Earth and Planetary Science Letters最新文献_第3页

High-resolution seismic tomography of the transition zone from normal to flat slab subduction in central Chile: Implications for volcanoes, plate coupling and flat subduction

IF 4.8 1区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Earth and Planetary Science Letters

Pub Date : 2025-02-01 DOI: 10.1016/j.epsl.2024.119167

Lei Gao , Zixin Chen , Ying Liu , Haijiang Zhang , Jiashun Hu , Diana Comte , Francisco Hernán Ortega Culaciati

To better understand factors controlling the distribution of volcanoes, plate coupling along the subducting plate interface, and the transition from normal to flat slab subduction, we have determined high-resolution Vp, Vs and Vp/Vs models in the central Chile subduction zone where normal slab subduction transits to flat slab subduction. In the study region spanning latitudes of 22° to 31°S, volcanoes to the north of latitude 25.5°S are underlaid by intensive intermediate-depth earthquakes, but those to the south are correlated with very few. Based on velocity features, we proposed that volcanoes to the north are likely caused by partial melting of mantle wedge by incorporation of fluids released during the dehydration reactions of various hydrous minerals in the slab that are responsible for inducing intermediate-depth earthquakes, while volcanoes to the south are likely caused by sub-slab hot materials migrating upwards through the tear or gap due to the transition from normal subduction to flat subduction. Along the plate surface constructed based on our inverted velocity models and relocated earthquakes, higher plate coupling is spatially correlated with lower Vp/Vs values and fewer earthquakes, whereas lower plate coupling is correlated with relatively higher Vp/Vs values and intensive small earthquakes. These features suggest that the plate coupling state is controlled by the existence of fluids along the plate interface, with high degree of fluids reducing plate coupling and causing the creep deformation. In the region where the flat slab subduction is evident, there exist apparent high velocity anomalies above the intraslab seismicity. This indicates that some buoyant materials such as oceanic plateaus, aseismic ridges and seamount chains that featured high velocity anomalies were subducted with the slab and caused the nominal flat subduction.

{"title":"High-resolution seismic tomography of the transition zone from normal to flat slab subduction in central Chile: Implications for volcanoes, plate coupling and flat subduction","authors":"Lei Gao , Zixin Chen , Ying Liu , Haijiang Zhang , Jiashun Hu , Diana Comte , Francisco Hernán Ortega Culaciati","doi":"10.1016/j.epsl.2024.119167","DOIUrl":"10.1016/j.epsl.2024.119167","url":null,"abstract":"<div><div>To better understand factors controlling the distribution of volcanoes, plate coupling along the subducting plate interface, and the transition from normal to flat slab subduction, we have determined high-resolution Vp, Vs and Vp/Vs models in the central Chile subduction zone where normal slab subduction transits to flat slab subduction. In the study region spanning latitudes of 22° to 31°S, volcanoes to the north of latitude 25.5°S are underlaid by intensive intermediate-depth earthquakes, but those to the south are correlated with very few. Based on velocity features, we proposed that volcanoes to the north are likely caused by partial melting of mantle wedge by incorporation of fluids released during the dehydration reactions of various hydrous minerals in the slab that are responsible for inducing intermediate-depth earthquakes, while volcanoes to the south are likely caused by sub-slab hot materials migrating upwards through the tear or gap due to the transition from normal subduction to flat subduction. Along the plate surface constructed based on our inverted velocity models and relocated earthquakes, higher plate coupling is spatially correlated with lower Vp/Vs values and fewer earthquakes, whereas lower plate coupling is correlated with relatively higher Vp/Vs values and intensive small earthquakes. These features suggest that the plate coupling state is controlled by the existence of fluids along the plate interface, with high degree of fluids reducing plate coupling and causing the creep deformation. In the region where the flat slab subduction is evident, there exist apparent high velocity anomalies above the intraslab seismicity. This indicates that some buoyant materials such as oceanic plateaus, aseismic ridges and seamount chains that featured high velocity anomalies were subducted with the slab and caused the nominal flat subduction.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"651 ","pages":"Article 119167"},"PeriodicalIF":4.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143157730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mantle induced hydration and oxidation of intracontinental granite sources in the North China Craton

IF 4.8 1区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Earth and Planetary Science Letters

Pub Date : 2025-02-01 DOI: 10.1016/j.epsl.2024.119177

Chuan-Mao Yang , Yi-Gang Xu , Xiao-Ping Xia , Jin-Hui Yang , Xiao-Long Huang , Christopher J. Spencer , Jin-Feng Sun , Ze-Xian Cui , Meng-Jing Li , Wan-Feng Zhang , Qing Yang

Arc magmatism is typically highly oxidized, due to the influx of oxidizing aqueous fluids released from the subducting plate. The observation that some intracontinental A- and I-type granites also exhibit high oxidation presents a significant challenge in igneous petrology and geodynamics. This is particularly true for regions such as the North China Craton (NCC), situated over 1000 km from the trench. In this study, we measured water content, oxygen fugacity (

f O_{2}

), and O-Hf isotopes in zircons from the late Mesozoic granites from the NCC. The results reveal positive correlations between water content and

f O_{2}

, and between water content and

ε_{Hf} (t)

, indicating the predominant control of primary magma composition, rather than magmatic differentiation, on water content and

f O_{2}

of zircon. The Early Cretaceous A-type and I-type granites, which involved greater amount of mantle-derived melts, exhibit more elevated water, Nb, Ta, and

f O_{2}

than the Jurassic granites. This suggests that the hydration and oxidization of intracontinental granitoids of the NCC are strongly influenced by the ingress of mantle-derived oxidized hydrous melts/aqueous fluids to the granitoid source, which were likely released from the Paleo-Pacific plate at a greater depth than the sub-arc mantle. The proposed model involves significant water in intracontinental crustal melting, thereby challenging the paradigm of intraplate A- and I-type granite genesis and shedding light on the crustal and mantle processes during cratonic destruction.

