Log in

Relevant bibliographies by topics / Eburnean / Journal articles

To see the other types of publications on this topic, follow the link: Eburnean.

Journal articles on the topic 'Eburnean'

Author: Grafiati

Published: 4 June 2021

Last updated: 12 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Eburnean.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Rezaeifar, Maryam, and Mahdi Rezaeifar. "Effect of Amygdalus eburnea on third degree burns in rats and comparison with silver sulfadiazine ointment." Asian Journal of Pharmaceutical and Clinical Research 10, no. 5 (May 1, 2017): 376. http://dx.doi.org/10.22159/ajpcr.2017.v10i5.16877.

Full text

Abstract:

Amygdalus eburnea is a perennial herb that has been valued for its important biological perspectives and it has been used to treat the burn. In this study, the extract from the Iranian medicinal herb is investigated on its wound healing activity in comparison with silver sulfadiazine ointment as the standard treatment for burn wound in rats. Our results demonstrated that, Amygdalus eburnean can be an effective treatment for third degree burns. Advanced clinical and pharmaceutical studies are recommended in order to the production of novel natural drugs for burn wound treatment.

APA, Harvard, Vancouver, ISO, and other styles

2

Chardon, Dominique, Ousmane Bamba, and Kalidou Traoré. "Eburnean deformation pattern of Burkina Faso and the tectonic significance of shear zones in the West African craton." BSGF - Earth Sciences Bulletin 191 (2020): 2. http://dx.doi.org/10.1051/bsgf/2020001.

Full text

Abstract:

Shear zones of the Paleoproterozoic Eburnean accretionary Orogen (West African craton) are investigated by means of large-scale structural mapping. Regional scale (10-100 km) mapping was based on the aeromagnetic survey of Burkina Faso and craton-scale (1000 km) mapping on a compilation of fabric data. At both scales, shear zones are arranged as an anastomosed transpressional network that accommodated distributed shortening and lateral flow of the orogenic lithosphere between the converging Kénéma-Man and Congo Archean provinces. Structural interference patterns at both scales were due to three-dimensional partitioning of progressive transpressional deformation and interactions among shear zones that absorbed heterogeneities in the regional flow patterns while maintaining the connectivity of the shear zone network. Such orogen-scale kinematic patterns call for caution in using the deformation phase approach without considering the “bigger structural picture” and interpreting displacement history of individual shear zones in terms of plate kinematics. The West African shear zone pattern is linked to that of the Guiana shield through a new transatlantic correlation to produce an integrated kinematic model of the Eburnean-Transamazonian orogen.

APA, Harvard, Vancouver, ISO, and other styles

3

Thiéblemont, Denis, Jean Christian Goujou, Emmanuel Egal, Alain Cocherie, Claude Delor, Jean Michel Lafon, and C. Mark Fanning. "Archean evolution of the Leo Rise and its Eburnean reworking." Journal of African Earth Sciences 39, no. 3-5 (June 2004): 97–104. http://dx.doi.org/10.1016/j.jafrearsci.2004.07.059.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Schofield, D. I., M. S. A. Horstwood, P. E. J. Pitfield, Q. G. Crowley, A. F. Wilkinson, and H. Ch O. Sidaty. "Timing and kinematics of Eburnean tectonics in the central Reguibat Shield, Mauritania." Journal of the Geological Society 163, no. 3 (May 2006): 549–60. http://dx.doi.org/10.1144/0016-764905-097.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Schofield, D. I., and M. R. Gillespie. "A tectonic interpretation of “Eburnean terrane” outliers in the Reguibat Shield, Mauritania." Journal of African Earth Sciences 49, no. 4-5 (November 2007): 179–86. http://dx.doi.org/10.1016/j.jafrearsci.2007.08.006.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Baratoux, Lenka, Václav Metelka, Séta Naba, Mark W. Jessell, Michel Grégoire, and Jérôme Ganne. "Juvenile Paleoproterozoic crust evolution during the Eburnean orogeny (∼2.2–2.0Ga), western Burkina Faso." Precambrian Research 191, no. 1-2 (November 2011): 18–45. http://dx.doi.org/10.1016/j.precamres.2011.08.010.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Ouzegane, Khadidja, Abderrahmane Bendaoud, Jean‐Robert Kienast, and Jacques L. R. Touret. "Pressure‐Temperature‐Fluid Evolution in Eburnean Metabasites and Metapelites from Tamanrasset (Hoggar, Algeria)." Journal of Geology 109, no. 2 (March 2001): 247–63. http://dx.doi.org/10.1086/319238.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Dabo, Moussa, and Tahar Aïfa. "Late Eburnean deformation in the Kolia-Boboti sedimentary basin, Kédougou-Kéniéba Inlier, Sénégal." Journal of African Earth Sciences 60, no. 3 (May 2011): 106–16. http://dx.doi.org/10.1016/j.jafrearsci.2011.02.005.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Aïfa, Tahar, and Moussa Dabo. "Microstructures and temperature variability during the Eburnean deformations in the Daléma area, Eastern Senegal." Arabian Journal of Geosciences 8, no. 2 (January 7, 2014): 677–89. http://dx.doi.org/10.1007/s12517-013-1254-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Zamil, M. Sh. "A possible model of the Paleozoic sedimentary basins evolution at the North African platform." Proceedings of higher educational establishments. Geology and Exploration, no. 6 (December 28, 2017): 68–73. http://dx.doi.org/10.32454/0016-7762-2017-6-68-73.

