the first two basalt flows in the basin: the Hickory Grove and Mount Zion Church basalts. The most common rocks in the formation are dark reddish interbedded sandstones and siltstones, representative of fluvial (stream) environments. Rare but fossiliferous calcareous shale and limestone also occurs, representing recurring lacustrine (lake) conditions. The Midland Formation is considered equivalent to the Shuttle Meadow Formation of the Hartford Basin, the Feltville Formation of the Newark Basin, and the Bendersville Formation of the Gettysburg Basin. Some sources prefer to classify the Midland Formation as part of the Shuttle Meadow Formation.

The Catharpin Creek Formation is a Late Triassic geologic formation in Maryland and Virginia. It is found along the western edge of the Culpeper Basin, one of the largest sedimentary basins in the Newark Supergroup. Compared to the underlying Bull Run Formation, the Catharpin Creek Formation is dominated by much coarser sedimentary rocks such as sandstone and conglomerate. The base of the formation is reddish arkosic sandstone, which grades into drabber thin-bedded siltstone and shale in cyclical sequences.

References

  1. Portland Formation - USGS
  2. 1 2 3 4 5 6 7 8 Weishampel et al., 2004, pp.530–532
  3. Olsen, P.E. (2002). "Stratigraphy and Age of the Early Jurassic Portland Formation of Connecticut and Massachusetts: A Contribution to the Time Scale of the Early Jurassic". Geological Society of America (Abstract). Archived from the original on 2018-11-28. Retrieved 2017-07-07.
  4. Weems, R. E.; Tanner, L. H.; Lucas, S. G. (2016). "Synthesis and revision of the lithostratigraphic groups and formations in the Upper Permian?–Lower Jurassic Newark Supergroup of eastern North America". Stratigraphy. 13 (2): 111–153.
  5. Getty, Patrick (2004). "Ornithischian ichnites from Dinosaur Footprint Reservation (Early Jurassic Portland Formation), Holyoke, MA". Journal of Vertebrate Paleontology. 23 (Supp 3): 63A. doi:10.1080/02724634.2003.10010538. S2CID   220410105.
  6. "PBDB". paleobiodb.org. Retrieved 2024-02-09.
  7. "Table 3.1," in Weishampel et al., 2004, p.48
  8. McMenamin, M. (2021). Large neotheropod from the Lower Jurassic of Massachusetts. AcademiaLetters, Article 3591. doi : 10.20935/AL3591.1©2021 by the author — Open Access — Distributed under CC BY 4.0
  9. von Huene, Friedrich (1922). "The Triassic reptilian order Thecodontia". American Journal of Science. 4 (19): 22–26. Bibcode:1922AmJS....4...22H. doi:10.2475/ajs.s5-4.19.22.
  10. https://www.researchgate.net/publication/355340350_Early_Jurassic_pterosaur_from_Massachusetts
  11. 1 2 "PBDB". paleobiodb.org. Retrieved 2024-02-09.
  12. "PBDB". paleobiodb.org. Retrieved 2024-02-09.
  13. 1 2 3 "PBDB". paleobiodb.org. Retrieved 2024-02-09.

Bibliography