Geoscience frontiers最新文献

{"title":"Spatial distributions of macronutrients, heavy metals and microplastics in surface sediments of the mainstem and lakes in the middle part of the Yellow River Basin","authors":"Xiajie Zhai ,&nbsp;Lijuan Cui ,&nbsp;Wei Li ,&nbsp;Xinsheng Zhao ,&nbsp;Chenxi Liu ,&nbsp;Hua Ma ,&nbsp;Mingshuo Xiong","doi":"10.1016/j.gsf.2025.102214","DOIUrl":"10.1016/j.gsf.2025.102214","url":null,"abstract":"<div><div>The Yellow River provides an important foundation for the sustainable development of Chinese civilization. Compared with the upper part (dominated by the Tibetan Plateau) and the lower part (represented by the Yellow River Delta), the central part of the Yellow River Basin (encompassing most of the Loess Plateau) is the most arid and exhibits the most complex relationship between humans and nature. The Chinese government is continuously promoting the protection and management of the ecological environment in the central part of the Yellow River Basin, as it is related to the country’s food security and people’s health, biodiversity conservation and sustainable socio-economic development. However, the distribution patterns and evolution of key ecological elements in the region, which are important determinants of ecosystem productivity and health, have yet to be revealed. This study focused on three key ecological elements, namely, macronutrients (sediment organic carbon, SOC, total nitrogen, TN and total phosphorous, TP), heavy metals (Cu, Ni, Pb, Zn, Cr, Cd, Hg, and As) and microplastics, and aimed to systematically elucidate the change patterns of their concentrations and compositions in sediments from the mainstem of the Yellow River and neighboring typical lakes. The results revealed that the TN content was mostly greater than the SOC content in the sediments from the mainstem of the Yellow River. Moreover, the TN, SOC and heavy metal concentrations increased significantly as a result of agricultural cultivation. Among the six typical lakes, the highest concentrations of both macronutrients and heavy metals were observed in sediment samples from Mingcui Lake (MC; an urban wetland), followed by those in sediment samples from Wuliangsuhai Lake (WLS; surrounded by agricultural fields). Among the heavy metals, the concentrations of Zn and Cr were highest. The abundance of microplastics in the sediments from the mainstream of the Yellow River ranged from 233 to 3333 items kg⁻¹, while the abundance of microplastics in lake sediments ranged from 967 to 1556 items kg⁻¹. The other characteristics of microplastics were consistent, including the concentration of microplastic particles within the 0.2–2 mm range. The main colors of the sampled microplastics were blue, transparent, and gray-black. In addition, rayon accounted for the highest proportion among all polymer types, followed by PET and PE + PP. In general, the amount of the above three environmental elements is closely correlated with the intensity of human activities such as agriculture and urbanization. Stronger correlations were obtained between the concentrations of macronutrients and heavy metals. This study systematically reveals the change patterns of key ecological elements in the study area and advances the understanding of environmental changes, ecosystem evolution and sustainable development in the Yellow River Basin.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 1","pages":"Article 102214"},"PeriodicalIF":8.9,"publicationDate":"2025-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145690947","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}

