The Mesoproterozoic Nampula Subdomain in southern Malawi: Completing the story from Mozambique
International audience New field mapping, lithostratigraphic, whole-rock geochemical, U–Pb zircon and radiogenic isotope data on the Nampula Subdomain of southernmost Malawi show good correlation with those published from adjacent NE and NW Mozambique. The oldest rocks, dated between ∼1180 and 1070...
Published in: | Journal of African Earth Sciences |
---|---|
Main Authors: | , , , , , , , , |
Other Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2022
|
Subjects: | |
Online Access: | https://brgm.hal.science/hal-03844437 https://doi.org/10.1016/j.jafrearsci.2022.104667 |
id |
ftccsdartic:oai:HAL:hal-03844437v1 |
---|---|
record_format |
openpolar |
spelling |
ftccsdartic:oai:HAL:hal-03844437v1 2023-12-24T10:10:57+01:00 The Mesoproterozoic Nampula Subdomain in southern Malawi: Completing the story from Mozambique Thomas, Robert Fullgraf, Thomas Macey, Paul Boger, Steven Hölttä, Pentti Lach, Philippe Le Roux, Petrus Dombola, Kondwani Zammit, Carol Council for Geosciences (CGS) Service Geologique d'Afrique du Sud Bureau de Recherches Géologiques et Minières (BRGM) (BRGM) University of Cape Town Geological Survey of Finland = Geologian tutkimuskeskus tuottaa (GKT) Geological survey Department, Malawi 2022-12 https://brgm.hal.science/hal-03844437 https://doi.org/10.1016/j.jafrearsci.2022.104667 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jafrearsci.2022.104667 hal-03844437 https://brgm.hal.science/hal-03844437 doi:10.1016/j.jafrearsci.2022.104667 ISSN: 1464-343X EISSN: 1879-1956 Journal of African Earth Sciences https://brgm.hal.science/hal-03844437 Journal of African Earth Sciences, 2022, 196, pp.104667. ⟨10.1016/j.jafrearsci.2022.104667⟩ [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2022 ftccsdartic https://doi.org/10.1016/j.jafrearsci.2022.104667 2023-11-25T23:58:30Z International audience New field mapping, lithostratigraphic, whole-rock geochemical, U–Pb zircon and radiogenic isotope data on the Nampula Subdomain of southernmost Malawi show good correlation with those published from adjacent NE and NW Mozambique. The oldest rocks, dated between ∼1180 and 1070 Ma form a complexly interlayered sequence of supracrustal layered paragneisses and migmatites (Nampula Group), intimately interlayered with intermediate-basic (Mocuba Suite) and felsic (Mamala Suite) gneisses, likely meta-volcanic and meta-plutonic in origin. The Mocuba Suite has typical calc-alkaline, I-Type granitoid, TTG compositions, with generally positive ϵNd values, NdTdm ages around 1.2 Ga and low initial 87Sr/86Sr ratios. These characteristics indicate generation in a juvenile volcanic arc setting at this time. Minor exceptions include a few samples which show limited input of Palaeoproterozoic crust. The Nampula arc is viewed as one of a number that developed in a closing oceanic basin which lay between the Archaean-Palaeoproterozoic Congo-Bangweulu-Ubendian-Tanzania cratonic blocks in the north and the Zimbabwe Craton to the SW, and which can be traced “southwards” in Gondwana to continue in the NE part of the ∼1 Ga Maud belt in East Antarctica. The Nampula arc-complex was intruded at ∼1040 by syn-to late tectonic sheets of megacrystic granite/augen gneisses of the Culicui Suite and, at ∼1000 Ma, by a number of bodies of late-to post-tectonic, massif-type anorthosite (Tengani Suite), which are unique to the Malawian segment of the Nampula Subdomain. The anorthosites are considered to have intruded at a post-tectonic stage under a late Mesoproterozoic extensional regime. The rocks underwent deformation and high grade metamorphism in both the Mesoproterozoic (Irumide) and Neoproterozoic-Cambrian (Pan-African) orogenies. P-T data suggest the latter attained peak granulite facies conditions of ∼800 °C at a maximum of 13–18 kbar, comparable with Neoproterozoic granulites in adjacent areas. The data presented ... Article in Journal/Newspaper Antarc* Antarctica East Antarctica Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) East Antarctica Mamala ENVELOPE(129.800,129.800,67.867,67.867) Journal of African Earth Sciences 196 104667 |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences Thomas, Robert Fullgraf, Thomas Macey, Paul Boger, Steven Hölttä, Pentti Lach, Philippe Le Roux, Petrus Dombola, Kondwani Zammit, Carol The Mesoproterozoic Nampula Subdomain in southern Malawi: Completing the story from Mozambique |
