The Nanjemoy Formation is a

geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

pertaining to both the Wilcox Group and the Pamunkey Group of the eastern United States, stretching across the states of

Virginia Virginia, officially the Commonwealth of Virginia, is a U.S. state, state in the Southeastern United States, Southeastern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States between the East Coast of the United States ...

Maryland Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It borders the states of Virginia to its south, West Virginia to its west, Pennsylvania to its north, and Delaware to its east ...

, and the

District of Columbia Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and Federal district of the United States, federal district of the United States. The city is on the Potomac River, across from ...

. The formation crops out east of the

Appalachians The Appalachian Mountains, often called the Appalachians, are a mountain range in eastern to northeastern North America. The term "Appalachian" refers to several different regions associated with the mountain range, and its surrounding terrain ...

and dates back to the

Paleogene The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the fir ...

period Period may refer to: Common uses * Period (punctuation) * Era, a length or span of time *Menstruation, commonly referred to as a "period" Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (o ...

. Specifically to the

Ypresian In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...

stage of the Early Eocene epoch, about 55 to 50 Ma or

Wasatchian The Wasatchian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 55,400,000 to 50,300,000 years Before Present, BP lasting . I ...

in the NALMA classification, defined by the contemporaneous

Wasatch Formation The Wasatch Formation (Tw)Shroba & Scott, 2001, p.3 is an extensive highly fossiliferous Formation (geology), geologic formation stretching across several basins in Idaho, Montana, Wyoming, Utah and western Colorado.marl Marl is an earthy material rich in carbonate minerals, Clay minerals, clays, and silt. When Lithification, hardened into rock, this becomes marlstone. It is formed in marine or freshwater environments, often through the activities of algae. M ...

, than the upper Woodstock Member, probably characteristic of less storm influences in the shallow shelf sediments. The formation has provided a wealth of fossils of mainly fish, but also mammals, reptiles, birds and flora. The presence of the sharks '' Otodus obliquus'' and ''

Otodus aksuaticus ''Otodus aksuaticus'' is an extinct species of large shark in the family Otodontidae which may represent a transitional species between '' Otodus obliquus'' and '' Otodus auriculatus''. They are similar in overall morphology to '' Otodus obliquus ...

'', as well as various other shark and ray species are notable. Crocodylian, snake, turtle, mammal, and bird remains have all been found in the Nanjemoy Formation.Weems & Grimsley, 1999

Etymology

Algonquian language map with states and provinces

The formation is named after Nanjemoy Creek, a left tributary of the

Potomac River The Potomac River () is in the Mid-Atlantic (United States), Mid-Atlantic region of the United States and flows from the Potomac Highlands in West Virginia to Chesapeake Bay in Maryland. It is long,U.S. Geological Survey. National Hydrography D ...

.Joseph Norris, TheBayNet, 2016 Nanjemoy is probably an

Ojibwe The Ojibwe (; Ojibwe writing systems#Ojibwe syllabics, syll.: ᐅᒋᐺ; plural: ''Ojibweg'' ᐅᒋᐺᒃ) are an Anishinaabe people whose homeland (''Ojibwewaki'' ᐅᒋᐺᐘᑭ) covers much of the Great Lakes region and the Great Plains, n ...

word, meaning "one goes downward," representing the many rivers and creeks in the wet watershed of

Chesapeake Bay The Chesapeake Bay ( ) is the largest estuary in the United States. The bay is located in the Mid-Atlantic (United States), Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula, including parts of the Ea ...

, an area originally inhabited by the

Algonquin Algonquin or Algonquian—and the variation Algonki(a)n—may refer to: Languages and peoples *Algonquian languages, a large subfamily of Native American languages in a wide swath of eastern North America from Canada to Virginia **Algonquin la ...

-speaking Nanticoke and

Powhatan Powhatan people () are Indigenous peoples of the Northeastern Woodlands who belong to member tribes of the Powhatan Confederacy, or Tsenacommacah. They are Algonquian peoples whose historic territories were in eastern Virginia. Their Powh ...

