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Langelier Complex
Stratigraphic label: [arch]lgl
Map symbol: Algl

First published: 24 May 2018
Last modified: 30 April 2019

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Translation of original French

 

 

Informal subdivision(s)
Numbering does not necessarily reflect the stratigraphic position.
 
Algl4 Intrusive breccia with tonalite and diorite fragments
Algl3 Foliated biotite-hornblende ± magnetite tonalite, locally gneissic
Algl2 Diorite, local hornblende-quartz ± biotite diorite, with local amphibolite enclaves
Algl1 Tonalitic to granitic or hornblende-biotite dioritic gneiss, gneissic tonalite, migmatite
Algl Mixed unit of biotite-hornblende ± magnetite tonalite, gneissic tonalite and tonalitic to dioritic gneiss
 
Author:Goutier et al., 1998
Age:Archean
Reference section: 
Type area:The reference section proposed by Goutier et al. (1999b) follows the James Bay Highway in NTS sheet 33F03. At two locations, tonalite was sampled for U-Pb isotopic dating.Another important section is in the Shpogan Lake area (sheet 33F03). The relationship between the oldest granitic gneiss dated from the La Grande Subprovince (3452 ±16 Ma; Davis et al., 2015) and the unconformable stratigraphic relationship with the neoarchean Apple Formation (Davis et al., 2015).
Geological province:Superior Province
Geological subdivision:La Grande Subprovince
Lithology:Gneiss, migmatite, diorite and deformed tonalite
Unit type:Lithodemic
Rank:Complex
Status:Formal
Use:Active

 

 

Background

Gneiss, migmatite, diorite and deformed tonalite were grouped into a new complex called the Langelier Complex due to the abundance of these rocks in NTS sheet 33F03 of the lake of the same name. This complex was defined following geological mapping in sheet 33F (Goutier et al., 1998a, 1998b, 1999a and 1999b) and particularly in sheet 33F03 (Goutier et al., 1999b). In sheet 33F03, subunits Algl1, Algl2 and Algl3 are present and the stratigraphic relationship between granitic gneiss and the Apple Formation is observed (Davis et al., 2015). Subsequently, the work of Goutier et al. (2000, 2001 and 2002) led to the extension of this unit to the east.

Bandyayera et al. (2011) first described the fourth informal subdivision of the complex (unit Algl4). Subsequently, Simard and Lafrance (2011) identified the Langelier Complex in sheets 33J and 33K. The latest work on the Langelier Complex is Hammouche et al. (2017) and Goutier et al. (in preparation).

Description

The Langelier Complex represents all the oldest rocks in the La Grande Subprovince, which are divided into five units. The first subdivision (Algl) contains tonalite and tonalitic to dioritic gneiss. The second (Algl1) consists of a tonalitic gneiss and a granitic gneiss (2811 ±2 Ma, 3452 ±16 Ma). The third unit (Algl2) is minor and consists of granoblastic diorite that forms discontinuous bands. The fourth unit, designated Algl3, is the dominant unit and consists of hornblende and biotite tonalite (2796.5-2788 Ma) foliated to gneissic. The last and fifth unit, restricted to sheet 33G10, is a magmatic breccia. 

 

Langelier Complex (Algl): Mixed Unit of Biotite-Hornblende ± Magnetite Tonalite, Gneissic Tonalite and Tonalitic to Dioritic Gneiss

The first unit corresponds to lithological variations ranging from foliated biotite tonalite to biotite and hornblende tonalitic gneiss. These variations are too narrow to be mapped (Goutier et al., 2001a). Bandyayera et al. (2011) also noted breccia in this unit. 

 

Langelier Complex 1 (Algl1): Tonalitic to Granitic or Hornblende-Biotite Dioritic Gneiss, Gneissic Tonalite, Migmatite

The gneiss is composed of grey to white bands of tonalitic composition of millimetre to centimetre thickness, alternating with ferromagnesian bands of hornblende and biotite. Locally, some felsic bands are granodioritic to granitic. The grain size varies from fine to medium. Mafic bands are less abundant than felsic bands and are generally in negative relief (Goutier et al., 1999b). Some mafic bands can be several metres thick (Goutier et al., 1998a). Locally, bands of fine-grained and granoblastic diorite alternate with gneiss (Goutier et al., 2000).

