The Rundle Group is a stratigraphical

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 Mississippian 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 Mount Rundle

Mount Rundle

Mount Rundle is a mountain in Banff National Park overlooking the towns of Banff and Canmore, Alberta. The mountain was named by John Palliser in 1858 after Reverend Robert Rundle, who had visited the Banff area during the 1840s....

 (itself taking the name from Robert Terrill Rundle), and was first described in outcrops at the northern side of the mountain in Banff National Park

Banff National Park

Banff National Park is Canada's oldest national park, established in 1885 in the Rocky Mountains. The park, located 110–180 kilometres west of Calgary in the province of Alberta, encompasses of mountainous terrain, with numerous glaciers and ice fields, dense coniferous forest, and alpine...

 by R.J.W. Douglas in 1953.

Lithology

The Rundle Group consists of massive limestone

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

 interbedded with dark argillaceous limestone. Chert

Chert

Chert is a fine-grained silica-rich microcrystalline, cryptocrystalline or microfibrous sedimentary rock that may contain small fossils. It varies greatly in color , but most often manifests as gray, brown, grayish brown and light green to rusty red; its color is an expression of trace elements...

 nodules are observed in the shaley beds, and crinoid

Crinoid

Crinoids are marine animals that make up the class Crinoidea of the echinoderms . Crinoidea comes from the Greek word krinon, "a lily", and eidos, "form". They live both in shallow water and in depths as great as 6,000 meters. Sea lilies refer to the crinoids which, in their adult form, are...

s and brachiopod

Brachiopod

Brachiopods are a phylum of marine animals that have hard "valves" on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection...

s are observed in the clean massive beds. Dolimitization

Dolomite

Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone....

 is observed in the Elkton Member of the Turner Valley Formation.

Distribution

The Rundle Group reaches a maximum thickness of 741 feet (225.9 m) at Tunnel Mountain

Tunnel Mountain

Tunnel Mountain is a mountain located in the Bow River Valley of Banff National Park in Alberta, Canada. The mountain is nearly completely encircled by the town of Banff and the Banff Springs Hotel grounds.-History:...

. It thins out toward east and north and is completely eroded

Erosion

Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...

 or absent in east central

Central Alberta

Central Alberta is a region located in the Canadian province of Alberta.Central Alberta is the most densely populated rural area in the province...

 and only the lower part occurs in southern Alberta

Southern Alberta

Southern Alberta is a region located in the Canadian province of Alberta. As of the year 2004, the region's population was approximately 272,017. The primary cities are Lethbridge and Medicine Hat...

.

Relationship to other units

The Rundle Group is disconformably

Unconformity

An unconformity is a buried erosion 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 of time before deposition of the younger, but the term is used to describe...

 overlain by the Rocky Mountain Formation in the front ranges of the Canadian Rockies

Canadian Rockies

The Canadian Rockies comprise the Canadian segment of the North American Rocky Mountains range. They are the eastern part of the Canadian Cordillera, extending from the Interior Plains of Alberta to the Rocky Mountain Trench of British Columbia. The southern end borders Idaho and Montana of the USA...

 and by the Fernie Formation

Fernie Formation

The Fernie Formation is a stratigraphical unit of Jurassic age in the Western Canadian Sedimentary Basin. In some interpretation it has Group status.It takes the name from the town of Fernie, British Columbia, and was first defined by Leach in 1914....

 in the foothills and by Cretaceous

Cretaceous

The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 beds in the prairies. It conformably overlies the Banff Formation

Banff 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...

.

The Rundle Group can be correlated with the Mission Canyon Formation in southern Saskatchewan

Saskatchewan

Saskatchewan is a prairie province in Canada, which has an area of . Saskatchewan is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, and on the south by the U.S. states of Montana and North Dakota....

, northeastern Montana

Montana

Montana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...

 and North Dakota

North Dakota

North Dakota is a state located in the Midwestern region of the United States of America, along the Canadian border. The state is bordered by Canada to the north, Minnesota to the east, South Dakota to the south and Montana to the west. North Dakota is the 19th-largest state by area in the U.S....

.

Subdivisions

The Rundle Group comprises the Mount Head Formation and Livingstone Formation in the Rocky Mountains

Rocky Mountains

The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...