Full text

Abstract:

A dual model of the Paleozoic basins development, disposing on the Late Proterozoic (Pan-African) and the Early Proterozoic (Eburnean) crust, has been proposed. The formation of the first group basins is connected with the subsiding of the sections of the cooling gneissic-domes of«rejuvenated» (Early Precambrian but tectonically reworked at the end of the Proterozoic) Pan-African crust. Accordingly, the development of the second group basins is a result of the Precambrian deep sited (mantle) magmatic chambers cooling and subsiding together with the sites of the old lithosphere, covering them. The manifestation of the Vendian volcanic units on Anti-Atlas, Ugarta, Regibat-Eglab uplifts is the most possible evidence of the mantle magmatic activity, which could create those chambers.

APA, Harvard, Vancouver, ISO, and other styles

11

Djeneb, Camara, Coulibaly Kiyinlma, Kanga Yao, Bisanz Cordelia, Delauw Marie-France, and Zirihi Guédé Noël. "Activité anti-toxoplasmose, screening phytochimique et étude de la cytotoxicité de l’extrait éthanolique 70% de Hunteria eburnea Pichon (Apocynaceae)." European Scientific Journal, ESJ 14, no. 30 (October 31, 2018): 37. http://dx.doi.org/10.19044/esj.2018.v14n30p37.

Full text

Abstract:

Hunteria eburnea is a medicinal plant used in traditional medicine in the Sassandra Region (Ivory Coast) in the treatment of malaria and skin diseases. The aim of this study is to study the inhibitory effect of 70% ethanolic extract of Hunteria eburneaa stem bark on Toxoplasma gondii, a protozoan parasite such as Plasmodium falciparum that causes toxoplasmosis. The 70% ethanolic extract was obtained from the parts of the plant that are used by traditional health practitioners in the Haut-Sassandra Region (Ivory Coast).The 70% ethanolic extract of Hunteria eburnea stem bark revealed high anti-Toxoplasma gondii activity with an estimated IC50 of 0.72 mg / mL and no cytotoxicity to HFF cells. (Human Foreskin Fibroblasts). Also, the phytochemical screening of this extract revealed the presence of sterols / triterpenes as well as alkaloids. This result indicates a promising source of new anti-Toxoplasma drugs from Hunteria eburnea, a West African medicinal plant.

APA, Harvard, Vancouver, ISO, and other styles

12

Tairou, Mahaman Sani, Pascal Affaton, Solomon Anum, and Thomas Jules Fleury. "Pan-African Paleostresses and Reactivation of the Eburnean Basement Complex in Southeast Ghana (West Africa)." Journal of Geological Research 2012 (July 17, 2012): 1–15. http://dx.doi.org/10.1155/2012/938927.

Full text

Abstract:

This faulting tectonics analysis concerns the southernmost segment of the Dahomeyide Orogen and the West-African craton eastern margin in southeast Ghana. The analysis of strike-slip faults in the frontal units of the Dahomeyide Belt indicates that four distinct compressive events (NE-SW, ENE-WSW to E-W, ESE-WNW to SE-NW and SE-NW to SSE-NNW) originated the juxtaposition of the Pan-African Mobile Zone and the West-African craton. These paleostress systems define a clockwise rotation of the compressional axis during the structuring of the Dahomeyide Orogen (650–550 Ma). The SE-NW and SSE-NNW to N-S compressional axes in the cratonic domain and its cover (Volta Basin) suggest that the reactivation of the eastern edge of the West African craton is coeval with the last stages of the Pan-African tectogenesis in southeast Ghana. An extensional episode expressed as late normal faulting is also recorded in this study. This E-W to SE-NW extension, which is particular to the southernmost part of the Dahomeyide Belt, appears to be post-Pan-African. This extension probably contributed to the formation of a major Jurassic rifting zone that originated the Central Atlantic and the Benue Trough.

APA, Harvard, Vancouver, ISO, and other styles

13

FERRÉ, E., J. DÉLÉRIS, J. L. BOUCHEZ, A. U. LAR, and J. J. PEUCAT. "The Pan-African reactivation of Eburnean and Archaean provinces in Nigeria: structural and isotopic data." Journal of the Geological Society 153, no. 5 (September 1996): 719–28. http://dx.doi.org/10.1144/gsjgs.153.5.0719.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Parra-Avila, Luis A., Lenka Baratoux, Aurélien Eglinger, Marco L. Fiorentini, and Sylvain Block. "The Eburnean magmatic evolution across the Baoulé-Mossi domain: Geodynamic implications for the West African Craton." Precambrian Research 332 (September 2019): 105392. http://dx.doi.org/10.1016/j.precamres.2019.105392.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Bouchot, Vincent, and Jean-Louis Feybesse. "Palaeoproterozoic gold mineralization of the Etéké Archaean greenstone belt (Gabon): its relation to the Eburnean orogeny." Precambrian Research 77, no. 3-4 (April 1996): 143–59. http://dx.doi.org/10.1016/0301-9268(95)00047-x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

