Article Versions
Export Article
Cite this article
  • Normal Style
  • MLA Style
  • APA Style
  • Chicago Style
Research Article
Open Access Peer-reviewed

Preserved Sedimentary Features in the Pan-African High-Grade Metamorphic Rocks from the Yaoundé Series (Cameroon)

Milan Stafford Tchouatcha , Arnaud Patrice Kouske, Evine Laure Tanko Njiosseu, Paul Aubin Ngouem, Timoleon Ngnotue, Divine Ngong Njinchuki, Jean Paul Nzenti
Journal of Geosciences and Geomatics. 2018, 6(3), 94-102. DOI: 10.12691/jgg-6-3-1
Received July 13, 2018; Revised August 27, 2018; Accepted September 05, 2018

Abstract

The ortho- and paraderived metamorphic formations of the Yaoundé series belong to the southern domain of the North Equatorial Pan-African Fold Belt. Para-derived formations of granulitic facies, which, unlike the other granulitic domains in the world, still contain preserved sedimentary features. These include the lithological banding which constitutes intercalation of garnet and kyanite-rich gneisses and quartzites, sometimes bedded, this banding of sedimentary origin is accentuated by the D1 tangential deformation which transposes the S0 bedding into foliation; the P1 intrafolial folds with horizontal fold axis and parallel to the bedding; lenticular structures marked by horizontal quartzite veins or boudins parallel to S0/S1 or S0/S1/S2 foliations, intercalated between the garnet and kyanite-rich gneisses, and sometimes lenses of garnet and kyanite-rich gneisses intercalated between the quartzites. They are either syn-D1 (quartzite or banded quartzite) sometimes transposing S0 stratification, or syn-D2 (quartzite, garnet-rich quartzite, granitic leucosome) linked to the in-situ partial melting of the garnet and kyanite-rich gneisses. The post-metamorphic and recent rock splitting, in contact with banded quartzite, quartzitic gneiss and other gneiss types, reflects an original pile of sedimentary formations of varied composition. The brittle (competent) behaviour of quartzite compared to the garnet and kyanite-rich gneisses which is rather ductile suggests the original pelitic nature for the garnet and kyanite-rich gneisses and sandstone for quartzites.

1. Introduction

Sedimentary structures are valuable elements in the reconstitution of deposit environments, this is the case for most post-orogenic sedimentary basin, Cretaceous basins 1, 2, 3. In Cameroon 4 and some surrounding countries, as Congo 5, 6, Central African Republic 7, 8, Gabon 7, 9, these sedimentary structures are still preserved in the Precambrian deposits spared from the Pan-African orogeny. These structures are also sometimes preserved in granulitic facies of paraderived metamorphic rocks. This is the case in the Yaoundé series related to the Pan-African orogeny. The North-Equatorial Pan-African Fold Belt 10 or Neoproterozoic Central African Orogenic Belt 11 represents one of the most important suturing orogens, as its deformation history is critical for the Gondwanaland reconstitution 11. It is made up of juxtaposed rock Units of varying crustal levels that are considered to represent imbricate large, crystalline, south-directed Yaoundé nappes emplaced onto the Congo craton 10, 12, 13, 14, 15, 16, 17, 18.

Inspite of indications of collisional tectonics such as intense migmatisation and high- pressure granulite 10, 19, the existence of South-verging, large, crystalline Yaoundé nappes remains controversial because no clear evidence for either thrust faults or suture marking a north-south oceanic closure has yet been found in the area, and the nappes are inconsistent with a regional non-mylonitic flat-laying composite S1/S2 foliation 11.

Thus, our study area is located to the southern part of this Pan-African North Equatorial Fold Beld in the Yaoundé series 10, 14, belonging to the Yaoundé group. In this region, several works have been carried out with the aims to constrain the origin or tectono-metamorphic evolution of these gneisses 10, 11, 20, 21, 22. The studied outcrops of this series are paraderived granulitic facies rocks 10 made up of essentially kyanite and garnet rich gneiss. Despite their granulitic character, they are marked by some structures remembering their sedimentary origin.. The aims of this paper is to highlight the sedimentary protolith evidence of gneiss and quartzite of the Yaoundé series from observed structures, as tabular to sub-tabular bedding, lenticular structures, horizontal or interstratified fissures or fractures, lithological splitting and the difference of competence.

2. Geological Setting

The studied area (Figure 1b 11, 23, 24) is located in the southern part of the Pan-African North-Equatorial Fold Belt in Cameroon 10 at south of the Central Cameroon Shear Zone 25. It belongs to the Yaoundé series 10, 16. This series includes chlorite- rich schists, garnet- and (or) kyanite rich micaschistes, and garnet- and kyanite or garnet- and plagioclase or garnet and two micas rich high grade gneisses sometimes comprising lenticular levels or intercalation of calc-silicated rocks, marble, and quartzite 10, 26, or interbedded with talcschist rocks 27. Their protoliths are the sedimentary rocks that include pelites, greywackes, dolomite and evaporite with interstratified basic volcanic layers 10, 26, 28, 29. The metasedimentary rocks are locally intruded by meta-igneous rocks formed by pyriclasites and pyroxenites 10, 30. The protolith of the rocks from the Yaoundé series is composed of a mixture of Neoproterozoic and Paleoproterozoic sources 31, 32, 33, 34. The whole of the sedimentary sequence and the isotopic data suggest the existence of a continental basin or a shallow epicontinental environment on the northern edge of Congo craton 10, 26, 30, 35, or a marginal back-arc basin that underwent collisional tectonic 19, 28, 34. These rocks are commonly thought to have experienced a Neoproterozoic nappe tectonic event that is transpressional and responsible for thrusting the large Yaoundé nappe onto to Congo craton 16, 17. The rocks of this series have been affected by two major or main ductile deformation events D1 and D2 10, 11, 30, 37, D1 laid to the formation of nappes that resulted in high pressure granulite metamorphism of soft sediments and D2 is marked by a southern thrusting of the rocks onto the Archean Congo craton. They were further buckled by D3 and D4 folding phases (Figure 2A) 11. To these ductile or folding phases, are associated ductile-brittle to brittle phases as C2 and C3 shear zones with either dextral or sinistral movements, and the D4 phase characterized by various oriented joints and veins 38. The conditions of paroxysmal metamorphism of the Yaoundé series are evaluated at 650 – 800°C and 9 – 12Kb 10, 14, 19, 20, 27, 29, 37.

