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The Fermeuse Formation is a fossil-bearing
On
Ediacaran
The Ediacaran Period ( ) is a geological period that spans 96 million years from the end of the Cryogenian Period 635 million years ago (Mya), to the beginning of the Cambrian Period 538.8 Mya. It marks the end of the Proterozoic Eon, and th ...
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 ...
in Newfoundland
Newfoundland and Labrador (; french: Terre-Neuve-et-Labrador; frequently abbreviated as NL) is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region ...
.
Palaeobiological community
On Avalon Peninsula
The Avalon Peninsula (french: Péninsule d'Avalon) is a large peninsula that makes up the southeast portion of the island of Newfoundland. It is in size.
The peninsula is home to 270,348 people, about 52% of Newfoundland's population, according ...
there is low diversity, and includes rare 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, ''Palaeopascichnus
''Palaeopascichnus'' is an Ediacaran fossil comprising a series of lobes, first originating before the Gaskiers glaciation; it is plausibly a protozoan, but probably unrelated to the classical ' Ediacaran biota'. Once thought to represent a tr ...
'', and ''Aspidella
:Aspidella'' is also a homonym for the mushroom genus ''Saproamanita.
''Aspidella'' is an Ediacaran disk-shaped fossil of uncertain affinity. It is known from the single species ''A. terranovica''.
Morphology
''Aspidella'' consists of disk-s ...
'' discs, sometimes in great concentrations.
On Bonavista Peninsula
The Bonavista Peninsula is a large peninsula on the east coast of the island of Newfoundland in the Canadian province of Newfoundland and Labrador. It consists of 50 incorporated towns/unincorporated communities which have a population of 12,176 ...
there is higher diversity, including more fronds (rangeomorph
The rangeomorphs are a form taxon of frondose Ediacaran Ediacaran biota, fossils that are united by a similarity to ''Rangea''. Some researchers, such as Pflug and Narbonne, suggest that a natural taxon Rangeomorpha may include all similar-look ...
s) and better preserved than on Avalon Peninsula.
Depositional environment
On Bonavista Peninsula thedepositional 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 be ...
was a slope
In mathematics, the slope or gradient of a line is a number that describes both the ''direction'' and the ''steepness'' of the line. Slope is often denoted by the letter ''m''; there is no clear answer to the question why the letter ''m'' is use ...
and outer shelf–below photic zone
The photic zone, euphotic zone, epipelagic zone, or sunlight zone is the uppermost layer of a body of water that receives sunlight, allowing phytoplankton to perform photosynthesis. It undergoes a series of physical, chemical, and biological proc ...
Turbidites
A turbidite is the geologic deposit of a turbidity current, which is a type of amalgamation of fluidal and sediment gravity flow responsible for distributing vast amounts of clastic sediment into the deep ocean.
Sequencing
Turbidites were ...
probably were the dominant sediment transport
Sediment transport is the movement of solid particles (sediment), typically due to a combination of gravity acting on the sediment, and/or the movement of the fluid in which the sediment is entrained. Sediment transport occurs in natural system ...
ers.
It is predominantly 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 with water. Silt usually has a floury feel when ...
s and sands, in contrast to underlying Trepassey Formation, which is mostly dark grey shale
Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especial ...
s. There is a coarsening up sequence throughout the two formations, such that the top of the Fermeuse is predominantly 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) ...
s.
On Avalon Peninsula there were much shallower waters, particularly than in underlying Mistaken Point Formation
The Mistaken Point Formation is a geologic formation in Newfoundland and Labrador. It is recognized as a Lagerstätte preserving fossils dating back to the Ediacaran period. It contains a stratum dated to .
Geology
Mistaken Point Formation incl ...
and Trepassey Formation. It is indicated by sandy channel fills, slumping, occasional silts. There is a possible delta front and shallow slope setting.
See also
*List of fossiliferous stratigraphic units in Newfoundland and Labrador
This is a list of fossiliferous stratigraphic units in Newfoundland and Labrador.
References
*
{{Lists of fossiliferous stratigraphic units in Canada
Fossiliferous stratigraphic units of Canada, Newfoundland and Labrador
Geology of Newf ...
References
* Ediacaran Newfoundland and Labrador {{Newfoundland-stub