The Potsdam Sandstone, more formally known as the Potsdam Group, is a

geologic unit A stratigraphic unit is a volume of rock of identifiable origin and relative age range that is defined by the distinctive and dominant, easily mapped and recognizable petrographic, lithologic or paleontologic features (facies) that characterize ...

of mid-to-late

Cambrian The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ...

age found in Northern New York and northern

Vermont Vermont () is a state in the northeast New England region of the United States. Vermont is bordered by the states of Massachusetts to the south, New Hampshire to the east, and New York to the west, and the Canadian province of Quebec to ...

and

Quebec Quebec ( ; )According to the Canadian government, ''Québec'' (with the acute accent) is the official name in Canadian French and ''Quebec'' (without the accent) is the province's official name in Canadian English is one of the thirtee ...

and

Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central Ca ...

. A well-cemented

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

of nearly pure

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical form ...

, in the 19th century it was widely used in construction and in

refractory In materials science, a refractory material or refractory is a material that is resistant to decomposition by heat, pressure, or chemical attack, and retains strength and form at high temperatures. Refractories are polycrystalline, polyphase, ...

linings for iron furnaces.James Carl
Potsdam Sandstone: Composition and Qualities
Potsdam Public Museum website, accessed July 29, 2011

Name and type locality

The Potsdam Sandstone is named for its type locality in

Potsdam, New York Potsdam ( moh, Tsi tewate’nehtararénies) is a town in St. Lawrence County, New York, United States. The town population was 14,901 at the 2020 census. The ZIP Code is 13676. When SUNY Potsdam and Clarkson University are in session, the popul ...

, where in 1838

Ebenezer Emmons Ebenezer Emmons (May 16, 1799October 1, 1863), was a pioneering American geologist whose work includes the naming of the Adirondack Mountains in New York as well as a first ascent of Mount Marcy. Early life Emmons was born at Middlefield, Massa ...

described it in

outcrop An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth. Features Outcrops do not cover the majority of the Earth's land surface because in most places the bedrock or superficial ...

s along the

Raquette River The Raquette River ( moh, Ahná:wate), sometimes spelled Racquette, originates at Raquette Lake in the Adirondack Mountains in New York. long, it is the third longest river entirely in the state of New York. The river is a popular destination ...

.Geologic Unit: Potsdam

U.S. Geological Survey The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and ...

Geolex Database, accessed August 1, 2011James Carl
Potsdam Sandstone: Bedrock Geology
Potsdam Public Museum website, accessed July 29, 2011

Stratigraphic setting and lithology

The Potsdam Sandstone lies

unconformably An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval ...

on a surface of Precambrian

metamorphic rock Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causin ...

. It is the earliest unit in the marine-transgressive

sedimentary rock Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...

sequence deposited during the early

Paleozoic The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ' ...

as sea level rose to gradually inundate the

craton A craton (, , or ; from grc-gre, κράτος "strength") is an old and stable part of the continental lithosphere, which consists of Earth's two topmost layers, the crust and the uppermost mantle. Having often survived cycles of merging and ...

of the

paleocontinent A paleocontinent or palaeocontinent is a distinct area of continental crust that existed as a major landmass in the geological past. There have been many different landmasses throughout Earth's time. They range in sizes, some are just a collection ...

Laurentia Laurentia or the North American Craton is a large continental craton that forms the ancient geological core of North America. Many times in its past, Laurentia has been a separate continent, as it is now in the form of North America, although ...

. The rock, which is formed from

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand an ...

s eroded off unvegetated terrestrial landscapes and deposited in near-shore coastal environments, consists almost entirely of

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of s ...

-size quartz grains held together by quartz

cement A cement is a binder, a chemical substance used for construction that sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel ( aggregate) together. Cement mix ...

. It ranges in color from gray to tan, yellow, and red, with the colors imparted by small amounts of the red

iron oxide Iron oxides are chemical compounds composed of iron and oxygen. Several iron oxides are recognized. All are black magnetic solids. Often they are non-stoichiometric. Oxyhydroxides are a related class of compounds, perhaps the best known of whic ...

mineral

hematite Hematite (), also spelled as haematite, is a common iron oxide compound with the formula, Fe2O3 and is widely found in rocks and soils. Hematite crystals belong to the rhombohedral lattice system which is designated the alpha polymorph of . ...

, Fe₂O₃, and the yellow iron oxide mineral

goethite Goethite (, ) is a mineral of the diaspore group, consisting of iron(III) oxide-hydroxide, specifically the "α" polymorph. It is found in soil and other low-temperature environments such as sediment. Goethite has been well known since ancient t ...