The granulite facies or metasediment of the Yaounde series have been metamorphosed at 620 ± 10 Ma (U-Pb age zircon 31) or at 616 Ma (U-Pb age on zircon and Sm – Nd 32) and between 613 ± 33 Ma and 586 ± 15 Ma (Th - U – Pb age on monazite 39. The leucosomes was melting between 592 – 558 Ma (U – Th – Pb monazite ages) and between 626 – 654 Ma (U – Pb zircon ages), and the metasediment (host rock of leucosomes) reveals the overprinting of Pan-African age, around 911 Ma (U – Pb zircon age) and of Palaeoproterozoic age, around 2127 Ma (U – Pb zircon age) 22.

3. Methods

Field works consisted in the identification of the different structural elements and recording their structural attitude (strike, dip, and dip direction) in the para-derivated gneisses, followed by sampling of the different rock facies. A chronological analysis of these elements was subsequently established. Twelve thin sections were manufactured at the LTM Nkolbisson Laboratory (Cameroon) and studied under polarized microscope at the Laboratory of Petrology and Structural Geology in the University of Yaoundé 1, Cameroon.

4. Results

4.1. Bedding

Bedding constitutes, from place to place, either banded quartitze (Photo G, Figure 3), or an intercalation of kyanite and garnet- rich gneiss, quartzite and leucocratic gneiss (Photo F, Figure 4) with a varying thickness of either quartzite from 3mm to 10 cm, and leucocratic gneiss from 3 to 17 cm and that of kyanite and garnet-rich gneiss are pluricentrimetric to plurimetric. The disposition of the beds are either repetitive (only quartzite or quartzite and gneiss) or composite (quartzite, garnet and kyanite-rich gneiss and leucocratic gneiss). Generally, they have gentle dip (0 - 20°). The mineralogical composition of the garnet- and kyanite- rich gneiss is as follows: Garnet (10 –30 %) kyanite (5 -10%) with other minerals such as biotite (10 – 15%), feldspars are dominated by microcline (10 – 20%), quartz (60 – 65%), rutile <1%) and muscovite <1%, generally displaying a granoblastic microstructure, oriented and heterogranular sometimes with granolepidoblastic tendency. Meanwhile leucocratic gneiss (dominated by quartz with a proportion of 60 – 65%, with garnet, <1.5%; kyanite, 2% and 3%; biotite, 3– 5%; muscovite, < 1%; feldspath dominated by microcline 15 – 25%; rutile, 1<%) and quartzites display an oriented granoblastic heterogranular microstructure. Grain size is variable, fine to medium (quartzite and leucocratic gneiss), and medium to coarse (kyanite- and garnet-rich gneiss).

4.2. Lenticular Structure with Pseudo-boudins

The lenticular structure is underlined either by quartzite veins sometimes sigmoid (Photos A and B, Figure 3) intercalated within the garnet and kyanite-rich gneisses, of pluricentimetric to decimetric thickness, and of metric to plurimetric length, the lenses of kyanite and garnet-rich gneisses (Photo F, Figure 3) intercalated within the quartzites, of centimetric to pluricentimetric thickness and pluridecimetric length and the pluridecimetric lenses or pseudo-boudins of garnet-bearing quartzite within the garnet and kyanite-rich gneisses (Photo E, Figure 5). These lenses are all parallel to the foliation or banding, and the contact with the host is generally sharp.

4.3. Lithological Splitting

The phenomenon of lithological flaking (Photos C and E, Figure 3) is quite conspicuous and can be observed either in contact with facies of different mineralogical composition (garnet-kyanite-rich gneiss and leucocratic gneiss or quartzite), or between the bedded quartzite bands. The cleavage surfaces or planes are sharp.

4.4. Difference in Competence

Locally, the outcrops of garnet and kyanite-rich gneisses with quartzite beds or veins show different deformation behaviour (Photos B and D, Figure 3). The quartzite bands are affected by vertical and horizontal fracture networks which almost or not affect the gneissic surrounding, thus highlighting the process of competence associated to the difference in the nature of the facies. If the origin or genesis of these two types of fractures is questionable, the average trend of the vertical fracture plane network corresponds to that of the major average trend of the fractures affecting the entire study area.

  • Figure 3. Field photographs of different identified structures, A: Fractured quartzite vein in the kyanite and garnet rich gneiss; B: Fractured and sigmoid lenticular quartzite in the kyanite and garnet rich gneiss; C: Spliting affecting banded quartzite and gneiss; D: Vertical fracture network; E: Level splitting affecting various gneiss (1 and 3: leucocratic gneiss, 2 and 4: garnet and kyanite-rich gneiss); F: Lenticular gneiss interbedded in the quartzite, and the whole are interstratified in the gneiss (1 and 5: garnet and kyanite rich gneiss, 2 and 4: quartzite, 3: garnet and kyanite-rich gneiss lenses; G: Banded quartzite interstratified in the Kyanite and garnet rich gneiss (S0/S1); H: Network of P1 intrafolial fold with horizontal axis associated with S1 foliation

