First published: 29 March 2021
Last modified:
DISCLAIMER: This English version is translated from the original French. In case of any discrepancy, the French version shall prevail.
| Author(s): | Dimroth, 1968 |
| Age: | Paleoproterozoic |
| Stratotype: | The area south and west of Uvé Pond was defined as the type locality (approximate coordinates: UTM NAD 23 Zone 19, 535399 m E, 6227313 m N). |
| Type area: | Otelnuk Lake area, SE of the southern end of Chakonipau Lake (NTS sheet 24C01) |
| Geological province: | Churchill Province |
| Geological subdivision: | New Quebec Orogen (Labrador Trough)/Cambrien, Howse, Romanet (formerly Wheeler) and Schefferville lithotectonic zones |
| Lithology: | Mudstone, siltstone, dolomite, sandstone, quartzitic arenite |
| Category: | Lithostratigraphic |
| Rank: | Formation |
| Status: | Formal |
| Use: | Active |
Background
The Uvé Formation was introduced by Dimroth (1968) in the area south and west of Uvé Pond (sheet 24C01) to describe a massive, dark grey dolomite unit having a brown alteration patina. Rocks of this unit were mainly described by Dimroth (1965, 1969, 1972, 1978), Dressler (1973, 1979), Clark (1984, 1986) and Brouillette (1989). They were also studied by Kish and Tremblay-Clark (1978) to evaluate their mineral potential.
Description
The Uvé Formation is an autochthonous/parautochthonous or allochthonous sedimentary unit occupying the summit of the Pistolet Group. It consists mainly of massive, dark grey dolomite having a brown or beige patina and forming 30 to 90 m-thick beds (Dimroth, 1969, 1978). The type section of the formation is located at Uvé Pond (sheet 24C01), SE of Chakonipau Lake (Table 1; Dimroth, 1969, 1978). Other stratigraphic sections were made in other areas (Table 2; Dimroth, 1978).
At the type section, the lower member (unit pPuv9) of the formation consists of 30 m of red and green siltstone interbedded (0.1-1.8 m thick) with grey dolomite having a brown alteration patina or grey dolomitic sandstone. Towards the top, this member comprises a 10 m-thick bed of massive grey dolomite having a brown alteration patina and slightly sandy at the base. The top of the lower member consists of 15 m of red and green siltstone, with interbedded (0.1-1.8 m thick) very fine-grained grey dolomitic sandstone having a brown alteration patina. According to Dimroth (1969, 1978), red and green siltstone of the lower member of the Uvé Formation closely resembles that of the Lace Lake Formation. The upper member (Unit Puv5) consists of generally massive grey dolomite having a brown alteration patina. Locally, dolomite display deformed beds (Dimroth, 1969, 1978).
Table 1: Characteristics of the Type Locality (Dimroth, 1978)
| Type locality: area south and west of Uvé Pond (approximate coordinates: UTM NAD 23 Zone 19, 535399 m E, 6227313 m N) | ||||||||||
| Member | Thickness (m) | Description | ||||||||
| Upper | 60 | Generally massive grey dolomite having a brown patina | ||||||||
| Lower | 15 | Red and green siltstone; interbedded (0.1-1.8 m thick) very fine-grained grey dolomitic sandstone having a brown patina | ||||||||
| 10 | Massive grey dolomite having a brown patina | |||||||||
| 30 | Red and green siltstone; interbedded (0.1-1.8 m thick) brown-patina grey dolomite or grey dolomitic sandstone | |||||||||
Table 2: Characteristics of Some Representative Localities (Dimroth, 1978)
| Locality | North of Pistolet Lake (sheet 24C02) | NE of Lace Lake (sheet 24C02) | Nona Lake (sheet 24C01) | ||||||||
| Upper member | Summit not outcropping | Absent | Summit not outcropping | ||||||||
| Massive grey dolomite having a beige patina and containing black chert nodules – 90 m Grey dolomitique sandstone having a brown patina – 10 m | Massive grey dolomite having a beige patina – 60 m | ||||||||||
| Lower member | Very-fine grained red and green siltstone; intebedded (1-10 m thick) massive grey dolomite having a beige patina – 60 m | Grey siltstone and fine-grained sandstone with a bed (10 m thick) of grey dolomite having a beige patina – 60 m | Grey siltstone and mudstone; interbedded (0.3-1.8 m thick) grey dolomite having a beige patina and fine-grained sandstone – 60 m | ||||||||
| Locality | Trident Lake (sheet 24C02) | North of Veronot Lake (sheet 24C01) | SW of Otelnuk Lake (sheet 24C01) | ||||||||
| Upper member | Summit not outcropping | Summit not outcropping | Summit not outcropping | ||||||||
| Massive grey dolomite having a beige patina – 60 m | Massive grey dolomite having a beige patina – 30 m | Massive grey dolomite having a beige patina – 30 m Black chert Grey slate | |||||||||
