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| Open AccessCompleting the loop of the Late Jurassic–Early Cretaceous true polar wander event
The authors report three palaeomagnetic poles from the North China craton and document a large round-trip true polar wander oscillation during 155−141 Ma that may have affected biotic evolution in East Asia and global extinction and endemism.
- Yifei Hou
- , Pan Zhao
- & Rixiang Zhu
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| Open AccessHigh-latitude platform carbonate deposition constitutes a climate conundrum at the terminal Mesoproterozoic
Deposition of 1.2-billion-year-old Indian limestone in shallow seas near the poles imply balmy conditions of more than 15 °C and significantly higher atmospheric greenhouse gas concentrations, which expands the spectrum of Earth’s climatic extremes.
- Michiel O. de Kock
- , Ingrit Malatji
- & L. P. Maré
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| Open AccessPaleogene India-Eurasia collision constrained by observed plate rotation
Dynamic 3D modelling of counterclockwise rotation of the Indian plate, which peaked at 52-44 and 33-20 Ma, reveals the diachronous India-Eurasia collision from western-centre to east since 55 ± 5 Ma and complete collision since 40 ± 5 Ma.
- Xiaoyue Wu
- , Jiashun Hu
- & Lijun Liu
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Article
| Open AccessIndian Ocean glacial deoxygenation and respired carbon accumulation during mid-late Quaternary ice ages
Ocean oxygenation regulates respired carbon storage and atmospheric CO2. This study applied a novel analysis using magnetic nanoparticle fossils and found glacial Indian Ocean oxygen decline and carbon accumulation to explain recent climate cycles.
- Liao Chang
- , Babette A. A. Hoogakker
- & Richard J. Harrison
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Article
| Open AccessLate Cambrian geomagnetic instability after the onset of inner core nucleation
An 80 thousand-year-long period of extreme non-geocentric dipole magnetic fields is recorded in Late Cambrian carbonate rocks of South China, suggesting that 495 million years ago Earth’s inner core had not grown large enough to stabilize the dynamo.
- Yong-Xiang Li
- , John A. Tarduno
- & Zhenyu Yang
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| Open AccessOrdovician–Silurian true polar wander as a mechanism for severe glaciation and mass extinction
Palaeomagnetic data from South China and compiled reliable palaeopoles from 4 other continents reveals a ~50˚ true polar wander (TPW) event occurring 450–440 million years ago. Sweeping Gondwana across the South Pole, this TPW event induced the Ordovician glaciation and mass extinction.
- Xianqing Jing
- , Zhenyu Yang
- & Bo Wan
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Article
| Open AccessEarly Cambrian renewal of the geodynamo and the origin of inner core structure
New single crystal paleointensity data show that the geomagnetic field was renewed in the early Cambrian after near collapse in the Ediacaran Period. This implies that the innermost/outermost structure of the inner core formed 450 million yrs. ago.
- Tinghong Zhou
- , John A. Tarduno
- & Frank Padgett III
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| Open AccessStalagmite paleomagnetic record of a quiet mid-to-late Holocene field activity in central South America
The South Atlantic Anomaly has the lowest intensity of the geomagnetic field. A stalagmite, from Brazil shows through its magnetic remanence that in mid-to-late Holocene this anomaly, was not being expressed or recurrent at surface in millennial scale.
- Plinio Jaqueto
- , Ricardo I. F. Trindade
- & R. Lawrence Edwards
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Article
| Open AccessA Late Cretaceous true polar wander oscillation
The authors present a high-resolution palaeomagnetic record for a Late Cretaceous limestone in Italy. They claim that their record robustly shows a ~12° true polar wander oscillation between 86 and 78 Ma, with the greatest excursion at 84–82 Ma.
- Ross N. Mitchell
- , Christopher J. Thissen
- & Joseph L. Kirschvink
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Article
| Open AccessQuantitative estimates of average geomagnetic axial dipole dominance in deep geological time
This study describes how the geomagnetic axial dipole dominance of Earth’s magnetic field remained stable through large parts of the geological time. Since other characteristics of the geomagnetic field have changed substantially on the same timescales, this new observation provides a challenge for future core modeling studies.