; by the Turner Valley Formation, Shunda Formation and Pekisko Formation in the foothills and plains. It is equivalent to the Debolt Formation

Debolt Formation

The Debolt Formation is a stratigraphical unit of Meramecian age in the Western Canadian Sedimentary Basin.It takes the name from the hamlet of Debolt, Alberta, and was first described in the Amerada Crown GF23-11 well near Debolt by G...

  and Prophet Formation in north-eastern 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 west-northern Alberta

Northern Alberta

Northern Alberta is a region located in the Canadian province of Alberta.Its primary industry is oil and gas, with large heavy oil reserves being exploited at the Athabasca Oil Sands and Wabasca Area in the east of the region...

. Debolt

Debolt Formation

The Debolt Formation is a stratigraphical unit of Meramecian age in the Western Canadian Sedimentary Basin.It takes the name from the hamlet of Debolt, Alberta, and was first described in the Amerada Crown GF23-11 well near Debolt by G...

, Shunda and Pekisko Formations are staked in the Fort Nelson

Fort Nelson, British Columbia

Fort Nelson is a town of approximately 5000 residents in British Columbia's northeastern corner. It is the administrative centre of the newly formed Northern Rockies Regional Municipality, a first for BC. The majority of Fort Nelson's economic activities have historically been concentrated in the...

 area.

Canadian Rockies

Canadian Rockies

The Canadian Rockies comprise the Canadian segment of the North American Rocky Mountains range. They are the eastern part of the Canadian Cordillera, extending from the Interior Plains of Alberta to the Rocky Mountain Trench of British Columbia. The southern end borders Idaho and Montana of the USA...

Sub-unit	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...	Lithology	Max. Thickness	Reference
Mount Head Formation	Visean Viséan The Visean, Viséan or Visian is an age in the ICS geologic timescale or a stage in the stratigraphic column. It is the second stage of the Mississippian, the lower subsystem of the Carboniferous. The Visean lasted from 345.3 ± 2.1 to 328.3 ± 1.6 Ma...	Wileman Member - silty dolomite Dolomite Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone.... Baril Member - ooid Oolite Oolite is a sedimentary rock formed from ooids, spherical grains composed of concentric layers. The name derives from the Hellenic word òoion for egg. Strictly, oolites consist of ooids of diameter 0.25–2 mm; rocks composed of ooids larger than 2 mm are called pisolites...  grainstone Grainstone Under the Dunham classification, grainstones are grain-supported carbonate sedimentary rocks that contain no micrite. The spaces between grains are filled with sparry cement.-References:... , dolomite Dolomite Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone.... Salter Member - dolomite Dolomite Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone.... , boundstone Boundstone Boundstone is a village in Surrey, England....  and wackestone Wackestone Wackestone is a matrix-supported carbonate rock that contains over 10% allochems in a carbonate mud matrix. This is part of the Dunham classification of carbonate rocks. In the other widely used classification due to Folk, an equivalent description would be, for example, an oopelmicrite, where the... , ooid grainstone Grainstone Under the Dunham classification, grainstones are grain-supported carbonate sedimentary rocks that contain no micrite. The spaces between grains are filled with sparry cement.-References:... , anhydrite Anhydrite Anhydrite is a mineral – anhydrous calcium sulfate, CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the orthorhombic barium and strontium sulfates, as might be expected from the... chert Chert Chert is a fine-grained silica-rich microcrystalline, cryptocrystalline or microfibrous sedimentary rock that may contain small fossils. It varies greatly in color , but most often manifests as gray, brown, grayish brown and light green to rusty red; its color is an expression of trace elements... Loomis Member - massive grainstone Grainstone Under the Dunham classification, grainstones are grain-supported carbonate sedimentary rocks that contain no micrite. The spaces between grains are filled with sparry cement.-References:... Marston Member - microcrystalline dolomite Dolomite Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone.... , boundstone Boundstone Boundstone is a village in Surrey, England.... , breccia Breccia Breccia is a rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix, that can be either similar to or different from the composition of the fragments.... , ooid limestone, shale Shale 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... , marlstone Opal Member - grainstone Grainstone Under the Dunham classification, grainstones are grain-supported carbonate sedimentary rocks that contain no micrite. The spaces between grains are filled with sparry cement.-References:... , subordinate marlstone, chert Chert Chert is a fine-grained silica-rich microcrystalline, cryptocrystalline or microfibrous sedimentary rock that may contain small fossils. It varies greatly in color , but most often manifests as gray, brown, grayish brown and light green to rusty red; its color is an expression of trace elements...  packstone and wackestone Wackestone Wackestone is a matrix-supported carbonate rock that contains over 10% allochems in a carbonate mud matrix. This is part of the Dunham classification of carbonate rocks. In the other widely used classification due to Folk, an equivalent description would be, for example, an oopelmicrite, where the... , shale Shale 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... , marlstone, breccia Breccia Breccia is a rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix, that can be either similar to or different from the composition of the fragments.... Carnarvon Member - wackestone Wackestone Wackestone is a matrix-supported carbonate rock that contains over 10% allochems in a carbonate mud matrix. This is part of the Dunham classification of carbonate rocks. In the other widely used classification due to Folk, an equivalent description would be, for example, an oopelmicrite, where the...  to packstone, shale Shale 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...  interbeds	7.6 m (24.9 ft) 39 m (128 ft) 67 m (219.8 ft) 101 m (331.4 ft) 68 m (223.1 ft) 161 m (528.2 ft) 90 m (295.3 ft)
Livingstone Formation	Tournaisian Tournaisian The Tournaisian is in the ICS geologic timescale the lowest stage or oldest age of the Mississippian, the oldest subsystem of the Carboniferous. The Tournaisian age lasted from 359.2 ± 2.5 Ma to 345.3 ± 2.1 Ma...  to Visean Viséan The Visean, Viséan or Visian is an age in the ICS geologic timescale or a stage in the stratigraphic column. It is the second stage of the Mississippian, the lower subsystem of the Carboniferous. The Visean lasted from 345.3 ± 2.1 to 328.3 ± 1.6 Ma...	crinoid Crinoid Crinoids are marine animals that make up the class Crinoidea of the echinoderms . Crinoidea comes from the Greek word krinon, "a lily", and eidos, "form". They live both in shallow water and in depths as great as 6,000 meters. Sea lilies refer to the crinoids which, in their adult form, are... al limestone Limestone Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera.... , massive limestone, thin argillaceous limestone beds, dolomite Dolomite Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone....	452 m (1,482.9 ft)

