IF 5.8 1区地球科学

Geology Pub Date : 2026-10-02 DOI: 10.1130/g54561.1

Wei Zhang,Yunchao Shu,Ryuichi Shinjo,Sune G. Nielsen

引用次数: 0

Large domal stromatolites in the Paleoarchean ocean at 3.47 Ga: REPLY 3.47 Ga古太古代海洋大型穹窿叠层石：回复

IF 5.8 1区地球科学

Geology Pub Date : 2026-10-01 DOI: 10.1130/g55190y.1

Eva E. Stüeken,Anthony R. Prave,Liam O’Connor,Jonas Kaempf,Anthony Clarke,Tim E. Johnson,Christopher L. Kirkland

引用次数: 0

Large domal stromatolites in the Paleoarchean ocean at 3.47 Ga: COMMENT 3.47 Ga古太古代海洋中的大型穹窿叠层石：评论

IF 5.8 1区地球科学

Geology Pub Date : 2026-10-01 DOI: 10.1130/g55044c.1

Martin J. Van Kranendonk,Raphael J. Baumgartner

引用次数: 0

From ridge to subduction zone: Dual-temperature serpentinization of the ophiolitic mantle revealed by triple oxygen isotopes and magnetite formation 从洋脊到俯冲带：由三氧同位素和磁铁矿形成揭示的蛇绿质地幔的双温蛇纹岩化

IF 5.8 1区地球科学

Geology Pub Date : 2026-09-30 DOI: 10.1130/g54915.1

Liang Qi,Guanghui Wu,Adrian R. Muxworthy,Xiaobin Cao,Xiaokai Yang,Simon Allerton,Yong Zhang

{"title":"From ridge to subduction zone: Dual-temperature serpentinization of the ophiolitic mantle revealed by triple oxygen isotopes and magnetite formation","authors":"Liang Qi,Guanghui Wu,Adrian R. Muxworthy,Xiaobin Cao,Xiaokai Yang,Simon Allerton,Yong Zhang","doi":"10.1130/g54915.1","DOIUrl":"https://doi.org/10.1130/g54915.1","url":null,"abstract":"Mantle sections in ophiolites are almost always serpentinized. However, it often remains unclear whether the serpentinization occurs near the ridge axis during lithospheric formation, or later within the subduction zone during ophiolite obduction and emplacement. To constrain serpentinization in ophiolites, we combine a triple-oxygen-isotope technique with rock magnetic and major-element analyses to establish an integrated framework linking fluid sources and temperatures to magnetite formation and iron behavior in serpentinite. We apply this framework to the Troodos ophiolite in Cyprus, where representative serpentinized samples were collected from ultramafic zones along a fossil ridge-transform intersection preserved within the ophiolite. Our analyses reveal fluid sources and distinct temperature regimes for ridge-axis and subduction mantle wedge serpentinization. Ridge-axis serpentinization is characterized by ~200−310 °C seawater circulation and strongly magnetic serpentinites, whereas mantle wedge serpentinization is associated with ~150−220 °C slab-derived fluids and weakly magnetic serpentinites. We further identify a temperature-dependent relationship linking serpentine iron content, magnetite formation, and magnetic properties. This relationship indicates the contrasting magnetic properties of serpentinite result from the preferential formation of magnetite over iron-rich serpentine at temperatures &gt;200−220 °C.","PeriodicalId":12642,"journal":{"name":"Geology","volume":"21 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2026-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149091320","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

Tropical Indo-Pacific intermediate waters remain in a Little Ice Age cold state 热带印度洋-太平洋中间水域仍处于小冰河时期的寒冷状态

IF 5.8 1区地球科学

Geology Pub Date : 2026-09-30 DOI: 10.1130/g55025.1

Xuefei Chen,Kaiwen Ta,Xuefeng Wang,Wenfeng Deng,Gangjian Wei,Xiaotong Peng,Xian-Hua Li