{"title":"Mantle induced hydration and oxidation of intracontinental granite sources in the North China Craton","authors":"Chuan-Mao Yang , Yi-Gang Xu , Xiao-Ping Xia , Jin-Hui Yang , Xiao-Long Huang , Christopher J. Spencer , Jin-Feng Sun , Ze-Xian Cui , Meng-Jing Li , Wan-Feng Zhang , Qing Yang","doi":"10.1016/j.epsl.2024.119177","DOIUrl":"10.1016/j.epsl.2024.119177","url":null,"abstract":"<div><div>Arc magmatism is typically highly oxidized, due to the influx of oxidizing aqueous fluids released from the subducting plate. The observation that some intracontinental A- and I-type granites also exhibit high oxidation presents a significant challenge in igneous petrology and geodynamics. This is particularly true for regions such as the North China Craton (NCC), situated over 1000 km from the trench. In this study, we measured water content, oxygen fugacity (<span><math><mrow><mi>f</mi><msub><mi>O</mi><mn>2</mn></msub></mrow></math></span>), and O-Hf isotopes in zircons from the late Mesozoic granites from the NCC. The results reveal positive correlations between water content and <span><math><mrow><mi>f</mi><msub><mi>O</mi><mn>2</mn></msub></mrow></math></span>, and between water content and <span><math><mrow><msub><mrow><mi>ε</mi></mrow><mtext>Hf</mtext></msub><mrow><mo>(</mo><mi>t</mi><mo>)</mo></mrow></mrow></math></span>, indicating the predominant control of primary magma composition, rather than magmatic differentiation, on water content and <span><math><mrow><mi>f</mi><msub><mi>O</mi><mn>2</mn></msub></mrow></math></span> of zircon. The Early Cretaceous A-type and I-type granites, which involved greater amount of mantle-derived melts, exhibit more elevated water, Nb, Ta, and <span><math><mrow><mi>f</mi><msub><mi>O</mi><mn>2</mn></msub></mrow></math></span> than the Jurassic granites. This suggests that the hydration and oxidization of intracontinental granitoids of the NCC are strongly influenced by the ingress of mantle-derived oxidized hydrous melts/aqueous fluids to the granitoid source, which were likely released from the Paleo-Pacific plate at a greater depth than the sub-arc mantle. The proposed model involves significant water in intracontinental crustal melting, thereby challenging the paradigm of intraplate A- and I-type granite genesis and shedding light on the crustal and mantle processes during cratonic destruction.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"651 ","pages":"Article 119177"},"PeriodicalIF":4.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143157732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Hydrologically-induced crustal stress changes and their association with seismicity rates in Taiwan

IF 4.8 1区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Earth and Planetary Science Letters

Pub Date : 2025-02-01 DOI: 10.1016/j.epsl.2024.119181

Ya-Ju Hsu , Roland Bürgmann , Zhongshan Jiang , Chi-Hsien Tang , Christopher W. Johnson , Da-Yi Chen , Hsin-Hua Huang , Miao Tang , Xinghai Yang

Studying crustal stress changes associated with hydrological cycles and their influence on seismicity rate illuminates the complex interplay between crustal stress conditions, faulting orientations, and earthquake nucleation. By analyzing GNSS position time series in 2006–2021 across Taiwan, we reveal a prevailing NW-SE trending seasonal contraction and expansion of the Earth's crust in response to hydrological loading and unloading in SW Taiwan, consistent with the maximum annual water storage change inferred from hydrological data. Inspection of seismicity rates in SW Taiwan indicates a positive correlation between excess seismicity rate and reduced NW-SE compression and/or decreasing vertical loading. Though hydrologically-induced contraction aligns with the tectonic compressive stress axis in the wet season, this alignment does not lead to more frequent earthquakes during peak water storage. Instead, seismicity peaks during the dry months, coinciding with maximum uplift and water unloading. This suggests that hydrologically-induced vertical stress or pressure changes play the dominant role in triggering earthquakes, as evidenced by vertical stress amplitudes 2∼4 times greater than the horizontal stress changes. The statistical correlation evaluating the timing of earthquakes and hydrologically-induced stress changes further affirms that the seismicity rate increases with reduced tectonic compression and enhanced vertical unloading in SW Taiwan. The observed relationship also implies the earthquake nucleation time is comparable to the stressing period of annual water cycles in SW Taiwan. Hydrologically-triggered earthquakes appear to be more sensitive to pressure variations than to shear stress changes, similar to tidally-modulated seismicity.