, FeO(OH). As sea level rose in the depositional environment, increasing amounts of carbonate minerals were deposited in the sediment, with the result that the unit grades upward into

dolomitic Dolomite () is an anhydrous carbonate mineral composed of calcium magnesium carbonate, ideally The term is also used for a sedimentary carbonate rock composed mostly of the mineral dolomite. An alternative name sometimes used for the dolomiti ...

sandstone in the upper Potsdam and then to sandy

dolomite Dolomite may refer to: *Dolomite (mineral), a carbonate mineral *Dolomite (rock), also known as dolostone, a sedimentary carbonate rock *Dolomite, Alabama, United States, an unincorporated community *Dolomite, California, United States, an unincor ...

at the base of the overlying Theresa Formation.

Paleontology

Fossil remains of whole animals are rare in the Potsdam Sandstone, but there are some significant occurrences of

trace fossil A trace fossil, also known as an ichnofossil (; from el, ἴχνος ''ikhnos'' "trace, track"), is a fossil record of biological activity but not the preserved remains of the plant or animal itself. Trace fossils contrast with body fossils, ...

s. Trace fossils in the unit include both vertical burrows, such as ''

Diplocraterion ''Diplocraterion'' is an ichnogenus describing vertical U-shaped burrows having a spreite (weblike construction) between the two limbs of the U. The spreite of an individual ''Diplocraterion'' trace can be either protrusive (between the paired ...

'' and ''

Skolithos ''Skolithos'' (formerly spelled ''Scolithus'' or ''Skolithus'') is a common trace fossil ichnogenus that is, or was originally, an approximately vertical cylindrical burrow. It is produced by a variety of organisms in shallow marine environmen ...

'' and horizontal trackways, such as ''

Diplichnites ''Diplichnites'' are arthropod trackways with two parallel rows of blunt to elongate, closely spaced tracks oriented approximately perpendicularly to the mid-line of the trackway. The term is more often used for the ichnofossils of this descripti ...

'', ''

Protichnites ''Protichnites'' is an ichnogenus of trace fossil consisting of the imprints made by the walking activity of certain arthropods. It consists of two rows of tracks and a medial furrow between the two rows. This furrow, which may be broken, set at ...

'', and ''

Climactichnites ''Climactichnites'' is an enigmatic, Cambrian fossil formed on or within sandy tidal flats around . It has been interpreted in many different ways in the past, but is now thought to be a trace fossil of a slug-like organism that moved by crawling ...

''. In 1903, a 20-ton (18-tonne) slab of Potsdam Sandstone from

Clinton County, New York Clinton County is a county in the north-easternmost corner of the state of New York, in the United States and bordered by the Canadian province of Quebec. As of the 2020 United States Census, the population was 79,843. Its county seat is the ci ...

, displaying tracks attributed to

trilobite Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the At ...

s, was placed in the

New York State Museum The New York State Museum is a research-backed institution in Albany, New York, United States. It is located on Madison Avenue, attached to the south side of the Empire State Plaza, facing onto the plaza and towards the New York State Capitol. ...

. Fossil impressions of the whole bodies of

jellyfish Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals with umbrella- ...

have also been found in the Potsdam.

Geographic occurrence

In New York state, the Potsdam is found primarily north and west of the

Adirondack Mountains The Adirondack Mountains (; a-də-RÄN-dak) form a massif in northeastern New York with boundaries that correspond roughly to those of Adirondack Park. They cover about 5,000 square miles (13,000 km2). The mountains form a roughly circular ...

. Outcrop exposures of the Potsdam Sandstone occur throughout the

Saint Lawrence lowlands In religious belief, a saint is a person who is recognized as having an exceptional degree of holiness, likeness, or closeness to God. However, the use of the term ''saint'' depends on the context and denomination. In Catholic, Eastern Ortho ...

, western

Lake Champlain , native_name_lang = , image = Champlainmap.svg , caption = Lake Champlain-River Richelieu watershed , image_bathymetry = , caption_bathymetry = , location = New York/Vermont in the United States; and Quebec in Canada , coords = , type = , ...

Valley, and northern

Mohawk Valley The Mohawk Valley region of the U.S. state of New York is the area surrounding the Mohawk River, sandwiched between the Adirondack Mountains and Catskill Mountains, northwest of the Capital District. As of the 2010 United States Census, th ...