5. Discussion

The low dip in bedding or foliation of granulitic formations (Para- and ortho- derives) in Yaoundé is attributed to tangential deformation D1 11, 16. Garnet and kyanite-rich gneiss are of sedimentary origin with pelitic protolith 10, 21, 22, affected by granitic leucosomes associated to the in-situ partial melting of metapelites, and injected linked to the melting of greywakes 22. However, field and petrographic data show that bedding is sometimes repetitive or composite (garnet and kyanite rich gneisses, leucocratic gneisses, quartzites) and with grains of variable size, on the other hand, this bedding is clear in the para-derivated rocks contrary to ortho-derivated rocks. Furthermore, in addition to the intra-folial folds (Photo H, Figure 3) with horizontal axis parallel to bedding, the presence of quartzite bands intercalated between the garnet- and kyanite- rich gneisses represent the elements in favour of a sedimentary origin of these facies, as well as their sub-horizontal to horizontal attitude which would be original accentuated by the tangential tectonics D1. The stereogram of the foliation planes S1/S2 (Figure 2A) does not only display a gentle dip, but also that they are folded during D3 or D3/D4 deformation phases.

Garnet and kyanite-rich gneisses are generally intercalated, as noted above, by quartzite veins and attributed to syn-D2 melting 16, 22. These veins are either in situ, parallel to the foliation, or injected, not parallel to the foliation, of granitic composition, and more recent, Neoproterozoic, than the host or surrounding rock, Neo- to Mesoproterozoic 22. New data and petrographic analyses show that garnet- and kyanite- gneisses are also intercalated by garnet quartzite veins and pure quartzite, and are always parallel to the foliation. The fact that these veins are of variable mineralogical composition, parallel to bedding or foliation, may therefore be linked on the one hand to in situ fusion according to the S0/S1 stratification plane, and on the other hand to in situ metamorphism of old sedimentary lenses (veins or lenses of arenaceous facies intercalated within the clayey facies). These structures are almost always present in non-metamorphosed Cretaceous sedimentary formations; sand or sandstone lenses in the clay layers or the reverse 1, 3, 40, 41.

The splitting that affects both gneisses and quartzite bands intercalating each other points to an original pile of sediments of different mineralogical composition, alternations of pelitic and sandy facies affected by a metamorphism with the preserved original bedding.

Finally, the diverse behaviour of the brittle deformation (vertical fractures) observed between the intercalated gneisses and quartzites is related to the lithological difference, although the two formations belong to the same granulitic facies, and the ductile nature of the pelitic protolith of the garnet and kyanite gneisses would have influenced these gneisses. This brittle deformation is recent according to its association with the major fractures, with the average trends of N155°E (Figure 2C and Figure 2D) that affects the entire study area, and these fractures occurred as a result of the relaxation of tectonic stresses during the Plio-Pleistocene exhumation of the Yaoundé massif 42. If vertical fractures are the expression of relaxation of tectonic stresses, interstratified (horizontal) fractures would be syn-metamorphic related to sediment piling during burial.

6. Conclusion

The metasediments of the Yaoundé series, although belonging to the granulitic facies, still retain structural elements recalling their sedimentary origin such as:

- Horizontal to sub-horizontal bedding or foliation (S0/S1 or S0/S1/S2);

- P1 intrafolial folds with horizontal fold axis;

- The lenticular structures underlined by veins and boudins parallel to the bedding or foliation linked on the one hand to the partial in situ fusion of the metasediments (Syn-D2), and on the other hand, undoubtedly, to the metamorphism of old pelitic and arenaceous lenses (Syn-D1) sometimes transposing S0;

- The lithological splitting indicating on the one hand, a stacking of the original materials of different mineralogical composition and on the other hand syn- sedimentary weakness planes to D1 phase;

- The phenomenon of rock competence indicates the original pelitic nature of garnet- and kyanite- rich gneisses and sandstone nature for quartzites.

Finally, the fracturing affecting these formations is recent and related to the relaxation of stresses during the exhumation of the massif.

Acknowledgments

The authors thank Dr Sylvestre Ganno for his constructive observations that improve the quality of this work.

References

[1]  Eyong, J.T. Lithostratigraphy of the Mamfe Cretaceous basin, South-west province of Cameroon-West Africa. Unpublished Ph.D thesis, University of Leeds, 256 p., 2003.
In article      
 
[2]  Ntamak-Nida, M.J., Baudin, F., Schnyder, J., Makong, J.C., Komguem, P.B., Abolo, G.M. Depositional environments and Characterization of the organic matter of the Lower Mundeck Formation (Barremian?-Aptian) of the Kribi-Campo sub-basin (South Cameroon): implications for petroleum exploration. Journal of African Earth Sciences, 51, 207-219, 2008.
In article      View Article
 
[3]  Tchouatcha, M.S. Les bassins du Mbéré et du Djerem dans le contexte régional Sud Adamaoua: genèse, évolution stratigraphique et reconstitution des paléoenvironnements. Thèse de Doctorat/Ph.D. Université de Yaoundé 1, 225p., 2011
In article      
 
[4]  Caron, V., Ekomane, E., Mahieu, G., Moussango, P., Ndjeng, E. The Mintom Formation (new): Sedimentology and geochemistry of a Neoproterozoic paralic succession in south-east Cameroon. Journal of African Earth Sciences 57, 4, 367-385, 2010.
In article      View Article
 
[5]  Alvarez, Ph. Evidence for Neoproterozoic carbonate ramp on the northern edge of the Central African craton: relations with Late Proterozoic intracratonic troughs. Geologische Rundschau 84, 3, 636-648, 1995.
In article      View Article
 
[6]  Préat, A., Delpomdor, F., Mfere Ackouala, P.A., Callec, Y. Paleoenvironment , δ13 and δ18 signatures in the Neoproterozoic carbonates of the Comba Basin, Republic of Congo: Implications for regional correlation and Marinoan event. Journal of African Earth Sciences, 137, 69-90, 2018.
In article      View Article
 