| Lower member | Grey siltstone and mudstone; interbedded (1.5-6 m thick) grey dolomite having a brown patina and very fine-grained sandstone – 60 m | Siltstone et mudstone gris; interbedded very fine-grained green sandstone; interbedded dolomite (0.3 m thick) – 60 m | Massive grey dolomite having a brown patina – 30 m Grey mudstone and siltstone – 30 m | ||||||||
| Locality | Alder Hill (sheet 24C01) | SW of Castignon Lake (sheet 24C07) | West of Castignon Lake (sheet 24C07) | ||||||||
| Upper member | Generally massive grey dolomite having a brown patina – 60 m | Massive grey dolomite having a brown patina – 60 m | Summit not outcropping | ||||||||
| Massive grey dolomite having a brown patina – 60 m | |||||||||||
| Base not outcropping | |||||||||||
| Lower member | Red and green siltstone; interbedded (0.1-1.8 m thick) very fine-grained grey dolomite or dolomitic sandstone having a brown patina. A bed (10 m thick) of massive grey dolomite having a brown patina – 60 m | Grey mudstone and siltstone; interbedded grey dolomite having a brown patina – 60 m | Grey mudstone and siltstone; interbedded grey dolomite having a brown patina – 60 m | ||||||||
| Locality | NW of Castignon Lake (sheet 24C07) | Minowean Lake and west of Portage Lake (sheet 24C07) | Chambon Lake (sheet 24C08) | ||||||||
| Upper member | Summit not outcropping | Summit not outcropping | Massive grey dolomite having a brown patina – 45 m Grey dolomitic sandstone having a brown patina – 0-10 m White quartzitic arenite – 0-10 m | ||||||||
| Massive grey dolomite having a brown patina – unknown thickness | Recrystallized massive grey dolomite having a beige patina; interbedded dolomite and quartzitic arenite – 90 m | ||||||||||
| Base not outcropping | Base not outcropping | ||||||||||
| Lower member | Grey mudstone and siltstone; interbedded grey dolomite having a brown patina – unknown thickness | Grey siltstone and mudstone; interbedded (0.3 m thick) grey dolomite having a brown patina – unknown thickness | Grey siltstone and mudstone; interbedded grey dolomite having a brown patina and very fine-grained white sandstone – 0-10 m | ||||||||
| Locality | West of Romanet Lake (sheet 24B05) | ||||||||||
| Upper member | Massive grey dolomite having a brown patina – 60 m Grey dolomitic sandstone having a brown patina – 0-30 m White quartzitic arenite – 60 m | ||||||||||
| Lower member | Grey siltstone and mudstone; interbedded grey dolomite having a brown patina and very fine-grained white sandstone – 30 m | ||||||||||
| Locality | Maraude Lake (sheet 23N16) | Ritchie Lake (sheet 23O12) | SW of Pas Lake (sheet 23O13) | ||||||||
| Massive grey dolomite having a brown patina; interbedded black slate and mudrock – unknown thickness | Recrystallized massive grey dolomite having a brown patina – 90 m Black slate – 60 m | Massive grey dolomite having a brown patina, alternating with black shale and sandstone – 150 m Black slate, laminated slate, pebbly slate – 60 m | |||||||||
| Locality | SW of Calonne Lake (sheet 23O12) | North of Calonne Lake (sheet 23O12) | |||||||||
| Massive grey dolomite having a brown patina – 90 m Grey sandstone, grey and black shale, minor amount of granule sandstone (microconglomerate) – 60 m | Massive grey dolomite having a brown patina; possibly interbedded shale; interbedded granule sandstone (microconglomerate) – 60 m Medium-grained grey sandstone and black sandstone, shale, minor amount of granule sandstone (microconglomerate) – 130 m | ||||||||||
According to Dimroth (1978), the Uvé Formation is distinguished by subtle facies variations. North of Pistolet Lake (sheet 24C02), he describes a marginal facies in the lower member characterized by red and green siltstone and very fine-grained sandstone interbedded with massive grey dolomite having a brown alteration patina. Elsewhere, rocks of the lower member of the Uvé Formation consist of grey, locally graphitic siltstone and mudstone (Dimroth, 1978; Dressler, 1979; Brouillette, 1989). These rocks include interbedded grey dolomite having a brown alteration patina (Dimroth, 1978). The marginal facies changes laterally to the basin facies characterized in the upper member by massive grey dolomite having a brown or beige patina interbedded in places with slate, mudrock and chert. Grey dolomitic sandstone having a brown alteration patina and white quartzitic arenite form the base of the upper member in the Du Chambon Lake area and to the NW of Romanet Lake (Dimroth, 1978).
