Article
Geosciences, Multidisciplinary
J. R. Brown, G. F. Cooper, G. M. Nowell, C. G. Macpherson, I. Neill, J. Prytulak
Summary: The study of Martinique volcanic arc lavas reveals evidence of sediment assimilation in shallow crustal levels, leading to a wider range of Sr isotopic compositions in the magmas. This highlights the importance of constraining crustal contributions before using lava geochemistry to study sediment and volatile recycling at subduction zones and assessing potential heterogeneity of arc mantle sources.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Geochemistry & Geophysics
Yan Hu, Fang-Zhen Teng, Catherine Chauvel
Summary: This study used stable potassium isotopes to track the crustal signatures in lavas from Martinique Island in the Lesser Antilles arc. The results show that the variations in K isotopes in these lavas are related to chemical parameters and radiogenic isotope ratios, indicating modification of mantle sources by input of subducted sediments. Most lavas have <1% to 5% of subducted sediments added to their mantle sources, with some samples showing divergence likely caused by the addition of K-bearing fluids from slab dehydration.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Geochemistry & Geophysics
Rachel Bezard, Simon Turner, Bruce Schaefer, Gene Yogodzinski, Kaj Hoernle
Summary: This study investigated the behavior of Re and Os during eclogite melting in primitive submarine lavas from the western Aleutian Arc. The results show that the Os-187/Os-188 of adakitic and non-adakitic volcanic rocks vary significantly but largely overlap, with the most radiogenic values occurring in samples with the lowest Os concentrations. The source of the adakites is unlikely to comprise significant eclogite-derived Os, suggesting minimal mobilization of Os during eclogite melting.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Geochemistry & Geophysics
Elena Melekhova, Michal Camejo-Harry, Jon Blundy, Simon R. Wallis, Catherine Annen, Barbara E. Kunz, Frances E. Jenner, Matthew Thirlwall
Summary: A study of xenoliths from Petit St. Vincent reveals the construction of arc crust beneath the island and its compatibility with the regional arc magma flux. The presence of high-An plagioclase in the xenoliths suggests the importance of water-fluxed melting in deep arc crust sections worldwide.
JOURNAL OF PETROLOGY
(2022)
Article
Geochemistry & Geophysics
Long Li, Yuhan Qi, Yunzhe Chen, Kan Li, Fang Huang, Pierre Cartigny
Summary: The study examined the fixed nitrogen component in arc lavas from Kick'em Jenny (KEJ) to shed light on two longstanding controversies in the recycling of subducting slab material. The results indicate that the nitrogen isotopic signature in the lavas is best explained by a mixing between the mantle and two distinct endmembers, suggesting sediment recycling into the mantle source. Additionally, the modeling results show that the arc crust is not a major repository of subducted nitrogen in the Lesser Antilles.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geosciences, Multidisciplinary
G. F. Cooper, E. C. Inglis
Summary: The study reveals that lavas produced at subduction zones represent both source heterogeneity and an array of crustal processes, while plutonic xenoliths provide a complementary record of the deeper roots of the magmatic plumbing system and true chemical diversity of arc crust. Iron isotopic record demonstrates that magmatic processes within the sub-arc crust have a greater impact than sub-arc mantle inputs, and a light iron source is not necessary for producing the light iron isotopic compositions in volcanic arc lavas.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geochemistry & Geophysics
M. Boulanger, L. France, C. Ferrando, B. Ildefonse, B. Ghosh, A. Sanfilippo, C. -Z. Liu, T. Morishita, J. Koepke, O. Bruguier
Summary: Studies indicate that the lower oceanic crust in the Atlantis Bank region contains an interlayered section of fine- and coarse-grained olivine gabbros, which record the reactive porous migration of magma. The area also shows occurrences of partial melt percolation and modifications in rock compositions, indicating that the composition of crustal lithologies is strongly influenced by the type of magma migration and modalities of melt percolation.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Xianlei Geng, Zhengwei Liang, Wen Zhang, Yongsheng Liu, Zhaochu Hu, Lixu Deng
Summary: Green-core clinopyroxene (GCPX) widely occurs in diverse magmas and various tectonic settings. The in-situ trace element and Pb isotopic compositions of GCPXs in the Feixian and Sihetun primitive basalts from the eastern North China Craton were investigated to explore their potential origins. The results suggest that GCPXs can be simply formed through the two common magmatic processes of continental basaltic magmas, crystallization differentiation, and crustal assimilation.
