@article{NeuharthBruneWronaetal.2022,
  author    = {Neuharth, Derek and Brune, Sascha and Wrona, Thilo and Glerum, Anne and Braun, Jean and Yuan, Xiaoping},
  title     = {Evolution of rift systems and their fault networks in response to surface processes},
  series = {Tectonics},
  volume    = {41},
  journal   = {Tectonics},
  number    = {3},
  publisher = {American Geophysical Union},
  address   = {Washington},
  issn      = {0278-7407},
  doi       = {10.1029/2021TC007166},
  pages     = {22},
  year      = {2022},
  abstract  = {Continental rifting is responsible for the generation of major sedimentary basins, both during rift inception and during the formation of rifted continental margins. Geophysical and field studies revealed that rifts feature complex networks of normal faults but the factors controlling fault network properties and their evolution are still matter of debate. Here, we employ high-resolution 2D geodynamic models (ASPECT) including two-way coupling to a surface processes (SP) code (FastScape) to conduct 12 models of major rift types that are exposed to various degrees of erosion and sedimentation. We further present a novel quantitative fault analysis toolbox (Fatbox), which allows us to isolate fault growth patterns, the number of faults, and their length and displacement throughout rift history. Our analysis reveals that rift fault networks may evolve through five major phases: (a) distributed deformation and coalescence, (b) fault system growth, (c) fault system decline and basinward localization, (d) rift migration, and (e) breakup. These phases can be correlated to distinct rifted margin domains. Models of asymmetric rifting suggest rift migration is facilitated through both ductile and brittle deformation within a weak exhumation channel that rotates subhorizontally and remains active at low angles. In sedimentation-starved settings, this channel satisfies the conditions for serpentinization. We find that SP are not only able to enhance strain localization and to increase fault longevity but that they also reduce the total length of the fault system, prolong rift phases and delay continental breakup.},
  language  = {en}
}
@article{NeuharthBruneGlerumetal.2021,
  author    = {Neuharth, Derek and Brune, Sascha and Glerum, Anne and Morley, Chris K. and Yuan, Xiaoping and Braun, Jean},
  title     = {Flexural strike-slip basins},
  series = {Geology : a venture in earth science reporting / the Geological Society of America},
  volume    = {50},
  journal   = {Geology : a venture in earth science reporting / the Geological Society of America},
  number    = {3},
  publisher = {American Institute of Physics},
  address   = {Boulder},
  issn      = {0091-7613},
  doi       = {10.1130/G49351.1},
  pages     = {361 -- 365},
  year      = {2021},
  abstract  = {Strike-slip faults are classically associated with pull-apart basins where continental crust is thinned between two laterally offset fault segments. We propose a subsidence mechanism to explain the formation of a new type of basin where no substantial segment offset or synstrike-slip thinning is observed. Such "flexural strike-slip basins" form due to a sediment load creating accommodation space by bending the lithosphere. We use a two-way coupling between the geodynamic code ASPECT and surface-processes code FastScape to show that flexural strike-slip basins emerge if sediment is deposited on thin lithosphere close to a strike slip fault. These conditions were met at the Andaman Basin Central fault (Andaman Sea, Indian Ocean), where seismic reflection data provide evidence of a laterally extensive flexural basin with a depocenter located parallel to the strike-slip fault trace.},
  language  = {en}
}
@article{RichterBruneRiedletal.2021,
  author    = {Richter, Maximilian and Brune, Sascha and Riedl, Simon and Glerum, Anne and Neuharth, Derek and Strecker, Manfred},
  title     = {Controls on asymmetric rift dynamics},
  series = {Tectonics / American Geophysical Union, AGU ; European Geophysical Society, EGS},
  volume    = {40},
  journal   = {Tectonics / American Geophysical Union, AGU ; European Geophysical Society, EGS},
  number    = {5},
  publisher = {American Geophysical Union},
  address   = {Washington},
  issn      = {0278-7407},
  doi       = {10.1029/2020TC006553},
  pages     = {21},
  year      = {2021},