White, Alistair, Ray Burgess, Norman Charnley, David Selby, Martin Whitehouse, Laurence Robb, and David Waters. "Constraints on the timing of late-Eburnean metamorphism, gold mineralisation and regional exhumation at Damang mine, Ghana." Precambrian Research 243 (April 2014): 18–38. http://dx.doi.org/10.1016/j.precamres.2013.12.024.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Block, S., J. Ganne, L. Baratoux, A. Zeh, L. A. Parra-Avila, M. Jessell, L. Ailleres, and L. Siebenaller. "Petrological and geochronological constraints on lower crust exhumation during Paleoproterozoic (Eburnean) orogeny, NW Ghana, West African Craton." Journal of Metamorphic Geology 33, no. 5 (April 3, 2015): 463–94. http://dx.doi.org/10.1111/jmg.12129.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Weber, Francis, François Gauthier-Lafaye, Hubert Whitechurch, Marc Ulrich, and Abderrazak El Albani. "The 2-Ga Eburnean Orogeny in Gabon and the opening of the Francevillian intracratonic basins: A review." Comptes Rendus Geoscience 348, no. 8 (November 2016): 572–86. http://dx.doi.org/10.1016/j.crte.2016.07.003.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Caen-Vachette, M., and A. C. Umeji. "Geology and geochronology of the Okene area: evidence for an Eburnean orogenic cycle in south-central Nigeria." Journal of African Earth Sciences (and the Middle East) 7, no. 1 (January 1988): 121–26. http://dx.doi.org/10.1016/0899-5362(88)90058-9.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Aidoo, Felix, Prosper M. Nude, Fang-Yuan Sun, Ting Liang, and Shao-Bing Zhang. "Paleoproterozoic TTG-like metagranites from the Dahomeyide Belt, Ghana: Constraints on the evolution of the Birimian-Eburnean Orogeny." Precambrian Research 353 (February 2021): 106024. http://dx.doi.org/10.1016/j.precamres.2020.106024.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Dabo, Moussa, and Tahar Aïfa. "Pure shear to simple shear-dominated transpression during the Eburnean major D2 deformation, Daléma sedimentary basin, eastern Senegal." International Geology Review 55, no. 9 (January 21, 2013): 1073–86. http://dx.doi.org/10.1080/00206814.2012.760711.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Mapeo, R. B. M., L. V. Ramokate, F. Corfu, D. W. Davis, and A. B. Kampunzu. "The Okwa basement complex, western Botswana: U–Pb zircon geochronology and implications for Eburnean processes in southern Africa." Journal of African Earth Sciences 46, no. 3 (October 2006): 253–62. http://dx.doi.org/10.1016/j.jafrearsci.2006.05.005.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Tanko Njiosseu, Evine Laure, Jean-Paul Nzenti, Théophile Njanko, Badibanga Kapajika, and Anne Nédélec. "New UPb zircon ages from Tonga (Cameroon): coexisting Eburnean–Transamazonian (2.1 Ga) and Pan-African (0.6 Ga) imprints." Comptes Rendus Geoscience 337, no. 6 (April 2005): 551–62. http://dx.doi.org/10.1016/j.crte.2005.02.005.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Metelka, Václav, Lenka Baratoux, Séta Naba, and Mark W. Jessell. "A geophysically constrained litho-structural analysis of the Eburnean greenstone belts and associated granitoid domains, Burkina Faso, West Africa." Precambrian Research 190, no. 1-4 (October 2011): 48–69. http://dx.doi.org/10.1016/j.precamres.2011.08.002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Denchev, Teodor T., and Cvetomir M. Denchev. "Anthracoidea caricis-reznicekii (Anthracoideaceae), a new species on Carex reznicekii, and A. eburneae, a new record for the USA." Phytotaxa 244, no. 1 (January 15, 2016): 69. http://dx.doi.org/10.11646/phytotaxa.244.1.5.

Full text

Abstract:

A new ovariicolous smut fungus, Anthracoidea caricis-reznicekii on Carex reznicekii (C. sect. Acrocystis), is described and illustrated from the USA. The new species is compared with the known Anthracoidea species on sedges in Carex sect. Acrocystis and other closely related sections. Anthracoidea caricis-reznicekii is characterized by a complex of characters: medium-sized spores (15–24.5 μm long), thick spore wall (up to 6.0 μm thick), with conspicuous, often numerous (up to 8) protuberances, and warts 0.2–0.5 μm high. A key to the four known Anthracoidea species on sedges in section Acrocystis is provided. Anthracoidea eburneae, previously known only from Canada, is reported for the first time from the USA, on Carex eburnea.

APA, Harvard, Vancouver, ISO, and other styles

26

Ganne, J., M. Gerbault, and S. Block. "Thermo-mechanical modeling of lower crust exhumation—Constraints from the metamorphic record of the Palaeoproterozoic Eburnean orogeny, West African Craton." Precambrian Research 243 (April 2014): 88–109. http://dx.doi.org/10.1016/j.precamres.2013.12.016.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Bowell, R. J., R. P. Foster, and C. J. Stanley. "Telluride mineralization at Ashanti gold mine, Ghana." Mineralogical Magazine 54, no. 377 (December 1990): 617–27. http://dx.doi.org/10.1180/minmag.1990.054.377.15.

Full text

Abstract:

AbstractGold mineralization at the Ashanti Mine occurs in shear zones which are second-order components of a major transcrustal shear zone. However, gold-rich telluride mineralization in veins in the hangingwall of the Obuasi ore zone at Ashanti appears to have post-dated development of the major gold-bearing shear zone. Complex assemblages of goethite, chalcocite, coloradoite, calaverite, sylvanite, kostovite, petzite, stutzite, hessite, altaite, rickardite, weissite and henryite were succeeded by a relatively simple assemblage of altaite-petzite-hessite ± sylvanite ± coloradoite. Precipitation occurred over a temperature range of approximately 220°C to 165°C from a CO2-bearing, low salinity (<5 wt. % NaCl equiv.) fluid under conditions of high ƒo2 and high ƒTe2/ƒS2. Replacement of earlier gold-sulphide mineralization is indicated.The fluids were introduced during late activation of the Obuasi shear zone, which evolved during the c.2000 Ma Eburnean tectonothermal event that marked the onset of cratonization of the West African shield. The localized and time-specific distribution of the telluride mineralization may be indicative of a late influx of tellurium-rich fluid linked to emplacement of a synorogenic, Cape Coast-type granitoid intrusion.