.Library of Congress - National atlas. Indian tribes, cultures & languages: United States
/ref> ''Wicomico'' is the name of two separate rivers, one on Maryland's Eastern Shore,

Wicomico River (Maryland eastern shore) The Wicomico River ( ) is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed April 1, 2011 tributary of the Chesapeake Bay on the eastern shore of Maryland. It drains an area of low mar ...

, and another in Southern Maryland, Wicomico River (Potomac River tributary), and is the name of a small thoroughfare in southeastern

Charles County Charles County is a county located in the U.S. state of Maryland. As of the 2020 United States census, the population was 166,617. The county seat is La Plata. The county was named for Charles Calvert (1637–1715), third Baron Baltimore. The ...

. ''Wigh'' or ''wik'', representing "pleasant" and ''accomico'' "dwelling, village" was the native's way of telling the Europeans they liked living there. Potapaco was an early name for Port Tobacco CreekUoC, 1938, p.1713 that was named after the

Piscataway Piscataway may refer to: *Maryland (place) **Piscataway, Maryland, an unincorporated community ** Piscataway Creek, Maryland ** Piscataway Park, historical park at the mouth of Piscataway Creek ** Siege of Piscataway, siege of Susquehannock fort sou ...

people. Mattawoman, found in Charles County,

Prince George's County Prince George's County (often shortened to PG County or PG) is located in the U.S. state of Maryland bordering the eastern portion of Washington, D.C. As of the 2020 U.S. census, the population was 967,201, making it the second-most populous ...

, and on the Eastern Shore, has remnants of not only Algonquin, but

Fox Foxes are small-to-medium-sized omnivorous mammals belonging to several genera of the family Canidae. They have a flattened skull; upright, triangular ears; a pointed, slightly upturned snout; and a long, bushy tail ("brush"). Twelve species ...

and

as well, and translates to "where one goes pleasantly."

Definition

The Nanjemoy Formation was defined by Clark and Martin in 1901, as part of the mapping by the

Maryland Geological Survey The Maryland Department of Natural Resources (DNR) is a government agency in the state of Maryland charged with maintaining natural resources including state parks, public lands, state forests, state waterways, wildlife, and recreation areas. I ...

. The Nanjemoy Formation was divided into two members, the lower or Potapaco, and the upper or Woodstock. The main lithologic distinction is that the lower part of the Nanjemoy is much more clayey than the upper part. In the subsurface, the distinction between the members is less evident than in outcrops, especially in Maryland, so the formation has been left undivided. In the outcrops along the Potomac River near Popes Creek, the contact between the Woodstock and Potapaco at about above the water level.

Extent

The Nanjemoy Formation, represented as Tn on the geologic map of the Washington West 30' × 60' Quadrangle, Maryland, Virginia, and Washington D.C., restricted to the southeastern side of the Potomac Basin represented in the quadrangle.Geologic Map MD; VA; D.C., USGS, 2017 Scott (2005) in his thesis included a map showing the thin bands of outcrops of both the underlying Marlboro Clay and the Nanjemoy Formation, restricted to the many creeks feeding the Chesapeake Bay.Scott, 2005, p.67 The Nanjemoy Formation (Eocene), the Marlboro Clay (

Paleocene The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...

), and the Aquia Formation (Paleocene) are present in the westernmost part of the Potomac channel.McCartan et al., 1995, p.7 The outcrop area of the formation is designated Nanjemoy Wildlife Management Area.

Geology

Geologically, the area of deposition of the Nanjemoy Formation is part of the Atlantic coastal plain province.

Potomac Basin

The Potomac Basin represents the central part of the

Atlantic coastal plain The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

that stretches along the Atlantic coast of Canada and the United States. The basin stretches across parts of four states (Maryland, Pennsylvania, Virginia and

West Virginia West Virginia is a mountainous U.S. state, state in the Southern United States, Southern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States.The United States Census Bureau, Census Bureau and the Association of American ...