  abstract  = {Complex, time-dependent, and asymmetric rift geometries are observed throughout the East African Rift System (EARS) and are well documented, for instance, in the Kenya Rift. To unravel asymmetric rifting processes in this region, we conduct 2D geodynamic models. We use the finite element software ASPECT employing visco-plastic rheologies, mesh-refinement, distributed random noise seeding, and a free surface. In contrast to many previous numerical modeling studies that aimed at understanding final rifted margin symmetry, we explicitly focus on initial rifting stages to assess geodynamic controls on strain localization and fault evolution. We thereby link to geological and geophysical observations from the Southern and Central Kenya Rift. Our models suggest a three-stage early rift evolution that dynamically bridges previously inferred fault-configuration phases of the eastern EARS branch: (1) accommodation of initial strain localization by a single border fault and flexure of the hanging-wall crust, (2) faulting in the hanging-wall and increasing upper-crustal faulting in the rift-basin center, and (3) loss of pronounced early stage asymmetry prior to basinward localization of deformation. This evolution may provide a template for understanding early extensional faulting in other branches of the East African Rift and in asymmetric rifts worldwide. By modifying the initial random noise distribution that approximates small-scale tectonic inheritance, we show that a spectrum of first-order fault configurations with variable symmetry can be produced in models with an otherwise identical setup. This approach sheds new light on along-strike rift variability controls in active asymmetric rifts and proximal rifted margins.},
  language  = {en}
}
@article{GlerumBruneStampsetal.2020,
  author    = {Glerum, Anne and Brune, Sascha and Stamps, D. Sarah and Strecker, Manfred},
  title     = {Victoria continental microplate dynamics controlled by the lithospheric strength distribution of the East African Rift},
  series = {Nature Communications},
  volume    = {11},
  journal   = {Nature Communications},
  number    = {1},
  publisher = {Nature Publishing Group},
  address   = {London},
  issn      = {2041-1723},
  doi       = {10.1038/s41467-020-16176-x},
  pages     = {15},
  year      = {2020},
  abstract  = {The Victoria microplate between the Eastern and Western Branches of the East African Rift System is one of the largest continental microplates on Earth. In striking contrast to its neighboring plates, Victoria rotates counterclockwise with respect to Nubia. The underlying cause of this distinctive rotation has remained elusive so far. Using 3D numerical models, we investigate the role of pre-existing lithospheric heterogeneities in continental microplate rotation. We find that Victoria's rotation is primarily controlled by the distribution of rheologically stronger zones that transmit the drag of the major plates to the microplate and of the mechanically weaker mobile belts surrounding Victoria that facilitate rotation. Our models reproduce Victoria's GPS-derived counterclockwise rotation as well as key complexities of the regional tectonic stress field. These results reconcile competing ideas on the opening of the rift system by highlighting differences in orientation of the far-field divergence, local extension, and the minimum horizontal stress. One of the largest continental microplates on Earth is situated in the center of the East African Rift System, and oddly, the Victoria microplate rotates counterclockwise with respect to the neighboring African tectonic plate. Here, the authors' modelling results suggest that Victoria microplate rotation is caused by edge-driven lithospheric processes related to the specific geometry of rheologically weak and strong regions.},
  language  = {en}
}
@article{RajaonarisonStampsFishwicketal.2020,
  author    = {Rajaonarison, Tahiry A. and Stamps, D. Sarah and Fishwick, Stewart and Brune, Sascha and Glerum, Anne and Hu, Jiashun},
  title     = {Numerical modeling of mantle flow beneath Madagascar to constrain upper mantle rheology beneath continental regions},
  series = {Journal of geophysical research : Solid earth},
  volume    = {125},
  journal   = {Journal of geophysical research : Solid earth},
  number    = {2},
  publisher = {American Geophysical Union},
  address   = {Washington},
  issn      = {2169-9313},
  doi       = {10.1029/2019JB018560},
  pages     = {23},
  year      = {2020},
