Preliminary exploration using pXRF in the Cassinga region
DOI:
https://doi.org/10.21701/bolgeomin/136.2/004Keywords:
Pathfinders, NIPALS, Exploration, Au Mineralizations, AngolaAbstract
A study was conducted in the Cassinga region with a portable XRF (pXRF) device to measure chemical elements in soils and rocks. Measurements were made in 318 outcrops and 1638 soils of the area. Four areas part of the Cassinga region were studied: Cuíma-Samboto, Chipindo, Jamba and M’Popo-Tchamutete where chemical elements were reported individually, and a multivariate study was conducted in each area. The main conclusions of this ongoing study are that the group pf elements/oxides such as MnO, Fe2O3,V, Cr, Co, Ni, Zn, Sb and As, corresponds to the pathfinders of Au mineralisations (As and Sb) and basic origin of elements, such as, Cr, Co, Ni and sulphides (Cu, Zn) and confirms enrichment in the four areas studied, Cuíma-Samboto, Chipindo, Jamba and M´Popo-Tchamutete. The geochemical behavior in terms of pathfinders for Au is associated with the major regional direction of NE-SW faults where hydrothermal fluids could have transported Au. Perpendicular structures associated with this major regional direction NE-SW also exhibit high concentrations of this group of elements especially associated with Neoarchean formations of the Jamba and Chipindo groups and in the adjacent limits of the old granites.
Downloads
References
Anhaeusser, C.R. (2014). Archaean greenstone belts and associated granitic rocks - A review. Journal of African Earth Sciences 100: 684-732. https://doi.org/10.1016/j.jafrearsci.2014.07.019
Araújo, A.G. de Perevalov, O.V., Guimarães, F.R., and Kondrátiev, A.I., (2001). Catálogo de Recursos Minerais de Angola. Public. Ministério de Geologia e Minas, Angola.
Astromineral (1981). Estudo de Viabilidade. Projecto de minérios de ferro e de indústria siderúrgica na República Popular de Angola. Reativação da mina de ferro em Kassinga, Vol. 1. 260p + anexos.
Batista, M.J., Lisboa, V., Represas, P., Alves, D., Prazeres, C., Oliveira, D, Pereira, E., Rodrigues, J.F., and Francés, A. (2021). Geologia Económica, in: Memória Explicativa da Carta Geológica de Angola à escala 1:500.000, UTE-2 (coords: E. Pereira, E. Ferreira, E. Merino-Martínez, J. F. Rodrigues). UTE (IGME, LNEG, Impulso) IGEO, Luanda,136 pp.
Beetz, P.F.W. (1933). Geology of South West Angola between Cunene and Lunda axis. Transactions of Geologic Society of South Africa vol. XXXVI, pp. 132-176.
Carvalho, H., and Simões, M. (1969). Contribuição para o conhecimento geológico da região de M'Popo (Cassinga). Direcção Provincial dos Serviços de Geologia e Minas, Província de Angola.
Carvalho, H. De, and Alves, P. (1993). The Precambrian of SW Angola and NW Namíbia: Instituto de Investigacao Cientifica Tropical, Série Ciencias da Terra Communicacoes, 4, 1-38.
De Witt, M., and Thiart, C. (2005). Metallogenic fingerprints of Archaean cratons . In: McDonald, L, Boyce, A. J. , Butler, I. B., Herrington, R . J. & Polya, D. A. (eds ) Mineral Deposits and Earth Evolution. Geological Society, London, Special Publications, 248, 59-70. https://doi.org/10.1144/GSL.SP.2005.248.01.03
De Wit, M.J., and Linol, B. (2015). Precambrian Basement of the Congo Basin and Its Flanking Terrains. In M.J. De Wit, F. Guillocheau, M.C.J. de Wit (eds.) Geology and Resource Potential of the Congo Basin, Regional Geology Reviews, pp. 19-37, Springer-Verlag. https://doi.org/10.1007/978-3-642-29482-2_2
Frimmel, H.E. (2008). Earth's continental crustal gold endowment. Earth and Planetary Science Letters 267, pp. 45-55. https://doi.org/10.1016/j.epsl.2007.11.022
Godinho, J. (1960). Relatório de Reconhecimento e demarcação do Claim de dragagem "Samboto", de Ouro. Relatório inédito. 5p.