), as well as the District of Columbia. This area is also called the Potomac watershed. It includes all of the land area where water drains towards the mouth of the Potomac – the point where the river spills into the

. The Potomac River basin is the 2nd largest watershed in the Chesapeake Bay watershed.Nardolilli et al., 2020 ;Land The drainage area of the Potomac includes 14,670 square miles in four states: Virginia (5,723 sq. mi.), Maryland (3,818 sq. mi.), West Virginia (3,490 sq. mi.), Pennsylvania (1,570 sq. mi.), and the District of Columbia (69 sq. mi.). The basin’s total area varies depending on map projection used. The basin lies in five geological provinces: the Appalachian Plateau, the Ridge and Valley, Blue Ridge, Piedmont Plateau, and Coastal Plain. The Potomac meanders over 383 miles from Fairfax Stone, West Virginia to Point Lookout, Maryland. The river’s distance will vary with map projection and location of measuring tool in the river (ie. middle of the river, Maryland shoreline, Virginia shoreline). Based on information from the NLCD 2011 database, the majority of the basin’s land area is covered by forests at 54.6 percent of the land area. Developed land makes up 14.1 percent of the basin’s land area, while agriculture covers 26.0 percent. Water and wetlands make up 5.9 percent of the basin’s land area. The Potomac's major tributaries include: the

Anacostia River The Anacostia River is a river in the Mid-Atlantic states, Mid Atlantic region of the United States. It flows from Prince George's County, Maryland, Prince George's County in Maryland into Washington, D.C., where it joins with the Washington Ch ...

Antietam Creek Antietam Creek () is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed August 15, 2011 tributary of the Potomac River located in south central Pennsylvania and western Maryland in the ...

, the

Cacapon River The Cacapon River ( ; meaning Medicine Waters), located in the Appalachian Mountains of West Virginia's eastern panhandle region, is an shallow river known for its fishing, boating, wildlife, hunting, and wilderness scenery. As part of the Potoma ...

, Catoctin Creek,

Conococheague Creek Conococheague Creek, a tributary of the Potomac River, is a free-flowing stream that originates in Pennsylvania and empties into the Potomac River near Williamsport, Maryland, Williamsport, Maryland. It is in length,U.S. Geological Survey. Natio ...

, the

Monocacy River The Monocacy River () is a free-flowing left tributary to the Potomac River, which empties into the Atlantic Ocean via the Chesapeake Bay. The river is long,U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data ...

, the North Branch, the South Branch, the

Occoquan River The Occoquan River is a tributary of the Potomac River in Northern Virginia, where it serves as part of the boundary between Fairfax and Prince William counties. The river is a scenic area, and several local high schools and colleges use the r ...

, the Savage River, the Seneca Creek, and the

Shenandoah River The Shenandoah River is the principal tributary of the Potomac River, long with two River fork, forks approximately long each,U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map accessed August ...

. ;People The population of the basin is approximately 6.11 million (2010 estimated census). The population has increased by about five percent since 2005. The following information is based on 2010 estimated census data.

Stratigraphy

The Nanjemoy Formation belongs to two geologic groups; the Wilcox Group of the Gulf of Mexico Basin in the southernmost surface expression of the formation and the Pamunkey Group in the northern and central portions from

in the north through

and

the Carolinas The Carolinas, also known simply as Carolina, are the U.S. states of North Carolina and South Carolina considered collectively. They are bordered by Virginia to the north, Tennessee to the west, and Georgia to the southwest. The Atlantic Ocean ...

. Both geologic groups have been dated to the early

; the

and

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

periods, or in the commonly used NALMA classification;

, defined by the age-equivalent

Wasatch Formation The Wasatch Formation (Tw)Shroba & Scott, 2001, p.3 is an extensive highly fossiliferous Formation (geology), geologic formation stretching across several basins in Idaho, Montana, Wyoming, Utah and western Colorado.Wyoming Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...