South of latitude 56° N, Dimroth (1978) did not recognize lower and upper members. In the Maraude Lake area (sheet 23N16), the Uvé Formation is represented by interbedded black slate, mudrock and grey dolomite having a brown alteration patina belonging to the basin facies. Towards the SE, Dimroth (1978) describes a particular facies (Wakuach facies) characterized by black slate as well as massive grey dolomite having a brown alteration patina, locally interbedded with shale, sandstone and granule sandstone (microconglomerate). In the Calonne Lake and Wakuach Lake area, granule sandstones are similar to those of the Alder Formation (Dimroth, 1978).
According to Dimroth (1978), the scarcity of stromatolitic dolomite and the local presence of graphitic mudstone suggest that the Uvé Formation was deposited in a relatively quiet and deep marine environment associated with locally reducing conditions (Dimroth, 1970, 1978; Dressler, 1979; Clark, 1986; Clark and Wares, 2004). Red and green mudstones of the lower member, located near the western margin of the Labrador Trough, are thought to have originated from a source area to the west. Arenaceous rocks at the base of the upper member are absent or in very thin layers in the western part of the Trough, but gradually increase in thickness towards the east, suggesting a continental source to the east. Another source is also possible in the centre of the Trough, in the area east of Wakuach Lake (Dimroth, 1970, 1978).
Uvé Formation, Undivided (pPuv): Dolomite with a Brown Patina, Green and Red Mudstone and Siltstone, Dolomitic Sandstone
This undivided unit includes all the rocks found in the Uvé Formation. It consists of dolomite having a brown patina, green and red mudstone and siltstone and dolomitic sandstone.
Uvé Formation 2 (pPuv2): Grey Siltstone and Mudstone; Interbedded Grey Dolomite with a Brown Patina and Fine-Grained Sandstone
Unit pPuv2 generally forms the lower member of the Uvé Formation (Dimroth, 1969, 1978; Dressler, 1979; Clark, 1984, unpublished report) with the exception of the type locality and the area north of Pistolet Lake. Its thickness varies from 30 m SW of Otelnuk Lake to 60 m NE of Lace Lake and in the Castignon Lake area (Dimroth, 1978). At Cambrien Lake, the thickness of the unit is estimated to be between 14 and 50 m (Clark, 1984). In the area north of Du Chambon Lake, the unit reaches 10 m thick and thickens eastward to 30 m NW of Romanet Lake (Dimroth, 1978). Unit Puv2 consists of grey to greenish grey siltstone and mudstone interbedded (0.3-10 m thick) with grey dolomite having a brown patina and very fine-grained green or white sandstone. Siltstone and mudstone occur in beds 2 to 30 cm thick, banded and very finely laminated on a millimetre scale (Dimroth, 1978; Clark, 1984; Brouillette, 1989). In the Cambrien Lake area, siltstone is commonly calcareous and locally has ripples (Clark, 1984). Siltstone and mudstone are locally graphitic (Dressler, 1979; Clark, 1984; Brouillette, 1989). According to Brouillette (1989), the graphite content can reach 15 to 20%. Mudstone is commonly marked by regular millimetric fracture cleavage (Clark, 1984; Brouillette, 1989). Siltstone and mudstone are composed of detrital grains of quartz and plagioclase (5-10%) in a strongly graphitic chlorite-sericite matrix (Brouillette, 1989). These rocks are very similar to those of the Lace Lake Formation (Dimroth, 1969, 1978; Clark, 1984).