{"title":"Hydrologically-induced crustal stress changes and their association with seismicity rates in Taiwan","authors":"Ya-Ju Hsu , Roland Bürgmann , Zhongshan Jiang , Chi-Hsien Tang , Christopher W. Johnson , Da-Yi Chen , Hsin-Hua Huang , Miao Tang , Xinghai Yang","doi":"10.1016/j.epsl.2024.119181","DOIUrl":"10.1016/j.epsl.2024.119181","url":null,"abstract":"<div><div>Studying crustal stress changes associated with hydrological cycles and their influence on seismicity rate illuminates the complex interplay between crustal stress conditions, faulting orientations, and earthquake nucleation. By analyzing GNSS position time series in 2006–2021 across Taiwan, we reveal a prevailing NW-SE trending seasonal contraction and expansion of the Earth's crust in response to hydrological loading and unloading in SW Taiwan, consistent with the maximum annual water storage change inferred from hydrological data. Inspection of seismicity rates in SW Taiwan indicates a positive correlation between excess seismicity rate and reduced NW-SE compression and/or decreasing vertical loading. Though hydrologically-induced contraction aligns with the tectonic compressive stress axis in the wet season, this alignment does not lead to more frequent earthquakes during peak water storage. Instead, seismicity peaks during the dry months, coinciding with maximum uplift and water unloading. This suggests that hydrologically-induced vertical stress or pressure changes play the dominant role in triggering earthquakes, as evidenced by vertical stress amplitudes 2∼4 times greater than the horizontal stress changes. The statistical correlation evaluating the timing of earthquakes and hydrologically-induced stress changes further affirms that the seismicity rate increases with reduced tectonic compression and enhanced vertical unloading in SW Taiwan. The observed relationship also implies the earthquake nucleation time is comparable to the stressing period of annual water cycles in SW Taiwan. Hydrologically-triggered earthquakes appear to be more sensitive to pressure variations than to shear stress changes, similar to tidally-modulated seismicity.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"651 ","pages":"Article 119181"},"PeriodicalIF":4.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143158957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Unity of terrestrial and extraterrestrial soils in granular configuration

IF 4.8 1区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Earth and Planetary Science Letters

Pub Date : 2025-02-01 DOI: 10.1016/j.epsl.2025.119239

Jun Zhang , Yong Li , Yifei Cui , Zi Wu , Yuan Xue , Jianyi Cheng , Hu Jiang , Yao Li , Jian Guo , Jiayan Nie , Guodong Wang , Ao Luo

Grain size distribution (GSD) is crucial for understanding soil properties and surface processes. We find that both terrestrial soils and lunar soils are subjected to a unified GSD function, P(D)= g(μ)D^-μexp(-D/D_c), reducing the textural fractions and grade modes to a parameter pair (μ, D_c), which unifies terrestrial and extraterrestrial soils in granular configuration, beyond the environments and mechanisms of soil genesis. To construct a framework of the soil formation, we generalize the textural composition to a grade space representing the granular configuration, and conceptualize soil genesis as the random aggregation of the fractal fragmentation of parent lithospheric material and fragments from other sources (e.g., meteorites impacts or surface transport processes). Random simulation reproduces the multiple grade modes observed in soils, and spontaneously derives the unified GSD function. Then we numerically generate the (μ, D_c)-fields for soils on earth and moon, which refine the digital data mapping based on site measurements and depict the local fluctuation of soil parameters. The GSD unity also provides a tool of generating “numerical simulants” of lunar soils to fill the gap in material simulants. The study leads to a GSD-paradigm (in contrast to the conventional landscape-paradigm) in soil study, which is expected to facilitate the data harmonization on earth and promote the generation of lunar regolith data in favor of the in-situ resource utilization and base construction on moon.

{"title":"Unity of terrestrial and extraterrestrial soils in granular configuration","authors":"Jun Zhang , Yong Li , Yifei Cui , Zi Wu , Yuan Xue , Jianyi Cheng , Hu Jiang , Yao Li , Jian Guo , Jiayan Nie , Guodong Wang , Ao Luo","doi":"10.1016/j.epsl.2025.119239","DOIUrl":"10.1016/j.epsl.2025.119239","url":null,"abstract":"<div><div>Grain size distribution (GSD) is crucial for understanding soil properties and surface processes. We find that both terrestrial soils and lunar soils are subjected to a unified GSD function, <em>P</em>(<em>D</em>)= <em>g</em>(<em>μ</em>)<em>D<sup>-μ</sup></em>exp(-<em>D/D</em><sub>c</sub>), reducing the textural fractions and grade modes to a parameter pair (<em>μ, D</em><sub>c</sub>), which unifies terrestrial and extraterrestrial soils in granular configuration, beyond the environments and mechanisms of soil genesis. To construct a framework of the soil formation, we generalize the textural composition to a grade space representing the granular configuration, and conceptualize soil genesis as the random aggregation of the fractal fragmentation of parent lithospheric material and fragments from other sources (e.g., meteorites impacts or surface transport processes). Random simulation reproduces the multiple grade modes observed in soils, and spontaneously derives the unified GSD function. Then we numerically generate the (<em>μ, D</em><sub>c</sub>)-fields for soils on earth and moon, which refine the digital data mapping based on site measurements and depict the local fluctuation of soil parameters. The GSD unity also provides a tool of generating “numerical simulants” of lunar soils to fill the gap in material simulants. The study leads to a GSD-paradigm (in contrast to the conventional landscape-paradigm) in soil study, which is expected to facilitate the data harmonization on earth and promote the generation of lunar regolith data in favor of the in-situ resource utilization and base construction on moon.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"654 ","pages":"Article 119239"},"PeriodicalIF":4.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143300332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

How does the newly-formed drainage divide migrate after a river capture event?