{"title":"Tropical Indo-Pacific intermediate waters remain in a Little Ice Age cold state","authors":"Xuefei Chen,Kaiwen Ta,Xuefeng Wang,Wenfeng Deng,Gangjian Wei,Xiaotong Peng,Xian-Hua Li","doi":"10.1130/g55025.1","DOIUrl":"https://doi.org/10.1130/g55025.1","url":null,"abstract":"Model simulations predict that the deep Pacific Ocean still harbors cooling from the Little Ice Age (LIA; ca. 1450 to 1850 CE), implying vast unrealized heat uptake. Yet proxy records capable of testing this prediction at intermediate depths over the past millennium remain scarce across the Pacific. We address this gap using Li/Mg thermometry on a living cold-water coral from 1345 m in the South China Sea, with U-Th dating confirming continuous growth from the Medieval Climate Anomaly (MCA; ca. 850 to 1250 CE) to present. Li/Mg data reveal a cooling of 1.0 ± 0.2 °C from the MCA to the LIA, with the trend persisting at a reduced rate into the early Current Warm Period (ca. 1850 CE to present) and no recovery to MCA levels, a pattern also captured by Community Earth System Model (CESM) Last Millennium Ensemble simulations. In contrast, sea-surface temperatures have recovered from LIA levels, revealing a pronounced vertical thermal decoupling. These results demonstrate that deeper intermediate waters beneath the Indo-Pacific Warm Pool remain in a LIA cold state, implying that the ocean interior’s heat uptake capacity is far from exhausted and that recent increases in intermediate-depth heat content likely mark the onset of a protracted equilibration process rather than the approach to a new steady state.","PeriodicalId":12642,"journal":{"name":"Geology","volume":"242 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2026-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149091322","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

Mesozoic ocean plate stratigraphy reveals a Franciscan plate separating Farallon and North America 中生代海洋板块地层学揭示了法拉隆和北美之间的方济各板块

IF 5.8 1区地球科学

Geology Pub Date : 2026-09-30 DOI: 10.1130/g55100.1

Goran Andjić,John Wakabayashi,Alexey Ulianov,Douwe J.J. van Hinsbergen

{"title":"Mesozoic ocean plate stratigraphy reveals a Franciscan plate separating Farallon and North America","authors":"Goran Andjić,John Wakabayashi,Alexey Ulianov,Douwe J.J. van Hinsbergen","doi":"10.1130/g55100.1","DOIUrl":"https://doi.org/10.1130/g55100.1","url":null,"abstract":"Ocean plate stratigraphy preserved in the Franciscan Complex records the Mesozoic plate tectonic evolution of the North American Cordillera and eastern Pacific basin, yet it has not been widely used to constrain plate tectonic reconstructions of these regions. New and published ocean floor and accretion ages for Jurassic−Cretaceous oceanic crust, derived from detrital zircons and radiolarians, indicate that eastward younging ocean floor existed between the Farallon and North American plates during the Mesozoic. Our new plate reconstruction shows that, to the south, this lithosphere subducted southward at an intraoceanic subduction zone beneath Caribbean lithosphere, which was still part of Farallon during the Early Cretaceous. The east-younging lithosphere was thus not the Farallon plate, but a separate Franciscan plate. Our kinematic model shows that it formed as part of a back-arc basin during the Mesozoic that must have been bounded by eastward-dipping subduction zones on both its western and eastern margins. The paleolatitude and age of the Wrangellia superterrane of the Northern Cordillera fit well with this prediction. A Late Cretaceous plate reorganization and formation of the north-moving Kula plate offer kinematic explanations for why the intraoceanic arc records formed at low latitude are currently found only from British Columbia northward.","PeriodicalId":12642,"journal":{"name":"Geology","volume":"24 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2026-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149091321","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

CO2 flux distribution at Grindavík and Sundhnúkur craters prior to the August 2024 eruption at Reykjanes, SW Iceland 2024年8月冰岛西南部雷克雅内斯火山喷发前Grindavík和Sundhnúkur火山口的二氧化碳通量分布

IF 5.8 1区地球科学

Geology Pub Date : 2026-09-28 DOI: 10.1130/g54652.1

Bettina Strauch,Maria Hurley,Pınar Büyükakpınar,Martin Zimmer,Thomas R. Walter,Torsten Queißer,Egill Á. Gudnason,Magnús T. Gudmundsson,Celine L. Mandon,Andri Stefánsson,Daniel Müller,Marius Isken,Torsten Dahm,Jana Doubravová

