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Structural and lithological controls of disseminated gold mineralization of the MEM2 deposit, Murchison Greenstone Belt, South Africa
Thesis (MSc)--Stellenbosch University, 2025.
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Stellenbosch : Stellenbosch University
2025
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| _version_ | 1867613963700666368 |
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| access_status_str | Open Access |
| author | Carlton, Luke Roos |
| author2 | Kisters, Alexander |
| author_browse | Carlton, Luke Roos Kisters, Alexander |
| author_facet | Kisters, Alexander Carlton, Luke Roos |
| author_sort | Carlton, Luke Roos |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MSc)--Stellenbosch University, 2025. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/132094 |
| institution | Stellenbosch University (South Africa) |
| last_indexed | 2026-06-10T12:44:29.748Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/132094 Structural and lithological controls of disseminated gold mineralization of the MEM2 deposit, Murchison Greenstone Belt, South Africa Carlton, Luke Roos Kisters, Alexander Koegelenberg, Corne Stellenbosch University. Faculty of Science. Dept. of Earth Science. Gold ores -- Geology -- South Africa -- Murchison Greenstone Belt Ore deposits -- South Africa -- Murchison Greenstone Belt Geology, Structural -- South Africa -- Archaean Sedimentation and deposition -- South Africa -- Murchison Greenstone Belt Antimony ores -- South Africa -- Murchison Range Volcanism -- South Africa -- Central Murchison UCTD Thesis (MSc)--Stellenbosch University, 2025. Carlton, L. R. 2025. Structural and Lithological Controls of Disseminated Gold Mineralization of the MEM2 Deposit, Murchison Greenstone Belt, South Africa. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/942b3ca1-2c35-4153-9fdc-c997aa6ec439 ENGLISH ABSTRACT: The Antimony Line is a 35 km-long shear zone in the central parts of the Murchison Greenstone Belt of South Africa. It exhibits both gold-only and antimony-gold polyphase mineralization, which is uncommon within most Archean greenstone belts. Despite this atypical mineral endowment, the conditions under which this polyphase mineralization developed are still poorly constrained, as previous studies have primarily focused on its world-class antimony-gold mineralization. This study characterizes the disseminated, gold-only mineralization of the MEM2 deposit, located along the eastern extent of the Antimony Line. The 3D modelling, structural mapping and petrographic analyses of the wallrocks and gold-sulphide mineralization reveal that mineralization developed as vein-hosted gold-sulphide mineralization during higher-temperature (T >500 °C) amphibolite-facies conditions, corresponding to the peak metamorphic conditions of the Central Murchison Unit. Gold mineralization, hosted by a series of felsic quartz-carbonate schists within a mafic- to ultramafic talc-chlorite schist package, has subsequently been overprinted, deformed and transposed by greenschist-facies shear bands which reflect the pervasive greenschist facies (T ~450-350 °C) retrogression of the Central Murchison Unit. Economic mineralization is hosted within mm-scale, discontinuous and boudinaged quartz-carbonate-sulphide lenses and stringers that are overprinted and enveloped by anastomosing, finer-grained, high-strain shear bands. The intensity of the structural overprint is such that, on a micro- to deposit-scale, gold mineralization has been completely remobilized and attenuated into the pervasive greenschist-facies subvertical foliation and steeply plunging lineation fabrics of the Antimony Line. Despite this extensive structural overprint, the preservation of the high-temperature mineralization is attributed to MEM2’s position within a subtle 20° clockwise rotation in the subvertical foliation, constituting a restraining bend within the Antimony Line. Contraction along this bend during sinistral-transpressional deformation resulted in a relatively low fluid influx during retrograde deformation. The recognition of this higher-temperature, amphibolite-facies gold-only mineralization and its subsequent greenschist-facies overprint, allows for the temporal contextualization of the gold-only and antimony-gold polyphase mineralization along the Antimony Line. This study suggests that the gold-only mineralization, such as that at MEM2, occurred earlier within the metamorphic evolution of the Central Murchison Unit with antimony-gold mineralization developed during later, lower-temperature, greenschist-facies conditions. AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar. Masters 2025-05-23T08:00:23Z 2025-05-23T08:00:23Z 2025-03 Thesis https://scholar.sun.ac.za/handle/10019.1/132094 Stellenbosch University viii, 103 pages : illustrations, maps application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Gold ores -- Geology -- South Africa -- Murchison Greenstone Belt Ore deposits -- South Africa -- Murchison Greenstone Belt Geology, Structural -- South Africa -- Archaean Sedimentation and deposition -- South Africa -- Murchison Greenstone Belt Antimony ores -- South Africa -- Murchison Range Volcanism -- South Africa -- Central Murchison UCTD Carlton, Luke Roos Structural and lithological controls of disseminated gold mineralization of the MEM2 deposit, Murchison Greenstone Belt, South Africa |
| title | Structural and lithological controls of disseminated gold mineralization of the MEM2 deposit, Murchison Greenstone Belt, South Africa |
| title_full | Structural and lithological controls of disseminated gold mineralization of the MEM2 deposit, Murchison Greenstone Belt, South Africa |
| title_fullStr | Structural and lithological controls of disseminated gold mineralization of the MEM2 deposit, Murchison Greenstone Belt, South Africa |
| title_full_unstemmed | Structural and lithological controls of disseminated gold mineralization of the MEM2 deposit, Murchison Greenstone Belt, South Africa |
| title_short | Structural and lithological controls of disseminated gold mineralization of the MEM2 deposit, Murchison Greenstone Belt, South Africa |
| title_sort | structural and lithological controls of disseminated gold mineralization of the mem2 deposit murchison greenstone belt south africa |
| topic | Gold ores -- Geology -- South Africa -- Murchison Greenstone Belt Ore deposits -- South Africa -- Murchison Greenstone Belt Geology, Structural -- South Africa -- Archaean Sedimentation and deposition -- South Africa -- Murchison Greenstone Belt Antimony ores -- South Africa -- Murchison Range Volcanism -- South Africa -- Central Murchison UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/132094 |
| work_keys_str_mv | AT carltonlukeroos structuralandlithologicalcontrolsofdisseminatedgoldmineralizationofthemem2depositmurchisongreenstonebeltsouthafrica |