Portland Formation

The Portland Formation is a geological formation in the northeastern United States. It dates back to the Early Jurassic period.[1] 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).[2]

Not to be confused with Portland Group (geology) or Portland stone.

Portland Formation Stratigraphic range: Hettangian-Sinemurian ~199–195 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Geological formation
Unit of	Newark Group
Sub-units	Deerfield Basin, Turners Falls Sandstone & Mount Toby Formation
Lithology
Primary	Sandstone
Other	Mudstone, siltstone, limestone
Location
Coordinates	42.3°N 72.5°W / 42.3; -72.5
Approximate paleocoordinates	24.0°N 18.6°W / 24.0; -18.6
Region	Connecticut, Massachusetts
Country	USA
Portland Formation (the United States) Show map of the United States Portland Formation (Massachusetts) Show map of Massachusetts

Vertebrate fauna

Dinosaur coprolites located in Massachusetts, USA.[1] Ornithischian tracks located in Massachusetts and Connecticut, USA.[1] Theropod tracks located in Massachusetts and Connecticut, USA.[1] Prosauropod tracks located in Massachusetts and Connecticut, USA.[1]

Dinosaurs
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Anchisaurus[1]	A. polyzelus[1]	Connecticut[1] Massachusetts[1]				Anchisaurus
Podokesaurus[1]	P. holyokensis	Connecticut[1]		Partial postcranial skeleton.[3]	All known remains of this species have been destroyed.

See also

• List of dinosaur-bearing rock formations

References

1. Weishampel, David B; et al. (2004). "Dinosaur distribution (Early Jurassic, North America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 530–532. ISBN 0-520-24209-2.
2. 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". Archived from the original on 2018-11-28. Retrieved 2017-07-07.CS1 maint: BOT: original-url status unknown (link). Session No. 26 Studies of Depositional Systems and Sedimentary Rocks: In Honor of Edward Scudder Belt. 37th Annual Meeting (March 25-27, 2002).
3. "Table 3.1," in Weishampel, et al. (2004). Page 48.

Bibliography

• Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. ISBN 0-520-24209-2