IF 4.8 1区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Earth and Planetary Science Letters

Pub Date : 2025-02-01 DOI: 10.1016/j.epsl.2024.119165

Shuang Bian , Xibin Tan , Andrew V. Zuza , Chao Zhou , Feng Shi , Yiduo Liu , Junfeng Gong

Tectonic and climatic perturbations can drive drainage adjustment. A river capture event is usually a landmark shift in drainage evolution, which significantly changes the river network topology. Although these events can be identified through field observations and provenance analysis, reconstructing this evolution and pinpointing the capture timing remain challenging. Here, we provide a new way of determining capture timing via drainage divides, based on theory, numerical simulations, and two natural cases. Our theoretical studies show that the steady-state elevation of the captor and beheaded rivers will decrease and increase following a capture event, respectively. The newly-formed drainage divide that emerged between the beheaded river and capture point will have large cross-divide differences in steady-state elevation and erosion rate and thus migrates towards the beheaded-river side until reaching a new steady state (no cross-divide difference in steady-state elevation). Numerical simulations reproduce the characteristic phenomena of drainage-divide migration following capture events. We find that (1) the migration of newly-formed drainage divides after capture events may last for tens of millions of years, with the migration rate decreasing exponentially over time; (2) a larger captured area, higher uplift rate, or lower erosion coefficient may cause higher migration rate of the newly-formed drainage divide in the other same conditions. These insights from theoretical analysis and numerical simulations are further applied to the Dadu-Anning and Yarlung-Yigong capture events in the southeastern Tibet. We predict that the present Dadu-Anning drainage divide would further migrate ∼94–123 km southward to reach a steady state in tens of millions of years. The Yarlung-Yigong capture event occurred earlier, in the early-middle Cenozoic, because the newly-formed drainage divide has already reached a steady state.

{"title":"How does the newly-formed drainage divide migrate after a river capture event?","authors":"Shuang Bian , Xibin Tan , Andrew V. Zuza , Chao Zhou , Feng Shi , Yiduo Liu , Junfeng Gong","doi":"10.1016/j.epsl.2024.119165","DOIUrl":"10.1016/j.epsl.2024.119165","url":null,"abstract":"<div><div>Tectonic and climatic perturbations can drive drainage adjustment. A river capture event is usually a landmark shift in drainage evolution, which significantly changes the river network topology. Although these events can be identified through field observations and provenance analysis, reconstructing this evolution and pinpointing the capture timing remain challenging. Here, we provide a new way of determining capture timing via drainage divides, based on theory, numerical simulations, and two natural cases. Our theoretical studies show that the steady-state elevation of the captor and beheaded rivers will decrease and increase following a capture event, respectively. The newly-formed drainage divide that emerged between the beheaded river and capture point will have large cross-divide differences in steady-state elevation and erosion rate and thus migrates towards the beheaded-river side until reaching a new steady state (no cross-divide difference in steady-state elevation). Numerical simulations reproduce the characteristic phenomena of drainage-divide migration following capture events. We find that (1) the migration of newly-formed drainage divides after capture events may last for tens of millions of years, with the migration rate decreasing exponentially over time; (2) a larger captured area, higher uplift rate, or lower erosion coefficient may cause higher migration rate of the newly-formed drainage divide in the other same conditions. These insights from theoretical analysis and numerical simulations are further applied to the Dadu-Anning and Yarlung-Yigong capture events in the southeastern Tibet. We predict that the present Dadu-Anning drainage divide would further migrate ∼94–123 km southward to reach a steady state in tens of millions of years. The Yarlung-Yigong capture event occurred earlier, in the early-middle Cenozoic, because the newly-formed drainage divide has already reached a steady state.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"651 ","pages":"Article 119165"},"PeriodicalIF":4.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143157734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cadmium isotopes as a tracer for deep carbon recycling

IF 4.8 1区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Earth and Planetary Science Letters

Pub Date : 2025-02-01 DOI: 10.1016/j.epsl.2024.119168

Sheng-Ao Liu, Tianhao Wu, Ziteng Wang, Dandan Li, Kexin Song

Global marine carbonates have cadmium (Cd) concentrations much higher than those of mantle peridotites, and especially, Phanerozoic carbonates are uniquely characterized by heavier Cd isotopic composition (expressed as δ^114/110Cd against NIST 3108) relative to the mantle. These characteristics make the Cd systematics potentially useful for tracing recycled carbonates in the mantle. We test the feasibility of this application through analyses of seventeen well-characterized Cenozoic intraplate basalts from Eastern China, and for comparison, six mid-ocean ridge basalts (MORB) are also investigated. The MORB have a mean δ^114/110Cd value of 0.13 ± 0.04 ‰ (2sd), in accord with previous analyses for other MORB, illustrating a relatively homogeneous Cd isotopic composition of global MORB and the depleted upper mantle. The Eastern China basalts have δ^114/110Cd values varying between 0.17 ± 0.05 ‰ (2sd) and 0.65 ± 0.05 ‰ (2sd), which are slightly to notably higher than those of the mantle and MORB. The maximum δ^114/110Cd offset (∼0.5–0.6 ‰) between these basalts and the mantle fairly exceeds the magnitude of Cd isotope fractionation even at low degrees of partial melting. The high δ^114/110Cd values cannot also be explained by volatilization-induced Cd loss, given the positive correlation between δ^114/110Cd and Cd concentrations. Instead, this correlation points to a key role of recycled carbonates, supported by the “carbonated” geochemical signals of these basalts (e.g., low Ti/Eu ratios). Binary mixing model indicates that recycling of approximately 2–10 % carbonates into sources can explain the high δ^114/110Cd observed in these basalts. Given that Cd is a trace element in the mantle (∼38 ng/g), the Cd isotopic composition of mantle rocks is sensitive to even a tiny amount of recycled carbonates. Therefore, we propose for the first time that Cd isotopes are a new and powerful tool of tracing Earth's deep carbon recycling over geologic time.