Ausable Chasm Ausable Chasm is a sandstone gorge and tourist attraction located near the hamlet of Keeseville, New York, United States. It is directly due west of Port Kent. The Ausable River runs through it and then empties into Lake Champlain. The gorge ...

, near

Plattsburgh Plattsburgh ( moh, Tsi ietsénhtha) is a city in, and the seat of, Clinton County, New York, United States, situated on the north-western shore of Lake Champlain. The population was 19,841 at the 2020 census. The population of the surrounding ...

, has a continuous exposure of a section more than thick.James W. Hagadorn and Edward S. Belt (2008), Stranded in Upstate New York: Cambrian Scyphomedusae from the Potsdam Sandstone, ''

PALAIOS ''PALAIOS'' is a bimonthly academic journal dedicated to the study of the impact of life on Earth history, combining the fields of palaeontology and sedimentology. It has been published by the Society for Sedimentary Geology since its inception i ...

'', v. 23, p. 424–441, The formation reaches its maximum thickness of about in the northern Champlain lowland.

Uses in construction and industry

In the 19th century, Potsdam Sandstone was highly regarded as a building material. There was extensive

quarrying A quarry is a type of open-pit mine in which dimension stone, rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some jurisdictions to reduce their environ ...

for Potsdam Sandstone in the Potsdam area, beginning in 1809.The Potsdam Red Sandstone quarries
''

Scientific American ''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many famous scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it. In print since 1845, it i ...

'', January 7, 1893, page 8-10. Properties of the rock that give it value as a building material include high

compressive strength In mechanics, compressive strength or compression strength is the capacity of a material or structure to withstand loads tending to reduce size (as opposed to tensile strength which withstands loads tending to elongate). In other words, compre ...

, attractive reddish coloring, and resistance to weathering. The rock also was said to be "soft and easy to carve" when freshly quarried but "extremely hard" and "weather-resistant" after exposure to the air, but modern geologists suggest that this is a misconception. Potsdam Sandstone resists

spalling Spall are fragments of a material that are broken off a larger solid body. It can be produced by a variety of mechanisms, including as a result of projectile impact, corrosion, weathering, cavitation, or excessive rolling pressure (as in a ball ...

when exposed to fire, making it highly suitable for use as a refractory for lining iron furnaces. Local sandstone was used for many buildings in Potsdam, as well as for purposes such as

gravestone A headstone, tombstone, or gravestone is a stele or marker, usually stone, that is placed over a grave. It is traditional for burials in the Christian, Jewish, and Muslim religions, among others. In most cases, it has the deceased's name, da ...

s and

sidewalk A sidewalk (North American English), pavement (British English), footpath in Australia, India, New Zealand and Ireland, or footway, is a path along the side of a street, street, highway, terminals. Usually constructed of concrete, pavers, brick ...

s. Buildings in other cities constructed with this rock include portions of Canada's Parliament Buildings (original

Centre Block The Centre Block (french: Édifice du Centre) is the main building of the Canadian parliamentary complex on Parliament Hill, in Ottawa, Ontario, containing the House of Commons and Senate chambers, as well as the offices of a number of members ...

and

Library of Parliament The Library of Parliament (french: Bibliothèque du Parlement) is the main information repository and research resource for the Parliament of Canada. The main branch of the library sits at the rear of the Centre Block on Parliament Hill in Ottawa ...

) in

Ottawa Ottawa (, ; Canadian French: ) is the capital city of Canada. It is located at the confluence of the Ottawa River and the Rideau River in the southern portion of the province of Ontario. Ottawa borders Gatineau, Quebec, and forms the core ...

, and the Cathedral of All Saints in

Albany, New York Albany ( ) is the capital of the U.S. state of New York, also the seat and largest city of Albany County. Albany is on the west bank of the Hudson River, about south of its confluence with the Mohawk River, and about north of New York City ...

.Potsdam Sandstone office
(photo and description), New York Heritage website, accessed July 29, 2011 Potsdam Sandstone and its stratigraphic equivalents also have been quarried for use as building stone at several sites in Quebec.