Uvé Formation 3 (pPuv3): Black Slate and Mudrock; Interbedded Massive Grey Dolomite with a Brown Patina
Unit pPuv3 is located NE of Maraude Lake (sheet 23N16) and belongs to the basin facies of Dimroth (1978). It consists of ~10 to 60 m of black slate and mudrock interbedded with 10 layers (3-18 m) of massive grey dolomite having a brown patina. Unit pPuv3 is similar to unit pPuv4, but slate is dominant.
Uvé Formation 4 (pPuv4): Massive Grey Dolomite with a Brown Patina; Interbedded Slate, Mudrock and Chert
Unit pPuv4 represents the upper member of the Uvé Formation in the area NW of Du Chambon Lake (Clark, 1986). It consists of massive grey to light grey dolomite having a beige, orange-brown or brown alteration patina, and interbedded slate, mudrock and chert. Dolomite is not stromatolitic. It is fine grained (up to 0.5 mm). In places, it may be slightly sandy and contain thin grey or green mudrock beds. The thickness of grey or black chert beds can reach 2 m, especially near Du Chambon Lake. Grey to black slate beds are abundant near the contact with the overlying Du Chambon Formation. Irregular white quartz veins and coarse carbonate veins are very abundant in places. Locally, pyrite cubes are observed in a carbonate vein. Traces of chalcopyrite were also observed in a quartz vein, as well as ~1% pyrite in a thin bed of green laminated mudrock. Dolomite also contains small amounts of disseminated pyrite in places (Clark, 1986). South of latitude 56° N, this unit belongs to the basin facies of Dimroth (1978). It consists mainly of massive grey dolomite having a brown patina, locally interbedded with black slate and mudrock. Unit pPuv4 is similar to unit pPuv3, but dolomite dominates.
Uvé Formation 5 (pPuv5): Massive Grey or Yellow Dolomite, Commonly Brecciated, Locally Sandy, with a Brown or Beige Patina; Locally Dolomitic, Quartzitic Sandstone
Unit pPuv5 generally forms the upper member of the Uvé Formation (Dimroth, 1965, 1969, 1978; Dressler, 1979; Clark, 1984, unpublished report) with the exception of the area NW of Du Chambon Lake. At the type locality, this unit is 60 m thick. Elsewhere, it occurs in 30 to 90 m thick beds (Tables 1 and 2). It consists mainly of massive grey or yellow dolomite, commonly brecciated, locally sandy, having a brown or beige alteration patina (Dimroth, 1965, 1969, 1978; Clark, 1984, unpublished report). Two dolomite varieties are recognized: unrecrystallized and recrystallized (Dimroth, 1969, 1978; Dressler, 1979). Unrecrystallized dolomite dominates south, west and NW of Castignon Lake, as well as at Du Chambon Lake and NW of Romanet Lake. In the areas to the NE of Pistolet Lake, to the west and SW of Otelnuk Lake and to the south of latitude 56° N, recrystallized dolomite prevails (Dimroth, 1978). According to Dimroth (1978), changes from one variety to another are abrupt.
Unrecrystallized dolomite is dark grey, aphanitic and has a brown alteration patina, commonly with a characteristic purple-brown tinge (Dimroth, 1978). The rock may be stratified, massive or locally stromatolitic (Dimroth, 1969). Syn-sedimentary deformation and brecciation structures are common. Stratification is only visible on the altered surface. In places, Dimroth (1978) points out the transition from deformed stratified dolomite to brecciated dolomite and then to lenticular and irregular stratified dolomite. Beds of coarse-grained, massive dolomitic quartzitic sandstone are observed in places at the base of dolomite beds. Unrecrystallized dolomite does not contain chert (Dimroth, 1965, 1969).