. The third-oldest unit in the Pamunkey Group is the Nanjemoy Formation that overlies the Marlboro Clay and is partly overlain by the Piney Point Formation and in many areas covered by the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

Calvert Formation The Calvert Formation is a Formation (geology), geologic formation in Maryland, Virginia, and Delaware. It preserves fossils dating back to the early to middle Miocene, Miocene epoch of the Neogene Period (geology), period. It is one of the three ...

, separated by an

unconformity 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 ...

representing about 34 Ma. The upper surface reaches an elevation of about and is overlain in most places by the

(Tc). The unit is present only in the southeastern part of the map area of Washington D.C., and it reaches a maximum thickness of about .

Petrology

The formation comprises

glauconitic Glauconite is an iron potassium phyllosilicate (mica group) mineral of characteristic green color which is very friable and has very low weathering resistance. It crystallizes with a monoclinic geometry. Its name is derived from the Greek () m ...

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tet ...

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

, dark-grayish-green to olive-black (tan to orange where

weathered ''Weathered'' is the third studio album by American rock band Creed, released on November 20, 2001. It was the last Creed album to be released until '' Full Circle'' came out in October 2009, with Creed disbanding in June 2004. It is the only Cr ...

), fine to medium-grained; and dark-greenish-gray

silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension (chemistry), suspension with water. Silt usually ...

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolinite, ). Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impuriti ...

. In places, the sand is very muddy or contains many small quartz pebbles, and the clay is silty or sandy. Both lithologies contain richly fossiliferous beds including abundant mollusk shells. Robert E. Weems and Gary J. Grimsley (1999) described the geology of the Fisher/Sullivan site in Virginia as:Weems & Grimsley, 1999, p.5

Paleogeography

Climate

The climate of the Early Eocene and Late Paleocene was very hot and rich in CO₂. Based on the fossils of the terrifyingly large '' Titanoboa cerrejonensis'', dating to the latest Paleocene, a body mass of for the snake was estimated. This enormous size could only have been possible under the most ideal conditions for such large species, around 6 to 8 Ma after the extinction of the previous megafauna; the

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

s. The climate of the Neotropical biome was estimated at average yearly temperatures and 2000 ppm atmospheric CO₂.Head et al., 2009

Depositional environment

The

depositional environment In geology, depositional environment or sedimentary environment describes the combination of physical, chemical, and biological processes associated with the deposition of a particular type of sediment and, therefore, the rock types that will b ...

of the Nanjemoy Formation is mostly shallow shelf. The more clayey beds suggest an area or time of quiet water, not affected by waves, tides, or current activity; intercalated sandier zones may reflect the higher energy of waves or currents during episodic storms. Its regional dip is eastward at 15–20 ft per mile (3-3.5 m/km).McCartan et al., 1995, p.17

Paleontology

The floral and faunal assemblage of the Nanjemoy Formation is very varied and provides an insight into the paleobiological and paleoclimatological environment of the early

. Fossils of bivalves, sharks, rays, actinopterygian fishes, reptiles, birds and mammals, and of fruits and seeds are common in the Potapaco Member. More than 2000 vertebrate

coprolite A coprolite (also known as a coprolith) is fossilized feces. Coprolites are classified as trace fossils as opposed to body fossils, as they give evidence for the animal's behaviour (in this case, diet) rather than morphology. The name ...

s from the Potapaco Member at the Fisher/Sullivan Site in Virginia were analyzed by Dentzien Dias et al. (2019). The chemical composition (phosphatic), inclusions and morphology suggest that only carnivorous scats were preserved.Dentzien Dias et al., 2019 All Nanjemoy coprolites were produced by fishes;

chondrichthyan Chondrichthyes (; ) is a class (biology), class of jawed fish that contains the cartilaginous fish or chondrichthyans, which all have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fish'', which ...

Carcharhiniformes Carcharhiniformes ( from Classical Greek ' (karcharos) 'sharp/jagged' and ' (rhinos) 'nose', plus Latin ''forme'' 'shape'), commonly known as ground sharks, are the largest order of sharks, with over 270 species. They include a number of common ...

