Geochemistry Geophysics Geosystems最新文献

{"title":"Volcanic Facies From Probabilistic Multi-Physics Characterization of an Andesite Island Volcano, Whakaari/White Island, New Zealand","authors":"C. A. Miller,&nbsp;F. Caratori Tontini","doi":"10.1029/2025GC012383","DOIUrl":"https://doi.org/10.1029/2025GC012383","url":null,"abstract":"<p>Collapse of hydrothermally weakened rock on the flanks of volcanic islands is a recognized cause of tsunamis generated by volcanoes. Here we use a multiphysics clustering method to derive a volcanic facies model for Whakaari/White Island, an andesite arc volcanic island in New Zealand. Through probabilistic inversion of magnetic and gravity data, combined with airborne electromagnetic data inversion we derive density, susceptibility, resistivity and saturation models of the island. Petrophysical relationships between density, P-wave velocity and mean effective stress extends the range of physical properties mapped. A clustering algorithm identifies four clusters, that is facies, related to rock volumes characterized by varying degrees of hydrothermal alteration and saturation that occupy specific spatial locations in the edifice. Two volumes of rock (0.05–0.1 km³) in the west and north of the island, with contrasting facies properties are identified as the most hydrothermally altered or fractured parts of the island. Saturation models derived from resistivity models show the upper flanks are at low saturation, reducing their likelihood of failure. The submerged flanks become progressively more saturated with depth, in line with existing models of the hydrothermal system that show significant seawater input. The gravity and magnetic models delineate subcrater boundaries and highlight regions with different styles of alteration, including pore filling that increases rock density, and rock dissolution that decreases density. The model identifies new areas of potential slope instability, context for interpreting volcano monitoring data and quantified rock volumes for generation of scenarios which simulate tsunamis caused by volcanic landslides.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 7","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GC012383","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144705413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid Incorporation of Metasediments Into Lower Crust of the Gangdese Magmatic Arc, Southern Tibet","authors":"Sheng-Kai Qin,&nbsp;Ze-Ming Zhang,&nbsp;Richard M. Palin,&nbsp;Xin Dong,&nbsp;Hui-Xia Ding,&nbsp;Zuo-Lin Tian","doi":"10.1029/2024GC012051","DOIUrl":"https://doi.org/10.1029/2024GC012051","url":null,"abstract":"<p>Deeply exhumed crustal terranes of continental arcs worldwide commonly contain metasedimentary components, but the nature of these lithologies and how they became incorporated into the lower crust are not fully understood. Here, we present petrological, geochemical and geochronological data from exhumed deep-crustal metapelites and orthogneisses from the eastern Gangdese magmatic arc, southern Tibet. Geochemical and geochronological affinity between metapelites and forearc sediments indicates that their protoliths were probably deposited in an Early Cretaceous (&lt;120 Ma) forearc basin of the Gangdese arc, while the orthogneisses represent metamorphosed equivalents of Late Jurassic (157–140 Ma) arc-type magmatic rocks. Petrological modeling and zircon U-Pb dating show that metapelites and orthogneisses simultaneously experienced high-pressure granulite-facies metamorphism at peak pressure-temperature conditions of 810–840°C and 12–16 kbar at 87–85 Ma. Our findings suggest that both the Mesozoic forearc sediments and igneous rocks that were initially emplaced into the upper crust of the Gangdese arc were subsequently transported to its lower crust within c. 25 Myr by crustal shortening, folding and underthrusting during the Late Cretaceous. When combined with previous data collected from the region, we propose that tectonic burial within arc crust and slab subduction-related mechanisms most likely operate together in magmatic arcs, promoting crustal recycling. The transport of surficial silica-rich materials into the lower crust is likely a basic process that has driven the growth and differentiation of continental arcs throughout geological time.