Article
Geography
Romain Monassier, Marylise Cottet, Helene Mathian, Anne Riviere-Honegger, Quentin Hejda
Summary: Understanding human-nature relationships has become a crucial issue in environmental management, and PPGIS methods have been widely used to demonstrate these relationships spatially on maps. However, the spatial data generated by PPGIS methods often lack the insights provided by participants' discourses. In this study, a web-mapping survey was conducted in Martinique to investigate the relationship between inhabitants' perceptions of rich nature and its spatial representation. The results showed a strong correlation between rich nature perception and spatial representation, highlighting the value of combining mapping and participants' discourses in participatory mapping.
Article
Geochemistry & Geophysics
Margaret E. Hartley, Jan C. M. de Hoog, Oliver Shorttle
Summary: Trace elements and volatile heterogeneity in the Earth's mantle are affected by the recycling of oceanic lithosphere through subduction processes. Boron isotopes are utilized as a tracer for recycled subducted materials, showing the fate of these materials in the mantle and the composition heterogeneity in various tectonic settings. The new data suggest the presence of depleted and enriched mantle components intrinsic to the Icelandic mantle source, highlighting the role of recycled subducted lithosphere in melt generation at ocean islands.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Review
Geochemistry & Geophysics
H. Y. Hu, R. J. Stern, Y. Rojas-Agramonte, A. Garcia-Casco
Summary: This study compiled geochronologic and geochemical data of igneous and metamorphic rocks in the Greater Antilles islands to investigate the formation and evolution of the Greater Antilles Arc (GAA). The results indicate that the GAA started in the Early Cretaceous and ceased in the Paleogene, and it was influenced by the Caribbean Large Igneous Province.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geochemistry & Geophysics
Lorenzo Fedele, Paul D. Cole, Claudio Scarpati, Richard E. A. Robertson
Summary: The petrological features of scoria samples and enclosed holocrystalline xenoliths from the last similar to 1000 years of activity of the La Soufriere volcano of St. Vincent (Lesser Antilles) are described in detail here. The products of the investigated prehistoric eruptions (pre-1440, 1440, 1580 CE) are relatively homogeneous basaltic andesites commonly hosting gabbroic xenoliths. Scoria samples from the historical eruptions (1718-1812 and 1902-03 CE) are mostly similar to the former in terms of whole-rock composition, mineral chemistry and types of xenoliths, but include also a mafic-rich scoria type in the products of the 1902-03 eruption that is less evolved in composition and encloses ol-gabbro and ultramafic xenoliths. Crystal fractionation appears as the main evolutionary process affecting both scoria types, while different types of xenoliths suggest different origins and processes. The tapping of such magma could mark a major rejuvenation event, which is the process that likely triggered the 1902-03 eruption.
Article
Geochemistry & Geophysics
R. W. Allen
Summary: The formation of the Grenada back-arc Basin remains mysterious and controversial, but a new study using wide-angle seismic data suggests the presence of oblique magmatic spreading in the southern basin. This research not only contributes to understanding the tectonic history of the eastern Caribbean region, but also sheds light on the complexities of back-arc processes globally that the Lesser Antilles arc may help illuminate.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geosciences, Multidisciplinary
Archisman Dhar, Biswajit Ghosh, Debaditya Bandyopadhyay, Tomoaki Morishita, Akihiro Tamura, Lyderic France, Du K. Nguyen, Marine Boulanger, Manojit Koley, Sankhadeep Roy, Soumi Chattopadhaya
Summary: This study presents a detailed petro-geochemical investigation of lower crustal gabbroic rocks recovered from the Atlantis Bank oceanic core complex in the Southwest Indian Ridge. The results shed new light on the dynamic accretion process at ultraslow-spreading ridges and support the theory of assimilation-fractional crystallization as the key mechanism in lower crust formation. The study also demonstrates the relationship between modal mineralogical evolution and assimilation/fractionation ratios.