- Andrew J. Biggin
- , Richard K. Bono
- & Pavel V. Doubrovine
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Article
| Open AccessOrbital climate variability on the northeastern Tibetan Plateau across the Eocene–Oligocene transition
Marine records indicate a greenhouse to icehouse climate transition at ~34 million years ago, but how the climate changed within continental interiors at this time is less well known. Here, the authors show an orbital climate response shift with aridification on the northeastern Tibetan Plateau during this time.
- Hong Ao
- , Guillaume Dupont-Nivet
- & Zhisheng An
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Article
| Open AccessRapid geomagnetic changes inferred from Earth observations and numerical simulations
The authors here use numerical simulations combined with a time-dependent model of Earth’s magnetic field spanning the last 100 kyrs. They identify field directional changes to be 10 times faster than previously thought.
- Christopher J. Davies
- & Catherine G. Constable
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Article
| Open AccessHotspot motion caused the Hawaiian-Emperor Bend and LLSVPs are not fixed
Controversy surrounds the fixity of both hotspots and large low shear velocity provinces (LLSVPs). Here, the authors present new paleomagnetic data to show that the great bend in the Hawaiian-Emperor seamount chain can be attributed to mantle plume motion and that LLSVPs are mobile.
- Richard K. Bono
- , John A. Tarduno
- & Hans-Peter Bunge
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| Open AccessCoupled microbial bloom and oxygenation decline recorded by magnetofossils during the Palaeocene–Eocene Thermal Maximum
Understanding the response of marine productivity and CO2 drawdown to past warming events can provide important insights into the future. Here, the authors use bacterial magnetite nanoparticle fossils to reconstruct nutrient supply and marine deoxygenation during the Palaeocene–Eocene Thermal Maximum.
- Liao Chang
- , Richard J. Harrison
- & Xiang Zhao
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| Open AccessGlobal cooling and enhanced Eocene Asian mid-latitude interior aridity
The role Tibetan Plateau uplift played in Asian inland aridification remains unclear due to a paucity of accurately dated records. Here, the authors present a continuous aeolian sequence for the period >51–39 Ma, analysis of which indicates that aridification was driven by global climatic forcing rather than uplift.
- J. X. Li
- , L. P. Yue
- & Q. S. Liu
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Article
| Open AccessThe oldest magnetic record in our solar system identified using nanometric imaging and numerical modeling
Magnetic fields are thought to have been influential in the formation of our solar system. Here, the authors observe thermomagnetically stable, non-uniformly magnetized kamacite grains within chondritic meteorites, and calculate the grains to retain recordings of these magnetic fields.
- Jay Shah
- , Wyn Williams
- & Rafal E. Dunin-Borkowski
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Correspondence
| Open AccessCorrespondence: Numerical modelling of the PERM anomaly and the Emeishan large igneous province
- Trond H. Torsvik
- & Mathew Domeier
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Article
| Open AccessPacific plate motion change caused the Hawaiian-Emperor Bend
The Hawaiian-Emperor Chain has a 60° bend that has been interpreted as the result of Pacific plate motion at 47 Ma or drift of the Hawaiian hotspot. Here, the authors show that hotspot drift cannot be the dominant mechanism for bend formation, but involves a change in the direction of Pacific plate motion at ∼47 Ma.
- Trond H. Torsvik
- , Pavel V. Doubrovine
- & Mathew Domeier
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Article
| Open AccessGeomagnetic spikes on the core-mantle boundary
Rapid and spatially localized geomagnetic field variations around 1000 BC are hard to reconcile with expected field behaviour arising from the core dynamo. Here, the authors show that the intensity spike is consistent with an intense flux patch on the core-mantle boundary (8–22°) located under Saudi Arabia.
- Christopher Davies
- & Catherine Constable
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| Open AccessGeomagnetic reversal rates following Palaeozoic superchrons have a fast restart mechanism
The mechanism behind the initiation and termination of superchrons remains unclear. Here, the author provides insight into Palaeozoic superchrons, showing that the 10 million year interal adjacent to each superchron is characterized by asymmetry in reversal rates and unusually long duration chrons.
- Mark W. Hounslow
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Article |
Magnetic force microscopy reveals meta-stable magnetic domain states that prevent reliable absolute palaeointensity experiments
Obtaining reliable estimates of the absolute palaeointensity of the Earth’s magnetic field is difficult and many methods induce alteration. de Groot et al.present a means to see and explain changes in magnetization in unreliable samples, explaining why some samples systematically fail paleointensity experiments.
- Lennart V. de Groot
- , Karl Fabian
- & Mark J. Dekkers