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 7","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GC012051","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144687882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultra-Mafic Cumulates From Kaupulehu, Hualālai Volcano, Hawai'i: Geochemical Resetting of Mantle-Inherited Olivine","authors":"A. D. Dujardin,&nbsp;S. Demouchy,&nbsp;O. Alard,&nbsp;E. Gardés,&nbsp;M. Laubier,&nbsp;F. Barou","doi":"10.1029/2024GC012128","DOIUrl":"https://doi.org/10.1029/2024GC012128","url":null,"abstract":"<p>We characterized the chemical composition and microstructure of six ultramafic cumulates from the Kaupulehu lava flow, Hualālai (Hawai'i Island), to decipher their origin. The samples are mostly wehrlites with poikilitic textures. The chemical compositions obtained from electron probe microanalyses and laser ablation inductively coupled plasma mass spectrometry confirm the magmatic origin of pyroxenes. Olivines display homogeneous compositions in major, minor and trace elements. Their Fo# (81–88) are typical of magmatic compositions, but first row transition element concentrations are intermediate between mantle and magmatic olivine compositions. Rare Earth element (REE) patterns are similar to those of mantle olivine, but Kaupulehu olivines are more enriched in heavy REE than mantle specimens. Results from Fourier transform infrared spectroscopy showed that nominally anhydrous minerals are very poor in hydrogen: 1.3–2.2 ppm H₂O by weight in olivine, 6.4 in orthopyroxene, and 12.6–48.2 in clinopyroxene. Nevertheless, fluid inclusions and bubbles evidenced by scanning electron microscopy demonstrate the presence of volatiles, which are expected to exsolve during degassing. Despite the undeniable magmatic imprint in these ultra-mafic cumulates, electron backscatter diffraction maps evidence subgrain boundaries in olivine, important internal misorientation (&gt;10°), and Crystallographic preferred orientation (CPO) (axial [010], orthorhombic and transitional toward axial-[001]), not associated with shape preferred orientation or euhedral olivine shape. All these features are evidence of high temperature dislocation creep within the asthenospheric mantle, prior to melt percolation and chemical resetting, well before their mobilization by the volcanic eruption. We conclude that olivines are mantle-inherited, whereas clinopyroxenes result from crystallization of percolating melt.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 7","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GC012128","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144681155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oxide Gabbros: Transformation From Oceanic Ridge-Transform Systems to Subduction","authors":"Thomas Gyomlai,&nbsp;Cécile Prigent,&nbsp;Sampriti Mukherjee,&nbsp;Alexandre Janin,&nbsp;Mathilde Cannat,&nbsp;Saskia Erdmann","doi":"10.1029/2025GC012283","DOIUrl":"https://doi.org/10.1029/2025GC012283","url":null,"abstract":"<p>Fluid composition and fluxes in subduction zones are primarily governed by the nature and degree of hydrothermal alteration of the subducting oceanic lithosphere. However, spatial and temporal heterogeneities inherited from mid-ocean ridge and oceanic transform fault (OTF) systems introduce significant uncertainties in constraining these fluid variations. Here, we focus on the effect of subducting Fe-Ti-rich gabbroic rocks (oxide gabbros), which are commonly found in (ultra)slow-spread oceanic crust along OTF walls, in detachment faults forming at the inside corners of ridge-transform intersections (RTIs) and within subducted oceanic metamorphic units. We carried out a petrological and geochemical characterization of oxide gabbros from the Vema OTF which segments the mid-Atlantic Ridge to document and discuss their abundance, composition, formation and transformation processes at RTIs. Results illustrate spatially variable magmatic and hydrothermal processes at RTIs, resulting in variable Fe-Ti-(P)-(H₂O)-V enrichment (ilmenite + titanomagnetite ± apatite ± amphibole ± olivine) of primary gabbroic rocks. Thermodynamic modeling reveals significant variability in the stability of hydrated phases across different gabbroic compositions, indicating that, in subduction zones, Fe-Ti-enriched lithologies release fluids at shallower depths. Oxide gabbros, like the ones studied, represent a significant but often overlooked source of H₂O, halogens and large ion lithophile elements to the mantle wedge. In addition, subducted P-rich oxide gabbros may serve as a deep (&gt;700 km) source of fluorine in the asthenosphere. Our results demonstrate that subduction of a compositionally heterogeneous slab containing significant amounts of oxide gabbros generates a broad dehydration domain with implications for seismicity, water transport along the subduction interface and fluid-mediated tectonic slicing.