Besa River Formation
Encyclopedia
The Besa River Formation is a stratigraphical
unit of Devonian
age
in the Western Canadian Sedimentary Basin
.
It takes the name from Besa River
, a tributary of the Prophet River
, and was first described in outcrop near the Muskwa River
, in the Muskwa Ranges
by F.A. Kidd in 1963.
. Sandstone, bedded chert or limestone beds can occur at the top of the formation. The shale is slightly calcareous or siliceous and contains sponge spicules and radiolarian
s.
, in the folded Rocky Mountain Thrust Belt and southern Mackenzie Fold Belt.
in its eastern extent, while to the west it is overlain by the Mattson Formation and Stoddart Group
, and abruptly overlays the Dunedin Formation in the west of its extent in British Columbia
, and the Slave Point Formation
in the east. In the Northwest Territories
, it rests on the Nahanni Formation
in the east and the Road River Formation in the west.
Towards the south-west,it passes laterally into the Fort Simpson Formation
and Exshaw Formation
. To the south, it poasses into the Dunedin Formation, Horn River Formation
and Exshaw Formation
. To the east it transforms into the calcareous Rundle Group
and Stoddart Group
. It is stratigraphically equivalent with the Fort Simpson Formation
, as well as the Canol Formation and Earn Group.
Stratigraphy
Stratigraphy, a branch of geology, studies rock layers and layering . It is primarily used in the study of sedimentary and layered volcanic rocks....
unit of Devonian
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
age
Geochronology
Geochronology is the science of determining the age of rocks, fossils, and sediments, within a certain degree of uncertainty inherent to the method used. A variety of dating methods are used by geologists to achieve this, and schemes of classification and terminology have been proposed...
in the Western Canadian Sedimentary Basin
Western Canadian Sedimentary Basin
The Western Canadian Sedimentary Basin is a vast sedimentary basin underlying of Western Canada including southwestern Manitoba, southern Saskatchewan, Alberta, northeastern British Columbia and the southwest corner of the Northwest Territories. It consists of a massive wedge of sedimentary rock...
.
It takes the name from Besa River
Besa River
Besa River is a river in northern British Columbia, Canada. It is a tributary of the Prophet River.The river flows through the Muskwa Ranges, and is the backbone of the Redfern-Keily Provincial Park, part of the larger Muskwa-Kechika Management Area....
, a tributary of the Prophet River
Prophet River
Prophet River is a river in northern British Columbia, Canada. It is a tributary of the Muskwa River.The Prophet River Hotsprings Provincial Park is established on the upper course, and the Prophet River Wayside Provincial Park is located along the middle course of the river...
, and was first described in outcrop near the Muskwa River
Muskwa River
The Muskwa River flows 257 km through northern British Columbia, Canada. It is a major tributary of the Fort Nelson River - part of the Mackenzie River system. The river rises at Fern Lake in the Bedaux Pass in the Northern Rocky Mountains. From there, it flows generally east, then north,...
, in the Muskwa Ranges
Muskwa Ranges
The Muskwa Ranges are a group of mountain ranges in northern British Columbia, Canada. They are part of the Northern Rockies section of the Rocky Mountains and are bounded on their west by the Rocky Mountain Trench and on their east by the Rocky Mountain Foothills...
by F.A. Kidd in 1963.
Lithology
The Besa River Formation is composed primarily of dark shaleShale
Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering...
. Sandstone, bedded chert or limestone beds can occur at the top of the formation. The shale is slightly calcareous or siliceous and contains sponge spicules and radiolarian
Radiolarian
Radiolarians are amoeboid protozoa that produce intricate mineral skeletons, typically with a central capsule dividing the cell into inner and outer portions, called endoplasm and ectoplasm. They are found as zooplankton throughout the ocean, and their skeletal remains cover large portions of the...
s.
Distribution
The Besa River Formation reaches a maximum thickness of 1655 metres (5,429.8 ft) in the foothills . The lower Besa River Formation is faulted and folded in the Northern Rockies. It occurs in the sub-surface in east-central British ColumbiaBritish Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
, in the folded Rocky Mountain Thrust Belt and southern Mackenzie Fold Belt.