, and

lamniform The Lamniformes (, from Greek ''lamna'' "fish of prey") are an order of sharks commonly known as mackerel sharks (which may also refer specifically to the family Lamnidae). It includes some of the most familiar species of sharks, such as the g ...

sharks, probably the genus ''

Carcharias ''Carcharias'', also known as sand tiger sharks, is a genus of mackerel sharks belonging to the family Carchariidae, of which it is the only extant member. Once bearing many prehistoric species, all have gone extinct with the exception of the cri ...

''. Other morphotypes were produced by

actinopterygian Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of skin ...

fishes. The surface marks and the lack of flatness on most coprolites suggests early lithification of the Potapaco Member. Main fossil sites of the Nanjemoy Formation are * Nanjemoy Creek; Charles County, MDNanjemoy Creek
at

Fossilworks Fossilworks was a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. History Fossilworks was cr ...

.org * Woodstock; King George County, VAWoodstock
at

.orgWoodstock 2
at

.orgWoodstock 3
at

.org * Fisher/Sullivan; Stafford County, VAFisher/Sullivan 1
at

.orgFisher/Sullivan 2
at

.org * Evergreen Plantation; Prince Charles County, VAEvergreen Plantation 1
at

.org

Fisher/Sullivan site, VA

In October 1990, Mr. Richard Brezina of the Maryland Geological Society (MGS) discovered an important fossil site east of Fredericksburg, in eastern

Stafford County, Virginia Stafford County is a county located in the Commonwealth of Virginia. It is approximately south of Washington, D.C. It is part of the Northern Virginia region, and the D.C area. It is one of the fastest-growing and highest-income counties in ...

. This locality, along an unnamed tributary of Muddy Creek, became known as the Fisher/Sullivan site in recognition of its principle landowners.Weems & Grimsley, 1999, p.3 Brezina immediately realized that the site was exceptional, because it yielded numerous shark teeth and other vertebrate remains from the sands and gravels in the unnamed tributary. Brezina notified other members of the Maryland Geological Society, and together members of the MGS began to screen stream sediments at the site for more shark teeth and other remains. It soon became apparent, from the types of teeth that were being found and from the color and texture of the sediments in the banks of the creek, that the fossils were being reworked from glauconitic ("greensand") horizons of the Lower Tertiary (Paleocene-Eocene) Pamunkey Group. Because the Pamunkey Group previously had yielded only sparse vertebrate remains, it seemed reasonable to suspect that this locality was scientifically important.

Fossil content

Among many invertebrates (such as

gastropods Gastropods (), commonly known as slugs and snails, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and from the land. Ther ...

bivalves Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed by a calcified exoskeleton consis ...

corals Corals are colonial marine invertebrates within the subphylum Anthozoa of the phylum Cnidaria. They typically form compact Colony (biology), colonies of many identical individual polyp (zoology), polyps. Coral species include the important Coral ...

, and

bryozoans Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic animal, aquatic invertebrate animals, nearly all living in sedentary Colony (biology), colonies. Typically about long, they have a spe ...

), the following fossils have been reported from the Nanjemoy Formation:

Ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

of the Nanjemoy Formation

Contemporaneous fossil formations

Ypresian, Wasatchian and Casamayoran formations:Fossilworks
org ;North America * Manasquan Formation, New Jersey * Bashi Formation, Alabama * Hatchetigbee Bluff and Sabinetown Bluff Formations, Southeastern United States *

Klondike Mountain Formation The Klondike Mountain Formation is an Early Eocene (Ypresian) geological formation located in the northeast central area of Washington (state), Washington state. The formation is composed of volcanic rocks in the upper unit and volcanic plus lacu ...