[7]  Alvarez, Ph. Repartition de la sedimentation dans le golfe proterozoique superieur du Schisto-Calcaire au Congo et au Gabon. Implications en Afrique Centrale. Palaeogeography, Palaeoclimatology and Palaeoecology, 96, 282-297, 1992.
In article      View Article
 
[8]  Poidevin, J.L. Stratigraphie isotopique du strontium et datations des formations carbonatées et glaciogeniques néoprotérozoïques du Nord et de l’Ouest du craton du Congo. Comptes Rendus Géosciences 339, 259-273, 2007.
In article      View Article
 
[9]  Préat, A., Kolo, K., Prian, J.P., Delpomdor, F. A peritidal evaporite environment in the Neoproterozoic of south Gabon (Schisto-Calcaire Subgroup, Nyanga Basin). Precambrian Research 177, 253-265, 2010.
In article      View Article
 
[10]  Nzenti, J.P., Barbey, P., Macaudière, J., Soba, D. Origin and evolution of the late Precambrian high-grade Yaoundé gneisses (Cameroun). Precambrian Research, 38: 91-109, 1988.
In article      View Article
 
[11]  Mvondo, H., Owona, S., Mvondo Ondoa, J., Essono, J. Tectonic evolution of the Yaounde segment of the Neoproterozoic Central African Orogenic Belt in southern Cameroon. Canadian Journal of Earth Sciences, 44, 433-444, 2007.
In article      View Article
 
[12]  Ball, E., Bard, J.P., Soba, D. Tectonique tangentielle dans la catazone pan-africaine du Cameroun: les gneiss de Yaoundé. Journal African Earth Sciences, 2 : 91-95, 1984.
In article      View Article
 
[13]  Jégouzo, P. Evolution structural du Sud-Ouest Cameroun durant l’orogenese Pan-Africaine. Association de tectonique cisaillante et chevauchante. Colloque C.N.R.S. Chevauchement et deformation, Toulouse, France, 23 p., 1984.
In article      
 
[14]  Nédélec, A., Macaudiere, J., Nzenti, J.P., Barbey, P. Evolution structural et métamorphique des schistes de Mbalmayo (Cameroun): implications pour la structure de la zone mobile panafricaine d’Afrique central au contact du craton du Congo. Comptes Rendus de l’Académie des Sciences Paris, 303 (III), 75-80, 1986.
In article      
 
[15]  Castaing, C., Feybesse, J.L., Thiéblemont, D., Triboulet, C., Chèvremont, P. Paleogeographical reconstructions of the Pan-African/Brasiliano orogen: closure of an oceanic domain or intracontinental convergence between major blocks? Precambrian Research, 69: 327-344, 1994.
In article      View Article
 
[16]  Ngako, V. Les déformations continentales panafricaines en Afrique centrale. Résultat d’un poinçonnement de type himalayen. Thèse de Doctorat d’État, Université de Yaoundé I, Cameroun, 1999.
In article      
 
[17]  Ngako, V., Affaton, P., Nnange, J.M., Njanko, T. Pan-African tectonic evolution in the central and southern Cameroon: transpressionand transtention during sinistral shear movements. Journal of African Earth Sciences, 36: 207-214, 2003.
In article      View Article
 
[18]  Toteu, S.F., Penaye, J.,Poudjom Djomani, Y.H. Geodynamic evolution of the Pan-African belt in central Africa with special reference to Cameroon. Canadian Journal of Earth Sciences, 41: 73-85, 2004.
In article      View Article
 
[19]  Mvondo, H., den Brok, S.W.J., Mvondo Ondoa, J. Evidence for symmetric extention and exhumation for the Yaoundé Nappe (Pan-African Fold Belt, Cameroon). Journal of African Earth Sciences, 36: 215-231, 2003.
In article      View Article
 
[20]  Nzenti, J.P., Barbey, P., Jegouzo, P., and Moreau, C. “Un Nouvel Exemple de Ceinture Granulitique dans une Chaine Protérozoïque de Transition : Les Migmatites de Yaoundé au Cameroun". Compte Rendu Academie des Sciencesde Paris, 299, 17, 1197-1199, 1984.
In article      
 
[21]  Nzenti, J.P. Prograde and retrograde zoning at high pressure and temperature in metapelitic and garnetite rocks from Yaoundé (Cameroon Pan-African north-equatorial fold belt). Journal of African Earth Sciences, 15: 73-79, 1992.
In article      View Article
 
[22]  Ngnotué, T., Ganno, S., Nzenti, J.P., Schulz, B., Tchaptchet Tchato, D., Suh Cheo, E. Geochemistry and geochronology of Peraluminous High-K Granitic Leucosomes of Yaoundé Series) Cameroon. Evidence for a Unique Pan-African Magmatism and Melting Event in North Equatorial Fold Belt. International Journal of Geosciences, 3, 525-548, 2012.
In article      View Article
 
[23]  Champetier de Ribes, G., Aubague, M. Carte géologique de reconnaissance au 1/500 000 , Notice explicative sur la feuille Yaoundé-est. Direction des Mines et de la Géologie, Yaoundé, Cameroun. Imprimerie Rébon, Paris, France, 1956.
In article      
 
[24]  Weecksteen, G. Carte géologique de reconnaissance à l’échelle du 1/500 000, feuille Douala-est avec notice explicative. Publication de la Direction des Mines et de la Géologie du Cameroun, 37p., 1957.
In article      
 
[25]  Ngako, V., Jegouzo, P., Nzenti, J.P. Le cisaillement Centre Camerounais. Role structural et géodynamique dans l’orogenèse panafricaine. Comptes Rendus Académiques des Sciences Paris 313, 457-463, 1991.
In article      
 
