Article
Geochemistry & Geophysics
Tingting Shen, Lifei Zhang, Jianxin Zhang, Thomas Bader, Zuolin Tian, Fenglin Liu, Jingsui Yang
Summary: Research has found ultrahigh-pressure serpentinites and eclogites in Changawuzi, southwestern Tianshan, China, providing an opportunity to study the mechanisms of exhumation. Field observations and petrological analyses indicate the evolution of eclogites under ultrahigh-pressure conditions and geochemical similarities between serpentinites and eclogites. The study also reveals different stages in the evolution and exhumation of Changawuzi serpentinites and eclogites.
Article
Geochemistry & Geophysics
Lucie Tajcmanova, Paola Manzotti, Matteo Alvaro
Summary: The mechanisms of burial and exhumation of crustal material during the Alpine orogeny are debated. New mechanical models suggest deviations from lithostatic pressure as a possible mechanism for forming high-pressure rocks. Through petrological, geochronological, and structural data, the relationship between pressure and depth in metamorphic rocks is assessed, challenging traditional depth measurement methods.
Article
Multidisciplinary Sciences
Cindy Luisier, Lucie Tajcmanova, Philippe Yamato, Thibault Duretz
Summary: Plate tectonics is a crucial factor influencing various natural phenomena on Earth, and understanding its evolution is a fundamental question in Earth sciences. By studying rocks formed during continental collision, researchers have discovered that radial cracks in ultrahigh-pressure garnets are caused by ultrafast decompression. This finding challenges the traditional interpretation of fast and significant vertical displacement during rock exhumation and suggests that substantial decompression rates may be related to abrupt changes in lithospheric stress state, rather than spatial displacement.
NATURE COMMUNICATIONS
(2023)
Article
Geology
Joshua D. Vaughan-Hammon, Cindy Luisier, Lukas P. Baumgartner, Stefan M. Schmalholz
Summary: The tectono-metamorphic evolution of the European Alps, specifically the Monte Rosa tectonic unit, is still debatable, with peak pressure and temperature estimates varying significantly between different lithologies. Petrological studies in the western portion of the Monte Rosa nappe revealed staurolite-chloritoid-bearing metapelitic assemblages indicating lower peak pressure estimates than previously reported for whiteschist lithologies. The region shows structural coherence, suggesting that the higher pressure in whiteschist lenses may be due to dynamic pressure rather than tectonic slices.
JOURNAL OF METAMORPHIC GEOLOGY
(2021)
Article
Geochemistry & Geophysics
A. Spang, T. S. Baumann, B. J. P. Kaus
Summary: This paper presents a simple and intuitive method to parameterize complex 3D geological bodies and incorporate them into geodynamic inverse problems. Two examples are used to demonstrate how small differences in the initial geometry of a model can lead to vastly different results. The importance of sensitivity analysis and inversion of the initial geometry in geodynamic studies is highlighted.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geosciences, Multidisciplinary
Yongsheng Gai, Liang Liu, Guowei Zhang, Chao Wang, Xiaoying Liao, Wenqiang Yang, Lei Kang, Tuo Ma, Yuting Cao
Summary: A study of HP-UHP rocks in South Altyn Tagh reveals a differential exhumation process for the eastern and western segments, with the rocks in the eastern segment experiencing distinct metamorphism and rapid exhumation compared to the western segment.
Article
Geochemistry & Geophysics
Bertram Uunk, Fraukje Brouwer, Manuel De Paz-Alvarez, Kirsten van Zuilen, Rosanne Huybens, Reinier van 't Veer, Jan Wijbrans
Summary: This study constrains the timing and conditions of subducted, exhumed, and exposed high pressure metamorphic rocks on the Cyclades islands in Greece, showing a progressive subduction and exhumation resulting in imbrication of a former continental margin. Different mechanisms may trigger consistent exhumation for mechanically strong rocks and weakly coupled supracrustal rocks.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Review
Geosciences, Multidisciplinary
Fabrizio Piana, Luca Barale, Carlo Bertok, Anna d'Atri, Andrea Irace, Pietro Mosca
Summary: The study of SW Piemonte suggests the presence of a regional transfer zone (SWAT) recording Oligocene-Miocene activity and the development of GVZ/SWAT and PF/IBF structures. The postcollisional evolution of the SW Alps is recorded by the TPB basin, influenced by transpressive faults and Apennine thrusts stacking Ligurian units. This correlation between the Alps and the Apennines highlights their kinematics and tectonic control on the same syn-orogenic basin.
Article
Geochemistry & Geophysics
Peng Feng, Lu Wang, Michael Brown, Tim E. Johnson, Andrew Kylander-Clark, Philip M. Piccoli
Summary: This study reveals a particular partial melting phenomenon in ultra-high pressure eclogite from the Sulu belt in China, shedding light on the melting mechanism during exhumation of eclogites and providing insight into the process of deeply-subducted continental crust returning to shallower depths.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geochemistry & Geophysics
Leonardo M. Pichel, Ritske S. Huismans, Robert Gawthorpe, Jan Inge Faleide, Thomas Theunissen
Summary: This study investigates the dynamics and controls on salt tectonics variability in continental rifted margins using 2D thermo-mechanical finite element modeling. The results show that different types of continental margins form different characteristics of salt basins, and the deposition and tectonic changes of salt are also influenced by syn-rift extension and basin architecture.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Cindy Luisier, Lukas P. Baumgartner, Benita Putlitz, Torsten Vennemann
Summary: Whiteschists from the Monte Rosa Nappe were examined using various methods to constrain their origin in the Alpine metamorphic context. Mineralogical boundaries and reaction zones suggest pervasive fluid infiltration, while geochemical analysis indicates a magmatic-hydrothermal fluid source and pre-Alpine fluid infiltration. This study suggests that whiteschists in the Alps may have a similar origin in granitic bodies.