Recrystallized dolomite is light grey or yellow, rarely dark grey in fresh exposure, light brown or beige in altered patina and fine to medium grained (Dimroth, 1978; Dressler, 1979). The rock generally has a saccharoidal structure, but coarser-grained varieties (≥3 mm) are observed locally. The rock lacks primary sedimentary structures. According to Dimroth (1978), they have probably been lost by recrystallization. Dolomite is generally brecciated and fractured. Black chert nodules or lenses are ubiquitous (Dimroth, 1969, 1978; Dressler, 1979). Brecciated dolomite is formed of intraclasts, usually stromatolite fragments, in an aphanitic paste (Dimroth, 1969).
In the area west of Cambrien Lake (Clark, 1984), unit Puv5 forms a layer 1 to 20 m thick (minimum). Dolomite is grey, more or less brecciated, and occurs in massive beds little or not deformed. East of Cambrien Lake, the unit consists of grey dolomitic breccia of unknown thickness. The latter is formed of rounded dolomite blocks, 0.3 to 1 m long (up to 3 m locally), in a matrix of schistose and chloritic mudstone. It also includes angular dolomite fragments, 0.01 to 1 m in diameter, in a matrix of slightly sandy dolomite. Cavities are filled with black chert and quartz.
Uvé Formation 6 (pPuv6): Massive Dolomite with a Brown Patina; May Contain Interbedded Shale, Sandstone and Granule Sandstone (Microconglomerate)
Unit pPuv6 belongs to the Wakuach facies of Dimroth (1978). In the area between Wakuach and Pas lakes (sheets 23O12 and 23O13), its thickness is estimated to be between 60 and 150 m (Table 2). The unit consists of thick (10-60 cm) beds of massive grey dolomite having a brown or light brown alteration patina. The rock exhibits deformed stratification planes. In places, dolomite may contain interbedded black shale, sandstone and granule sandstone (microconglomerate).
Uvé Formation 7 (pPuv7): Black Slate
Unit pPuv7 belongs to the Wakuach facies of Dimroth (1978). In the area SW of Pas Lake (sheet 23O13), it is ~60 m thick (Table 2). It consists of black slate, generally highly fissile laminated slate and pebbly slate. The unit may include a minor amount of sandstone (Baragar, 1967; Dimroth, 1978).
Uvé Formation 8 (pPuv8): Greyish Green or Grey Felsic Tuff; Interbedded Dolomite with a Brown Patina
Unit pPuv8 is located east of the neck of Cambrien Lake (sheet 24C06) (Clark, 1984), where it forms a strip ~15 m thick visible for ≥3 km. It consists of greyish green to grey tuff with interbedded (2-20 cm thick) dolomite having a brown alteration patina. Tuff is hard, with a conchoidal fracture and bedded at scale ≤1 cm. Some lighter coloured beds or laminae are siliceous. Interbedded dolomite locally forms up to 50% of the sequence. Folds are observed in places. According to Clark (1984), these folds may be due to syn-sedimentary sliding, as the units immediately above (pPuv2) and below (Alder Formation [pPad14]) are relatively undeformed. In thin sections, the rock is mainly composed of small irregular to lenticular, light brown or colourless rods in natural light, possibly representing altered glass fragments. Fine detrital quartz is also observed. According to Clark (1984), this unit probably consists of vitreous tuff of felsic composition.
Uvé Formation 9 (pPuv9): Red, Purple and Green Siltstone and Very Fine-Grained Sandstone; Interbedded Grey Dolomite with a Brown or Beige Patina
Unit pPuv9 forms the lower member of the Uvé Formation in areas SE of Chakonipau Lake (type locality) and NE of Pistolet Lake (Tables 1 and 2; Dimroth, 1969, 1978). At the type locality, this unit is 55 m thick (Dimroth, 1978). It consists of red and green siltstone and very fine-grained grey dolomitic sandstone with centimetric to metric interbeds of massive grey dolomite having a brown patina. Red and green siltstone of the lower member of the Uvé Formation is similar to that of the Lace Lake Formation. According to Dimroth (1969), dolomite beds are <2 m thick and can reach 15 m. Dolomite is very similar to that of unit Puv5.