In sheets 33F15 and 33F16, a hornblende dioritic gneiss has been defined as belonging to unit Algl1. This dioritic gneiss is interbedded in the tonalitic gneiss. A variation is visible according to the mineralogical composition of the diorite which is poor in quartz and potassium feldspar. The dioritic gneiss is of darker grey to greenish, with medium-grained plagioclase, hornblende, biotite, magnetite and epidote. Its banded structure is pronounced and the mafic bands can be composed of up to 50% hornblende (Goutier et al., 2001a). These bands are generally millimetric to centimetric and alternate with pale grey and whitish bands rich in plagioclase. Gneiss is migmatized (Goutier et al., 2001b).

The gneissic tonalite is present in the northeast quarter of sheet 33G. It consists of alternating millimetric to centimetric bands rich in biotite and hornblende (<15%) with whitish bands richer in plagioclase (<50%). This gneissic tonalite is intruded into an older banded tonalite (Bandyayera et al., 2011). The banded tonalite is composed of mostly tonalitic, but locally granodioritic grey-white centimetric bands alternating with bands of more mafic composition. These bands can be up to 40 m thick. This banding is underlined by late intrusions of tonalite, granodiorite, diorite and aplite along gneissosity planes. This rock was not migmatized as there was no evidence of partial melting (Bandyayera et al., 2011).

Locally, unit Algl1 can hold about 5% metric highly deformed locally banded amphibolite enclaves, with amphibole crystals and plagioclase parallel to foliation. The proportion of enclaves increases to as much as 20% near the breccia unit Algl4.

 

Langelier Complex 2 (Algl2): Diorite, Local Hornblende-Quartz ± Biotite Diorite, with Local Amphibolite Enclaves

The hornblende quartz diorite defined by Goutier et al. (1999b) is medium grained and dark grey. It is locally porphyritic with plagioclase phenocrystals. It is rich in coarse amphibolite enclaves with a shiny green tint. This band is, in some places, closely linked to the surrounding gneiss making it difficult to separate them (Goutier et al., 1998a). It is generally found in metric bands within other units.

 

 

Langelier Complex 3 (Algl3): Foliated Biotite-Hornblende ± Magnetite Tonalite, Locally Gneissic

Hornblende and biotite tonalite has foliation that can show a gneissic structure (Goutier et al., 2001a). It is fine to medium grained and granoblastic. The rock is greyish to pinkish white. It is low in K-feldspar (<10%) while hornblende, biotite and epidote make up 30% of the rock. However, in some places, tonalite is less rich in ferromagnesian minerals (33F03 and 33F06; Goutier et al., 1998a). Chlorite, sphene and magnetite can be observed. Different variations of unit Algl3 are identified based on the abundance of hornblende and biotite in the rock.

The foliated tonalite (Algl3) contains metric to decametric biotite tonalitic gneiss (Algl1) enclaves indicating a younger age for unit Algl3. Amphibolite enclaves are also present. These could have a lateral extension of 100 m to 1 km per 100 m to 500 m wide. The enclaves are few in the unit, but are strongly foliated that is to say banded and epidotised. Due to their size and composition, they were attached to the Guyer Group amphibolite unit mAgy1 (Bandyayera et al., 2011).

This unit is located on the edge of contact with the Guyer Group and the tonalite is then banded, mylonitic or even gneissic. This implies an area of deformation between the two units (Goutier et al., 2001b). Quartz is then banded and plagioclase is porphyroclastic. The latter is present in small amounts (<7%), as is the case for biotite (2-10%) that appears on the surface as aggregate lenses in negative relief.

 

Langelier Complex 4 (Algl4): Intrusive Breccia with Tonalite and Diorite Fragments

This unit is defined by Bandyayera et al. (2011). It is an intrusive breccia with fragments of tonalite, diorite and ultramafic to mafic rocks. This unit is heterogeneous with fragmented material representing 30 to 90% of the rock. Multiple intrusions of diorite and tonalite also define this unit. The composition of the fragments varies greatly. The majority of fragments are 1 to 40 cm wide and 5 to 80 cm long, but can be angular to rounded without particular orientation. The mafic and ultramafic fragments have metasomatic aureoles locally. The composition of the matrix varies from tonalitic to dioritic and undergoes polyphase brecciation marked by several magmatic intrusions of dioritic or tonalitic nature. Finally, in deformation zones, the fragments are stretched, flattened and realigned according to the surrounding host rock fabric. Some of the fragments are foliated indicating an early deformation phase in the brecciation phase. 