Foothills and plains

Sub-unit	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...	Lithology	Max. Thickness	Reference
Turner Valley Formation	Visean Viséan The Visean, Viséan or Visian is an age in the ICS geologic timescale or a stage in the stratigraphic column. It is the second stage of the Mississippian, the lower subsystem of the Carboniferous. The Visean lasted from 345.3 ± 2.1 to 328.3 ± 1.6 Ma...	crinoid Crinoid Crinoids are marine animals that make up the class Crinoidea of the echinoderms . Crinoidea comes from the Greek word krinon, "a lily", and eidos, "form". They live both in shallow water and in depths as great as 6,000 meters. Sea lilies refer to the crinoids which, in their adult form, are... al limestone Limestone Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....  and crystalline dolomite Dolomite Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone.... ; two porous intervals are separated by a middle tight unit; diagenetically Diagenesis In geology and oceanography, diagenesis is any chemical, physical, or biological change undergone by a sediment after its initial deposition and during and after its lithification, exclusive of surface alteration and metamorphism. These changes happen at relatively low temperatures and pressures...  dolomitized in west southern Alberta Southern Alberta Southern Alberta is a region located in the Canadian province of Alberta. As of the year 2004, the region's population was approximately 272,017. The primary cities are Lethbridge and Medicine Hat... ; Lower porous zone is defined as Elkton Member	110 m (360.9 ft)
Shunda Formation	Tournaisian Tournaisian The Tournaisian is in the ICS geologic timescale the lowest stage or oldest age of the Mississippian, the oldest subsystem of the Carboniferous. The Tournaisian age lasted from 359.2 ± 2.5 Ma to 345.3 ± 2.1 Ma...  to Visean Viséan The Visean, Viséan or Visian is an age in the ICS geologic timescale or a stage in the stratigraphic column. It is the second stage of the Mississippian, the lower subsystem of the Carboniferous. The Visean lasted from 345.3 ± 2.1 to 328.3 ± 1.6 Ma...	argillaceous Shale 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...  limestone Limestone Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....  and dolomite Dolomite Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone.... , siltstone Siltstone Siltstone is a sedimentary rock which has a grain size in the silt range, finer than sandstone and coarser than claystones.- Description :As its name implies, it is primarily composed of silt sized particles, defined as grains 1/16 - 1/256 mm or 4 to 8 on the Krumbein phi scale... , sandstone Sandstone Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,... , shale Shale 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... , breccia Breccia Breccia is a rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix, that can be either similar to or different from the composition of the fragments.... , anhydrite Anhydrite Anhydrite is a mineral – anhydrous calcium sulfate, CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the orthorhombic barium and strontium sulfates, as might be expected from the...	122 m (400.3 ft)
Pekisko Formation	Tournaisian Tournaisian The Tournaisian is in the ICS geologic timescale the lowest stage or oldest age of the Mississippian, the oldest subsystem of the Carboniferous. The Tournaisian age lasted from 359.2 ± 2.5 Ma to 345.3 ± 2.1 Ma...	Upper Pekisko - lithographic limestone Lower Pekisko - massive crinoid Crinoid Crinoids are marine animals that make up the class Crinoidea of the echinoderms . Crinoidea comes from the Greek word krinon, "a lily", and eidos, "form". They live both in shallow water and in depths as great as 6,000 meters. Sea lilies refer to the crinoids which, in their adult form, are... al limestone Limestone Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....	134 m (439.6 ft)

