Article
Geosciences, Multidisciplinary
David Iacopini, Stefano Tavani, Sara Pentagallo, Vittorio Maselli, Marina Dottore Stagna, Cynthia Ebinger, David Reynolds, Arjan van Vliet
Summary: The southeastern portion of the East African Rift System has seen the reactivation of Mesozoic transform faults, indicating the separation of Madagascar from Africa. The Seagap fault zone, which affects the Tanzania margin, has been continuously active from the late Eocene to the present day. The fault's architecture is expressed through localized structures on the seafloor, with growth geometries observed in the Miocene sediments.
Article
Geochemistry & Geophysics
Maren Vormann, Wilfried Jokat
Summary: The study reveals the influence of the Davie Fracture Zone on the crustal structure in the northern Mozambique offshore area, with the formation of a continent-ocean transition zone due to rift activity. Despite recent seismicity, no significant crustal modifications or reduced seismic velocities were observed. The geological structures in the research area may have formed during an early Jurassic stage, with some regions possibly reactivated in a strike-slip sense during the Neogene.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geosciences, Multidisciplinary
Francesca Innocenzi, Sara Ronca, Stephen Foley, Samuele Agostini, Michele Lustrino
Summary: This study investigates two volcanic provinces in the western branch of the East African Rift and finds that the volcanic products show wide variability in chemical and mineralogical characteristics. Petrographic and geochemical analysis reveals enriched and heterogeneous sub-lithospheric mantle sources. The differences in isotopic features between the two volcanic provinces may indicate changes in the composition, mineralogy, and depth of melting in the lithospheric mantle source.
Article
Geosciences, Multidisciplinary
Laurent Michon, Vincent Famin, Xavier Quidelleur
Summary: Through studying the East African Rift System, we have found a complex spatial and temporal relationship between rift and magmatic activity, leading to the identification of two distinct regimes of volcanism in the rift system.
EARTH-SCIENCE REVIEWS
(2022)
Article
Geochemistry & Geophysics
Felicie Korostelev, Yang Lu, Fabrizio Magrini, Lapo Boschi, Sylvie Leroy, William Vetel
Summary: This study maps the entire East African Rift System (EARS) using a global surface-wave velocity model in order to understand the underlying mantle structure and its relationship with the Mozambique Channel. By analyzing seismic data from the African continent, the researchers obtain dispersion curves and phase-velocity maps, revealing the discontinuous nature of magmatic activity along the EARS and low-velocity anomalies beneath certain volcanic islands and seamounts. The presence of a low-velocity anomaly in the Mozambique Channel suggests the existence of an important magmatic system.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Engineering, Civil
Joanna M. Holmgren, Maximilian J. Werner, Katsuichiro Goda, Manuela Villani, Vitor Silva, Patrick Chindandali, Victoria Stevens
Summary: This article introduces a newly compiled ground motion database for the southern East African rift system, which includes waveform records of 882 earthquakes from 1994 to 2022. It provides essential data for ground motion studies in the region.
EARTHQUAKE SPECTRA
(2023)
Article
Multidisciplinary Sciences
Rene Dommain, Simon Riedl, Lydia A. Olaka, Peter deMenocal, Alan L. Deino, R. Bernhart Owen, Veronica Muiruri, Johannes Mueller, Richard Potts, Manfred R. Strecker
Summary: This study reconstructs a river system that existed for thousands of years in the Kenya Rift Valley and explores its influence on the postglacial dispersal of fishes and mammals. The degree of hydrological connectivity between adjacent river basins determines the spatial diversity gradients for East African fishes. The findings contribute to our understanding of the drivers behind diversity gradients and the assembly of species diversity in the East African biodiversity hotspot.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Multidisciplinary Sciences
Athanas S. Macheyeki, Hassan Mdala
Summary: The stress kinematics of the Nyasa/Malawi rift (NMR) has sparked a debate, with some viewing it as a transform fault and others as a rift structure characterized by normal faulting. By conducting paleostress analysis and studying focal mechanisms, it has been found that the central part of the rift experiences radial or sub-radial extension, while the southern half is subject to oblique transtensive tectonic forces. Fault slip data shows that the NMR primarily experiences normal faulting regime, with a significant strike-slip component.