[26]  Ngnotué,T., Nzenti, J.P., Barbey, P., Tchoua, F.M. The Ntui-Betamba high-grade gneisses : a northward extention of the Pan-African Yaoundé gneisses in Cameroon. Journal of African Earth Sciences, 31: 369-381, 2000.
In article      View Article
 
[27]  Yonta-Ngouné, C., Nkoumbou, C., Barbey, P., Le Breton, N., Montel, J.M., Villieras, F. Geological context of the Boumnyebel talcschists (Cameroon): inferences on the Pan-African Belt of Central Africa. Comptes Rendus Geosciences, 342, 108-115, 2010.
In article      View Article
 
[28]  Stendal, H., Toteu, S.F., Frei, R., Penaye, J., Njel, U.O., Bassahak, J., Nni, J., Kankeu, B., Ngako, V., Hell, J.V. Derivation of detrital rutile in the Yaoundé region from the Neoproterozoic Pan-African belt in southern Cameroon (Central Africa), Journal of African Earth Sciences 44, 443-458, 2006.
In article      View Article
 
[29]  Owona, S., Mvondo Ondoa, J., Ratschbacher, L., Ndzana, M.P.S., Tchoua, F.M., Ekodeck, G.E. La géométrie de la tectonique archéenne, Paléo et néoprotérozoïque dans le Sud-Ouest du Cameroun. Comptes Rendus Geosciences, 343, 312-322, 2011.
In article      View Article
 
[30]  Nzenti, J.P. Pétrogenèse des migmatites de Yaoundé (Cameroun). Eléments pour un modèle géodynamique de la chaine Pan-Africaine nord-équatoriale. Thèse de Doctorat, Universite de Nancy I, France, 1987.
In article      
 
[31]  Penaye, J., Toteu, S.F., Van Schmus, W.R., Nzenti, J.P. U-Pb and Sm-Nd preliminary geochronologic data on the Yaoundé series, Cameroon: re-interpretation of the granulitic rocks as the suture of a collision in the “Centrafrican” belt. Comptes Rendus de l’Academie des Sciences de Paris, 317: 789-794, 1993.
In article      
 
[32]  Toteu, S.F., Van Schmus, W.R., Penaye, J., Nyobé, J.B. U-Pb and Sm-Nd evidence for Eburnian and Pan-African high-grade metamorphism in cratonic rocks of southern Cameroon. Precambrian Research, 67: 321-347, 1994.
In article      View Article
 
[33]  Toteu, S. F., Van, Schmus, W.R., Penaye, J., Michard, A. New U-Pb and Sm-Nd data from north-central Cameroon and its rich on the pre-Pan-African history of central Africa. Precambrian Research, 108, 45-73, 2001.
In article      View Article
 
[34]  Toteu, S.F., Yongue, Fouateu, R., Penaye, J., Tchakounte, J., Seme, Mouangue, A.C., Van Schmus, W.R., Deloule, E., Stendal, H. U-Pb dating of plutonic rocks involved in the nappe tectonic in southern Cameroon: consequence for the Pan-African orogenic evolution of the central African fold belt. Journal of African Earth Sciences 44, 479-493, 2006.
In article      View Article
 
[35]  Nzenti, J.P., Tchoua, F. Signification pétrogénétique des grenatites dans les migmatites de Yaoundé (Chaine Panafricaine North-Equatoriale au Cameroun). In Géosciences au Cameroun, Vicat J.P. et Bilong P., éditeurs, collection GEOCAM, I/1998, Université de Yaoundé I, 277-284, 1998.
In article      
 
[36]  Mvondo, H. Analyse structurale et pétrogéochimique des roches de la région de Yaoundé nord ; arguments contribuant à la connaissance de l’évolution géotectonique de la chaine Pan-Africaine au Cameroun. Thèse de Doctorat, Université de Yaoundé I, Cameroun, 2003.
In article      
 
[37]  Barbey, P., Macaudiere, J., Nzenti, J.P. High pressure dehydration melting of metapelites : evidence from the migmatites of Yaoundé (Cameroon). Journal of Petrology, 31 (2), 401-427, 1990.
In article      View Article
 
[38]  Metang, V., Nkoumbou, C., Tchakounte Numbem, J., Njopwouo, D. Application of Remote Sensing for the Mapping of Geological Structures in Rainforest Area: A case Study at the Matomb-Makak Area, Centre-South Cameroon. Journal of Geosciences and Geomatics, 2 (5), 196-207, 2014.
In article      
 
[39]  Owona, S., Schulz, B., Ratschbacher, L., Mvondo ondoa, J., Ekodeck, G.E., Tchoua, M.F., Affaton, P. Pan-African metamorphic evolution in the southern Yaounde group (Oubanguide Complex, Cameroon) as revealed by EMP- monazite dating and thermobarometry of garnet pelite. Journal of African Earth Sciences 59, 125-139, 2010.
In article      View Article
 
[40]  Njiké Ngaha, P. R. Contribution à l’étude géologique, stratigraphique et structurale de la bordure du bassin atlantique au Cameroun. Thèse de Doctorat 3eme cycle. Université de Yaoundé, 131 p., 1984.
In article      
 
[41]  Ndjeng, E. Etudes da la sédimentation et du modèle d’évolution géodynamique de deux bassins du Crétacé inferieur du Nord-Cameroun : Babouri-Figuil et Mayo Oulo-Léré. Thèse de Doctorat d’Etat. Université de Yaoundé, 311p., 1992.
In article      
 
[42]  Vicat, J.P., Mvondo, H., Willems, L., Pouclet, A. Phénomènes de karstiques fossiles et actuels au sein des formations métamorphiques silico-alumineuses de la nappe pan-africaine de Yaoundé (Sud-Cameroun). Comptes Rendus Géosciences 334, 545-550, 2002.
In article      View Article
 