Thickness and Distribution

The Langelier Complex occupies a very large part of the Eeyou Istchee James Bay territory (sheets 33F, 33G, 33H, 33J and 33K), covering an area of nearly 8,000 km².

UnitArea (km²)
Algl1086
Algl11720
Algl2280
Algl34814
Algl494
Total

7994

 

Dating

The ages shown in the table below are based on U-Pb dating taken mostly from tonalite or tonalitic gneiss samples. The Langelier Complex is dated 3452 to 2788 Ma (Davis et al., 2014). The most recent age of 2760 Ma is interpreted as an episode of metamorphism that affected the bedrock lithologies prior to the emplacement of volcano-sedimentary sequences (Goutier et al., 1999b).

Isotopic System

Mineral

Age (Ma)

(+)

(-)

References

U-Pb

Titanite

2760

2

2

Goutier et al., 1999

U-Pb

Zircon

2788

4

4

Goutier et al., 1999

U-Pb

Zircon

2794

2

2

Goutier et al., 1999

U-Pb

Zircon

2796,5

5,3

5,3

David et al., 2018

U-Pb

Zircon and sphene

2811,4

2,4

2,4

Mortensen et Ciesielski, 1987

U-Pb

Zircon

2832

5

5

Goutier et al., 1998

U-Pb

Zircon

3431

1,2

1,2

Davis et al., 2014

U-Pb     

Zircon

3452

16

16

Davis et al., 2014

 

Stratigraphic Relationship(s)

The Langelier Complex is interpreted as the bedrock and corresponds to a very ancient event. As a result, other formations are generally intrusive into the complex or are delimited by shears. However, the Apple Formation (nAap) conformably lies on rocks of the Langelier Complex (Goutier et al., 1999b). At the edge of contact with the Guyer Group amphibolites (mAgy1) in sheets 33G05 and 33G11 (Goutier et al., 2002) and 33G07 and 33G10 (Bandyayera et al., 2011), the foliated tonalite (Algl3) shows a banded, mylonitic or even gneissic structure indicating an area of major deformation or shear between the two units. Quartz is then in the form of ribbons and plagioclase is porphyroclastic. The contact area also contains several mafic and felsic dykes that are either boudinaged or transposed following banding. The unit Algl3 tonalite located just south of the Griault Belt (Agri) contains volcano-sedimentary rock enclaves belonging to this belt; this indicates that the tonalite is younger (Simard & Lafrance, 2011). If rocks of the Griault Belt are coeval to the Yasinski Group (nAya), which conformably lie on the Apple Formation, unit Algl3 tonalite would be related to a much younger tonalitic magmatic event than that of the Langelier Complex.

Finally, many decimetric to metric dykes cut rocks of the Langelier Complex. The most common are granodiorites, pegmatic granites and lamprophyres. 

Paleontology

Does not apply.