  abstract  = {Over the past few decades, azimuthal seismic anisotropy measurements have been widely used proxy to study past and present-day deformation of the lithosphere and to characterize convection in the mantle. Beneath continental regions, distinguishing between shallow and deep sources of anisotropy remains difficult due to poor depth constraints of measurements and a lack of regional-scale geodynamic modeling. Here, we constrain the sources of seismic anisotropy beneath Madagascar where a complex pattern cannot be explained by a single process such as absolute plate motion, global mantle flow, or geology. We test the hypotheses that either Edge-Driven Convection (EDC) or mantle flow derived from mantle wind interactions with lithospheric topography is the dominant source of anisotropy beneath Madagascar. We, therefore, simulate two sets of mantle convection models using regional-scale 3-D computational modeling. We then calculate Lattice Preferred Orientation that develops along pathlines of the mantle flow models and use them to calculate synthetic splitting parameters. Comparison of predicted with observed seismic anisotropy shows a good fit in northern and southern Madagascar for the EDC model, but the mantle wind case only fits well in northern Madagascar. This result suggests the dominant control of the measured anisotropy may be from EDC, but the role of localized fossil anisotropy in narrow shear zones cannot be ruled out in southern Madagascar. Our results suggest that the asthenosphere beneath northern and southern Madagascar is dominated by dislocation creep. Dislocation creep rheology may be dominant in the upper asthenosphere beneath other regions of continental lithosphere.},
  language  = {en}
}
@article{NaliboffGlerumBruneetal.2020,
  author    = {Naliboff, John B. and Glerum, Anne and Brune, Sascha and P{\´e}ron-Pinvidic, G. and Wrona, Thilo},
  title     = {Development of 3-D rift heterogeneity through fault network evolution},
  series = {Geophysical Research Letters},
  volume    = {47},
  journal   = {Geophysical Research Letters},
  number    = {13},
  publisher = {John Wiley \& Sons, Inc.},
  address   = {New Jersey},
  pages     = {11},
  year      = {2020},
  abstract  = {Observations of rift and rifted margin architecture suggest that significant spatial and temporal structural heterogeneity develops during the multiphase evolution of continental rifting. Inheritance is often invoked to explain this heterogeneity, such as preexisting anisotropies in rock composition, rheology, and deformation. Here, we use high-resolution 3-D thermal-mechanical numerical models of continental extension to demonstrate that rift-parallel heterogeneity may develop solely through fault network evolution during the transition from distributed to localized deformation. In our models, the initial phase of distributed normal faulting is seeded through randomized initial strength perturbations in an otherwise laterally homogeneous lithosphere extending at a constant rate. Continued extension localizes deformation onto lithosphere-scale faults, which are laterally offset by tens of km and discontinuous along-strike. These results demonstrate that rift- and margin-parallel heterogeneity of large-scale fault patterns may in-part be a natural byproduct of fault network coalescence.},
  language  = {en}
}
@article{CortiCioniFranceschinietal.2019,
  author    = {Corti, Giacomo and Cioni, Raffaello and Franceschini, Zara and Sani, Federico and Scaillet, Stephane and Molin, Paola and Isola, Ilaria and Mazzarini, Francesco and Brune, Sascha and Keir, Derek and Erbello Doelesso, Asfaw and Muluneh, Ameha and Illsley-Kemp, Finnigan and Glerum, Anne},
  title     = {Aborted propagation of the Ethiopian rift caused by linkage with the Kenyan rift},
  series = {Nature Communications},
  volume    = {10},
  journal   = {Nature Communications},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {2041-1723},
  doi       = {10.1038/s41467-019-09335-2},
  pages     = {11},
  year      = {2019},
  abstract  = {Continental rift systems form by propagation of isolated rift segments that interact, and eventually evolve into continuous zones of deformation. This process impacts many aspects of rifting including rift morphology at breakup, and eventual ocean-ridge segmentation. Yet, rift segment growth and interaction remain enigmatic. Here we present geological data from the poorly documented Ririba rift (South Ethiopia) that reveals how two major sectors of the East African rift, the Kenyan and Ethiopian rifts, interact. We show that the Ririba rift formed from the southward propagation of the Ethiopian rift during the Pliocene but this propagation was short-lived and aborted close to the Pliocene-Pleistocene boundary. Seismicity data support the abandonment of laterally offset, overlapping tips of the Ethiopian and Kenyan rifts. Integration with new numerical models indicates that rift abandonment resulted from progressive focusing of the tectonic and magmatic activity into an oblique, throughgoing rift zone of near pure extension directly connecting the rift sectors.},
  language  = {en}
}