Published with license by Science and Education Publishing, Copyright © 2018 Milan Stafford Tchouatcha, Arnaud Patrice Kouske, Evine Laure Tanko Njiosseu, Paul Aubin Ngouem, Timoleon Ngnotue, Divine Ngong Njinchuki and Jean Paul Nzenti

Creative CommonsThis work is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

Cite this article:

Normal Style
Milan Stafford Tchouatcha, Arnaud Patrice Kouske, Evine Laure Tanko Njiosseu, Paul Aubin Ngouem, Timoleon Ngnotue, Divine Ngong Njinchuki, Jean Paul Nzenti. Preserved Sedimentary Features in the Pan-African High-Grade Metamorphic Rocks from the Yaoundé Series (Cameroon). Journal of Geosciences and Geomatics. Vol. 6, No. 3, 2018, pp 94-102. http://pubs.sciepub.com/jgg/6/3/1
MLA Style
Tchouatcha, Milan Stafford, et al. "Preserved Sedimentary Features in the Pan-African High-Grade Metamorphic Rocks from the Yaoundé Series (Cameroon)." Journal of Geosciences and Geomatics 6.3 (2018): 94-102.
APA Style
Tchouatcha, M. S. , Kouske, A. P. , Njiosseu, E. L. T. , Ngouem, P. A. , Ngnotue, T. , Njinchuki, D. N. , & Nzenti, J. P. (2018). Preserved Sedimentary Features in the Pan-African High-Grade Metamorphic Rocks from the Yaoundé Series (Cameroon). Journal of Geosciences and Geomatics, 6(3), 94-102.
Chicago Style
Tchouatcha, Milan Stafford, Arnaud Patrice Kouske, Evine Laure Tanko Njiosseu, Paul Aubin Ngouem, Timoleon Ngnotue, Divine Ngong Njinchuki, and Jean Paul Nzenti. "Preserved Sedimentary Features in the Pan-African High-Grade Metamorphic Rocks from the Yaoundé Series (Cameroon)." Journal of Geosciences and Geomatics 6, no. 3 (2018): 94-102.
Share
  • Figure 1. (A) Geological map of Cameroon [22] and (B) Geological map of South Cameroon showing the main rock units [11,23,24]; and the location of the studied area
  • Figure 2. (A) Schematic models showing the different phases of deformation, D0 –D4, [11] (B) Stereogram of foliation planes and (C-D) stereogram of fracture planes of the studied area
  • Figure 3. Field photographs of different identified structures, A: Fractured quartzite vein in the kyanite and garnet rich gneiss; B: Fractured and sigmoid lenticular quartzite in the kyanite and garnet rich gneiss; C: Spliting affecting banded quartzite and gneiss; D: Vertical fracture network; E: Level splitting affecting various gneiss (1 and 3: leucocratic gneiss, 2 and 4: garnet and kyanite-rich gneiss); F: Lenticular gneiss interbedded in the quartzite, and the whole are interstratified in the gneiss (1 and 5: garnet and kyanite rich gneiss, 2 and 4: quartzite, 3: garnet and kyanite-rich gneiss lenses; G: Banded quartzite interstratified in the Kyanite and garnet rich gneiss (S0/S1); H: Network of P1 intrafolial fold with horizontal axis associated with S1 foliation
  • Figure 4. Field and microstructures photographs; A, B, C, D and E: oriented granoblastic heterogranular microstructure photographs (PL); F: vertical banded metamorphic rocks; 1, 4 and 6: Medium to coarse grained kyanite and garnet rich gneiss; 2: Fine to medium grained banded quartzite; 3 and 5: Medium grained leucocratic gneiss
  • Figure 5. Field and microstructure photographs A: oriented grano- to granolepidoblastic heterogranular microstructure (Garnet-kyanite-mica gneisses); B and C: Granoblastic more or less isogranular microstructure (garnet quartzite, A: PL; B: PPL); D: oriented grano- to granolepidoblastic heterogranular microstructure (Garnet-kyanite-mica gneiss); E: Elongated boudin of garnet rich quartzite in the garnet-kyanite-mica gneisses
[1]  Eyong, J.T. Lithostratigraphy of the Mamfe Cretaceous basin, South-west province of Cameroon-West Africa. Unpublished Ph.D thesis, University of Leeds, 256 p., 2003.
In article      
 
[2]  Ntamak-Nida, M.J., Baudin, F., Schnyder, J., Makong, J.C., Komguem, P.B., Abolo, G.M. Depositional environments and Characterization of the organic matter of the Lower Mundeck Formation (Barremian?-Aptian) of the Kribi-Campo sub-basin (South Cameroon): implications for petroleum exploration. Journal of African Earth Sciences, 51, 207-219, 2008.
In article      View Article
 
[3]  Tchouatcha, M.S. Les bassins du Mbéré et du Djerem dans le contexte régional Sud Adamaoua: genèse, évolution stratigraphique et reconstitution des paléoenvironnements. Thèse de Doctorat/Ph.D. Université de Yaoundé 1, 225p., 2011
In article      
 
[4]  Caron, V., Ekomane, E., Mahieu, G., Moussango, P., Ndjeng, E. The Mintom Formation (new): Sedimentology and geochemistry of a Neoproterozoic paralic succession in south-east Cameroon. Journal of African Earth Sciences 57, 4, 367-385, 2010.
In article      View Article
 
[5]  Alvarez, Ph. Evidence for Neoproterozoic carbonate ramp on the northern edge of the Central African craton: relations with Late Proterozoic intracratonic troughs. Geologische Rundschau 84, 3, 636-648, 1995.
In article      View Article
 
[6]  Préat, A., Delpomdor, F., Mfere Ackouala, P.A., Callec, Y. Paleoenvironment , δ13 and δ18 signatures in the Neoproterozoic carbonates of the Comba Basin, Republic of Congo: Implications for regional correlation and Marinoan event. Journal of African Earth Sciences, 137, 69-90, 2018.
In article      View Article
 