{"title":"Collision-related tin metallogeny: Insight from a new discovery of the volcanic-subvolcanic-hosted Sn deposit in the western Gangdese, Xizang","authors":"Hao Chen ,&nbsp;Xin Chen ,&nbsp;Youye Zheng ,&nbsp;Xian Che ,&nbsp;Yuanping Lai ,&nbsp;Xingkai Huang ,&nbsp;Shunbao Gao ,&nbsp;Bei Pang","doi":"10.1016/j.gsf.2025.102216","DOIUrl":"10.1016/j.gsf.2025.102216","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The Gangdese metallogenic belt in Xizang, a world-class copper polymetallic province, has a poorly understood western segment due to extensive volcanic cover and limited historical exploration. The recent discovery of the Sangmoladong (SMLD) deposit, the first undocumented volcanic- to subvolcanic-hosted, tin-dominant polymetallic system in western Gangdese, provides a unique opportunity to investigate collisional metallogeny. Through integrated LA-ICP-MS U-Pb geochronology of zircon and cassiterite, comprehensive whole-rock geochemistry, and Nd-Hf isotopes, this research establishes a genetic link between Paleocene magmatism and Sn-polymetallic mineralization. The mineralization is hosted within granite porphyry stocks and associated rhyolitic tuff breccias of a volcanic dome complex. It comprises two main stages: an early, disseminated cassiterite-sulfide stage with chloritic alteration, followed by later fluorite-cassiterite-tourmaline veins and veinlets. New LA-ICP-MS U-Pb dating constrains the timing of granite porphyry emplacement to 61.3 ± 0.2 Ma and rhyolitic tuff deposition to 61.8 ± 0.5 Ma. Cassiterite mineralization occurred between 61.0 ± 2.2 Ma and 59.3 ± 3.5 Ma, confirming that Sn metallogenesis was coeval with this Paleocene magmatic pulse during the Indo-Asian collision. The ore-forming granitic porphyries are highly evolved, A-type granites, characterized by high SiO&lt;sub&gt;2&lt;/sub&gt; (77.50 – 80.40 wt.%), elevated zircon saturation temperatures (831 – 870 °C), and high Ga/Al ratios (10,000 × Ga/Al = 5.75 – 6.51). Their Nd-Hf isotopic signatures (&lt;em&gt;ε&lt;/em&gt;&lt;sub&gt;Nd&lt;/sub&gt;(&lt;em&gt;t&lt;/em&gt;) =  −6.5 to −6.3; zircon &lt;em&gt;ε&lt;/em&gt;&lt;sub&gt;Hf&lt;/sub&gt;(&lt;em&gt;t&lt;/em&gt;) =  −5.2 to +2.1) indicate an origin from anatexis of ancient Lhasa terrane metapelites, likely triggered by lithospheric extension during Neo-Tethyan slab rollback. This generated a reduced, fluorine- and boron-rich magmatic-hydrothermal system highly efficient at mobilizing and concentrating tin. On a regional scale, a metallogenic framework is proposed where Fe-Cu mineralization is sourced from hybridized mantle-crust magmas, whereas Pb-Zn and Sn systems derive from similar crustal-dominated sources. This metallogenic divergence of Pb-Zn and Sn reflects contrasting thermal regimes and magma crystallization pathways during a transtensional setting with local extension in pull-apart and uplift structures. The formation of the SMLD tin deposit is attributed to prolonged fractional crystallization of a high-temperature, low &lt;em&gt;f&lt;/em&gt;O&lt;sub&gt;2&lt;/sub&gt; magma within a subvolcanic dome complex. These conditions suppressed early cassiterite saturation and promoted extreme tin enrichment in the residual melt. This study makes two key contributions: (1) it identifies the first volcanic-hosted tin system in the western Gangdese, challenging traditional exploration models focused on porphyry skarn Cu-Pb-Zn deposits; and (2) it establishes a new tectono-metallogenic model that elucidates the spatiotempor","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 2","pages":"Article 102216"},"PeriodicalIF":8.9,"publicationDate":"2025-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145748583","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}

{"title":"Topographic and morphological effects of global earthquake- and rainstorm-induced landslides","authors":"Wenchao Huangfu ,&nbsp;Haijun Qiu ,&nbsp;Jiading Wang ,&nbsp;Ninglian Wang ,&nbsp;Yang Zhang ,&nbsp;Ya Liu ,&nbsp;Ali Darvishi Boloorani ,&nbsp;Mohib Ullah","doi":"10.1016/j.gsf.2025.102215","DOIUrl":"10.1016/j.gsf.2025.102215","url":null,"abstract":"<div><div>Landslides have different topographic and morphological characteristics due to their different triggering mechanisms. However, the differences in the characteristics of earthquake- and rainstorm-induced landslides remain unclear. In this paper, we collect 12 cases of earthquake- and rainstorm-induced landslides around the world and reveal the differences in characteristics of the two types of landslides. By examining the geometric characteristics and location distribution of the landslides, the results show that earthquake-induced landslides tend to have larger areas, perimeter, lengths, widths, area to perimeter ratios (area/perimeter), major axis (<em>S</em>_M), and minor axis (<em>s</em>_m) than rainstorm-induced landslides. In addition, earthquake-induced landslides have more complex, rounded, and compact shapes than rainstorm-induced landslides. Earthquake-induced landslides are predominantly clustered near ridges, whereas rainstorm-induced landslides are predominantly clustered near valleys. The results also indicate that earthquake- and rainstorm-induced landslides mostly occur on 30°–50° and 10°–30° slopes, respectively, and both types are more likely to occur on sunny slopes. Moreover, the compactness and major axis are negatively logarithmically correlated for earthquake-induced landslides, while they are negatively exponentially correlated for rainstorm-induced landslides. Additional earthquake- and rainstorm-induced landslide events have verified the reliability and extensibility of the research conclusions. This work is beneficial for the management of landslide hazards and the effective implementation of landslide prediction and risk assessment.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 2","pages":"Article 102215"},"PeriodicalIF":8.9,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145645721","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}