APA, Harvard, Vancouver, ISO, and other styles

28

Block, Sylvain, Mark Jessell, Laurent Aillères, Lenka Baratoux, Olivier Bruguier, Armin Zeh, Delphine Bosch, Renaud Caby, and Emmanuel Mensah. "Lower crust exhumation during Paleoproterozoic (Eburnean) orogeny, NW Ghana, West African Craton: Interplay of coeval contractional deformation and extensional gravitational collapse." Precambrian Research 274 (March 2016): 82–109. http://dx.doi.org/10.1016/j.precamres.2015.10.014.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

McFarlane, H. B., L. Ailleres, P. Betts, J. Ganne, L. Baratoux, M. W. Jessell, and S. Block. "Episodic collisional orogenesis and lower crust exhumation during the Palaeoproterozoic Eburnean Orogeny: Evidence from the Sefwi Greenstone Belt, West African Craton." Precambrian Research 325 (June 2019): 88–110. http://dx.doi.org/10.1016/j.precamres.2019.02.012.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Peucat, Jean-Jacques, Ramon Capdevila, Amar Drareni, Yamina Mahdjoub, and Mohamed Kahoui. "The Eglab massif in the West African Craton (Algeria), an original segment of the Eburnean orogenic belt: petrology, geochemistry and geochronology." Precambrian Research 136, no. 3-4 (February 2005): 309–52. http://dx.doi.org/10.1016/j.precamres.2004.12.002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

D’Lemos, R. S., J. D. Inglis, and S. D. Samson. "A newly discovered orogenic event in Morocco: Neoproterozic ages for supposed Eburnean basement of the Bou Azzer inlier, Anti-Atlas Mountains." Precambrian Research 147, no. 1-2 (June 2006): 65–78. http://dx.doi.org/10.1016/j.precamres.2006.02.003.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Egal, Emmanuel, Denis Thiéblemont, Didier Lahondère, Catherine Guerrot, Cristian Adi Costea, Dan Iliescu, Claude Delor, et al. "Late Eburnean granitization and tectonics along the western and northwestern margin of the Archean Kénéma–Man domain (Guinea, West African Craton)." Precambrian Research 117, no. 1-2 (July 2002): 57–84. http://dx.doi.org/10.1016/s0301-9268(02)00060-8.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Debat, Pierre, Serge Nikiéma, Alain Mercier, Martin Lompo, Didier Béziat, François Bourges, Martin Roddaz, Stefano Salvi, Francis Tollon, and Urbain Wenmenga. "A new metamorphic constraint for the Eburnean orogeny from Paleoproterozoic formations of the Man shield (Aribinda and Tampelga countries, Burkina Faso)." Precambrian Research 123, no. 1 (May 20, 2003): 47–65. http://dx.doi.org/10.1016/s0301-9268(03)00046-9.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Frimmel, Hartwig E., Ian R. Jonasson, and Petronella Mubita. "An Eburnean base metal source for sediment-hosted zinc-lead deposits in Neoproterozoic units of Namibia: Lead isotopic and geochemical evidence." Mineralium Deposita 39, no. 3 (May 1, 2004): 328–43. http://dx.doi.org/10.1007/s00126-004-0410-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Melcher, Frank. "Genesis of chemical sediments in Birimian greenstone belts: evidence from gondites and related manganese-bearing rocks from Northern Ghana." Mineralogical Magazine 59, no. 395 (June 1995): 229–51. http://dx.doi.org/10.1180/minmag.1995.059.395.08.

Full text

Abstract:

AbstractEarly Proterozoic chemical sediments of the Birimian Supergroup in northern Ghana host several types of metamorphosed manganese-bearing rocks. Differences in the mineralogy and geochemistry can be attributed to facies changes in a mixed volcanic-volcaniclastic depositional environment. Manganese oxide-bearing phyllite, which is enriched in transition metals (Cu, Ni, Co, Zn), formed on the flanks of submarine volcanic edifices above an oxidation boundary. Towards the deeper basin, manganese silicate-rich gondites occur. These consist either of spessartine + quartz + ilmenite, or of spessartine + quartz + Mn amphiboles ± rhodonite ± hyalophane ± Mn stilpnomelane ± ilmenite. The Mn amphiboles are identified as manganoan actinolite, tirodite, and dannemorite. Sulphides are widespread as premetamorphic inclusions in Mn garnet grains. In the basin centre, chlorite schist containing garnet with 50–60 mol.% spessartine represents the most distal manganese-bearing rock which is highly diluted by volcanogenic background sedimentation. The origin of Mn-rich rocks is explained by heat-driven seawater convection systems active in submarine volcanic centres that provided hydrothermal solutions. Precipitation of different minerals depended on the geochemical conditions prevailing on the seafloor. During the Eburnean event (around 2000 Ma), the chemical sediments were metamorphosed to upper greenschist or lower amphibolite facies. Mineral assemblages in the gondites point to metamorphic conditions in the range of 450–500°C at 2–3 kbar.