[7]  Alvarez, Ph. Repartition de la sedimentation dans le golfe proterozoique superieur du Schisto-Calcaire au Congo et au Gabon. Implications en Afrique Centrale. Palaeogeography, Palaeoclimatology and Palaeoecology, 96, 282-297, 1992.
In article      View Article
 
[8]  Poidevin, J.L. Stratigraphie isotopique du strontium et datations des formations carbonatées et glaciogeniques néoprotérozoïques du Nord et de l’Ouest du craton du Congo. Comptes Rendus Géosciences 339, 259-273, 2007.
In article      View Article
 
[9]  Préat, A., Kolo, K., Prian, J.P., Delpomdor, F. A peritidal evaporite environment in the Neoproterozoic of south Gabon (Schisto-Calcaire Subgroup, Nyanga Basin). Precambrian Research 177, 253-265, 2010.
In article      View Article
 
[10]  Nzenti, J.P., Barbey, P., Macaudière, J., Soba, D. Origin and evolution of the late Precambrian high-grade Yaoundé gneisses (Cameroun). Precambrian Research, 38: 91-109, 1988.
In article      View Article
 
[11]  Mvondo, H., Owona, S., Mvondo Ondoa, J., Essono, J. Tectonic evolution of the Yaounde segment of the Neoproterozoic Central African Orogenic Belt in southern Cameroon. Canadian Journal of Earth Sciences, 44, 433-444, 2007.
In article      View Article
 
[12]  Ball, E., Bard, J.P., Soba, D. Tectonique tangentielle dans la catazone pan-africaine du Cameroun: les gneiss de Yaoundé. Journal African Earth Sciences, 2 : 91-95, 1984.
In article      View Article
 
[13]  Jégouzo, P. Evolution structural du Sud-Ouest Cameroun durant l’orogenese Pan-Africaine. Association de tectonique cisaillante et chevauchante. Colloque C.N.R.S. Chevauchement et deformation, Toulouse, France, 23 p., 1984.
In article      
 
[14]  Nédélec, A., Macaudiere, J., Nzenti, J.P., Barbey, P. Evolution structural et métamorphique des schistes de Mbalmayo (Cameroun): implications pour la structure de la zone mobile panafricaine d’Afrique central au contact du craton du Congo. Comptes Rendus de l’Académie des Sciences Paris, 303 (III), 75-80, 1986.
In article      
 
[15]  Castaing, C., Feybesse, J.L., Thiéblemont, D., Triboulet, C., Chèvremont, P. Paleogeographical reconstructions of the Pan-African/Brasiliano orogen: closure of an oceanic domain or intracontinental convergence between major blocks? Precambrian Research, 69: 327-344, 1994.
In article      View Article
 
[16]  Ngako, V. Les déformations continentales panafricaines en Afrique centrale. Résultat d’un poinçonnement de type himalayen. Thèse de Doctorat d’État, Université de Yaoundé I, Cameroun, 1999.
In article      
 
[17]  Ngako, V., Affaton, P., Nnange, J.M., Njanko, T. Pan-African tectonic evolution in the central and southern Cameroon: transpressionand transtention during sinistral shear movements. Journal of African Earth Sciences, 36: 207-214, 2003.
In article      View Article
 
[18]  Toteu, S.F., Penaye, J.,Poudjom Djomani, Y.H. Geodynamic evolution of the Pan-African belt in central Africa with special reference to Cameroon. Canadian Journal of Earth Sciences, 41: 73-85, 2004.
In article      View Article
 
[19]  Mvondo, H., den Brok, S.W.J., Mvondo Ondoa, J. Evidence for symmetric extention and exhumation for the Yaoundé Nappe (Pan-African Fold Belt, Cameroon). Journal of African Earth Sciences, 36: 215-231, 2003.
In article      View Article
 
[20]  Nzenti, J.P., Barbey, P., Jegouzo, P., and Moreau, C. “Un Nouvel Exemple de Ceinture Granulitique dans une Chaine Protérozoïque de Transition : Les Migmatites de Yaoundé au Cameroun". Compte Rendu Academie des Sciencesde Paris, 299, 17, 1197-1199, 1984.
In article      
 
[21]  Nzenti, J.P. Prograde and retrograde zoning at high pressure and temperature in metapelitic and garnetite rocks from Yaoundé (Cameroon Pan-African north-equatorial fold belt). Journal of African Earth Sciences, 15: 73-79, 1992.
In article      View Article
 
[22]  Ngnotué, T., Ganno, S., Nzenti, J.P., Schulz, B., Tchaptchet Tchato, D., Suh Cheo, E. Geochemistry and geochronology of Peraluminous High-K Granitic Leucosomes of Yaoundé Series) Cameroon. Evidence for a Unique Pan-African Magmatism and Melting Event in North Equatorial Fold Belt. International Journal of Geosciences, 3, 525-548, 2012.
In article      View Article
 
[23]  Champetier de Ribes, G., Aubague, M. Carte géologique de reconnaissance au 1/500 000 , Notice explicative sur la feuille Yaoundé-est. Direction des Mines et de la Géologie, Yaoundé, Cameroun. Imprimerie Rébon, Paris, France, 1956.
In article      
 
[24]  Weecksteen, G. Carte géologique de reconnaissance à l’échelle du 1/500 000, feuille Douala-est avec notice explicative. Publication de la Direction des Mines et de la Géologie du Cameroun, 37p., 1957.
In article      
 
[25]  Ngako, V., Jegouzo, P., Nzenti, J.P. Le cisaillement Centre Camerounais. Role structural et géodynamique dans l’orogenèse panafricaine. Comptes Rendus Académiques des Sciences Paris 313, 457-463, 1991.
In article      
 