Article
Geochemistry & Geophysics
Zhimin Zhu, Yi Ding, Zhenggang Li, Yanhui Dong, Hao Wang, Jiqiang Liu, Jihao Zhu, Xiaohu Li, Fengyou Chu, Xianglong Jin
Summary: Crustal assimilation and subducted sediment input have significant impacts on the geochemistry of arc and back-arc lavas along the Okinawa Trough. Different stages of back-arc development exert first-order controls on the extent of crustal assimilation, resulting in marked effects on the geochemical and isotopic compositions of lavas in the region.
Article
Geochemistry & Geophysics
Simon Turner, Michael Turner, Bernard Bourdon, Kari Cooper, Don Porcelli
Summary: The research reveals large U-Th-Ra disequilibria in very young lavas from mantle xenoliths, indicating ongoing infiltration of carbonatitic melts/fluids and crystallization of pargasite may explain the U-series disequilibria observations. Despite unclear details, the nuclides' half-lives suggest the disturbance is extremely young, potentially impacting the crust significantly.
PHYSICS OF THE EARTH AND PLANETARY INTERIORS
(2021)
Article
Geochemistry & Geophysics
Lucy McGee, Mark Reagan, Simon Turner, R. Stephen Sparks, Heather Handley, Rosa Didonna, Kim Berlo, Sarah Hansen, Jenni Barclay
Summary: The study investigates the mass exchange history between mafic enclaves and andesite hosts during the 2010 eruption at Soufriere Hills Volcano, revealing the complexity of volatile and metal element transfer between magmas and the potential of enclaves as eruption triggers. Results suggest loss of a volatile phase and transport of metals within the deeper plumbing system during differentiation of magmas feeding SHV.
Article
Geochemistry & Geophysics
Rachel Bezard, Simon Turner, Bruce Schaefer, Gene Yogodzinski, Kaj Hoernle
Summary: This study investigated the behavior of Re and Os during eclogite melting in primitive submarine lavas from the western Aleutian Arc. The results show that the Os-187/Os-188 of adakitic and non-adakitic volcanic rocks vary significantly but largely overlap, with the most radiogenic values occurring in samples with the lowest Os concentrations. The source of the adakites is unlikely to comprise significant eclogite-derived Os, suggesting minimal mobilization of Os during eclogite melting.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Geochemistry & Geophysics
C. W. Firth, S. P. Turner, H. K. Handley, M. B. Turner, S. J. Cronin, G. Girard, I. E. M. Smith
Summary: The study investigates the relationship between persistent low magnitude volcanic activity and more severe eruptions using uranium-series isotopes, finding that continuous magma supply drives persistent activity. The storage location and geological structure of different volcanoes can impact eruption frequency and magnitude.
Article
Multidisciplinary Sciences
Simon Turner, Lucy McGee, Munir Humayun, John Creech, Brigitte Zanda
Summary: Carbonaceous chondritic meteorites are primordial Solar System materials and a potential source of water delivery to Earth. Analyzing short-lived uranium isotopes in these meteorites reveals fluid movement within the past few hundred thousand years, possibly due to impact heating melting ice on the parent bodies.
Article
Geology
Simon Turner, Heather Handley, Paul Hesse, Bruce Schaefer, Anthony Dosseto
Summary: Studies show that Australian dust deposits are linked to aridification and the disappearance of inland megalakes similar to 30-120 k.y. ago, suggesting the potential of dust age as a new hydrological indicator in arid environments.
Article
Geochemistry & Geophysics
Rachel Bezard, Kaj Hoernle, Jorg A. Pfander, Brian Jicha, Reinhard Werner, Folkmar Hauff, Maxim Portnyagin, Blanka Sperner, Gene M. Yogodzinski, Simon Turner
Summary: By conducting extensive 40Ar/39Ar dating and geochemical analysis on 40 samples from the lower units of the Aleutian ridge, this study provides constraints on the timing of the Aleutian Arc initiation and its pre-Quaternary evolution. The results reveal three distinct periods of enhanced magmatic activity during the arc's evolution, with temporal changes in magma types corresponding to variations in arc crustal thickness beneath the active front.
Article
Geochemistry & Geophysics
Rosa Didonna, Fidel Costa, Heather Handley, Simon Turner, Jenni Barclay
Summary: This study investigates the dynamics of magma mingling and mixing using chemical and textural zoning patterns recorded in plagioclase crystals. The results shed new light on the nature and timing of magmatic interactions driving volcanic eruptions.