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 7","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GC012283","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144672011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tectono-Magmatic Processes of the Western Parece Vela Basin: Insights Derived From Seismic Imaging and Gravity Modeling","authors":"Changliang Chen,&nbsp;Pin Yan,&nbsp;Weidong Luo,&nbsp;Yufang Tan,&nbsp;Junhui Yu,&nbsp;Yanlin Wang,&nbsp;Xubo Zhang,&nbsp;Zhanying Chen,&nbsp;Wenkai Huang,&nbsp;Jiale Chen","doi":"10.1029/2024GC012115","DOIUrl":"https://doi.org/10.1029/2024GC012115","url":null,"abstract":"<p>The western Parece Vela Basin (PVB) contains three distinct geomorphological zones aligned with the seafloor spreading direction: the west abyssal hill zone, the central Chaotic Terrain zone, and the east abyssal hill zone. However, the tectono-magmatic processes responsible for the lateral geomorphologic variations remain enigmatic. By processing and analyzing new multi-channel seismic data and ship-borne gravity data across three zones, we characterize the structures of the oceanic crust and elucidate the tectono-magmatic processes involved in seafloor spreading. The west abyssal hill zone exhibits a wavy basement influenced by several normal faults with minor displacements, suggesting the presence of limited tectonic extension. The discontinuous seismic reflections from Moho are imaged in segments, with a crustal thickness of ∼5–7 km, indicating an abundant magma supply. The central Chaotic Terrain zone features three large-scale seafloor domes. Strong reflectors at different depths within the domes are interpreted as sills, suggesting the presence of multi-phase magmatic intrusions. Gravity modeling indicates that the crust at the apexes of the domes is roughly twice as thick as at the edges, showing that the domes were formed through variable magmatism. The east abyssal hill zone shows a flat basement devoid of faults, exhibits continuous sub-horizontal Moho reflections, and predominantly consists of oceanic crust thicker than 6 km. This suggests an abundant magma supply without extension. The findings indicate a dynamic tectono-magmatic process in the western PVB, characterized by an initial stable magma supply with limited tectonic extension, followed by fluctuations in magmatic activity, and ultimately a robust magma supply.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 7","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GC012115","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144666474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Capturing Vegetation Gradients Along the West African Margin Using Terrestrial Plant Biomarkers in Marine Sediments","authors":"Nicholas A. O’Mara,&nbsp;Peter B. de Menocal,&nbsp;Kevin T. Uno,&nbsp;Jessica E. Tierney,&nbsp;Gisela Winckler,&nbsp;Pratigya J. Polissar","doi":"10.1029/2025GC012274","DOIUrl":"https://doi.org/10.1029/2025GC012274","url":null,"abstract":"<p>Understanding the transport mechanisms of terrestrial biomarkers to marine sediments is critical for interpreting past environmental and climate changes from these valuable archives. Here, we produce new estimates of two classes of terrestrial plant biomarkers, <i>n</i>-alkane waxes and pentacyclic triterpene methyl ethers (PTMEs), from a transect of marine core top sediments that span the full length of the West African margin. We determine the chain length distributions, mass accumulation rates, carbon isotope signatures (δ¹³C) of <i>n</i>-alkanes and the mass accumulation rates of PTMEs and assess the extent to which these proxy characteristics reflect vegetation and climate patterns within source areas on adjacent land. We achieve this via comparisons with a variety of satellite-based vegetation and climate data sets and with atmospheric back trajectory and river basin estimates. The mass accumulation rate of grass-produced PTMEs to core top marine sediments shows good spatial agreement with the presence of C₄ grasses on land and appears to have shorter transport distances than <i>n</i>-alkanes. The mass accumulation rate of <i>n</i>-alkanes roughly corresponds to changes in the landscape net primary productivity. The δ¹³C signature of <i>n</i>-alkanes records changes in landscape C₃ versus C₄ vegetation balance while longer chain length <i>n</i>-alkane distributions indicate drier conditions and grassier vegetation. Apparent discrepancies between the zonal distribution of biomarkers in the marine sediments versus the observed vegetation patterns can mostly be explained by the influence of long-range atmospheric transport, with modest contributions from river inputs.