Article
Geology
D. S. Stamps, C. Kreemer, R. Fernandes, T. A. Rajaonarison, G. Rambolamanana
Summary: The East African Rift System plate geometries and surface motions are among the least constrained in global plate motion models. Through the use of GPS data and geological data, it was found that Madagascar is fragmenting, with southern Madagascar rotating with the Lwandle microplate, and eastern and south-central Madagascar moving with the Somalian plate.
Article
Geochemistry & Geophysics
Tahiry A. Rajaonarison, D. Sarah Stamps, John Naliboff, Andrew Nyblade, Emmanuel A. Njinju
Summary: Geodynamicists use high-resolution 3D thermomechanical models to investigate the forces driving continental rifting in the East African Rift. They find that the anomalous surface deformation and seismic anisotropy in the rift are primarily driven by northward mantle flow associated with the African Superplume.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Review
Multidisciplinary Sciences
Juliet Biggs, Atalay Ayele, Tobias P. Fischer, Karen Fontijn, William Hutchison, Emmanuel Kazimoto, Kathy Whaler, Tim J. Wright
Summary: New observations of volcanic and magmatic activity in Africa are reshaping our understanding of continental rifting and highlighting the associated hazards. Despite efforts to shift from crisis response to reducing disaster risks, limited capacity in sub-Saharan Africa hinders effective mitigation of geohazards.
NATURE COMMUNICATIONS
(2021)
Article
Geochemistry & Geophysics
F. Albino, J. Biggs
Summary: The study utilized Sentinel-1 data to provide InSAR time series along the East African Rift System (EARS) from 2015 to 2020, detecting 18 ground deformation signals on 14 volcanoes including Tullu Moje and Suswa. The results show that around 20% of Holocene volcanoes in the EARS deformed during this 5-year period, demonstrating the diversity of processes occurring.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Geochemistry & Geophysics
G. Boudoire, G. Giuffrida, M. Liuzzo, N. Bobrowski, S. Calabrese, J. Kuhn, J-C Kazadi Mwepu, F. Grassa, S. Caliro, A. L. Rizzo, F. Italiano, M. Yalire, K. Karume, A. Muhindo Syavulisembo, D. Tedesco
Summary: The chemical composition of volcanic gas emissions and fumaroles at Nyiragongo and Nyamulagira in the Democratic Republic of Congo provides insights into the origin of magmatic fluids along the East African Rift System. The study suggests that these volcanic fluids mainly come from the Sub-Continental Lithospheric Mantle (SCLM) or the Depleted Morb Mantle (DMM) and deeper sources. Additionally, carbonate metasomatism in the lithospheric mantle source contributes to the high CO2/He-3 ratio in the fumaroles.
Article
Geochemistry & Geophysics
N. S. Muravyeva, V. G. Senin, A. Ivanov, B. Belyatsky
Summary: The detailed investigation of leucite basanites from the Visoke and Muhavura volcanoes in the Virunga province revealed that the rocks are likely derived from an enriched mantle source and have been contaminated by deep metamorphic rocks. The isotopic composition suggests a complex origin involving processes such as mantle melting, fractional crystallization, magma mixing, and crustal contamination.