An occurrence of unit pPuv9 was mapped by Clark (1984) on the western shore of Cambrien Lake. In this area, it forms an 8 m-thick layer overlying pink dolomite of the Alder Formation (pPad11). The rock consists of calcareous siltstone and purple argillaceous siltstone having planar bedding and, less frequently, cross bedding. Beds (1-30 cm thick) of laminated pinkish grey dolomite having a yellow or beige patina may make up to 10% of the unit. Low-throw syn-sedimentary faults are also observed.
Uvé Formation 11 (pPuv11): Grey Dolomitic Sandstone with a Brown Patina
Unit pPuv11 belongs to the upper member of the Uvé Formation in the area north of Du Chambon Lake and NW of Romanet Lake (Dimroth, 1978). North of Du Chambon Lake, the unit reaches a thickness of 10 m and thickens towards the east to reach 30 m NW of Romanet Lake (Dimroth, 1978). The unit consists mainly of grey or white dolomitic sandstone having a dark brown or dark grey to black alteration patina (Dimroth, 1978; Clark, 1986). The latter underlies brown-patina dolomite (pPuv5) and overlies a quartzitic arenite unit (pPuv12) (Table 2). According to Dimroth (1978), unit pPuv11 dolomitic sandstone is similar to that of the Alder Formation. It occurs in beds a few centimetres to 2 m thick, laminated or massive, and locally displays cross bedding (Dimroth, 1978; Clark, 1986). North of Du Chambon Lake, dolomitic sandstone commonly contains interbedded (1-10 cm thick) laminated dolomite having a beige to grey alteration patina (Clark, 1986). It is composed of 1 to 2 mm quartz grains (40-60%), oolites (0-15%), limestone intraclasts (0-15%), calcareous siltstone fragments (0-5%) and locally shale fragments, in a coarse-grained dolomite matrix (Dimroth, 1978).
Uvé Formation 12 (pPuv12): Massive White or Grey Quartzitic Arenite
Unit pPuv12 belongs to the upper member of the Uvé Formation in the area north of Du Chambon Lake and NW of Romanet Lake (Dimroth, 1978). North of Du Chambon Lake, the unit reaches a thickness of 10 m and thickens towards the east to reach 60 m NW of Romanet Lake (Dimroth, 1978). The unit consists essentially of grey quartzitic arenite having a white or grey alteration patina. It is overlain by dolomitic sandstone (pPuv11) and forms the base of the upper member of the Uvé Formation in this area (Table 2). Quartzitic arenite is generally massive. In places, it is laminated (uncharacteristic) and occurs in beds a few centimetres to 1 m thick (Dimroth, 1978; Clark, 1986). It is slightly deformed. According to Dimroth (1978), unit pPuv12 quartzitic arenite is similar to that of the Alder Formation. North of Du Chambon Lake, it is interbedded with dolomitic sandstone and sandy dolomite. The contact of the unit with the overlying pPuv11 unit is marked by a decrease in the number of quartzitic arenite beds (Clark, 1986). In thin sections, the rock is composed mainly of quartz and a lesser amount of plagioclase in a cement of cherty quartz and some dolomite. Quartz grains have undulatory extinction (Dimroth, 1978). Grain size is ~0.5 mm. Some pyrite crystals are also observed (Clark, 1986).
Thickness and distribution
The Uvé Formation belongs to the Cambrien, Schefferville and Romanet (formerly Wheeler) lithotectonic zones as defined by Clark and Wares (2004). It extends from the area west of Patu Lake (sheet 24C10) to Wakuach Lake (sheet 23O12), a distance of ~150 km. Further SE, the rocks belonging to the Uvé Formation have been recognized SE of Wakuach Lake (Dimroth, 1978). The Uvé Formation also forms a highly folded strip ~23 km long extending from the NW end of Romanet lake to the NW end of Du Chambon Lake.