References

Author(s)TitleYear of PublicationHyperlink (EXAMINE or Other)
BANDYAYERA, D. – BURNIAUX, P. – MORFIN, S.Géologie de la région du lac Brune (33G07) et de la baie Gavaudan (33G10). Ministère des Ressources naturelles et de la Faune, Québec; RP-2011-01, 25 pages, 2 plans.2011RP 2011-01
DAVID, J. – BANDYAYERA, D. – HAMMOUCHE, H. – LECLERC, F. – GOUTIER, J. – TALLA TAKAM, F.Datations U-Pb dans la Province du Supérieur effectuées au GEOTOP en 2015-2016. Ministère de l’Énergie et des Ressources naturelles, Québec; MB 2018-16, 24 pages.2018MB 2018-16
DAVIS, D. W. – SIMARD, M. – HAMMOUCHE, H. – BANDYAYERA, D. – GOUTIER, J. – PILOTE, P. – LECLERC, F. – DION, C.Datations U-Pb effectuées dans les provinces du Supérieur et de Churchill en 2011-2012.. Ministère de l’Énergie et des Ressources Naturelles et Geochronological Laboratory, Québec; RP 2014-05, 62 pages.  2014RP 2014-05
GOUTIER, J. – DOUCET, P. – DION, C. – BEAUSOLEIL, C. – DION, D.J.Géologie de la région du lac Esprit (SNRC 33F/05). Ministère des Ressources naturelles du Québec; RG 98-09, 41 pages, 1 plan.1998bRG 98-09
GOUTIER, J. – DOUCET, P. – DION, C. – BEAUSOLEIL, C. – DAVID, J. – PARENT, M. – DION, D.J.Géologie de la région lac Kowskatehkakmow (SNRC 33F/06). Ministère des Ressources naturelles du Québec; RG 98-16, 50 pages, 1 plan.1998aRG 98-16
GOUTIER, J. – DION, C. – DAVID, J. – DION, D.J.Géologie de la région de la passe Shimusuminu et du lac Vion (SNRC 33F/11, 33F/12). Ministère des Ressources naturelles du Québec; RG 98-17, 43 pages, 2 plans.1999aRG 98-17
GOUTIER, J. – DION, C. – LAFRANCE, I. – DAVID, J. – PARENT, M. – DION, D.J.Géologie de la région des lacs Langelier et Threefold. Ministère des Ressources naturelles du Québec; RG 98-18, 54 pages, 2 plans.1999bRG 98-18
GOUTIER, J. – DION, C. – OUELLET, M.C. – DAVID, J. – PARENT, M.Géologie de la région des lacs Guillaumat et Sakami (33F/02 et 33F/07). Ministère des Ressources naturelles du Québec; RG 99-15, 40 pages, 2 plans.2000RG 99-15
GOUTIER, J. – DION, C. – OUELLET, M.C. – MERCIER-LANGEVIN, P. – DAVIS, D.W.Géologie de la colline Masson (33F/09), de la passe Awapakamich (33F/10), de la baie Carbillet (33F/15) et de la passe Pikwahipanan (33F/16). Ministère des Ressources naturelles du Québec; RG 2000-10, 69 pages, 4 plans.2001aRG 2000-10
GOUTIER, J. – DION, C. – OUELLET, M.-CGéologie de la région de la colline Bezier (33G/12) et du lac de la Montagne du Pin (33G/13). Ministère des Ressources naturelles du Québec; RG 2001-13, 55 pages, 2 plans.2001bRG 2001-13
GOUTIER, J. – DION, C. – OUELLET, M.-C. – DAVIS, D.W. – DAVID, J. – PARENT, M.Géologie de la région du lac Guyer (33G/05, 33G/06 et 33G/11). Ministère des Ressources naturelles du Québec; RG 2001-15, 55 pages, 3 plans.2002RG 2001-15
GOUTIER, J. – GIGON, J. – BURNIAUX, P. – DION, C. – TALLA TAKAM, F. – CHARTIER-MONTREUIL, W. – BANDYAYERA, D.Géologie de la région du lac de la Corvette, Eeyou Istchee Baie-James (33G01 33G02 33G08 33H04 33H05). Ministère de l’Énergie et des Ressources naturelles, Québec.In preparation
HAMMOUCHE, H. – BURNIAUX, P. – KHARIS, A.A.Géologie de la région du lac des Vœux (SNRC 33H10, 33H15 et 33H16), municipalité d’Eeyou Istchee Baie-James. Ministère de l’Énergie et des Ressources naturelles et l’Université du Québec de l’Abitibi-Témiscamingue, Québec; RG 2016-01, 39 pages, 2 plans. 2017RG 2016-01
MORTENSEN, J. K. – CIESIELSKI, A. U-Pb zircon and sphene geochronology of Archean plutonic and orthogneissic rocks of the James Bay region and Bienville Domain, Quebec. In: Radiogenic Age and Isotopic Studies; Report 1. Geological Survey of Canada; Paper 87-2, pages 129-134.1987
SIMARD, M. – LAFRANCE, I.Géologie de la région du lac Kinglet (SNRC 33J-33K01 et 33K02). Ministère des Ressources naturelles et de la Faune, Québec. RG 2011-05, 47 pages, 1 plan.2011RG 2011-05

 

12 novembre 2018