APA, Harvard, Vancouver, ISO, and other styles

36

Mériaud, Nicolas, Nicolas Thébaud, Quentin Masurel, Patrick Hayman, Mark Jessell, Anthony Kemp, Noreen J. Evans, Christopher M. Fisher, and Peter M. Scott. "Lithostratigraphic evolution of the Bandamian Volcanic Cycle in central Côte d’Ivoire: Insights into the late Eburnean magmatic resurgence and its geodynamic implications." Precambrian Research 347 (September 2020): 105847. http://dx.doi.org/10.1016/j.precamres.2020.105847.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Perrouty, Stéphane, Laurent Aillères, Mark W. Jessell, Lenka Baratoux, Yan Bourassa, and Brenton Crawford. "Revised Eburnean geodynamic evolution of the gold-rich southern Ashanti Belt, Ghana, with new field and geophysical evidence of pre-Tarkwaian deformations." Precambrian Research 204-205 (May 2012): 12–39. http://dx.doi.org/10.1016/j.precamres.2012.01.003.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Amores-Casals, Sandra, Antonio Olimpio Gonçalves, Joan-Carles Melgarejo, and Joan Martí Molist. "Nb and REE Distribution in the Monte Verde Carbonatite–Alkaline–Agpaitic Complex (Angola)." Minerals 10, no. 1 (December 19, 2019): 5. http://dx.doi.org/10.3390/min10010005.

Full text

Abstract:

The Angolan alkaline–carbonatite complex of Monte Verde has a semi-circular shape and is comprised of a central intrusion of foidolite rocks surrounded by concentrically arranged minor bodies of other alkaline rocks and carbonatite magmatic breccias. This rock association is hosted by fenitized Eburnean granites. Concentric swarms of alkaline dykes of late formation, mostly of nepheline trachyte composition, crosscut the previous units. Most high-field strength elements (HFSE) and rare earth elements (REE) are concentrated in pyrochlore crystals in the carbonatite and alkaline breccias. Magmatic fluornatropyrochlore is replaced and overgrown by five secondary generations of pyrochlore formed during subsolidus stages and have higher Th, REE, Si, U, Sr, Ba, Zr, and Ti contents. The second, third, and fourth pyrochlore generations are associated with late fluids also producing quartz and REE rich minerals; whereas fifth and sixth pyrochlore generations are linked to the fenitization process. On the other hand, minerals of the rinkite, rosenbuschite, wöhlerite, eudialyte groups, as well as loparite-(Ce), occur in accessory amounts in nepheline trachyte, recording low to moderate agpaicity. In addition, minor REE-bearing carbonates, silicates, and phosphates crystallize as late minor secondary minerals into carbonatite breccia and alkaline dykes. In conclusion, the scarcity of HFSE and REE minerals at the Monte Verde carbonatite-alkaline-agpaitic complex suggests low metallogenetic interest and economic potential for the outcrops analysed in this study. However, the potential for buried resources should not be neglected.

APA, Harvard, Vancouver, ISO, and other styles

39

Pawlowski, M. L., and G. L. Hartman. "Impact of Arbuscular Mycorrhizal Species on Heterodera glycines." Plant Disease 104, no. 9 (September 2020): 2406–10. http://dx.doi.org/10.1094/pdis-01-20-0102-re.

Full text

Abstract:

Soybean cyst nematode (SCN, Heterodera glycines) is a widely occurring pest and the leading cause of soybean yield losses in the U.S.A. There is a need to find additional SCN management strategies as sources of SCN resistance have become less effective in managing SCN populations. Arbuscular mycorrhizal fungi (AMF) form symbiotic relationships with roots of most plants including soybean. Research has shown that AMF can reduce disease severity in plants caused by pathogens and pests, including plant parasitic nematodes. The goal of this study was to evaluate the impact of AMF on SCN cyst production, SCN juveniles in roots, and SCN egg hatching. In one experiment, all five AMF species tested (Claroideoglomus claroideum, Diversispora eburnean, Dentiscutata heterogama, Funneliformis mosseae, and Rhizophagus intraradices) reduced (P < 0.05) the number of cysts on soybean roots by 59 to 81%, compared with soybean roots not inoculated with AMF. Inoculation with F. mosseae reduced SCN J2–J3 stage juveniles in soybean roots by 60% at 7 days post inoculation. A separate experiment showed that egg hatch was reduced (P < 0.05) in the presence of F. mosseae spores and their exudates by 27% and 62%, respectively. Further research is needed to evaluate the potential usefulness of AMF in field conditions and to determine the usefulness and potential of the exudates associated with SCN hatching suppression by F. mosseae. Making AMF a more effective biological control agent would provide another management tool to reduce the negative impact of SCN on soybean production.

APA, Harvard, Vancouver, ISO, and other styles

40

Wane, Ousmane, Jean-Paul Liégeois, Nicolas Thébaud, John Miller, Václav Metelka, and Mark Jessell. "The onset of the Eburnean collision with the Kenema-Man craton evidenced by plutonic and volcanosedimentary rock record of the Masssigui region, southern Mali." Precambrian Research 305 (February 2018): 444–78. http://dx.doi.org/10.1016/j.precamres.2017.11.008.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Bendaoud, Abderrahmane, Khadidja Ouzegane, Gaston Godard, Jean-Paul Liégeois, Jean-Robert Kienast, Olivier Bruguier, and Amar Drareni. "Geochronology and metamorphic P-T-X evolution of the Eburnean granulite-facies metapelites of Tidjenouine (Central Hoggar, Algeria): witness of the LATEA metacratonic evolution." Geological Society, London, Special Publications 297, no. 1 (2008): 111–46. http://dx.doi.org/10.1144/sp297.6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Gassama, Ibrahima, Moussa Dabo, Mamadou Ndiaye, Emmanuel Tama Samoura, and Fatou Bop Ndong. "Meaning of Rocks Basic Enclaves in the Eburnean Granitoids of Mako Area (Kédougou-Kéniéba Inlier, Senegal): Petrogenetic Implications." International Journal of Geosciences 12, no. 01 (2021): 39–56. http://dx.doi.org/10.4236/ijg.2021.121004.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Kouamelan, Alain Nicaise, Kouassi Serge Auguste Kra, Sagbrou Chérubin Djro, Jean-Louis Paquette, and Jean-Jacques Peucat. "The Logoualé Band: A large Archean crustal block in the Kenema-Man domain (Man-Leo rise, West African Craton) remobilized during Eburnean orogeny (2.05 Ga)." Journal of African Earth Sciences 148 (December 2018): 6–13. http://dx.doi.org/10.1016/j.jafrearsci.2017.09.004.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

