The role of pre-existing Precambrian structures in the development of Rukwa Rift Basin, southwest Tanzania

Lemna, O. S.; Stephenson, Randell; Cornwell, David G.

doi:10.1016/j.jafrearsci.2018.09.015

Cited by 22 publications

(22 citation statements)

References 92 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Further south, the curvilinear gradient connects with the Livingstone Fault, the northeastern border fault of the Northern Malawi Rift. This connecting magnetic gradient was highlighted in a recent study (Lemna et al, 2018). The curvilinear gradient coincides with the location and extent of the "Ngozi-Rungwe Line" of Fontijn et al (2010), described as a buried fault system that served as a conduit for magmatic fluids to migrate to the surface volcanic vents.…”

Section: The Northeastern Boundary Of the Rnmrs And Relationships Witsupporting

confidence: 55%

“…The tip of the Northern Ufipa Fault segment terminates against the WNW‐ESE Chisi Fault at a high angle (Figure a). The Chisi Fault aligns with a strong WNW‐ESE magnetic‐high lineament (discrete fabric; Figures b and c) consistent with the Chisi Suture Zone, which extends eastward into the rift basin (Boven et al, ; Boniface & Schenk, ; Lemna et al, ; Theunissen et al, ; Figure b). Also, the truncated Ufipa Fault segment aligns with the Ufipa Terrane basement fabrics (distributed fabrics).…”

Section: Resultsmentioning

confidence: 78%

“…The Ubendian Belt was reactivated several times, preserving geochronologic, petrographic, and geochemical evidence of successive terrane accretion (e.g., Boniface et al, ; Boniface & Schenk, ; Lenoir et al, ). Known terranes within the Ubendian Belt are separated by shear zones which include the Mughese Shear Zone, the Mtose Shear Zone (Figure ; Daly, ; Delvaux et al, ), and the Chisi Suture Zone which represents the major suture zone between the Precambrian Tanzania Craton and the Bangweulu Block (Boniface & Schenk, ; Lemna et al, ). Several studies have highlighted the role of these shear zones in fault development and the distribution of seismicity in southern Tanzania and northern Malawi (e.g., Camelbeeck & Iranga, ; Dawson et al, ; Delvaux et al, ; Kolawole et al, ; Lemna et al, ; Morley et al, ; Morley, ).…”

Section: Geologic Settingmentioning

confidence: 99%

“…Tectonics (Boven et al, 1999;Lemna et al, 2018;Theunissen et al, 1996;Figure 2b). Also, the truncated Ufipa Fault segment aligns with the Ufipa Terrane basement fabrics (distributed fabrics).…”

Section: 1029/2018tc005362mentioning

confidence: 99%

“…Mechanically, they represent areas of structural weakness that can become reactivated and allow rifts to propagate preferentially along them (e.g., Daly et al, 1989). Several studies have documented the relationships between rift faults and the preexisting basement fabrics (e.g., Corti, 2012;Corti et al, 2007;Katumwehe et al, 2015;Kinabo et al, 2007Kinabo et al, , 2008Kolawole et al, 2018;Lemna et al, 2018;Morley, 1999aMorley, , 2010Morley et al, 2004;Phillips et al, 2016;Siuda et al, 2018;Taylor et al, 2011;Wheeler & Karson, 1989). Further, recent studies have assessed the three-dimensional relationship between preexisting basement thrusts and extensional structures, revealing the control of the preexisting basement structures on the nucleation and strain distribution along the normal faults (e.g., Collanega et al, 2018;Kolawole et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Controls of Basement Fabric on the Linkage of Rift Segments