CONTRIBUTIONS TO MINERALOGY AND PETROLOGY
(2021)
Article
Geology
Philip Gross, Jan Pleuger, Mark R. Handy, Marisa Germer, Timm John
Summary: This study investigates the evolution of the three-dimensional thermal structure of a palaeo-subduction channel in the Eastern Alps. By analyzing temperature contours and rock metamorphism, important discoveries are made regarding the evolution of the subduction-related temperature field.
JOURNAL OF METAMORPHIC GEOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Michael P. Searle, Thomas N. Lamont
Summary: The study proposes a new view of the geodynamic evolution in the Aegean region, suggesting an association with an early subduction zone and multiple crustal shortening stages before regional lithospheric extension. These findings reveal a complex and diverse tectonic history in the area.
GEOSCIENCE FRONTIERS
(2022)
Article
Geochemistry & Geophysics
Zhenzhu Wu, Chao Wang, Shuguang Song, Mark B. Allen, Timothy Kusky, Li Su
Summary: This study reports on Archean ultrahigh-pressure peridotites in North China, providing direct evidence for the operation of continental collisional plate tectonics since at least 2.5 billion years ago. The peridotites are believed to be tectonic slivers of a collisional complex that were subducted to mantle depths and then exhumed to crustal levels during Neoarchean subduction and subsequent arc/continental collision.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geochemistry & Geophysics
Leonardo M. Pichel, Ritske S. Huismans, Robert Gawthorpe, Jan Inge Faleide, Thomas Theunissen
Summary: Research finds that wide rifted margins are characterized by gravity-driven updip extension and downdip shortening, and syn-depositional salt flow and salt stretching also occur in these margins. The results have significant implications for understanding the genesis and evolution of salt-bearing rifted margins.
Article
Geochemistry & Geophysics
Lingyu Zhang, Kristoffer Szilas
Summary: This study presents new petrological and geochemical data for the Narssaq Ultramafic Body (NUB) in the Itsaq Gneiss Complex of SW Greenland. The results indicate that the ultramafic rocks of NUB are not mantle residues, but instead represent crustal cumulates derived from high-Mg magmas.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Rong Xu, Sarah Lambart, Oliver Nebel, Ming Li, Zhongjie Bai, Junbo Zhang, Ganglan Zhang, Jianfeng Gao, Hong Zhong, Yongsheng Liu
Summary: This study investigated the iron isotope compositions of Cenozoic basalts in Southeast China, finding significant variations related to different types of basalts and their respective sources.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
C. J. Ebinger, Miriam C. Reiss, Ian Bastow, Mary M. Karanja
Summary: The East African rift system is formed above mantle upwellings and the formation of rifts is related to lithospheric thinning and magmatic activity. The amount of splitting varies spatially and the fast axes are predominantly parallel to the orientation of the rifts. Thick lithospheric modules have less splitting and different orientations, which may indicate mantle plume flow. Splitting rotates and increases in strength as it enters the rift zones, suggesting that the anisotropy is mainly present at shallow depths.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Correction
Geochemistry & Geophysics
Ekaterina Rojas-Kolomiets, Owen Jensen, Michael Bizimis, Gene Yogodzinski, Lukas Ackerman
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Robert W. Nicklas, Igor S. Puchtel, Ethan F. Baxter
Summary: Oxygen fugacity is a fundamental parameter for understanding redox processes in igneous systems. This study compares the Fe-XANES oxybarometry method with the V-in-olivine method for evaluating fO(2) in MORB lavas. The results show that the V-in-olivine method is not applicable to samples with low MgO content, and that the majority of Archean komatiite sources have lower fO(2) than modern MORB.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Chunfei Chen, Stephen F. Foley, Sebastian Tappe, Huange Ren, Lanping Feng, Yongsheng Liu
Summary: The volatile components CO2 and H2O play a major role in mantle melting and heterogeneity. In this study, Ca isotopes were used to trace the lithological heterogeneity in alkaline magmatic rocks. The results revealed the presence of K-richterite and carbonate components as the source of alkaline magmas with low delta 44/40Ca values. These findings highlight the importance of Ca isotopes as a robust tracer of lithological variation caused by volatiles in the Earth's upper mantle.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Timothee Jautzy, Gilles Rixhon, Regis Braucher, Romain Delunel, Pierre G. Valla, Laurent Schmitt, Aster Team
Summary: Although the current approach to estimate catchment-wide denudation rates using only 10Be concentrations has made significant progress in geomorphology, this study argues for the inclusion of 26Al measurements and testing of steady-state assumptions in slow eroding, formerly glaciated landscapes. The study conducted measurements of both 10Be and 26Al in stream sediments from the Vosges Massif in France and found that elevation, slope, channel steepness, and precipitation were the primary factors controlling denudation rates. The study also revealed a significant relationship between the extent of past glaciation and the cosmogenic (un-)steadiness in the stream sediments.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Erik van der Wiel, Douwe J. J. van Hinsbergen, Cedric Thieulot, Wim Spakman
Summary: Numerical models of Earth's mantle dynamics can predict the vigour and mixing of mantle flow, and the average slab sinking rates are an unexplored parameter that can provide intrinsic information on these characteristics. Through numerical experiments, it has been found that slab sinking rates are strongly correlated with mantle convection and mixing, and may explain geochemical observations from hotspot volcanoes.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)