The Battery Point 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
Quebec
Quebec ( ; )According to the Government of Canada, 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 ...
. 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 ...
dating back to the early
Emsian
The Emsian is one of three faunal stages in the Early Devonian Epoch. It lasted from 407.6 ± 2.6 million years ago to 393.3 ± 1.2 million years ago. It was preceded by the Pragian Stage and followed by the Eifelian Stage. It is named after ...
to early
Eifelian
The Eifelian is the first of two faunal stages in the Middle Devonian Epoch. It lasted from 393.3 ± 1.2 million years ago to 387.7 ± 0.8 million years ago. It was preceded by the Emsian Stage and followed by the Givetian Stage.
North American ...
the
lower Devonian
The Early Devonian is the first of three epochs comprising the Devonian period, corresponding to the Lower Devonian series. It lasted from and began with the Lochkovian Stage , which was followed by the Pragian from and then by the Emsian, w ...
period.
Description
A part of the
Gaspé Sandstones,
the Battery Point Formation is believed to have been deposited in a
fluvial
In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluv ...
environment based on the presence of rootlets as well as the abundance of trough and planar-tabular
cross bedding
In geology, cross-bedding, also known as cross-stratification, is layering within a stratum and at an angle to the main bedding plane. The sedimentary structures which result are roughly horizontal units composed of inclined layers. The origina ...
, and the lower part resembles modern
braided
Braided is a musical group consisting of Casey LeBlanc, Ashley Leitão, and Amber Fleury, who all competed on the third season of ''Canadian Idol'' in 2005. They are the third music group to come from an Idol show in the world, after Young Div ...
systems more than
meandering
A meander is one of a series of regular sinuous curves in the Channel (geography), channel of a river or other watercourse. It is produced as a watercourse erosion, erodes the sediments of an outer, concave bank (cut bank) and deposits sedimen ...
systems.
It rests unconformably on the shallow marine
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 of the
York River Formation
The York River Formation is a geologic formation in Quebec. It preserves fossils dating back to the Devonian period.
Description
The basal unit of the Gaspé Sandstones, the York River Formation is wholly marine and the Battery Point Formation ...
(the basal unit of the Gaspé Sandstones and making the Battery Point Formation the first continental unit of the sequence
), transitioning upwards into the
Malbaie Formation, and is 2,300 meters (7,550 feet) thick.
Fossil content
Limited intervals in the lower part of the formation contain remains of a few
brachiopod
Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, ...
s and
bivalves
Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, biv ...
, though marine fauna is not known from other parts of the formation.
Plant and freshwater fish fossils are also known.
See also
*
List of fossiliferous stratigraphic units in Quebec
References
*
Devonian Quebec
Devonian southern paleotemperate deposits
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