et al. 2019

View full text Add to dashboard Cite

The Rukwa and North Malawi Rift Segments (RNMRS) both define a major rift‐oblique segment of the East African Rift System and are often regarded as discrete rifts due to the presence of the uplifted Mbozi block between them. Here we investigate the influence of basement fabrics on the coupling and linkage of border faults across an interrift transfer zone between discrete juvenile rift segments. We utilized satellite digital elevation model to investigate the morphological architecture of the rift domains and aeromagnetic data to assess the relationships (plan view) between the rift structures and the prerift basement fabrics. Our results show that the present‐day morphology of the RNMRS is characterized by along‐rift alternation of rift shoulder polarity, characteristic of coupled rift segments. Interpretation of filtered aeromagnetic maps along the boundaries of the RNMRS reveals striking alignment of the rift‐bounding faults with colinear NW‐SE trending preexisting basement fabrics. We find that rift coupling along the NE boundary of the Mbozi transfer zone is accommodated by fault‐assisted magma plumbing, whereas coupling along the SW boundary is accommodated by strike‐slip and oblique‐normal faulting that reactivated the Proterozoic Mughese shear zone, within the collisional boundary between the Tanzania craton and the Bangweulu cratonic block. Further, we show how the configuration of the basement fabrics may influence the formation of rift bifurcation across inter‐rift transfer zones. We suggest that the structural connectivity of the boundary faults along the RNMRS and their alignment with colinear basement fabrics demonstrate the influence of structural inheritance on the amalgamation of approaching rift segments.

show abstract

Section: The Northeastern Boundary Of the Rnmrs And Relationships Witsupporting

confidence: 55%

Section: Resultsmentioning

confidence: 78%

Section: Geologic Settingmentioning

confidence: 99%

Section: 1029/2018tc005362mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Controls of Basement Fabric on the Linkage of Rift Segments

et al. 2019

View full text Add to dashboard Cite

show abstract

Strain Localization and Migration During the Pulsed Lateral Propagation of the Shire Rift Zone, East Africa

Kolawole

Vick

Atekwana³

et al. 2022

Preprint

View full text Add to dashboard Cite

We investigate the spatiotemporal patterns of strain accommodation during multiphase rift evolution in the Shire Rift Zone (SRZ), East Africa. The NW-trending SRZ records a transition from magma-rich rifting phases (Permian-Early Jurassic: Rift-Phase 1 (RP1), and Late Jurassic-Cretaceous: Rift-Phase 2 (RP2)) to a magma-poor phase in the Cenozoic (ongoing: Rift-Phase 3 (RP3)). Our observations show that although the rift border faults largely mimic the pre-rift basement metamorphic fabrics, the rift termination zones occur near crustal-scale rift-orthogonal basement shear zones (Sanangoe (SSZ) and the Lurio shear zones) during RP1-RP2. In RP3, the RP1-RP2 sub-basins were largely abandoned, and the rift axes migrated northeastward (rift-orthogonally) into the RP1-RP2 basin margin, and northwestward (strike-parallel) ahead of the RP2 rift-tip.The northwestern RP3 rift-axis side-steps across the SSZ, with a rotation of border faults across the shear zone and terminates further northwest at another regional-scale shear zone. We suggest that over the multiple pulses of tectonic extension and strain migration in the SRZ, pre-rift basement fabrics acted as: 1) zones of mechanical strength contrast that localized the large rift faults, and 2) mechanical 'barriers' that refracted and possibly, temporarily halted the propagation of the rift zone. Further, the cooled RP1-RP2 mafic dikes facilitated later-phase deformation in the form of border fault hard-linking transverse faults that exploited mechanical anisotropies within the dike clusters and served as mechanically-strong zones that arrested some of the RP3 fault-tips. Overall, we argue that during pulsed rift propagation, inherited strength anisotropies can serve as both strain-localizing, refracting, and transient strain-inhibiting tectonic structures.

show abstract

A strike slip fault dynamic and seismic hazard implications on the future big event: insights from the Mw 5.5 Rukwa earthquake of 21 March 2019

Mulibo

2024

Acta Geophys.

View full text Add to dashboard Cite

The role of pre-existing Precambrian structures in the development of Rukwa Rift Basin, southwest Tanzania

Cited by 22 publications

References 92 publications

Controls of Basement Fabric on the Linkage of Rift Segments

Controls of Basement Fabric on the Linkage of Rift Segments

Strain Localization and Migration During the Pulsed Lateral Propagation of the Shire Rift Zone, East Africa

A strike slip fault dynamic and seismic hazard implications on the future big event: insights from the Mw 5.5 Rukwa earthquake of 21 March 2019

Contact Info

Product

Resources

About