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 7","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GC012274","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144657616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polyphase Tectonic Evolution of the Puerto Rico-Virgin Islands Microplate Revealed by Fault-Slip Data and Stress Inversions","authors":"Jean-Claude Hippolyte,&nbsp;Paul Mann","doi":"10.1029/2025GC012227","DOIUrl":"https://doi.org/10.1029/2025GC012227","url":null,"abstract":"<p>The northeastern Caribbean plate boundary (NCPB) includes the Puerto Rico-Virgin Islands (PRVI) microplate that is bounded by oblique subduction zones in the Muertos and Puerto Rico Trenches, and by the Mona Rift, and the Anegada Passage rifts. Over the past 40 years, a variety of tectonic models have been proposed for the evolution of this complex plate boundary. We analyze fault kinematic data from 57 outcrops of Oligocene to Pliocene sedimentary rocks in Puerto Rico, Vieques, and St. Croix to shed light on the geodynamic evolution of the PRVI microplate and the Anegada Passage. Fault kinematic data reveal that the Eocene-Early Oligocene islands arc collision was followed by two contrasting extensional stress fields that occurred during and after the counterclockwise rotation of the PRVI microplate. Phase 1 compressional deformation related to Paleogene collision between the Caribbean arc and Bahama Platform was followed by: (a) Miocene, north-northeast-trending extension of tectonic Phase 2 resulting from counterclockwise rotation of the PRVI microplate; and (b) post-rotation, Pliocene-Quaternary, east-west to northwest-southeast extension of Phase 3. We propose that the Mona-Yuma rift system and the South-Puerto Rico-Anegada systems, characterized by different extensional directions, form two independent tears in the NCPBZ generated by its post-rotation left-lateral shearing. Southeastward extension reactivates the Anegada Passage with slightly oblique extension and produces left-lateral transtensional faulting along the southern margin of Puerto Rico. This active transtensional stress regime, documented in our previous studies, is confirmed by the moment tensors of the 2019–2023 earthquake sequence in southern Puerto Rico.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 7","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GC012227","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144606667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence for an Exceptionally Weak Cambrian Geomagnetic Field: New Paleointensity Estimates From the Florida Mountains, New Mexico","authors":"J. Michael Grappone,&nbsp;Annique van der Boon,&nbsp;Roger R. Fu,&nbsp;Andrew J. Biggin","doi":"10.1029/2025GC012234","DOIUrl":"https://doi.org/10.1029/2025GC012234","url":null,"abstract":"<p>The timing of the formation of the Earth's inner core remains a major mystery in the history of Earth's deep interior, with estimates ranging from &gt;1 billion years to &lt;500 million years. Inner core nucleation is expected to be characterized in the paleomagnetic record by a drop in magnetic field strength prior to inner core nucleation, followed by a sharp increase in strength after nucleation. Paleointensity data from the 1 Ga–500 Ma age range are, however, exceptionally sparse (with fewer than a dozen studies), which largely prevents any definitive conclusions. This study presents new paleointensity results from whole rocks aged 510 ± 5 Ma from the Florida Mountains in southwestern New Mexico. Exceptionally low paleointensity estimates (&lt;2 μT) were measured from three sites in granite and syenite outcrops of the southwestern portion of the Florida Mountains. Detailed rock magnetic and imaging investigations, including Quantum Diamond Microscopy, suggested that the two were unreliable because their remanence was unlikely a pure thermoremanent magnetization. The third site is more trustworthy and gave an estimate of 1.2 ± 0.2 μT (<i>N</i> = 5) corresponding to a virtual dipole moment of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>0.4</mn>\u0000 <mo>×</mo>\u0000 <msup>\u0000 <mn>10</mn>\u0000 <mn>22</mn>\u0000 </msup>\u0000 <mspace></mspace>\u0000 <msup>\u0000 <mtext>Am</mtext>\u0000 <mn>2</mn>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> $0.4times {10}^{22},{text{Am}}^{2}$</annotation>\u0000 </semantics></math>, which is of a similar magnitude to the lower bound of estimates from the Ediacaran (635–541 Ma). Such a low estimate at 510 Ma appears inconsistent with recent claims that the field strengthened rapidly following inner core nucleation in the late Ediacaran. Nevertheless, the risk of this single estimate being unrepresentative of the long-term field should be recognized alongside the urgent need for more paleointensity data spanning the interval 540–440 Ma.