Based on stratigraphic sections of Dimroth (1978), the thickness of the Uvé Formation is estimated to be between 60 and 160 m north of latitude 56° N, and between 150 and 210 m south of this limit (Table 2). At the type locality near Chakonipau Lake, Dimroth (1969, 1978) measured a thickness of 115 m, with 55 m of interbedded mudstone, siltstone and dolomite at the base (lower member) and 60 m of dolomite at the top (upper member). In the Mistamisk Lake and Romanet River area, Clark (1986) points out that the Uvé Formation is highly folded, which makes it impossible to estimate its thickness.
Dating
None.
Stratigraphic Relationship(s)
Rocks of the Uvé Formation were deposited between 2169 ±2 and 2142 +4/-2 Ma, i.e. during the deposition of sedimentary rocks of the first-volcano-sedimentary cycle of the Labrador Trough (T. Krogh and B. Dressler, unpublished data cited in Clark, 1984, page 4; Rohon et al., 1993; Clark and Wares, 2004). Recently, U-Pb ages of 2166 ±4 and 2171 ±2 Ma were obtained by Corrigan et al. (2020) for the beginning of the first cycle. The Uvé Formation represents the youngest unit of the Pistolet Group (Dimroth, 1969, 1978).
The lower and upper contacts of the Uvé Formation are clearly visible at the type locality. There, it conformably overlies the Alder Formation and is conformably overlain by the Hautes-Chutes Formation (Swampy Bay Group) (Dimroth, 1969, 1978). In the Du Chambon and Romanet lakes area, the contact of the Uvé Formation with the Alder Formation was observed by Clark (1986) on the north shore of Du Chambon Lake. At this location, polarity is indicated by stromatolites and cross bedding in dolomite of the underlying Alder Formation (Clark, 1986). The summit of the Uvé Formation is conformably overlain by the Du Chambon Formation (Swampy Bay Group) (Dimroth, 1978; Clark, 1986). This contact is well exposed east of Du Chambon Lake and NE of Duvic Cove where it is characterized by interbedded (10 cm to 1 m thick) slate, dolomite and chert (Clark, 1986). At the NW end of Du Chambon Lake, a thrust fault (Du Chambon Fault) mapped by Dimroth (1978) to the SE of the lake juxtaposes the Uvé Formation with the Dunphy Formation (Seward Group) (Clark, 1986). In the area south of Maraude Lake, rocks of the Uvé Formation are locally overlain (Maraude Fault) by Archean rocks of the Superior Province (Dimroth, 1978).
Polygenetic intrusive breccia bodies (Mistamisk Complex) were emplaced in the Uvé Formation between Du Chambon Lake and the Romanet River (sheets 24B05 and 24C08) (Kearvell, 1985; Clark, 1986; Kearvell and Clark, 1988).
Paleontology
Dolomites of the Uvé Formation locally exhibit cryptalgal and algal structures (stromatolites) (Dimroth, 1978).
References
Publications Available Through SIGÉOM Examine
BROUILLETTE, P., 1989. GEOLOGIE ET METALLOGENIE DE LA REGION DES LACS MINOWEAN ET DU PORTAGE (FOSSE DU LABRADOR). MRN; ET 88-06, 84 pages, 2 plans.
CLARK, T., 1984. GEOLOGIE DE LA REGION DU LAC CAMBRIEN – TERRITOIRE DU NOUVEAU-QUEBEC. MRN; ET 83-02, 77 pages, 1 plan.
CLARK, T., 1986. GEOLOGIE ET MINERALISATIONS DE LA REGION DU LAC MISTAMISK ET DE LA RIVIERE ROMANET. MRN; ET 83-22, 56 pages, 1 plan.
CLARK, T., WARES, R., 2004. SYNTHESE LITHOTECTONIQUE ET METALLOGENIQUE DE L’OROGENE DU NOUVEAU-QUEBEC (FOSSE DU LABRADOR). MRNFP; MM 2004-01, 182 pages, 1 plan.
CORRIGAN, D., SAPPIN, A.-A., HOULÉ, M. G., RAYNER, N., VAN ROOYEN, D. 2020. Corrugated Hills: les restes d’une grande province ignée d’environ 2,17 Ga dans la Fosse du Labrador. In Résumés des conférences et des photoprésentations, Québec Mines+Énergie 2019. MERN; DV 2019-01, 78 pages.