, Republic & Curlew Basin, Washington State * Crescent Formation, Washington * Allenby and Coldwater Beds Formations and Ootsa Lake and Kamloops Group, British Columbia * Lookingglass and Umpqua Formations, Oregon *

Wasatch Formation The Wasatch Formation (Tw)Shroba & Scott, 2001, p.3 is an extensive highly fossiliferous Formation (geology), geologic formation stretching across several basins in Idaho, Montana, Wyoming, Utah and western Colorado.Tatman, Willwood, Wind River, Pass Peak and Indian Meadows Formations, Wyoming * Challis Volcanics Formation, Idaho * Golden Valley Formation, North Dakota * Claron Formation, Utah *

Green River Formation The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes in three basins along the present-day Green River (Colorado River), Green River in Colorado, Wyoming, and Utah. The sedimen ...

, western United States * Coalmont, Cuchara and DeBeque Formations, Colorado *

Sheep Pass Formation The Sheep Pass Formation is a geologic formation in Nevada. It preserves fossils dating back to the Paleogene period. Fossil content Vertebrates Invertebrates See also * List of fossiliferous stratigraphic units in Nevada * Nevadapla ...

, Nevada * San Jose and Galisteo Formations, New Mexico * Capay, Juncal, Llajas, Maniobra, Matilija, Meganos & Santa Susana Formations, California * Margaret Formation, Northwest Territories and Nunavut, Canada * Mokka Fiord Formation, Remus Basin, Northern Territories * Bateque and Las Tetas de Cabra Formations, Baja California * Hannold Hill and Pendleton Ferry Formations, Gulf of Mexico *

Adjuntas Adjuntas () is a small mountainside Adjuntas barrio-pueblo, town and Municipalities of Puerto Rico, municipality in Puerto Rico located in the central midwestern portion of the island on the Cordillera Central, Puerto Rico, Cordillera Central, no ...

and Indio Formations and Lechería Limestone, Mexico * Descartes Formation, Costa Rica * Stettin Formation, Jamaica * Scotland Formation, Barbados * Lizard Springs Formation, Trinidad and Tobago ;South America *

Bogotá Formation The Bogotá Formation (, E1-2b, Tpb, Pgb) is a geological formation of the Eastern Hills and Bogotá savanna on the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The predominantly shale and siltstone formation, with sandstone ...

Altiplano Cundiboyacense The Altiplano Cundiboyacense () is a high plateau located in the Eastern Cordillera of the Colombian Andes covering parts of the departments of Cundinamarca and Boyacá. (Do not confuse with The Altiplano or the Altiplano Nariñense, both fur ...

, Colombia *

Cerrejón Formation The Cerrejón Formation is a geologic formation in Colombia dating back to the Middle-Late Paleocene. It is found in the El Cerrejón sub-basin of the Cesar-Ranchería Basin of La Guajira Department, La Guajira and Cesar Department, Cesar. The fo ...

Cesar-Ranchería Basin The Cesar-Ranchería Basin () is a sedimentary basin in northeastern Colombia. It is located in the southern part of the departments of Colombia, department of La Guajira Department, La Guajira and northeastern portion of Cesar Department, Cesar. ...

, Colombia * Los Cuervos Formation,

Catatumbo The Catatumbo River () is a river rising in northern Colombia, flowing into Lake Maracaibo in Venezuela. The Catatumbo River is approximately long. It forms a part of the international boundary between the two countries. The river flows throug ...

, Cesar-Ranchería and

Llanos Basin The Llanos Basin () or Eastern Llanos Basin () is a major sedimentary basin of in northeastern Colombia. The wikt:onshore, onshore foreland basin, foreland on Mesozoic rift basin covers the departments of Colombia, departments of Arauca Departmen ...

s, Colombia * Caballas Formation,

Pisco Basin Pisco Basin () is a sedimentary basin extending over in southwestern Peru.Solís Mundaca, 2018, p.1 The basin has a 2-kilometre (1.25-mile) thick sedimentary fill, which is about half the thickness of more northern foreland basins in Peru. The o ...

, Peru * Chacras and Negritos Formations, Peru * Fonseca Formation, Brazil *

Itaboraí Formation The Itaboraí Formation () is a highly list of fossiliferous stratigraphic units in Brazil, fossiliferous geologic Formation (geology), formation and LagerstätteKellner & Campos, 1999, p.399 of the Itaboraí Basin in Rio de Janeiro (state), Rio d ...