{"title":"Cadmium isotopes as a tracer for deep carbon recycling","authors":"Sheng-Ao Liu, Tianhao Wu, Ziteng Wang, Dandan Li, Kexin Song","doi":"10.1016/j.epsl.2024.119168","DOIUrl":"10.1016/j.epsl.2024.119168","url":null,"abstract":"<div><div>Global marine carbonates have cadmium (Cd) concentrations much higher than those of mantle peridotites, and especially, Phanerozoic carbonates are uniquely characterized by heavier Cd isotopic composition (expressed as δ<sup>114/110</sup>Cd against NIST 3108) relative to the mantle. These characteristics make the Cd systematics potentially useful for tracing recycled carbonates in the mantle. We test the feasibility of this application through analyses of seventeen well-characterized Cenozoic intraplate basalts from Eastern China, and for comparison, six mid-ocean ridge basalts (MORB) are also investigated. The MORB have a mean δ<sup>114/110</sup>Cd value of 0.13 ± 0.04 ‰ (2sd), in accord with previous analyses for other MORB, illustrating a relatively homogeneous Cd isotopic composition of global MORB and the depleted upper mantle. The Eastern China basalts have δ<sup>114/110</sup>Cd values varying between 0.17 ± 0.05 ‰ (2sd) and 0.65 ± 0.05 ‰ (2sd), which are slightly to notably higher than those of the mantle and MORB. The maximum δ<sup>114/110</sup>Cd offset (∼0.5–0.6 ‰) between these basalts and the mantle fairly exceeds the magnitude of Cd isotope fractionation even at low degrees of partial melting. The high δ<sup>114/110</sup>Cd values cannot also be explained by volatilization-induced Cd loss, given the positive correlation between δ<sup>114/110</sup>Cd and Cd concentrations. Instead, this correlation points to a key role of recycled carbonates, supported by the “carbonated” geochemical signals of these basalts (e.g., low Ti/Eu ratios). Binary mixing model indicates that recycling of approximately 2–10 % carbonates into sources can explain the high δ<sup>114/110</sup>Cd observed in these basalts. Given that Cd is a trace element in the mantle (∼38 ng/g), the Cd isotopic composition of mantle rocks is sensitive to even a tiny amount of recycled carbonates. Therefore, we propose for the first time that Cd isotopes are a new and powerful tool of tracing Earth's deep carbon recycling over geologic time.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"651 ","pages":"Article 119168"},"PeriodicalIF":4.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143158120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Carbon, nitrogen, and noble gas isotopes reveal deep volatile signatures in thermal springs in the Central Volcanic Zone (CVZ) of the Andes

IF 4.8 1区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Earth and Planetary Science Letters

Pub Date : 2025-02-01 DOI: 10.1016/j.epsl.2024.119169

PH Barry , JM de Moor , MW Broadley , AM Seltzer , DV Bekaert , K Patil , CGE Bartels , ED Young , BE Longworth , B Barosa , A Bastianoni , D Bastoni , M Cascone , SJ Turner , RL Tyne , M Anderson , K Li , J Curtice , N Kumar , GL Jessen , D Giovannelli

In subduction zones, thermal springs release deeply-sourced volatiles from Earth's mantle, crust, and/or subducted slab-derived material. The origin and apparent ages of these volatiles are important for understanding the deep volatile cycle, which in turn affects the distribution of microbial life in the subsurface. Here, we report carbon (¹³C, ¹⁴C), noble gas (He, Ne, Ar, Kr and Xe), and clumped nitrogen isotope data in gas and water samples from thermal springs within the Central Volcanic Zone (CVZ) of the Andean Convergent Margin (ACM). He isotopes show that CVZ gases are predominantly sourced from the crust (∼77 %), with smaller mantle contributions (∼23 %), consistent with previous studies from the CVZ. Thermal spring samples with non-atmospheric He-Ne characteristics have low ¹⁴C activities, and are deeply derived (i.e., from the mantle and crust) and old (>22,000 years). To gain additional constraints on volatile sources, a gas sample from Pirquitas Argentina was analyzed using a new high-precision technique to reveal significant geogenic anomalies in argon (⁴⁰Ar/³⁶Ar = 492), fissiogenic xenon (88 % crustal), and helium (84 % crustal) isotopes. Clumped N₂ isotopologue results also indicate that the N₂-rich Pirquitas sample is dominated by crustal and magmatic N₂, which was unambiguously released at high temperatures (indicated by Δ₃₀ of ∼0‰). When taken together, all carbon, noble gas and clumped N₂ isotope data from CVZ thermal springs point toward a predominantly crustal source of volatile elements, which is consistent with the thick crust beneath the arc. We conclude that thermal springs with noble gas isotopic evidence for minimal air contributions are old, suggesting that any microbial communities entrained in them are also supported by deeply-derived and old organic carbon.