WALDRON, JOHN W. F., DAVID I. SCHOFIELD, GRAHAM PEARSON, CHIRANJEEB SARKAR, YAN LUO, and ROBERT DOKKEN. "Detrital zircon characterization of early Cambrian sandstones from East Avalonia and SE Ireland: implications for terrane affinities in the peri-Gondwanan Caledonides." Geological Magazine 156, no. 07 (July 16, 2018): 1217–32. http://dx.doi.org/10.1017/s0016756818000407.

Full text

Abstract:

AbstractThe Caledonides of Britain and Ireland include terranes attributed to both Laurentian and Gondwanan sources, separated along the Solway line. Gondwanan elements to the south have been variably assigned to the domains Ganderia and East Avalonia. The Midland Platform forms the core of East Avalonia but its provenance is poorly known. Laser ablation split-stream analysis yields information about detrital zircon provenance by providing simultaneous U–Pb and Lu–Hf data from the same ablated volume. A sample of Red Callavia Sandstone from uppermost Cambrian Stage 3 of the Midland Platform yields a U–Pb age spectrum dominated by Neoproterozoic and Palaeoproterozoic sources, resembling those in the Welsh Basin, the Meguma Terrane of Nova Scotia and NW Africa. Initial εHf values suggest that the Neoproterozoic zircon component was derived mainly from crustal sources < 2 Ga, and imply that the more evolved Palaeoproterozoic grains were transported into the basin from an older source terrane, probably the Eburnean Orogen of West Africa. A sample from Cambrian Stage 4 in the Bray Group of the Leinster–Lakesman Terrane shows, in contrast, a distribution of both U–Pb ages and εHf values closely similar to those of the Gander Terrane in Newfoundland and other terranes attributed to Ganderia, interpreted to be derived from the margin of Amazonia. East Avalonia is clearly distinct from Ganderia, but shows evidence for older crustal components not present in West Avalonia of Newfoundland. These three components of the Appalachian–Caledonide Orogen came from distinct sources on the margin of Cambrian Gondwana.

APA, Harvard, Vancouver, ISO, and other styles

45

Fotze, Quentin Marc Anaba, Charles Antoine Basseka, Anatole Eugene Djieto Lordon, Albert Eyike Yomba, Yves Shandini, and Jean Marie Tadjou. "Geophysical Data Processing for the Delineation of Tectonic Lineaments in South Cameroon." Earth Science Research 8, no. 2 (March 25, 2019): 1. http://dx.doi.org/10.5539/esr.v8n2p1.

Full text

Abstract:

The processing of aeromagnetic and gravity data of the Northern part of Congo Craton (South Cameroon region), between latitudes 2°30’-3°30’ N and longitudes 12°-13° E, permitted the determination of the structural features ccurring within the Precambrian basement (Ntem Complex) southwards and the Pan-African belt (Yaounde Group) northwards. The maxima of the Horizontal Gradient within the study area, were obtained using the Blakely and Simpson method (1986). Those maxima were used to trace the magnetic lineaments of the study area. Furthermore, the Total Horizontal derivative of the Tilt derivative applied on the residual grid of Bouguer anomaly guaranteed the enhancement of linear structures which were automatically extracted using the CET Grid Analysis algorithm. The superimposition of both magnetic and gravity lineaments allowed us to display the structural framework of the area, whose major trending directions are E-W, ENE-WSW, and NE-SW. These major lineament directions are likely to be linked to one or more than a single tectonic event such as the ENE-WSW/NE-SW trends, considered as the subduction direction of the Congo craton beneath the Pan-African belt. These trends may be linked to the Eburnean orogeny and are also said to be connected to the Central African Shear Zone (CASZ). The geophysical lineaments identified in the study are defined as potential targets along which mineralization may have been formed, considering the economic potential of the area.

APA, Harvard, Vancouver, ISO, and other styles

46

Fernández-Suárez, Javier, Gabriel Gutiérrez-Alonso, George A. Jenner, and Simon E. Jackson. "Geochronology and geochemistry of the Pola de Allande granitoids (northern Spain): their bearing on the Cadomian-Avalonian evolution of northwest Iberia." Canadian Journal of Earth Sciences 35, no. 12 (December 1, 1998): 1439–53. http://dx.doi.org/10.1139/e98-074.