Itaboraí Basin Itaboraí (, ) is a city in the state of Rio de Janeiro (state), Rio de Janeiro in Brazil, that belongs to the Rio de Janeiro metropolitan area. It was founded in 1672. In 2020, it had a population of 242,543. Around the year 1000, Tupi-speakin ...

, Brazil * Lumbrera Formation,

Salta Basin Salta Basin or Salta Rift Basin is a sedimentary basin located in the Argentine Northwest. The basin started to accumulate sediments in the Early Cretaceous ( Neocomian) and at present it has sedimentary deposits reaching thicknesses of . The basi ...

, Argentina *

Laguna del Hunco Formation The Laguna del Hunco Formation or Laguna del Hunco Tuff () is a localized Early Eocene (Itaboraian in the SALMA classification) fossiliferous geological formation of the Cañadón Asfalto Basin in central Patagonia, Argentina. The thick formati ...

, Cañadón Asfalto Basin, Argentina * Huitrera Formation,

Neuquén Basin Neuquén Basin () is a sedimentary basin covering most of Neuquén Province in Argentina. The basin originated in the Jurassic and developed through alternating continental and marine conditions well into the Tertiary. The basin bounds to the wes ...

, Argentina *

Sarmiento Sarmiento may refer to: Places Argentina *Sarmiento Department, San Juan, a subdivision of the San Juan Province * Sarmiento Department, Santiago del Estero, a subdivision of the Santiago del Estero Province * Sarmiento Department, Chubut, a subdi ...

and Ventana Formations,

Golfo San Jorge Basin The Golfo San Jorge Basin () is a hydrocarbon-rich sedimentary basin located in eastern Patagonia, Argentina. The basin covers the entire San Jorge Gulf and an inland area west of it, having one half located in Santa Cruz Province and the other i ...

, Argentina * Las Flores Formation, Austral Basin, Argentina ;Antarctica * lower

La Meseta Formation The La Meseta Formation is a sedimentary sequence deposited during much of the Paleogene on Seymour Island off the coast of the Antarctic Peninsula. It is noted for its fossils, which include both marine organisms and the only terrestrial vertebr ...

;Europe * Kortrijk Clay, Bruxellian Formation and Dormaal Member of Tienen Formation, Belgium * Sables de Pierrefonds, Calcares marins à alvéolines, Lignites de Soissonais, Marnes de Foncouverte, Argiles d'lignite du Soissonnais, Marnes de Gan and Carcassonne Group, France *

Fur Formation The Fur Formation is a marine geological formation of Ypresian ( Lower Eocene Epoch, c. 56.0-54.5 Ma) age which crops out in the Limfjord region of northern Denmark from Silstrup via Mors and Fur to Ertebølle, and can be seen in many cliffs and ...

, Ølst Formation and southeastern North Sea Graben, Denmark * Balder Formation, Faroe-Shetland Basin, North Sea *

London Clay The London Clay Formation is a Sediment#Shores and shallow seas, marine formation (geology), geological formation of Ypresian (early Eocene Epoch, c. 54-50 million years ago) age which outcrop, crops out in the southeast of England. The London C ...

Bagshot Formation In geology, the Bagshot Beds are a series of sands and clays of shallow-water origin, some being fresh-water, some marine. They belong to the upper Eocene formation of the London and Hampshire basins, in England and derive their name from Bagsh ...

London Basin The London Basin is an elongated, roughly triangular sedimentary basin approximately long which underlies London and a large area of south east England, south eastern East Anglia and the adjacent North Sea. The basin formed as a result of compr ...

, England * Oldhaven Formation, England * Roterzschicht Formation, Austria * Lefkara Formation, Cyprus * Silveirinha Formation, Portugal * Armàncies, Corca and Roda Formations, Spain * Pesciara Formation, Italy * ,

Monte Bolca Monte Bolca is an Ypresian, Early Eocene-aged geologic site located near Verona, Italy, Verona, Italy. A ''Konservat-Lagerstätte'', it contains an extremely well-preserved and diverse marine biota, including the most diverse fish fauna of any Ce ...