Deep basin

Sub-unit	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...	Lithology	Max. Thickness	Reference
Debolt Formation Debolt Formation The Debolt Formation is a stratigraphical unit of Meramecian age in the Western Canadian Sedimentary Basin.It takes the name from the hamlet of Debolt, Alberta, and was first described in the Amerada Crown GF23-11 well near Debolt by G...	Meramecian	Upper Debolt - crystalline dolomite Dolomite Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone.... , anhydrite Anhydrite Anhydrite is a mineral – anhydrous calcium sulfate, CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the orthorhombic barium and strontium sulfates, as might be expected from the... , micritic Micrite Micrite is a limestone constituent formed of calcareous particles ranging in diameter up to 4 μm formed by the recrystallization of lime mud.The term was coined in 1959 by Robert Folk for his carbonate rock classification system...  limestone Limestone Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera.... Lower Debolt - cherty Chert Chert is a fine-grained silica-rich microcrystalline, cryptocrystalline or microfibrous sedimentary rock that may contain small fossils. It varies greatly in color , but most often manifests as gray, brown, grayish brown and light green to rusty red; its color is an expression of trace elements...  bioclastic (crinoid Crinoid Crinoids are marine animals that make up the class Crinoidea of the echinoderms . Crinoidea comes from the Greek word krinon, "a lily", and eidos, "form". They live both in shallow water and in depths as great as 6,000 meters. Sea lilies refer to the crinoids which, in their adult form, are... al) limestone Limestone Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera.... , argillaceous Shale 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...  in the north	366 m (1,200.8 ft)
Prophet Formation	middle Tournaisian Tournaisian The Tournaisian is in the ICS geologic timescale the lowest stage or oldest age of the Mississippian, the oldest subsystem of the Carboniferous. The Tournaisian age lasted from 359.2 ± 2.5 Ma to 345.3 ± 2.1 Ma...  to late Visean Viséan The Visean, Viséan or Visian is an age in the ICS geologic timescale or a stage in the stratigraphic column. It is the second stage of the Mississippian, the lower subsystem of the Carboniferous. The Visean lasted from 345.3 ± 2.1 to 328.3 ± 1.6 Ma...	chert Chert Chert is a fine-grained silica-rich microcrystalline, cryptocrystalline or microfibrous sedimentary rock that may contain small fossils. It varies greatly in color , but most often manifests as gray, brown, grayish brown and light green to rusty red; its color is an expression of trace elements... , skeletal to ooid Oolite Oolite is a sedimentary rock formed from ooids, spherical grains composed of concentric layers. The name derives from the Hellenic word òoion for egg. Strictly, oolites consist of ooids of diameter 0.25–2 mm; rocks composed of ooids larger than 2 mm are called pisolites...  limestone Limestone Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera.... , shale Shale 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... , marlstone, dolostone Dolostone Dolostone or dolomite rock is a sedimentary carbonate rock that contains a high percentage of the mineral dolomite. In old U.S.G.S. publications it was referred to as magnesian limestone. Most dolostone formed as a magnesium replacement of limestone or lime mud prior to lithification. It is...	760 m (2,493.4 ft)