Full text

Abstract:

The Pola de Allande pre-Variscan tonalite-granodiorite plutons are located in the Narcea Antiform, at the boundary zone between the Cantabrian and west Asturian Leonese zones of the Iberian Variscan belt. These granitoids were intruded into a Neoproterozoic siliciclastic sedimentary sequence with subordinate volcanic intercalations and were subsequently overprinted by Variscan thrust-related shear deformation. U-Pb laser ablation inductively coupled plasma - mass spectrometry (ICP-MS) dating of zircons from two plutons yielded concordant ages of intrusion of 605 ± 10 and 580 ± 15 Ma. To the authors' knowledge, this is the first reported U-Pb Cadomian-Avalonian age for igneous rocks in this section of the Iberian Variscan belt. These intrusions are coeval with the main episode of dominantly calc-alkaline magmatic activity related to Cadomian-Avalonian subduction. Major and trace element composition of the granitoids is characteristic of I-type high-K calc-alkaline granitoids generated in continental arc settings, and are comparable to those of coeval granitoids in other areas of the Cadomian-Avalonian belt. Sr and Nd isotopic signatures indicate that the genesis of the Pola de Allande granitoids involved either mixing of mantle melts of Cadomian extraction with an older enriched crust (Eburnean-Icarthian, i.e., ca. 2 Ga old crust) or melting of a mafic infracrustal protolith with a Grenville age (ca. 1.2 Ga) mantle extraction. The Neoproterozoic sediments, hosting the Pola de Allande granitoids and present in large areas of northwest Iberia, may represent the back-arc basin of the subduction complex in which the Avalon composite terrane constituted the main magmatic arc.

APA, Harvard, Vancouver, ISO, and other styles

47

Kanouo, Nguo Sylvestre, David Richard Lentz, Khin Zaw, Charles Makoundi, Emmanuel Afanga Archelaus Basua, Rose Fouateu Yongué, and Emmanuel Njonfang. "New Insights into Pre-to-Post Ediacaran Zircon Fingerprinting of the Mamfe PanAfrican Basement, SW Cameroon: A Possible Link with Rocks in SE Nigeria and the Borborema Province of NE Brazil." Minerals 11, no. 9 (August 30, 2021): 943. http://dx.doi.org/10.3390/min11090943.

Full text

Abstract:

The pre- to post-Late Neoproterozoic geological histories in the south to southwestern part of Mamfe Basin (SW Cameroon) were reported following analysis of the zircon crystals from their host rocks. A genetic model was developed for the zircon host rocks’ formation conditions, and the registered post-emplacement events were presented. The obtained ages were correlated with the data available for rocks in the Cameroon Mobile Belt, SE Nigeria, and the Borborema Province of NE Brazil. Separated zircons from Araru black to whitish gneiss, Araru whitish-grey gneiss, and Mboifong migmatite were analyzed for their morphology and texture U-Th-Pb composition, and U-Pb ages. Published U-Pb zircon ages for Otu granitic pegmatite, Babi mica schist, and Nkogho I-type anatectic granite were updated. Zircon ages in Araru black to whitish gneiss; Araru whitish-grey, Mboifong migmatite, Babi mica schist, Nkogho I-type anatectic granite, and Otu granitic pegmatite date the Eburnean tectono-magmatic/metamorphic event in Cameroon and SE Nigeria. The Late Paleoproterozoic to Early Mesoproterozoic ages record extensional (continental rift) settings and anorogenic magmatism in the Borborema Province in the NE of Brazil. These ages date collisional phases between the São Francisco–Congo and West African cratons and the Saharan metacraton with metamorphism and magmatism in Cameroon. They also date the Kibarian tectono-magmatic/metamorphism and PanAfrican tectono-magmatic/metamorphism in SE Nigeria. The Late Paleoproterozoic to Early Mesoproterozoic ages date the Cariris Velhos orogeny in the Borborema Province in NE Brazil, with Early Tonian crustal rifting, magmatism, and metamorphism and the collisional phase of the Brasiliano orogeny with syn-collisional plutons and extensive shear zoning and post-collisional granite intrusions.

APA, Harvard, Vancouver, ISO, and other styles

48

Hirdes, W., and D. W. Davis. "U–Pb Geochronology of Paleoproterozoic Rocks in the Southern Part of the Kedougou-Kéniéba Inlier, Senegal, West Africa: Evidence for Diachronous Accretionary Development of the Eburnean Province." Precambrian Research 118, no. 1-2 (September 2002): 83–99. http://dx.doi.org/10.1016/s0301-9268(02)00080-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Marzoli, Andrea, Hervé Bertrand, Nasrrddine Youbi, Sara Callegaro, Renaud Merle, Laurie Reisberg, Massimo Chiaradia, et al. "The Central Atlantic Magmatic Province (CAMP) in Morocco." Journal of Petrology 60, no. 5 (April 19, 2019): 945–96. http://dx.doi.org/10.1093/petrology/egz021.

Full text

Abstract:

Abstract The Central Atlantic Magmatic Province (CAMP) is a large igneous province (LIP) composed of basic dykes, sills, layered intrusions and lava flows emplaced before Pangea break-up and currently distributed on the four continents surrounding the Atlantic Ocean. One of the oldest, best preserved and most complete sub-provinces of the CAMP is located in Morocco. Geochemical, geochronologic, petrographic and magnetostratigraphic data obtained in previous studies allowed identification of four strato-chemical magmatic units, i.e. the Lower, Intermediate, Upper and Recurrent units. For this study, we completed a detailed sampling of the CAMP in Morocco, from the Anti Atlas in the south to the Meseta in the north. We provide a complete mineralogical, petrologic (major and trace elements on whole-rocks and minerals), geochronologic (40Ar/39Ar and U–Pb ages) and geochemical set of data (including Sr–Nd–Pb–Os isotope systematics) for basaltic and basaltic–andesitic lava flow piles and for their presumed feeder dykes and sills. Combined with field observations, these data suggest a very rapid (<0·3 Ma) emplacement of over 95% of the preserved magmatic rocks. In particular, new and previously published data for the Lower to Upper unit samples yielded indistinguishable 40Ar/39Ar (mean age = 201·2 ± 0·8 Ma) and U–Pb ages (201·57 ± 0·04 Ma), suggesting emplacement coincident with the main phase of the end-Triassic biotic turnover (c.201·5 to 201·3 Ma). Eruptions are suggested to have been pulsed with rates in excess of 10 km3/year during five main volcanic pulses, each pulse possibly lasting only a few centuries. Such high eruption rates reinforce the likelihood that CAMP magmatism triggered the end-Triassic climate change and mass extinction. Only the Recurrent unit may have been younger but by no more than 1 Ma. Whole-rock and mineral geochemistry constrain the petrogenesis of the CAMP basalts. The Moroccan magmas evolved in mid-crustal reservoirs (7–20 km deep) where most of the differentiation occurred. However, a previous stage of crystallization probably occurred at even greater depths. The four units cannot be linked by closed-system fractional crystallization processes, but require distinct parental magmas and/or distinct crustal assimilation processes. EC-AFC modeling shows that limited crustal assimilation (maximum c.5–8% assimilation of e.g. Eburnean or Pan-African granites) could explain some, but not all the observed geochemical variations. Intermediate unit magmas are apparently the most contaminated and may have been derived from parental magmas similar to the Upper basalts (as attested by indistinguishable trace element contents in the augites analysed for these units). Chemical differences between Central High Atlas and Middle Atlas samples in the Intermediate unit could be explained by distinct crustal contaminants (lower crustal rocks or Pan-African granites for the former and Eburnean granites for the latter). The CAMP units in Morocco are likely derived from 5–10% melting of enriched peridotite sources. The differences observed in REE ratios for the four units are attributed to variations in both source mineralogy and melting degree. In particular, the Lower basalts require a garnet peridotite source, while the Upper basalts were probably formed from a shallower melting region straddling the garnet–spinel transition. Recurrent basalts instead are relatively shallow-level melts generated mainly from spinel peridotites. Sr–Nd–Pb–Os isotopic ratios in the CAMP units from Morocco are similar to those of other CAMP sub-provinces and suggest a significant enrichment of the mantle-source regions by subducted crustal components. The enriched signature is attributed to involvement of about 5–10% recycled crustal materials introduced into an ambient depleted or PREMA-type mantle, while involvement of mantle-plume components like those sampled by present-day Central Atlantic Ocean Island Basalts (OIB, e.g. Cape Verde and Canary Islands) is not supported by the observed compositions. Only Recurrent basalts may possibly reflect a Central Atlantic plume-like signature similar to the Common or FOZO components.

APA, Harvard, Vancouver, ISO, and other styles

50

Gouedji, Franck, Christian Picard, Yacouba Coulibaly, Marc-Antoine Audet, Thierry Auge, Philippe Goncalves, Jean-Louis Paquette, and Naomi Ouattara. "The Samapleu mafic-ultramafic intrusion and its Ni-Cu-PGE mineralization: an Eburnean (2.09 Ga) feeder dyke to the Yacouba layered complex (Man Archean craton, western Ivory Coast)." Bulletin de la Société Géologique de France 185, no. 6 (June 1, 2014): 393–411. http://dx.doi.org/10.2113/gssgfbull.185.6.393.

Full text

Abstract:

Abstract The Yacouba layered complex intrudes the Archean (3.5–2.7 Ga) Kenema-Man craton in the Samapleu-Yorodougou area, western Ivory Coast. In Samapleu area, the complex was recognized in drill holes at three locations: Samapleu Main (SM); Samapleu Extension 1 (E1) and Yorodougou (Yo). It comprises websterites, peridotites and gabbro-norites arranged symmetrically with mafic layers at the center and ultramafic layers at both margins. The complex is inclined at 70–80° to the SE. The thickness of individual layers varies from 2 to 60 m and the total thickness is 120 to 200 m. At the E1 site, the complex extends to depths > 500 m. Contacts with the country rock gneiss are characterized by a hybrid zone that is a few meters thick and composed of plagioclase-orthopyroxene bearing metabasites, and locally (E1 site) a metamorphic assemblage of sapphirine-cordierite-sillimanite-spinel ± rutile. This assemblage is attributed to contact metamorphism during intrusion of the complex in the lower crust at a depth of about 25 km. Zircons in country rock gneisses and granulites, as well as in the hybrid facies, yield Archean ages of ~ 2.78 Ga, similar to ages reported in the Man craton. Rutiles in the hybrid zone give a U-Pb age of 2.09 Ga, which is interpreted as the age of contact metamorphism and emplacement of the intrusion. The Samapleu Main and Samapleu Extension 1 sites contain Ni and Cu sulfide deposit with reserves estimated as more than 40 million tons grading 0.25% Ni and 0.22% Cu (Sama Nickel-CI, August 2013). The Ni-Cu mineralization is composed of pentlandite, chalcopyrite, pyrrhotite and rare pyrite, which is disseminated mainly in pyroxenite or occurs as subvertical and semi-massive to massive sulfide veins. The sulfide textures range from matrix ore, net-textured, droplets or breccia textures. Zones enriched in PGM, particularly Pd, are associated with the sulfides and several chromite bands are also present. These observations suggest that an immiscible sulfide liquid formed from a parental silicate liquid and percolated through the crystal pile. The parental melt composition, determined using the Chai and Naldrett [1992] method, has a SiO2-rich mafic composition with 53% SiO2 and 10% MgO. This result, the presence of the hybrid zone, and the trace-element signature determined using the Bedard [1994] method, suggest a mantle-derived basaltic parental magma that had assimilated abundant continental crust. These observations indicate that Samapleu intrusion corresponds to a magmatic conduit of the Yacouba complex as at Jinchuan (China), Voisey’s bay (Canada), Kabanga (Tanzania) or Nkomati (South Africa).

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!