{"title":"CO2 flux distribution at Grindavík and Sundhnúkur craters prior to the August 2024 eruption at Reykjanes, SW Iceland","authors":"Bettina Strauch,Maria Hurley,Pınar Büyükakpınar,Martin Zimmer,Thomas R. Walter,Torsten Queißer,Egill Á. Gudnason,Magnús T. Gudmundsson,Celine L. Mandon,Andri Stefánsson,Daniel Müller,Marius Isken,Torsten Dahm,Jana Doubravová","doi":"10.1130/g54652.1","DOIUrl":"https://doi.org/10.1130/g54652.1","url":null,"abstract":"Diffuse volcanic degassing reflects subsurface magma and fluid transport, but its spatio-temporal relationship to seismicity and eruptions remains poorly constrained. Here, we present ground- and drone-based CO2 flux measurements acquired prior to the August 2024 eruption on the Reykjanes Peninsula, Iceland, together with seismic observations. The study focused on the highly fractured Grindavík and Sundhnúkur areas. A transect through Grindavík reveals a bimodal distribution of CO2 fluxes with values between 0.1 and 28 g·m−2·d−1, reflecting heterogeneous near-surface permeability and local correlations to fractures. Using a new drone-based gas flux detection system, measurements at the inaccessible Sundhnúkur fissure system were possible, identifying elevated CO2 fluxes, with up to 4400 g·m−2·d−1 close to the location where the next eruption initiated. A comparison with seismicity suggests (1) distributed pressurization with localized enhanced gas escape restricted to the Sundhnúkur area prior to the eruption, and (2) strongly focused seismicity in the Sundhnúkur area during the eruption.","PeriodicalId":12642,"journal":{"name":"Geology","volume":"26 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149091075","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

Evaluating evaporative peritidal dolomite formation and its potential as seawater archives with subrecent (younger than 7 ka) records 评价蒸发潮外白云岩的形成及其作为亚近代（小于7 ka）记录的海水档案的潜力

IF 5.8 1区地球科学

Geology Pub Date : 2026-09-24 DOI: 10.1130/g55014.1

Yuzhu Ge,Hanting Zhong,Chao Chen,Or M. Bialik,Adrian Immenhauser,Meng Ning,Xia Wang,Keke Huang,Han Wang,Xinyu Wang,Mingcai Hou

{"title":"Evaluating evaporative peritidal dolomite formation and its potential as seawater archives with subrecent (younger than 7 ka) records","authors":"Yuzhu Ge,Hanting Zhong,Chao Chen,Or M. Bialik,Adrian Immenhauser,Meng Ning,Xia Wang,Keke Huang,Han Wang,Xinyu Wang,Mingcai Hou","doi":"10.1130/g55014.1","DOIUrl":"https://doi.org/10.1130/g55014.1","url":null,"abstract":"Early marine diagenetic dolomites in peritidal settings are geologically abundant and regarded as promising seawater archives, yet their application is hindered by the still-enigmatic processes governing their formation. We investigate subrecent (&lt;7 ka) dolomites extracted from classical evaporative peritidal carbonates near Abu Dhabi, United Arab Emirates, one of the few settings documenting (sub)recent dolomite formation. The results are inconsistent with direct seawater precipitation or reflux dolomitization. Instead, we identify syndepositional dolomitization linked to organic-driven manganese redox cycling within a very shallow, hydrologically open system. Such dolomites as seawater archives are favored by the formation conditions, but they exhibit negative shifts of δ13C and δ18O relative to bulk carbonates and large deviations of δ26Mg from that of coeval open seawater. This paradox may be attributed to ineffective seawater−pore water exchange in the peritidal setting, where tidal forcing drives pore-water oscillation rather than efficient seawater replenishment. Together with previous studies, this subrecent case provides more direct and detailed insights into syndepositional dolomitization. It highlights the complex interplay among early diagenetic redox zones, seawater connectivity, and pore-water circulation that influences peritidal dolomites as seawater archives.","PeriodicalId":12642,"journal":{"name":"Geology","volume":"14 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149049764","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 fossil subduction system preserved beneath Sri Lanka 斯里兰卡地下保存着一个化石俯冲系统