Korpershoek, H. (1970). Geology of the Cassinga north area; explanatory note of the 1/50.000 geological map. Companhia Mineira do Lobito, unpublished report.
Machado e Silva S.C., Simões, J., Mira, J., Cruz, A., Godinho, J., Veiga, M., Monteiro, J., Martins, F., Neves Ferrão, C., and Mascarenhas Neto, M. (1966). Ocorrências Minerais. Direcção Provincial dos Serviços de Geologia e Minas. Província de Angola. Written and printed at Imprensa Nacional de Angola. Luanda. O.E.59-66. 59pp. 1966.
Martín-Méndez I., Feria M.C., Buzzi Marcos J., Merino-Martínez E., Rey Moral M.C., Chinchilla D., and Batista M.J. (2022a). Notícia explicativa da Carta de Recursos Minerais Metá licos de Angola, Cluster 1-Au-Fe à escala 1:50.000, Folha 361A. Ministério dos Recursos Minerais, Petróleo e Gás, UTE PLANAGEO (IGME-LNEG-Impulso) - Instituto Geológico de Angola (IGEO), Luanda, Angola, 181pp.
Martín-Méndez I., Merino Martínez E., Feria M.C., Chinchilla D., Potti J., Buzzi J., and Rey Moral M.C. (2022b). Notícia explicativa da Carta de Recursos Minerais Metálicos de Angola, Cluster 1-Au-Fe à escala 1:50.000, Folha 280B. Ministério dos Recursos Minerais, Petróleo e Gás, UTE PLANAGEO (IGME-LNEG-Impulso) - Instituto Geológico de Angola (IGEO), Luanda, Angola, 163pp.
Merino-Martínez E., Martín-Méndez I., Feria M.C., Buzzi Marcos J., Potti J., Rey Moral M.C., and Chinchilla D. (2022a). Notícia explicativa da Carta de Recursos Minerais Metálicos de Angola, Cluster 1-Au-Fe à escala 1:50.000, Folha 300C. Ministério dos Recursos Minerais, Petróleo e Gás, UTE PLANAGEO (IGME-LNEG-Impulso) - Instituto Geológico de Angola (IGEO), Luanda, Angola, 161pp.
Merino-Martínez, E., Rodrigues, J.F., Ferreira, E., Chamizo, M., Potti, J., Labaredas, J., Francés, A., Morais, A. Oliveira, A., and Pereira, E. (2022b). Mapa Geológico de Angola à escala 1:1.000.000, e Notícia Explicativa. Zona UTE, Região Sul de Angola. Ministério dos Recursos Minerais, Petróleo e Gás, UTE PLANAGEO (IGME-LNEG-Impulso) - Instituto Geológico de Angola (IGEO), Luanda, Angola, 105 p.
Meyer M., Saager, R. (1985). The gold content of some Archaean rocks and their possible relationship to epigenetic gold-quartz vein deposits. Mineralium Deposita 20, pp. 284-289. https://doi.org/10.1007/BF00204288
McKee Overseas Cooperation, USA (1975). Companhia Mineira do Lobito S.A.R.L., Pre-design and feasibility study of the Cassinga BHQ iron ore project. Volume II, Geological Report.
Kirk, J., Ruiz, J. Chesley, J., Walshe, J., and England, G. (2002). Major Archean, Gold- and Crust- Forming Event in the Kaapvaal Craton, South Africa. Science 297, 1856 (2002). https://doi.org/10.1126/science.1075270 PMid:12228713
Kirk, J., Ruiz, J. Chesley, J., Walshe, J., and England, G. (2003). The Origin of Gold in South Africa. American Scientist 94, 534-541. https://doi.org/10.1511/2003.38.534
Oliveira, J.T. (1980). O Pré-Câmbrico vulcano-sedimentar da região de Chipindo, Angola. Considerações sobre a estratigrafia e tectónica. Volume de homenagem ao Professor Doutor Carlos Teixeira. Boletim da Sociedade Geológica de Portugal, Volume XXII, pp. 315-327.