DIMROTH, E., 1965. GEOLOGIE DE LA REGION DU LAC OTELNUK, TERRITOIRE DU NOUVEAU-QUEBEC. MRN; RP 532, 30 pages, 1 plan.
DIMROTH, E., 1965. PRELIMINARY REPORT, GEOLOGY OF OTELNUK LAKE AREA, NEW QUEBEC TERRITORY. MRN; RP 532(A), 27 pages, 1 plan.
DIMROTH, E., 1969. GEOLOGIE DE LA REGION DU LAC CASTIGNON, TERRITOIRE DU NOUVEAU-QUEBEC. MRN; RP 571, 62 pages, 7 plans.
DIMROTH, E., 1969. PRELIMINARY REPORT, GEOLOGY OF THE CASTIGNON LAKE AREA, NEW QUEBEC TERRITORY. MRN; RP 571(A), 58 pages, 7 plans.
DIMROTH, E., 1972. STRATIGRAPHY OF PART OF THE CENTRAL LABRADOR TROUGH. MRN; DP 154, 304 pages, 6 plans.
DIMROTH, E., 1978. Région de la fosse du Labrador entre les latitudes 54° 30′ et 56° 30′. MRN; RG 193, 417 pages, 16 plans.
DRESSLER, B., 1973. GEOLOGIE DE LA REGION DU LAC PATU, TERRITOIRE DU NOUVEAU-QUEBEC. MRN; RP 603, 26 pages, 1 plan.
DRESSLER, B., CIESIELSKI, A., 1979. Région de la fosse du Labrador. MRN; RG 195, 136 pages, 14 plans.
KEARVELL, G., 1985. BRECHES ET ALTERATIONS ALBITIQUES DE LA RIVIERE ROMANET-FOSSE DU LABRADOR. MRN; DP-85-24, 2 plans.
KEARVELL, G., CLARK, T., 1987. ETUDE D’INDICES Au – U ET DE BRECHES POLYGENIQUES DANS LA VALLEE DES LACS MISTAMISK ET ROMANET – FOSSE DU LABRADOR -. MRN; DP-87-24, 32 pages, 1 plan.
KISH, L., TREMBLAY-CLARK, P., 1978. GEOCHIMIE ET RADIOACTIVITE DANS LA FOSSE DU LABRADOR. MRN; DPV 567, 73 pages.
Other Publications
BARAGAR, W.R.A., 1967. Wakuach Lake map-area, Quebec-Labrador (23O). Geological Survey of Canada; Memoir 344, 174 pages. https://doi.org/10.4095/123960
CLARK, T. Unpublished report. Géologie de la région du lac Patu – Territoire du Nouveau-Québec. MRN.
DIMROTH, E., 1968. The evolution of the central segment of the Labrador geosyncline; part I: stratigraphy, facies and paleogeography. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen; volume 132, pages 22-54.
DIMROTH, E., 1970. Evolution of the Labrador Geosyncline. Geological Society of America Bulletin; volume 81, pages 2717-2742. https://doi.org/10.1130/0016-7606(1970)81[2717:EOTLG]2.0.CO;2
ROHON, M.-L., VIALETTE, Y., CLARK, T., ROGER, G., OHNENSTETTER, D., VIDAL, P., 1993. Aphebian mafic-ultramafic magmatism in the Labrador Trough (New Quebec): its age and the nature of its mantle source. Canadian Journal of Earth Sciences; volume 30, pages 1582-1593. https://doi.org/10.1139/e93-136
Suggested Citation
Ministère de l’Énergie et des Ressources naturelles (MERN). Uvé Formation. Quebec Stratigraphic Lexicon. https://gq.mines.gouv.qc.ca/lexique-stratigraphique/province-de-churchill/formation-uve_en [accessed on Day Month Year].
Contributors
First publication | Charles St-Hilaire, GIT, M.Sc. charles.st-hilaire@mern.gouv.qc.ca; Thomas Clark, P. Geo., Ph.D. (redaction) Mehdi A. Guemache, P. Geo., Ph.D. (coordination); Claude Dion, Eng., M.Sc. (critical review); Simon Auclair, P. Geo., M.Sc. (editing); Céline Dupuis, P. Geo., Ph.D. (English version); André Tremblay (HTML editing). |