Article
Geochemistry & Geophysics
Emma L. Chambers, Nicholas Harmon, Catherine A. Rychert, Derek Keir
Summary: The seismic data inversion results in the magmatically rifting area show that melt is mainly stored in sills, and as the rift widens, vertical dyke intrusion becomes dominant. The largest anisotropy is observed in the upper part of the rift, and the influence of vertical micro-cracks and dykes on the rift center gradually weakens.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Review
Geosciences, Multidisciplinary
Gillian R. Foulger, Tony Dore, C. Henry Emeleus, Dieter Franke, Laurent Geoffroy, Laurent Gernigon, Richard Hey, Robert E. Holdsworth, Malcolm Hole, Armann Hoskuldsson, Bruce Julian, Nick Kusznir, Fernando Martinez, Ken J. W. McCaffrey, James H. Natland, Alexander L. Peace, Kenni Petersen, Christian Schiffer, Randell Stephenson, Martyn Stoker
EARTH-SCIENCE REVIEWS
(2020)
Correction
Geosciences, Multidisciplinary
Michael C. Drews, Wolfgang Bauer, Luca Caracciolo, Harald Stollhofen
MARINE AND PETROLEUM GEOLOGY
(2020)
Article
Geochemistry & Geophysics
Maren Vormann, Dieter Franke, Wilfried Jokat
Article
Anthropology
S. Hoare, J. S. Brink, A. I. R. Herries, D. F. Mark, L. E. Morgan, I. Onjala, S. M. Rucina, I. G. Stanistreet, H. Stollhofen, J. A. J. Gowlett
Summary: This study reports a newly extended stratigraphic sequence with associated Palaeolithic sites from the area of the extinct Kilombe volcano in central Kenya. The sedimentary sequences within the Kilombe caldera and south flanks of the mountain have been accurately dated through 40Ar/39Ar measurements and palaeomagnetic studies. These sites attest to hominin activity from an Oldowan horizon dated to 1.8 Ma up to Later Stone Age stone scatters within the last 100,000 years.
JOURNAL OF ARCHAEOLOGICAL SCIENCE
(2021)
Review
Geosciences, Multidisciplinary
Youssef Biari, Frauke Klingelhoefer, Dieter Franke, Thomas Funck, Lies Loncke, Jean-Claude Sibuet, Christophe Basile, James A. Austin, Caesar Augusto Rigoti, Mohamed Sahabi, Massinissa Benabdellouahed, Walter R. Roest
Summary: Deep seismic data and plate kinematic reconstructions were used to analyze the mechanisms of rifting at the Atlantic margins, focusing on the development of magma-rich and magma-poor margins and the role of inheritance in break-up processes. The study also investigated the formation and origin of transform marginal plateaus, characterized by volcanic phases, along the border of two ocean basins of different ages. Results showed variations in crustal thickness, oceanic plate thickness, and the influence of volcanism along the Atlantic margins.
MARINE AND PETROLEUM GEOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Rudiger Lutz, Peter Klitzke, Philipp Weniger, Martin Blumenberg, Dieter Franke, Lutz Reinhardt, Axel Ehrhardt, Kai Berglar
Summary: The Olga Basin, located in the northern Barents Sea, shows signs of active petroleum systems with gas seepage, but the impact of erosion on petroleum generation remains debated.
MARINE AND PETROLEUM GEOLOGY
(2021)
Article
Multidisciplinary Sciences
Stefan Ladage, Martin Blumenberg, Dieter Franke, Andreas Bahr, Ruediger Lutz, Sandro Schmidt
Summary: Methane emissions along the natural gas supply chain play a critical role in the climate benefits of switching from coal to natural gas in the power sector. For Germany, with methane leakage rates below specific break-even levels, transitioning to natural gas can significantly reduce CO2-equivalent GHG emissions.
SCIENTIFIC REPORTS
(2021)
Article
Geosciences, Multidisciplinary
D. Koeehn, S. Koeehler, R. Toussaint, I. Ghani, H. Stollhofen
Summary: Stylolites are rough dissolution surfaces that exhibit three different scaling regimes in space and time. These regimes are determined by the domination of surface or elastic energy, resulting in different growth and roughness exponents. There are also transitional and correlation length scales that determine the transition between scaling regimes and the constant amplitude on large scales. These scaling regimes can be observed in both numerical and natural stylolites.