{"title":"Carbon, nitrogen, and noble gas isotopes reveal deep volatile signatures in thermal springs in the Central Volcanic Zone (CVZ) of the Andes","authors":"PH Barry , JM de Moor , MW Broadley , AM Seltzer , DV Bekaert , K Patil , CGE Bartels , ED Young , BE Longworth , B Barosa , A Bastianoni , D Bastoni , M Cascone , SJ Turner , RL Tyne , M Anderson , K Li , J Curtice , N Kumar , GL Jessen , D Giovannelli","doi":"10.1016/j.epsl.2024.119169","DOIUrl":"10.1016/j.epsl.2024.119169","url":null,"abstract":"<div><div>In subduction zones, thermal springs release deeply-sourced volatiles from Earth's mantle, crust, and/or subducted slab-derived material. The origin and apparent ages of these volatiles are important for understanding the deep volatile cycle, which in turn affects the distribution of microbial life in the subsurface. Here, we report carbon (<sup>13</sup>C, <sup>14</sup>C), noble gas (He, Ne, Ar, Kr and Xe), and clumped nitrogen isotope data in gas and water samples from thermal springs within the Central Volcanic Zone (CVZ) of the Andean Convergent Margin (ACM). He isotopes show that CVZ gases are predominantly sourced from the crust (∼77 %), with smaller mantle contributions (∼23 %), consistent with previous studies from the CVZ. Thermal spring samples with non-atmospheric He-Ne characteristics have low <sup>14</sup>C activities, and are deeply derived (i.e., from the mantle and crust) and old (>22,000 years). To gain additional constraints on volatile sources, a gas sample from Pirquitas Argentina was analyzed using a new high-precision technique to reveal significant geogenic anomalies in argon (<sup>40</sup>Ar/<sup>36</sup>Ar = 492), fissiogenic xenon (88 % crustal), and helium (84 % crustal) isotopes. Clumped N<sub>2</sub> isotopologue results also indicate that the N<sub>2</sub>-rich Pirquitas sample is dominated by crustal and magmatic N<sub>2</sub>, which was unambiguously released at high temperatures (indicated by Δ<sub>30</sub> of ∼0‰). When taken together, all carbon, noble gas and clumped N<sub>2</sub> isotope data from CVZ thermal springs point toward a predominantly crustal source of volatile elements, which is consistent with the thick crust beneath the arc. We conclude that thermal springs with noble gas isotopic evidence for minimal air contributions are old, suggesting that any microbial communities entrained in them are also supported by deeply-derived and old organic carbon.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"651 ","pages":"Article 119169"},"PeriodicalIF":4.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143157736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

More than an age: U-Pb dating constrains alteration of Precambrian carbonates

IF 4.8 1区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Earth and Planetary Science Letters

Pub Date : 2025-02-01 DOI: 10.1016/j.epsl.2024.119154

Nathalie Neagu , Andrew Kylander-Clark , Woodward W. Fischer , Uri Ryb

The Campbellrand Platform (South Africa) is one of the best-preserved carbonate archives for studying Neoarchean marine environments immediately preceding the Great Oxygenation Event. These carbonates preserve depositional structure and textures, like a variety of dolomitized stromatolites and microbialites encased in herringbone calcite – a type of early marine calcite cement. The preservation of depositional textures in Precambrian carbonates is often used to argue for the retention of primary paleoenvironmental signals, which are, in turn, used to infer the conditions in ancient surface environments including the composition of seawater and climate. Here we tested this idea using laser-ablation ICP-MS U-Pb to independently date specific carbonate mineral fabrics from the ∼2.58 Ga Reivilo Formation and ∼2.52 Ga Gamohaan Formation at the Campbellrand platform in the Northern Cape Province of South Africa. U-Pb dates of dolomite fabrics are mostly younger than their expected stratigraphic age and their initial ²⁰⁷Pb/²⁰⁶Pb compositions follow the modeled terrestrial Pb-isotope evolution trend. These results suggested that dolomite fabrics have experienced open-system alteration in which diagenetic fluids carrying a terrestrial signature reset U-Pb dates and overprinted initial Pb-isotope compositions during deep diagenesis. In contrast, herringbone calcite fabrics yielded near-stratigraphic U-Pb dates that clustered around an average of 2403 (±93) Ma and initial ²⁰⁷Pb/²⁰⁶Pb values that plotted below the modeled terrestrial Pb-isotope evolution trend. These results revealed that Neoarchean herringbone calcite fabrics were minimally altered in a closed system with respect to Pb, at deposition or some 10-100 Ma later, and have remained closed with respect to both U and Pb since. The closed-system behavior of a highly sensitive system like U-Pb in herringbone calcites serves as an independent validation for the reliability of herringbone calcites as useful recorders of marine environments. U-Pb dating of ancient carbonates thus offers a complementary tool for petrographic analyses that can identify and evaluate the timing and nature of alteration (open or closed system) of primary geochemical signatures in Precambrian carbonates.

