The Redmond 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 ...
in
Newfoundland and Labrador
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 ...
. It preserves
fossils
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...
dating back to the mid-
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
(
Cenomanian
The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the s ...
). It was a thin (up to thick) and restricted unit traced for in a single mine (Redmond No. 1) in Labrador, overlying
Paleoproterozoic
The Paleoproterozoic Era (;, also spelled Palaeoproterozoic), spanning the time period from (2.5–1.6 Ga), is the first of the three sub-divisions (eras) of the Proterozoic Eon. The Paleoproterozoic is also the longest era of the Earth's ...
rocks, with large amounts of rubble, probably as a result of
graben
In geology, a graben () is a depressed block of the crust of a planet or moon, bordered by parallel normal faults.
Etymology
''Graben'' is a loan word from German, meaning 'ditch' or 'trench'. The word was first used in the geologic contex ...
subsidence within the
Labrador trough
The Labrador Trough or the New Quebec Orogen is a long and wide geologic belt in Canada, extending south-southeast from Ungava Bay through Quebec and Labrador.
The trough is a linear belt of sedimentary and volcanic rocks which developed in an ...
.
Argillite
:''"Argillite" may also refer to Argillite, Kentucky.''
Argillite () is a fine-grained sedimentary rock composed predominantly of indurated clay particles. Argillaceous rocks are basically lithified muds and oozes. They contain variable amounts ...
facies within the formation have produced a diverse flora and insect assemblage.
[Demers Potvin & Larsson, 2019]
Fossil content
Mesoraphidiidae
* ''
Alloraphidia dorfi''
Palaeoleontidae
* ''
Palaeoleon ferrogeneticus''
Susumaniidae
* ''
Palaeopteron complexum''
Coleoptera
Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...
* Coleoptera indet.
Labradorocoleidae
* ''
Labradorocoleus carpenteri''
Cupedidae
The Cupedidae are a small family of beetles, notable for the square pattern of "windows" on their elytra (hard forewings), which give the family their common name of reticulated beetles.
The family consists of about 30 species in 9 genera, with ...
* Cupedidae indet.
*
Haliplidae
The Haliplidae are a family of water beetles that swim using an alternating motion of the legs. They are therefore clumsy in water (compared e.g. with the Dytiscidae or Hydrophilidae), and prefer to get around by crawling. The family consists of ...
indet.
* ''
Peltodytes'' sp.
Tettigarctidae
The Tettigarctidae, known as the hairy cicadas, are a small relict (mostly extinct) family of primitive cicadas. Along with more than 20 extinct genera, Tettigarctidae contains a single extant genus, ''Tettigarcta'', with two extant species, on ...
* ''
Maculaferrum blaisi''
[Demers Potvin et al., 2020]
Dictyoptera
Dictyoptera (from Greek δίκτυον ''diktyon'' "net" and πτερόν ''pteron'' "wing") is an insect superorder that includes two extant orders of polyneopterous insects: the order Blattodea (termites and cockroaches together) and the ord ...
* ''
Cretatermes carpenteri''
*
''Labradormantis'' ''guilbaulti''
See also
*
References
Bibliography
*
* {{issn, 0031-0239
Geologic formations of Canada
Cretaceous Newfoundland and Labrador
Cenomanian Stage
Shale formations
Shallow marine deposits
Paleontology in Newfoundland and Labrador