IF 5.8 1区地球科学

Geology Pub Date : 2026-09-23 DOI: 10.1130/g54693.1

Gaoshan Guo,Haiqiang Lan,Lei Zhao,Sanjeewa P.K. Malaviarachchi,Qinya Liu

{"title":"A fossil subduction system preserved beneath Sri Lanka","authors":"Gaoshan Guo,Haiqiang Lan,Lei Zhao,Sanjeewa P.K. Malaviarachchi,Qinya Liu","doi":"10.1130/g54693.1","DOIUrl":"https://doi.org/10.1130/g54693.1","url":null,"abstract":"The long-term fate of lithosphere subducted during supercontinent assembly remains uncertain. Sri Lanka, located near the center of Gondwana and underlain by Precambrian basement, provides an ideal setting in which to search for remnants of ancient subduction. Using teleseismic tomography, we imaged upper-mantle velocity structure beneath Sri Lanka to test whether oceanic lithosphere subducted during Gondwana assembly has been preserved at depth. Our results revealed previously unrecognized mantle structure consistent with ancient subduction. A steep, coherent high-velocity body extends from ~100 to ~200 km depth, rooted near the Highland-Vijayan shear-thrust boundary and extending westward under the Wanni Complex. A localized uppermost-mantle low-velocity anomaly overlies its shallow portion, consistent with a fossil serpentinized mantle wedge above a former subduction zone. The geometry, amplitude, and depth continuity of the high-velocity anomaly suggest a relic oceanic slab emplaced during late Precambrian−Cambrian convergence along the Highland−southern India margin, marking a major suture associated with East Gondwana assembly. Coexisting slab and mantle-wedge signatures imply limited mantle reworking beneath central Gondwana since the early Paleozoic. These results provide the first seismic evidence for a fossil subduction system beneath Sri Lanka and new constraints on East Gondwana assembly.","PeriodicalId":12642,"journal":{"name":"Geology","volume":"15 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149049765","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

On the age of the Cretaceous−Paleogene boundary event and millennial-scale climate variability during its aftermath at Elles, Tunisia 突尼斯Elles白垩纪-古近纪边界事件的年龄及其余波的千年尺度气候变率

IF 5.8 1区地球科学

Geology Pub Date : 2026-09-21 DOI: 10.1130/g54885.1

Alessandro Mari,Lucas J. Lourens,Matthew Huber,Robert P. Speijer,Simone Galeotti

{"title":"On the age of the Cretaceous−Paleogene boundary event and millennial-scale climate variability during its aftermath at Elles, Tunisia","authors":"Alessandro Mari,Lucas J. Lourens,Matthew Huber,Robert P. Speijer,Simone Galeotti","doi":"10.1130/g54885.1","DOIUrl":"https://doi.org/10.1130/g54885.1","url":null,"abstract":"The Cretaceous−Paleogene boundary (KPB) marks one of the most abrupt environmental crises of the Phanerozoic, driven primarily by the Chicxulub asteroid impact, yet the pace of climate variability in its aftermath remains poorly constrained at millennial resolution, and its age is still debated. Here, we present a high-resolution coarse-fraction (&gt;32 µm) record from the expanded shallow-marine Elles I section, Tunisia, revealing a clear precession signal and its modulation by short eccentricity across the boundary. Our results place the KPB close to a short-eccentricity minimum, with a preferred astrochronological age of 65.967 ± 0.011 Ma and a sensitivity range across all tested solutions of 66.065−65.956 Ma. The earliest Danian shows robust millennial-scale climate variability with periodicities at ~4.0 and ~2.5 k.y. The ~4.0 k.y. band exhibits amplitude modulation by precession and obliquity, indicating that astronomical forcing continued to structure climate variability down to suborbital time scales after the impact. These results provide a new benchmark for the KPB age and reveal pervasive rapid climate variability during the earliest postimpact recovery.","PeriodicalId":12642,"journal":{"name":"Geology","volume":"1 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149022031","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

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