Relationship to other units
The Besa River Formation is conformably overlain by the Prophet Formation or Banff FormationBanff Formation
The Banff Formation is a stratigraphical unit of Devonian age in the Western Canadian Sedimentary Basin.It takes the name from the town of Banff, Alberta, and was first described on the north-west slope of Mount Rundle, near Banff by E.M...
in its eastern extent, while to the west it is overlain by the Mattson Formation and Stoddart Group
Stoddart Group
The Stoddart Group is a stratigraphical unit of Mississippian to Early Pennsylvanian age in the Western Canadian Sedimentary Basin.It takes the name from the Stoddart Creek, a creek that flows into Charlie Lake north of Fort St. John, and was first described in well Pacific Fort St. John #23 by...
, and abruptly overlays the Dunedin Formation in the west of its extent in British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
, and the Slave Point Formation
Slave Point Formation
The Slave Point Formation is a stratigraphical unit of Middle Devonian age in the Western Canadian Sedimentary Basin.It takes the name from Slave Point, a promontory on the north-west shore of the Great Slave Lake, and was first described in outcrop on the southern shore of the lake and along the...
in the east. In the Northwest Territories
Northwest Territories
The Northwest Territories is a federal territory of Canada.Located in northern Canada, the territory borders Canada's two other territories, Yukon to the west and Nunavut to the east, and three provinces: British Columbia to the southwest, and Alberta and Saskatchewan to the south...
, it rests on the Nahanni Formation
Nahanni Formation
The Nahanni Formation is a stratigraphical unit of Givetian age in the Western Canadian Sedimentary Basin.It takes the name from Nahanni Butte, a proeminent ridge at the confluence of the South Nahanni River and Liard River, and was first described in outcrop on the south face of the mountain by C.O...
in the east and the Road River Formation in the west.
Towards the south-west,it passes laterally into the Fort Simpson Formation
Fort Simpson Formation
The Fort Simpson Formation is a stratigraphical unit of Devonian age in the Western Canadian Sedimentary Basin.It takes the name from the settlement of Fort Simpson, and was first described in well Briggs Turkey Lake No. 1 by A.E...
and Exshaw Formation
Exshaw Formation
The Exshaw Formation is a stratigraphical unit of Mississippian age in the Western Canadian Sedimentary Basin.It takes the name from the hamlet of Exshaw, Alberta, and was first described in outcrops on the banks of Jura Creek, north of Exshaw by P.S. Warren in 1937. The formation is of late...
. To the south, it poasses into the Dunedin Formation, Horn River Formation
Horn River Formation
The Horn River Formation is a stratigraphical unit of Devonian age in the Western Canadian Sedimentary Basin.It takes the name from the Horn River, a tributary of the Mackenzie River, and was first described in outrop on the banks of Horn River in the Northwest Territories by Whittaker in 1922...
and Exshaw Formation
Exshaw Formation
The Exshaw Formation is a stratigraphical unit of Mississippian age in the Western Canadian Sedimentary Basin.It takes the name from the hamlet of Exshaw, Alberta, and was first described in outcrops on the banks of Jura Creek, north of Exshaw by P.S. Warren in 1937. The formation is of late...
. To the east it transforms into the calcareous Rundle Group
Rundle Group
The Rundle Group is a stratigraphical unit of Mississippian age in the Western Canadian Sedimentary Basin.It takes the name from Mount Rundle , and was first described in outcrops at the northern side of the mountain in Banff National Park by R.J.W...
and Stoddart Group
Stoddart Group
The Stoddart Group is a stratigraphical unit of Mississippian to Early Pennsylvanian age in the Western Canadian Sedimentary Basin.It takes the name from the Stoddart Creek, a creek that flows into Charlie Lake north of Fort St. John, and was first described in well Pacific Fort St. John #23 by...
. It is stratigraphically equivalent with the Fort Simpson Formation
Fort Simpson Formation
The Fort Simpson Formation is a stratigraphical unit of Devonian age in the Western Canadian Sedimentary Basin.It takes the name from the settlement of Fort Simpson, and was first described in well Briggs Turkey Lake No. 1 by A.E...
, as well as the Canol Formation and Earn Group.