{"title":"From prediction to regionalization: Enhancing flash flood susceptibility mapping using machine learning and GeoDetector","authors":"Xinyue Ke ,&nbsp;Ni Wang ,&nbsp;Tianhao Li ,&nbsp;Zheng Liu ,&nbsp;Zhiwei Li ,&nbsp;Ganggang Zuo ,&nbsp;Yiting Chen","doi":"10.1016/j.gsf.2025.102213","DOIUrl":"10.1016/j.gsf.2025.102213","url":null,"abstract":"<div><div>Flash floods cause substantial economic losses and casualties worldwide. Susceptibility-based flash flood mapping supports the development of effective flood mitigation strategies. While machine learning (ML) models offer superior accuracy, converting their outputs into spatially coherent and actionable maps remains challenging. Existing susceptibility maps often rely on subjective discretization and exhibit fragmented spatial patterns, limiting their utility in practice. In this context, this study proposes a novel framework that achieves the effective transformation of susceptibility prediction results into a management-oriented regionalization map. The framework integrates supervised learning, unsupervised clustering, and spatial explanatory feedback to enable information fusion and spatial restructuring of multi-model outputs. Flash flood susceptibility was first modelled using two supervised algorithms: Random Forest and CatBoost. Their outputs, along with exposed elements, were integrated and discretized using a two-stage clustering approach based on Self-Organizing Maps (SOM) and Ward’s method. Finally, a GeoDetector-based iterative optimization process was implemented to refine the regionalization by maximizing alignment with historical flash flood distributions. Results show that all susceptibility models achieved excellent predictive performance (AUC &gt; 0.95), with the CatBoost model trained on grid-based samples performing best (AUC = 0.997). The final regionalization map exhibits regional contiguity and effectively captures historical flood patterns, explaining 73% of their spatial variability. The integration of hybrid ML with explanatory feedback provides a novel perspective for generating susceptibility regionalization maps that are both expressive of flash flood risk and spatially coherent, in addition to providing support for exploring region-specific defense measures.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 1","pages":"Article 102213"},"PeriodicalIF":8.9,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145620319","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}