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 7","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GC012234","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144598422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Examining Controls on Fluid Overpressure in Buried Basement Highs of Oceanic Crust: Implications for Permeability of the Astoria Fan","authors":"Thomas Kyritz,&nbsp;Glenn A. Spinelli,&nbsp;Robert N. Harris","doi":"10.1029/2025GC012248","DOIUrl":"https://doi.org/10.1029/2025GC012248","url":null,"abstract":"<p>Vigorous hydrothermal circulation in the basement aquifer of the oceanic crust homogenizes temperatures within the aquifer and generates fluid overpressures at the tops of buried basement highs. At a site ∼25 km seaward of the Cascadia subduction zone deformation front, fluid overpressure at the top of the buried MARGIN seamount drives vertical fluid seepage through sediment overlying the seamount and results in anomalously high heat flux at the seafloor. In this study, we use numerical models of coupled heat and fluid transport to investigate the sensitivity of fluid overpressures to sediment thickness and basement relief for a 2D buried basement ridge. For ∼8 Ma oceanic crust buried by low permeability sediment, we find that the overpressure at the summit of a basement ridge increases by ∼0.10 kPa per meter of burial depth and by ∼0.71 kPa per meter of basement relief. For a 3D system with a geometry similar to the MARGIN seamount buried by low permeability sediment, the modeled fluid overpressure at the top of the seamount is ∼996 kPa. However, the Astoria Fan sediment above the MARGIN seamount likely has relatively high permeability, permitting rapid vertical seepage, thereby reducing fluid overpressure maintained at the top of the seamount. An overpressure of 492 kPa at the summit of the buried seamount at the MARGIN site and a bulk permeability of the Astoria Fan sediments of 4 × 10⁻¹⁵ m² are consistent with the seepage rate of 5.4 cm yr⁻¹ estimated from the elevated heat flux.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 7","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GC012248","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144606742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late Pleistocene-Holocene Paleosecular Variation Dating of Cave Sediments: Insights From Grotta Romanelli (Apulia, Italy)","authors":"E. Tema,&nbsp;L. Lanci,&nbsp;G. S. Mariani,&nbsp;P. Pieruccini,&nbsp;I. Mazzini,&nbsp;R. Sardella","doi":"10.1029/2024GC012148","DOIUrl":"https://doi.org/10.1029/2024GC012148","url":null,"abstract":"<p>Grotta Romanelli, located in southern Italy, is a natural coastal cave renowned for its exceptional stratigraphical record and its critical role in understanding the Middle Pleistocene-Holocene geomorphological and paleoenvironmental evolution of the Mediterranean region. Its importance has long been recognized with numerous studies focusing on dating its deposits using radiocarbon analyses and biological proxies. In this study, we introduce the use of the Paleosecular Variation (PSV) of the geomagnetic field to compute a depth-age model for the uppermost stratigraphic unit of Grotta Romanelli (Unit IUS5), traditionally referred to as “Terre Brune.” This Unit, previously associated with the Late Pleistocene-Holocene transition, lacked a precise chronological framework. Using stepwise alternating field demagnetization, we obtained well-defined paleomagnetic directions which were compared with the reference geomagnetic field curves calculated from the SHA.DIF.14k global geomagnetic field model. By incorporating the available radiocarbon dates, and considering the principle of stratigraphic superposition, we established a continuous age model, spanning the 14,000 to 8,000 years BP period. This model sheds light on the most recent phases of sedimentation and human activity in the cave before its complete infilling. The results demonstrate the high potential of PSV dating in providing absolute ages for fine-grained cave deposits. Furthermore, the new age-model offers a coherent timeline for the Final Epigravettian archeological and faunal records of Grotta Romanelli, revealing their connection with the climate changes at the Late Pleistocene-Holocene boundary.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 7","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GC012148","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144589610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}