Payne, B. (1967) Gold Exploration in the southern Angolan Concessions of CML Technical Report nº792, 49p.
Pereira E., and Ferreira, E. (2021). Geologia, in: Memória Explicativa da Carta Geológica de Angola à escala 1:500.000, UTE-2 (coords: E. Pereira, E. Ferreira, E. Merino Martínez, J. F. Rodrigues). UTE PLANAGEO (IGME, LNEG, Impulso) - IGEO, Luanda,136 pp.
Pereira, L., and Osório, A. (2021). Carta Geológica de Angola à escala 1:100 000, folha 341 - Jamba e Memória Explicativa (1ª edição). UTE PLANAGEO (IGME, LNEG, Impulso) - IGEO, Luanda, 215 pp.
Pereira, L.F., Osório, A., Represas, P., Carvalho, J., Prazeres, C., Morais, I., Albardeiro, L., and Batista, M.J. (2022). Notícia explicativa da Cartade Recursos Minerais Metálicos de Angola, Cluster 1-Au-Fe à escala 1:50.000, Folha 341a. Ministério dos Recursos Minerais, Petróleo e Gás, UTE PLANAGEO (IGME-LNEG-Impulso) - Instituto Geológico de Angola (IGEO), Luanda, Angola, 109pp.
Ravansari, R., Wilson, S., and Tighe, M. (2020). Portable X-ray fluorescence for environmental assessment of soils: Not just a point and shoot method. Environmental International 134, 105250. https://doi.org/10.1016/j.envint.2019.105250 PMid:31751829 PMCid:PMC11620409
Risvic, H. (2007). Principal component analysis (PCA) & NIPALS algorithm. http://folk.uio.no/henninri/pca_module/pca_nipals.pdf
Sales, M.A.S. (1998). The Geological Setting of The Lamego Banded Iron-Formation-Hosted Gold Deposit, Quadrilátero Ferrífero District, Minas Gerais - Brazil. A thesis submitted to the Department of Geological Sciences in conformity with the requirements for the degree of Master of Science. Queen's University Kingston, Ontario, Canada, 262 p.
SOMIL (1967). Relatório técnico nº 2007-II Vol., Exemplar nº 5. Sociedade Mineira do Lombige, Nova Lisboa.
Sousa, J.C, Oliveira, A., and Máximo, J. (2021). Carta Geológica de Angola à escala 1:250.000, folha Sul D-33/V (Cuvelai) e Memória Explicativa (2ª edição). UTE (IGME, LNEG, Impulso)-IGEO, Luanda, 211pp.
Torquato, J.R., and Oliveira, J.T. (1977). Sobre a idade dos granitos e do grupo vulcano sedimentar da região de Chipindo-Angola. In: Comunicações dos Serviços Geológicos de Portugal. Tomo LXI (1977), p. 223-238.
Viljoen, M.J. (1982). The Nature and Genesis Of Archaean Gold Mineralization in Southern Africa. Revista Brasileira de Geociências 12(1-3): pp. 522-530.
Wilton, D. (1996). Banded iron formation hosted gold deposits, Part I. The Northern Miner. 27 April-3 May.
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2026 Consejo Superior de Investigaciones Científicas (CSIC)
This work is licensed under a Creative Commons Attribution 4.0 International License.
© CSIC. Manuscripts published in both the print and online versions of this journal are the property of the Consejo Superior de Investigaciones Científicas, and quoting this source is a requirement for any partial or full reproduction.
All contents of this electronic edition, except where otherwise noted, are distributed under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence. You may read the basic information and the legal text of the licence. The indication of the CC BY 4.0 licence must be expressly stated in this way when necessary.
Self-archiving in repositories, personal webpages or similar, of any version other than the final version of the work produced by the publisher, is not allowed.