Stratigraphic equivalents and related units

Stratigraphically equivalent and lithologically similar sandstone extends across the international border into

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

, although

stratigraphic Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithostra ...

boundaries and nomenclature can differ.James W. Hagadorn and Edward S. Belt (2008), Stranded in Upstate New York: Cambrian Scyphomedusae from the Potsdam Sandstone, ''

'', v. 23, p. 424–441,
-->John H. Williams, Richard J. Reynolds, David A. Franzi, Edwin A. Romanowicz, and Frederick L. Paillet (2010)
Hydrogeology of the Potsdam Sandstone in Northern New York
''

Canadian Water Resources Journal Canadians (french: Canadiens) are people identified with the country of Canada. This connection may be residential, legal, historical or cultural. For most Canadians, many (or all) of these connections exist and are collectively the source of ...

'' Vol. 35(4): 399–416 (2010) In

, the Nepean Sandstone was formerly called "Potsdam" and is regarded as a stratigraphic equivalent to the Potsdam Sandstone. In

, the Potsdam Group is recognized, consisting of the Covey Hill Formation and the Cairnside Formation, both of which are sandstones. Historically the name "Potsdam sandstone" was also applied to various other North American sandstone bodies that directly overlie

Precambrian The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the ...

crystalline rocks, including sandstones in Canada,

Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...

Virginia Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the Atlantic Coast and the Appalachian Mountains. The geography and climate of the Commonwealth ar ...

Iowa Iowa () is a state in the Midwestern region of the United States, bordered by the Mississippi River to the east and the Missouri River and Big Sioux River to the west. It is bordered by six states: Wisconsin to the northeast, Illinois to the ...

Wisconsin Wisconsin () is a state in the upper Midwestern United States. Wisconsin is the 25th-largest state by total area and the 20th-most populous. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake M ...

Minnesota Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the 22nd most populous, with over 5.75 million residents. Minnesota is home to western prairies, now given over to ...

Michigan Michigan () is a state in the Great Lakes region of the upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the 10th-largest state by population, the 11th-largest by area, and the ...

, and

Indiana Indiana () is a U.S. state in the Midwestern United States. It is the 38th-largest by area and the 17th-most populous of the 50 States. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th s ...

, and attempts were made to identify or correlate various rocks with the Potsdam formation.Thomas W. Bjerstedt and J. Mark Erickson (1989), Trace Fossils and Bioturbation in Peritidal Facies of the Potsdam-Theresa Formations (Cambrian-Ordovician), Northwest Adirondacks, ''Palaios'', Vol. 4, No. 3, June 1989, pp. 203-224 The basal Cambrian sandstone formation in much of the upper

Mississippi Valley The Mississippi River is the List of longest rivers of the United States (by main stem), second-longest river and chief river of the second-largest Drainage system (geomorphology), drainage system in North America, second only to the Hudson B ...

and southern

Great Lakes The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lakes ...

region is now designated the

Mount Simon Sandstone The Mount Simon Sandstone is the basal sandstone of the Potsdam Sandstone. It was deposited in a nearshore environment, unconformably overlying Precambrian basement. It is overlain by the Eau Claire Formation or Ordovician strata. It is presume ...

and is, in turn, assigned to the Potsdam Supergroup, which takes its name from the Potsdam Sandstone.Indiana Geological Survey
Potsdam Supergroup, St. Croixan Series, Cambrian System
an
Mount Simon Sandstone, Potsdam Supergroup, Cambrian System
accessed July 29, 2011 Similar

quartz arenite A quartz arenite or quartzarenite is a sandstone composed of greater than 90% detrital quartz. Quartz arenites are the most mature sedimentary rocks possible, and are often referred to as ultra- or super-mature, and are usually cemented by sili ...

sandstone found in

Wyoming Wyoming () is a U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the south ...

was also identified historically as the "Potsdam sandstone."

Charles Doolittle Walcott Charles Doolittle Walcott (March 31, 1850February 9, 1927) was an American paleontologist, administrator of the Smithsonian Institution from 1907 to 1927, and director of the United States Geological Survey.Wonderful Life (book) by Stephen Jay G ...

(1891)
Correlation Papers: Cambrian
''Bulletin of the U.S. Geological Survey'', volume 15. Francis John Pettijohn, Paul Edwin Potter, and Raymond Siever (1987), ''Sand and Sandstone'', Springer, . Page 181.

References

{{reflist

External links

The Potsdam Red Sandstone Quarries
. ''

'', Vol. LXVIII, No. 1, New York, January 7, 1893, pp. 1, 8-10.
The Potsdam Red Sandstone Company’s Water Wheel
. ''

'', Vol. LXVIII, No. 3, January 21, 1893, pp. 37–38. Building stone Cambrian geology of New York (state) Sandstone in Canada Cambrian southern paleotemperate deposits Sandstone in the United States