CONTRIBUTIONS TO MINERALOGY AND PETROLOGY
(2022)
Article
Multidisciplinary Sciences
C. O'Neill, M. Brown, B. Schaefer, J. A. Gazi
Summary: The mid-Proterozoic period, known as the boring billion, was characterized by stable environmental conditions and limited tectonic activity. This period also witnessed unique magmatic and metamorphic events, such as the formation of anorthosites and Rapakivi granites. Researchers have developed a method to calculate plate velocities during this time and have found evidence supporting the hypothesis of a plate slowdown. The higher mantle temperatures during the Proterozoic resulted in increased intrusive magmatism and extreme thermobaric ratios of crustal metamorphism.
SCIENTIFIC REPORTS
(2022)
Article
Geochemistry & Geophysics
Saskia Ruttor, Oliver Nebel, Helen Williams, Christoph Beier, Marianne Richter, Yona Nebel -Jacobsen, Rene H. W. Romer, Simon P. Turner, Caroline R. Soderman
Summary: This study investigates the heterogeneity and sources of iron isotopes in primitive ocean island basalts (OIB). The results show that the magma source of the eastern Sao Miguel island is more enriched and has unique characteristics compared to the western Sao Miguel island. The study also reveals the spatial distribution of mantle components and the effects of secondary processes on the iron isotope systematics.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Geochemistry & Geophysics
Simon Turner, Trevor Ireland, John Foden, Elena Belousova, Gerhard Woerner, Jelte Keeman
Summary: New research on granites from the Delamerian Orogen in southeastern Australia reveals similarities in age and compositional evolution of the zircon, indicating that they are part of the same major orogen.
JOURNAL OF PETROLOGY
(2022)
Article
Geochemistry & Geophysics
Raham Jalil, Olivier Alard, Bruce Schaefer, Liaqat Ali, Muhammad Sajid, Mohamed Zaki Khedr, Mohammad Tahir Shah, Muhammad Naveed Anjum
Summary: The Waziristan ophiolite complex (WOC) is part of the paleo-suture zone between the Indo-Pakistan plate and the Afghan microplate. It mainly consists of serpentinized dunites and serpentinites, with crosscutting pyroxenites. The study reveals that the WOC peridotites underwent a high degree of melt extraction and subsequent geochemical depletion, resembling Izu-Bonin-Mariana (IBM) forearc peridotites.
Article
Geochemistry & Geophysics
Rachel Bezard, Tracy Rushmer, Simon Turner, Suemeyya Eroglu
Summary: In this study, the effects of source and magmatic differentiation on the Molybdenum isotopic composition (delta 98/95Mo) of lavas from Solander volcano were investigated. The study suggests that the extreme delta 98/95Mo variation in the lavas is mainly caused by magmatic differentiation processes, such as fluid loss, unmixing, and assimilation. The role of magmatic fluids in controlling the delta 98/95Mo of volcanic arc rocks should be considered in source assessments.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2023)
Article
Biochemistry & Molecular Biology
Brandon Mahan, Theo Tacail, Jamie Lewis, Tim Elliott, Mette Habekost, Simon Turner, Roger Chung, Frederic Moynier
Summary: Natural stable metal isotopes have shown potential in differentiating healthy and diseased brain states. Alzheimer's disease brains expel potassium, which is accompanied by increased serum potassium levels. Heavy potassium isotope enrichment is observed in the regions of amyloid beta accumulation, which correlates with potassium depletion. The composition of potassium isotopes in the brain differs from that in serum, suggesting the generation of an early Alzheimer's disease biomarker.
Article
Geochemistry & Geophysics
Xinze Lu, Geoffrey J. Gilleaudeau, Brian Kendall
Summary: The Late Ordovician mass extinction is the first major extinction event in the Phanerozoic, but the reasons for the decline in global biodiversity before the extinction are not well understood.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2024)
Article
Geochemistry & Geophysics
Junyao Kang, Daniel D. Gregory, Benjamin Gill, Shiqiang Huang, Changxin Lai, Zhaoshan Chang, Huan Cui, Ivan Belousov, Shuhai Xiao
Summary: Sedimentary pyrite is an important geological archive, but it can be altered by diagenetic and hydrothermal processes. This study successfully trained machine learning algorithms to distinguish pyrite origins using trace element data. The approach was validated and applied to identify the origins of pyrite in two sedimentary successions in South China.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2024)