{"title":"More than an age: U-Pb dating constrains alteration of Precambrian carbonates","authors":"Nathalie Neagu , Andrew Kylander-Clark , Woodward W. Fischer , Uri Ryb","doi":"10.1016/j.epsl.2024.119154","DOIUrl":"10.1016/j.epsl.2024.119154","url":null,"abstract":"<div><div>The Campbellrand Platform (South Africa) is one of the best-preserved carbonate archives for studying Neoarchean marine environments immediately preceding the Great Oxygenation Event. These carbonates preserve depositional structure and textures, like a variety of dolomitized stromatolites and microbialites encased in herringbone calcite – a type of early marine calcite cement. The preservation of depositional textures in Precambrian carbonates is often used to argue for the retention of primary paleoenvironmental signals, which are, in turn, used to infer the conditions in ancient surface environments including the composition of seawater and climate. Here we tested this idea using laser-ablation ICP-MS U-Pb to independently date specific carbonate mineral fabrics from the ∼2.58 Ga Reivilo Formation and ∼2.52 Ga Gamohaan Formation at the Campbellrand platform in the Northern Cape Province of South Africa. U-Pb dates of dolomite fabrics are mostly younger than their expected stratigraphic age and their initial <sup>207</sup>Pb/<sup>206</sup>Pb compositions follow the modeled terrestrial Pb-isotope evolution trend. These results suggested that dolomite fabrics have experienced open-system alteration in which diagenetic fluids carrying a terrestrial signature reset U-Pb dates and overprinted initial Pb-isotope compositions during deep diagenesis. In contrast, herringbone calcite fabrics yielded near-stratigraphic U-Pb dates that clustered around an average of 2403 (±93) Ma and initial <sup>207</sup>Pb/<sup>206</sup>Pb values that plotted below the modeled terrestrial Pb-isotope evolution trend. These results revealed that Neoarchean herringbone calcite fabrics were minimally altered in a closed system with respect to Pb, at deposition or some 10-100 Ma later, and have remained closed with respect to both U and Pb since. The closed-system behavior of a highly sensitive system like U-Pb in herringbone calcites serves as an independent validation for the reliability of herringbone calcites as useful recorders of marine environments. U-Pb dating of ancient carbonates thus offers a complementary tool for petrographic analyses that can identify and evaluate the timing and nature of alteration (open or closed system) of primary geochemical signatures in Precambrian carbonates.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"651 ","pages":"Article 119154"},"PeriodicalIF":4.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143158148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A significant doubling of rockfall rates since the Little Ice Age in the Mont-Blanc massif, inferred from 10Be concentrations and rockfall inventories

IF 4.8 1区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Earth and Planetary Science Letters

Pub Date : 2025-02-01 DOI: 10.1016/j.epsl.2024.119142

Léa Courtial-Manent , Jean-Louis Mugnier , Ludovic Ravanel , Julien Carcaillet , Philip Deline , Jean-François Buoncristiani

By combining cosmogenic nuclide data and rockfall inventories, we have employed a rigorous methodology to focus on long-term erosion trends and the increase in rockfall in the Mont-Blanc massif (European Alps) over the last century. To do this, we used mathematical formulations based on power law integration, which enabled us to identify the complex links between rockfall distribution and erosion rates. Our approach was applied to the Mer de Glace basin (Mont-Blanc massif), where we combined analyses of ¹⁰Be concentration in the supraglacial load (based on 8 samples) with Terrestrial Laser Scanning (TLS) data capturing 123 rockfalls ranging from 1 to 566 m³, as well as direct observations of 71 rockfalls ranging from 100 to 20,000 m³. Within the overlapping volume range of both inventories, power law fitting yields a common exponent (b-value) of 0.75 ± 0.18. However, the TLS-derived rockfall rate (ā in m^-2.yr^-1) is approximately 5 times higher than that derived from the observation-based inventory. This difference is probably linked to the current intense permafrost degradation affecting scanned rockwalls at altitudes below 3800 m a.s.l. The 20,000 m³ rockfall documented by the network of observers has a statistical return time estimated at <6 years, which suggests that larger or more significant rockfalls will occur in the future. Based on a two-segment power law, the erosion rate is estimated at > 4.1 mm.yr^-1 for the period 2006–2011.

According to our study of glacial dynamics, the supraglacial clasts sampled aggregate ̴800 rockfalls greater than 1 m³ that occurred diachronically between 1845 and 1987 but whose cumulative total corresponds to <7 years of present rockwall erosion rate in the upper Mer de Glace basin. The mean ¹⁰Be concentration of the 8 supraglacial samples is 2.7 ± 1.3 10⁴ at.g^-1 and was obtained when exposing rock faces subjected to erosion of <1.2 ± 1 mm.yr^-1. The erosion rate would, therefore, have significantly increased between the Little Ice Age (maximum 2.2 mm.yr^-1 from ¹⁰Be result) and the beginning of the 21st century (minimum 4.1 mm.yr^-1 for 2003–2011 surveys). These erosion rates do not consider past volume rockfalls greater than those observed recently and are minimal erosion rate estimates. Nevertheless, they highlight the increase in mass movement hazards linked to global warming via permafrost degradation in high-altitude rockwalls.

