Tectonic history of the mandawa basin and the underlying basement in the coastal Tanzania: a window to the assembly, rifting and break-up of gondwana supercontinent
| dc.contributor.author | Mtabazi, Epiphania Gelas | |
| dc.date.accessioned | 2020-07-23T12:50:20Z | |
| dc.date.available | 2020-07-23T12:50:20Z | |
| dc.date.issued | 2016 | |
| dc.description | Available in print form, East Africana Collection, Dr. Wilbert Chagula Library, Class mark ( THS EAF QE653.5.M7662) | en_US |
| dc.description.abstract | Petrological, geochronological, and structural data of the Mandawa basement and sedimentary rocks in the Basin, demonstrate the Gondwana assembly in Neoproterozoic time and its subsequent break-up in Jurassic time. The basement rocks experienced peak metamorphic conditions at T = 630 - 751 °C and P = 5.8 - 8.7 kbar, indicating the amphibolite facies conditions. The metamorphic ages between ~600 and —590 Ma fall in the time window of the Kuungan Orogenic cycle (600 - 500 Ma), i.e. the final event of Gondwana amalgamation. The magmatic ages between 614 ± 18 Ma to 554 ±3.9 Ma suggest that metamorphism and magmatism were synchronous. The age of orthogneiss at 790 ± 8.7 Ma indicate Neoproterozoic protolith ages, similar to magmatism in the Eastern granulite of Tanzania and the Cabo Delgado Nappe complex of NE Mozambique. The oldest gneiss in the area has a Mesoproterozoic protolith age at 1050 ± 20 Ma similar to the records in the Unango/Marrupa Complex of NE Mozambique.nNew structural data from the field structural observations, digital elevation model (DEM), seismic and magnetic data from the Triassic-Jurassic Mandawa Basin of coastal Tanzania, suggest two major deformational events named D1 and D2 in this study. The D1 event generated the NNW-SSE trending deep-seated normal faults, and T-fractures. The geometry of these structures suggests that, the ENE-WSW extensional movements, probably associated with the rifting of Gondwanaland during Permo-Triassic time, generated them. The D2 event is related with the NNW dextral shear zone with NW-SE extensional movements, to generate the NNE-SSW, NNW-SSE and ENE-WSW Riedal shears, dextral strike slip faults, sinistral faults, normal faults and T-fractures. This event probably was associated with the drifting of Madagascar along the Davie transform fault during the Jurassic time. The geometry of Mandawa Basin suggests pull-apart origin, generated by transtensional event, followed by successive reactivation. | en_US |
| dc.identifier.citation | Mtabazi, E G (2016), Tectonic history of the mandawa basin and the underlying basement in the coastal Tanzania: a window to the assembly, rifting and break-up of gondwana supercontinent, Master dissertation, University of Dar es Salaam. Dar es Salaam | en_US |
| dc.identifier.uri | http://41.86.178.5:8080/xmlui/handle/123456789/13179 | |
| dc.language.iso | en | en_US |
| dc.publisher | University of Dar es Salaam | en_US |
| dc.subject | Geology | en_US |
| dc.subject | stratigraphic | en_US |
| dc.subject | Geology | en_US |
| dc.subject | Coastal area | en_US |
| dc.subject | Mandawa basin | en_US |
| dc.subject | Tanzania | en_US |
| dc.title | Tectonic history of the mandawa basin and the underlying basement in the coastal Tanzania: a window to the assembly, rifting and break-up of gondwana supercontinent | en_US |
| dc.type | Thesis | en_US |