[26]  Ngnotué,T., Nzenti, J.P., Barbey, P., Tchoua, F.M. The Ntui-Betamba high-grade gneisses : a northward extention of the Pan-African Yaoundé gneisses in Cameroon. Journal of African Earth Sciences, 31: 369-381, 2000.
In article      View Article
 
[27]  Yonta-Ngouné, C., Nkoumbou, C., Barbey, P., Le Breton, N., Montel, J.M., Villieras, F. Geological context of the Boumnyebel talcschists (Cameroon): inferences on the Pan-African Belt of Central Africa. Comptes Rendus Geosciences, 342, 108-115, 2010.
In article      View Article
 
[28]  Stendal, H., Toteu, S.F., Frei, R., Penaye, J., Njel, U.O., Bassahak, J., Nni, J., Kankeu, B., Ngako, V., Hell, J.V. Derivation of detrital rutile in the Yaoundé region from the Neoproterozoic Pan-African belt in southern Cameroon (Central Africa), Journal of African Earth Sciences 44, 443-458, 2006.
In article      View Article
 
[29]  Owona, S., Mvondo Ondoa, J., Ratschbacher, L., Ndzana, M.P.S., Tchoua, F.M., Ekodeck, G.E. La géométrie de la tectonique archéenne, Paléo et néoprotérozoïque dans le Sud-Ouest du Cameroun. Comptes Rendus Geosciences, 343, 312-322, 2011.
In article      View Article
 
[30]  Nzenti, J.P. Pétrogenèse des migmatites de Yaoundé (Cameroun). Eléments pour un modèle géodynamique de la chaine Pan-Africaine nord-équatoriale. Thèse de Doctorat, Universite de Nancy I, France, 1987.
In article      
 
[31]  Penaye, J., Toteu, S.F., Van Schmus, W.R., Nzenti, J.P. U-Pb and Sm-Nd preliminary geochronologic data on the Yaoundé series, Cameroon: re-interpretation of the granulitic rocks as the suture of a collision in the “Centrafrican” belt. Comptes Rendus de l’Academie des Sciences de Paris, 317: 789-794, 1993.
In article      
 
[32]  Toteu, S.F., Van Schmus, W.R., Penaye, J., Nyobé, J.B. U-Pb and Sm-Nd evidence for Eburnian and Pan-African high-grade metamorphism in cratonic rocks of southern Cameroon. Precambrian Research, 67: 321-347, 1994.
In article      View Article
 
[33]  Toteu, S. F., Van, Schmus, W.R., Penaye, J., Michard, A. New U-Pb and Sm-Nd data from north-central Cameroon and its rich on the pre-Pan-African history of central Africa. Precambrian Research, 108, 45-73, 2001.
In article      View Article
 
[34]  Toteu, S.F., Yongue, Fouateu, R., Penaye, J., Tchakounte, J., Seme, Mouangue, A.C., Van Schmus, W.R., Deloule, E., Stendal, H. U-Pb dating of plutonic rocks involved in the nappe tectonic in southern Cameroon: consequence for the Pan-African orogenic evolution of the central African fold belt. Journal of African Earth Sciences 44, 479-493, 2006.
In article      View Article
 
[35]  Nzenti, J.P., Tchoua, F. Signification pétrogénétique des grenatites dans les migmatites de Yaoundé (Chaine Panafricaine North-Equatoriale au Cameroun). In Géosciences au Cameroun, Vicat J.P. et Bilong P., éditeurs, collection GEOCAM, I/1998, Université de Yaoundé I, 277-284, 1998.
In article      
 
[36]  Mvondo, H. Analyse structurale et pétrogéochimique des roches de la région de Yaoundé nord ; arguments contribuant à la connaissance de l’évolution géotectonique de la chaine Pan-Africaine au Cameroun. Thèse de Doctorat, Université de Yaoundé I, Cameroun, 2003.
In article      
 
[37]  Barbey, P., Macaudiere, J., Nzenti, J.P. High pressure dehydration melting of metapelites : evidence from the migmatites of Yaoundé (Cameroon). Journal of Petrology, 31 (2), 401-427, 1990.
In article      View Article
 
[38]  Metang, V., Nkoumbou, C., Tchakounte Numbem, J., Njopwouo, D. Application of Remote Sensing for the Mapping of Geological Structures in Rainforest Area: A case Study at the Matomb-Makak Area, Centre-South Cameroon. Journal of Geosciences and Geomatics, 2 (5), 196-207, 2014.
In article      
 
[39]  Owona, S., Schulz, B., Ratschbacher, L., Mvondo ondoa, J., Ekodeck, G.E., Tchoua, M.F., Affaton, P. Pan-African metamorphic evolution in the southern Yaounde group (Oubanguide Complex, Cameroon) as revealed by EMP- monazite dating and thermobarometry of garnet pelite. Journal of African Earth Sciences 59, 125-139, 2010.
In article      View Article
 
[40]  Njiké Ngaha, P. R. Contribution à l’étude géologique, stratigraphique et structurale de la bordure du bassin atlantique au Cameroun. Thèse de Doctorat 3eme cycle. Université de Yaoundé, 131 p., 1984.
In article      
 
[41]  Ndjeng, E. Etudes da la sédimentation et du modèle d’évolution géodynamique de deux bassins du Crétacé inferieur du Nord-Cameroun : Babouri-Figuil et Mayo Oulo-Léré. Thèse de Doctorat d’Etat. Université de Yaoundé, 311p., 1992.
In article      
 
[42]  Vicat, J.P., Mvondo, H., Willems, L., Pouclet, A. Phénomènes de karstiques fossiles et actuels au sein des formations métamorphiques silico-alumineuses de la nappe pan-africaine de Yaoundé (Sud-Cameroun). Comptes Rendus Géosciences 334, 545-550, 2002.
In article      View Article