JOURNAL OF STRUCTURAL GEOLOGY
(2022)
Article
Geosciences, Multidisciplinary
James Granath, Ansgar Wanke, Harald Stollhofen
Summary: This study conducts a structural analysis of the Waterberg Thrust in northern Namibia, clarifying its relationship to the deposition of Karoo sediments. The fault brings older crystalline rocks up against younger Karoo sediments, and the study also identifies various folds and unconformities.
JOURNAL OF STRUCTURAL GEOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Saskia Koehler, Florian Duschl, Hamed Fazlikhani, Daniel Koehn, Tobias Stephan, Harald Stollhofen
Summary: This study reconstructs the spatio-temporal variations of post-Triassic palaeostress fields in the Franconian Platform and Triassic strata, revealing a cyclic stress evolution from normal faulting to thrusting, strike-slip and back to normal faulting. Five main stress fields correlating with two stress cycles are determined for Late Jurassic to Cenozoic time.
GEOLOGICAL MAGAZINE
(2022)
Article
Multidisciplinary Sciences
Daniel Sauter, Gianreto Manatschal, Nick Kusznir, Charles Masquelet, Philippe Werner, Marc Ulrich, Paul Bellingham, Dieter Franke, Julia Autin
Summary: The source of massive magma production at volcanic rifted margins remains disputed. Accurate estimation of extruded and intruded melt products within rifted continental crust is still lacking using geophysical methods. This study investigates the magma budget along the South Atlantic margins, revealing that most of the southernmost Atlantic Ocean opened without anomalously hot mantle and high magma supply. Alternative explanations should be favored to explain the thick magmatic layer.
SCIENTIFIC REPORTS
(2023)
Article
Geosciences, Multidisciplinary
Charles Masquelet, Sylvie Leroy, Matthias Delescluse, Nicolas Chamot-Rooke, Isabelle Thinon, Anne Lemoine, Dieter Franke, Louise Watremez, Philippe Werner, Fabien Paquet, Carole Berthod, Victor Cabiativa Pico, Daniel Sauter
Summary: A multichannel seismic reflection profile obtained from the SISMAORE cruise in 2021 presents the first detailed image of the submarine volcanic edifice, Fani Maore, which formed 50 km east of Mayotte Island in 2018-2019. The volcanic edifice sits on a sedimentary layer approximately 140 m thick, below which lies a significant volcanic layer extending over 120 km along the profile. This volcanic layer is composed of distinct seismic facies, indicating successive volcanic phases and suggesting the main construction phase of Mayotte Island. A sedimentary unit of about 2.2-2.5 km thickness exists between the volcanic layer and the top of the crust.
COMPTES RENDUS GEOSCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Isabelle Thinon, Anne Lemoine, Sylvie Leroy, Fabien Paquet, Carole Berthod, Sebastien Zaragosi, Vincent Famin, Nathalie Feuillet, Pierre Boymond, Charles Masquelet, Nicolas Mercury, Anais Rusquet, Carla Scalabrin, Jerome Van der Woerd, Julien Bernard, Julie Bignon, Valerie Clouard, Cecile Doubre, Eric Jacques, Stephan J. Jorry, Frederique Rolandone, Nicolas Chamot-Rooke, Matthias Delescluse, Dieter Franke, Louise Watremez, Patrick Bachelery, Laurent Michon, Daniel Sauter, Stephane Bujan, Albane Canva, Emilie Dassie, Vincent Roche, Said Ali, Abdoul Hamid Sitti Allaouia, Christine Deplus, Setareh Rad, Ludivine Sadeski
Summary: Geophysical and geological data from the North Mozambique Channel reveal the presence of a recent volcanic and tectonic corridor within and north of the Comoros Archipelago. These features indicate a current regional dextral transtensional context and highlight the incipient Somalia-Lwandle dextral plate boundary between the East-African Rift System and Madagascar.
COMPTES RENDUS GEOSCIENCE
(2022)