, Italy ;Asia * Çeltek, Kirkkavak and Yoncali Formations, Turkey * Umm al-Rua’us Formation, Saudi Arabia * Alai Beds, Kyrgyzstan * Ghazij, Mami Khel and Shekhan Formations, Pakistan * Cambay Shale, Naredi and Subathu Formations, Sylhet Limestone and Upper Ranikot Group, India * Dabu, Qimugen Formation and Ulunguhe Formations,

Xinjiang Xinjiang,; , SASM/GNC romanization, SASM/GNC: Chinese postal romanization, previously romanized as Sinkiang, officially the Xinjiang Uygur Autonomous Region (XUAR), is an Autonomous regions of China, autonomous region of the China, People' ...

, China * Arshanto Formation,

Inner Mongolia Inner Mongolia, officially the Inner Mongolia Autonomous Region, is an Autonomous regions of China, autonomous region of China. Its border includes two-thirds of the length of China's China–Mongolia border, border with the country of Mongolia. ...

, China * Yangxi Formation,

Hubei Hubei is a province of China, province in Central China. It has the List of Chinese provincial-level divisions by GDP, seventh-largest economy among Chinese provinces, the second-largest within Central China, and the third-largest among inland ...

, China * Lingcha Formation,

Hunan Hunan is an inland Provinces of China, province in Central China. Located in the middle reaches of the Yangtze watershed, it borders the Administrative divisions of China, province-level divisions of Hubei to the north, Jiangxi to the east, Gu ...

, China * Wutu Formation,

Shandong Shandong is a coastal Provinces of China, province in East China. Shandong has played a major role in Chinese history since the beginning of Chinese civilization along the lower reaches of the Yellow River. It has served as a pivotal cultural ...

, China * Tadushi Formation,

Primorsky Krai Primorsky Krai, informally known as Primorye, is a federal subjects of Russia, federal subject (a krais of Russia, krai) of Russia, part of the Far Eastern Federal District in the Russian Far East. The types of inhabited localities in Russia, ...

, Russia * Takaradayskaya Formation,

Sakhalin Sakhalin ( rus, Сахали́н, p=səxɐˈlʲin) is an island in Northeast Asia. Its north coast lies off the southeastern coast of Khabarovsk Krai in Russia, while its southern tip lies north of the Japanese island of Hokkaido. An islan ...

, Russia * Ommai Formation,

Kamchatka The Kamchatka Peninsula (, ) is a peninsula in the Russian Far East, with an area of about . The Pacific Ocean and the Sea of Okhotsk make up the peninsula's eastern and western coastlines, respectively. Immediately offshore along the Pacific ...

, Russia * Akasaki Formation, Japan ;Africa *

Esna Esna ( , or ; ''Snē'' from ''tꜣ-snt''; ''Latópolis'' or (''Pólis Látōn'') or (''Lattōn''); Latin: ''Lato'') is a city of Egypt. It is located on the west bank of the Nile some south of Luxor. The city was formerly part of the ...

, El Rufuf Formation and Thebes Formations, Egypt * Al Jir and Jdeir Formations, Libya * Gafsa Phosphates Formation, Tunisia * Ait Ouarhitane Formation, Morocco * Tamaguélelt Formation, Mali * Thies Formation, Senegal * Auradu Formation, Somalia * Landana Formation, Cabinda, Angola ;Oceania * Red Bluff Tuff Formation, Tutuiri Greensand and Tumaio and Te Whanga Limestones, New Zealand * Macquarie Harbor Formation, Tasmania, Australia * Dilwyn Formation, Victoria * Redbank Plains Formation, Queensland * Jubilee Member of Cardabia Formation, Western Australia

References

Bibliography

;Nanjemoy * * ;Potomac Basin *

Geology publications

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Paleontology publications

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