topic_facet |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience New field mapping, lithostratigraphic, whole-rock geochemical, U–Pb zircon and radiogenic isotope data on the Nampula Subdomain of southernmost Malawi show good correlation with those published from adjacent NE and NW Mozambique. The oldest rocks, dated between ∼1180 and 1070 Ma form a complexly interlayered sequence of supracrustal layered paragneisses and migmatites (Nampula Group), intimately interlayered with intermediate-basic (Mocuba Suite) and felsic (Mamala Suite) gneisses, likely meta-volcanic and meta-plutonic in origin. The Mocuba Suite has typical calc-alkaline, I-Type granitoid, TTG compositions, with generally positive ϵNd values, NdTdm ages around 1.2 Ga and low initial 87Sr/86Sr ratios. These characteristics indicate generation in a juvenile volcanic arc setting at this time. Minor exceptions include a few samples which show limited input of Palaeoproterozoic crust. The Nampula arc is viewed as one of a number that developed in a closing oceanic basin which lay between the Archaean-Palaeoproterozoic Congo-Bangweulu-Ubendian-Tanzania cratonic blocks in the north and the Zimbabwe Craton to the SW, and which can be traced “southwards” in Gondwana to continue in the NE part of the ∼1 Ga Maud belt in East Antarctica. The Nampula arc-complex was intruded at ∼1040 by syn-to late tectonic sheets of megacrystic granite/augen gneisses of the Culicui Suite and, at ∼1000 Ma, by a number of bodies of late-to post-tectonic, massif-type anorthosite (Tengani Suite), which are unique to the Malawian segment of the Nampula Subdomain. The anorthosites are considered to have intruded at a post-tectonic stage under a late Mesoproterozoic extensional regime. The rocks underwent deformation and high grade metamorphism in both the Mesoproterozoic (Irumide) and Neoproterozoic-Cambrian (Pan-African) orogenies. P-T data suggest the latter attained peak granulite facies conditions of ∼800 °C at a maximum of 13–18 kbar, comparable with Neoproterozoic granulites in adjacent areas. The data presented ... |
author2 |
Council for Geosciences (CGS) Service Geologique d'Afrique du Sud Bureau de Recherches Géologiques et Minières (BRGM) (BRGM) University of Cape Town Geological Survey of Finland = Geologian tutkimuskeskus tuottaa (GKT) Geological survey Department, Malawi |
format |
Article in Journal/Newspaper |
author |
Thomas, Robert Fullgraf, Thomas Macey, Paul Boger, Steven Hölttä, Pentti Lach, Philippe Le Roux, Petrus Dombola, Kondwani Zammit, Carol |
author_facet |
Thomas, Robert Fullgraf, Thomas Macey, Paul Boger, Steven Hölttä, Pentti Lach, Philippe Le Roux, Petrus Dombola, Kondwani Zammit, Carol |
author_sort |
Thomas, Robert |
title |
The Mesoproterozoic Nampula Subdomain in southern Malawi: Completing the story from Mozambique |
title_short |
The Mesoproterozoic Nampula Subdomain in southern Malawi: Completing the story from Mozambique |
title_full |
The Mesoproterozoic Nampula Subdomain in southern Malawi: Completing the story from Mozambique |
title_fullStr |
The Mesoproterozoic Nampula Subdomain in southern Malawi: Completing the story from Mozambique |
title_full_unstemmed |
The Mesoproterozoic Nampula Subdomain in southern Malawi: Completing the story from Mozambique |
title_sort |
mesoproterozoic nampula subdomain in southern malawi: completing the story from mozambique |
publisher |
HAL CCSD |
publishDate |
2022 |
url |
https://brgm.hal.science/hal-03844437 https://doi.org/10.1016/j.jafrearsci.2022.104667 |
long_lat |
ENVELOPE(129.800,129.800,67.867,67.867) |
geographic |
East Antarctica Mamala |
geographic_facet |
East Antarctica Mamala |
genre |
Antarc* Antarctica East Antarctica |
genre_facet |
Antarc* Antarctica East Antarctica |
op_source |
ISSN: 1464-343X EISSN: 1879-1956 Journal of African Earth Sciences https://brgm.hal.science/hal-03844437 Journal of African Earth Sciences, 2022, 196, pp.104667. ⟨10.1016/j.jafrearsci.2022.104667⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jafrearsci.2022.104667 hal-03844437 https://brgm.hal.science/hal-03844437 doi:10.1016/j.jafrearsci.2022.104667 |
op_doi |
https://doi.org/10.1016/j.jafrearsci.2022.104667 |
container_title |
Journal of African Earth Sciences |
container_volume |
196 |
container_start_page |
104667 |
_version_ |
1786158902129197056 |