{"title":"A significant doubling of rockfall rates since the Little Ice Age in the Mont-Blanc massif, inferred from 10Be concentrations and rockfall inventories","authors":"Léa Courtial-Manent , Jean-Louis Mugnier , Ludovic Ravanel , Julien Carcaillet , Philip Deline , Jean-François Buoncristiani","doi":"10.1016/j.epsl.2024.119142","DOIUrl":"10.1016/j.epsl.2024.119142","url":null,"abstract":"<div><div>By combining cosmogenic nuclide data and rockfall inventories, we have employed a rigorous methodology to focus on long-term erosion trends and the increase in rockfall in the Mont-Blanc massif (European Alps) over the last century. To do this, we used mathematical formulations based on power law integration, which enabled us to identify the complex links between rockfall distribution and erosion rates. Our approach was applied to the Mer de Glace basin (Mont-Blanc massif), where we combined analyses of <sup>10</sup>Be concentration in the supraglacial load (based on 8 samples) with Terrestrial Laser Scanning (TLS) data capturing 123 rockfalls ranging from 1 to 566 m<sup>3</sup>, as well as direct observations of 71 rockfalls ranging from 100 to 20,000 m<sup>3</sup>. Within the overlapping volume range of both inventories, power law fitting yields a common exponent (<em>b</em>-value) of 0.75 ± 0.18. However, the TLS-derived rockfall rate (ā in m<sup>-2</sup>.yr<sup>-1</sup>) is approximately 5 times higher than that derived from the observation-based inventory. This difference is probably linked to the current intense permafrost degradation affecting scanned rockwalls at altitudes below 3800 m a.s.l. The 20,000 m<sup>3</sup> rockfall documented by the network of observers has a statistical return time estimated at <6 years, which suggests that larger or more significant rockfalls will occur in the future. Based on a two-segment power law, the erosion rate is estimated at > 4.1 mm.yr<sup>-1</sup> for the period 2006–2011.</div><div>According to our study of glacial dynamics, the supraglacial clasts sampled aggregate ̴800 rockfalls greater than 1 m<sup>3</sup> that occurred diachronically between 1845 and 1987 but whose cumulative total corresponds to <7 years of present rockwall erosion rate in the upper Mer de Glace basin. The mean <sup>10</sup>Be concentration of the 8 supraglacial samples is 2.7 ± 1.3 10<sup>4</sup> at.g<sup>-1</sup> and was obtained when exposing rock faces subjected to erosion of <1.2 ± 1 mm.yr<sup>-1</sup>. The erosion rate would, therefore, have significantly increased between the Little Ice Age (maximum 2.2 mm.yr<sup>-1</sup> from <sup>10</sup>Be result) and the beginning of the 21st century (minimum 4.1 mm.yr<sup>-1</sup> for 2003–2011 surveys). These erosion rates do not consider past volume rockfalls greater than those observed recently and are minimal erosion rate estimates. Nevertheless, they highlight the increase in mass movement hazards linked to global warming <em>via</em> permafrost degradation in high-altitude rockwalls.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"651 ","pages":"Article 119142"},"PeriodicalIF":4.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143158145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Nanoscale reservoirs store solar wind-derived water on the lunar surface

IF 4.8 1区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Earth and Planetary Science Letters

Pub Date : 2025-02-01 DOI: 10.1016/j.epsl.2024.119178

Alexander M. Kling , Jennika Greer , Michelle S. Thompson , Philipp R. Heck , Dieter Isheim , David N. Seidman

Observations of widespread hydration across the lunar surface could be attributed to water formed via the implantation of solar wind hydrogen ions into minerals at the surface. Solar wind irradiation produces a defect-rich outer rim in lunar regolith grains which can trap implanted hydrogen to form and store water. However, the ability of hydrogen and water to be retained in space weathered regolith at the lunar surface is not well-understood. Here, we present results of novel and coordinated high-resolution analyses using transmission electron microscopy and atom probe tomography to measure hydrogen and water within space weathered lunar grains. We find that hydrogen and water are present in the solar wind-damaged rims of lunar grains and that these species are stored in higher concentrations in the vesicles that are formed by solar wind irradiation. These vesicles may serve as reservoirs that store water over diurnal and possibly geologic timescales. Solar wind-derived water trapped in space weathered rims is likely a major contributor to observations of the widespread presence, variability, and behavior of the water across the lunar surface.

{"title":"Nanoscale reservoirs store solar wind-derived water on the lunar surface","authors":"Alexander M. Kling , Jennika Greer , Michelle S. Thompson , Philipp R. Heck , Dieter Isheim , David N. Seidman","doi":"10.1016/j.epsl.2024.119178","DOIUrl":"10.1016/j.epsl.2024.119178","url":null,"abstract":"<div><div>Observations of widespread hydration across the lunar surface could be attributed to water formed via the implantation of solar wind hydrogen ions into minerals at the surface. Solar wind irradiation produces a defect-rich outer rim in lunar regolith grains which can trap implanted hydrogen to form and store water. However, the ability of hydrogen and water to be retained in space weathered regolith at the lunar surface is not well-understood. Here, we present results of novel and coordinated high-resolution analyses using transmission electron microscopy and atom probe tomography to measure hydrogen and water within space weathered lunar grains. We find that hydrogen and water are present in the solar wind-damaged rims of lunar grains and that these species are stored in higher concentrations in the vesicles that are formed by solar wind irradiation. These vesicles may serve as reservoirs that store water over diurnal and possibly geologic timescales. Solar wind-derived water trapped in space weathered rims is likely a major contributor to observations of the widespread presence, variability, and behavior of the water across the lunar surface.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"651 ","pages":"Article 119178"},"PeriodicalIF":4.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143157739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0