{"title":"Using D/V Meng Xiang to drill intact magmatic crust in the Pacific to reveal the petrological nature of the oceanic Moho","authors":"Yaoling Niu","doi":"10.1016/j.gsf.2025.102211","DOIUrl":"10.1016/j.gsf.2025.102211","url":null,"abstract":"<div><div>I have recently published “Do we really need to drill through the intact ocean crust?” in this journal (Geoscience Frontiors, 2025, Volume 16, 101954), which is a theme talk at the “<em>International Workshop on Fulfilling the Quest of Drilling Through the Ocean Crust Using D/V Meng Xiang</em> (‘梦想号’)” held in Guangzhou (November 24 ‒ 27, 2024), and is an objective account of petrological properties of the oceanic Moho. The global geoscience community universally acknowledges that Moho is a seismic discontinuity representing the boundary between the crust (<em>V</em>_P ≤ 7 km/s) and mantle (<em>V</em>_P ≥ 8.0 km/s). However, the longstanding assumption of purely magmatic origin for the ocean crust has misled the subject field. Evidence shows that the ocean crust formed at many slow-spreading ridge localities maintains a globally constant seismic thickness of ∼ 6 ± 1 km yet paradoxically comprises predominantly serpentinited mantle peridotite. This observation rationalizes the 60-year-old Hess-type Ocean crust hypothesis, while also underscoring the imperative for direct verification through intact ocean crust drilling − the core objective of the abandoned <em>Project Mohole</em> (1957‒1966). The workshop participants unanimously concurred that <em>D/V Meng Xiang</em> is currently the only operational platform capable of achieving intact ocean crust penetration. However, selection of optimal drilling sites needs further multidisciplinary discussion for successful Moho penetration, allowing addressing the core question on the <em>petrological nature of the oceanic Moho</em>. Here, I suggest the following with justifications for consideration: (1) It is not possible and thus has no significance to drill into the Moho on seafloors formed at slow- and ultraslow-spreading ridges; (2) it is feasible to succeed with well-prepared efforts in drilling through intact magmatic crust at ideal sites of seafloors produced at the fast-spreading East Pacific Rise; (3) if the Pacific Moho is discovered to be serpentinization front, this will bring about a paradigm shift.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 1","pages":"Article 102211"},"PeriodicalIF":8.9,"publicationDate":"2025-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145620322","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}

{"title":"Imaging the seismic LAB and deeper asthenospheric low-velocity layers in the Ibero-Maghrebian region","authors":"J.A. Parera-Portell ,&nbsp;F.d.L. Mancilla ,&nbsp;J. Morales ,&nbsp;X. Yuan ,&nbsp;B. Heit ,&nbsp;J. Diaz","doi":"10.1016/j.gsf.2025.102210","DOIUrl":"10.1016/j.gsf.2025.102210","url":null,"abstract":"<div><div>We present a new lithosphere-asthenosphere boundary (LAB) depth map of Iberia and adjacent areas built using <span><math><mrow><mo>∼</mo></mrow></math></span>34500 Sp receiver functions from 998 broadband seismic stations, alongside an updated Ps-derived crustal thickness map of Iberia. We found an overall shallow LAB, with a minimum depth of 70–80 km in areas of Cenozoic extension such as the eastern coast of Iberia and the Gibraltar-Alboran subduction back-arc, as well as in the Massif Central and the tectonically stable northwest of Iberia. LAB depths from 90 km to 110 km were only found within the areas of thickened crust in north-central Iberia and bordering the Gulf of Cádiz. The much deeper (150–180 km) oceanic LAB of the Gibraltar-Alboran slab was also imaged in the western Gibraltar Arc. Sublithospheric negative-velocity gradients (NVG) in the 110–140 km depth range are widespread in the back-arc of the Gibraltar-Alboran subduction system and in north-central Iberia, picturing a layered asthenospheric structure. In the Gibraltar Arc, the detachment of the slab through the subduction-transform edge propagator fault in the eastern Betics seems linked to the formation of the NVG, which are limited to the north by this structure.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 1","pages":"Article 102210"},"PeriodicalIF":8.9,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145620320","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}

{"title":"Experimental simulation of the formation processes of natural metal hydrides in sedimentary basins","authors":"Yutong Su ,&nbsp;Renbiao Tao ,&nbsp;Zhijun Jin ,&nbsp;Runchao Liu ,&nbsp;Yunhua Fu ,&nbsp;Lu Wang ,&nbsp;Haozhe Zhang","doi":"10.1016/j.gsf.2025.102206","DOIUrl":"10.1016/j.gsf.2025.102206","url":null,"abstract":"<div><div>Metal hydrides are essential materials with broad scientific and technological significance, showing unique properties in the fields of energy storage, catalysis, and superconductivity. Inspired by material science, we propose that natural hydrides can form in the Earth’s sedimentary basins due to existing favorable basis of matter and energy, which may provide a new perspective on understanding the geological origin and storage of natural hydrogen. In this study, we use a high-pressure gas reaction analyzer system to explore the hydrogenation reaction of typical transition metal powders (i.e., titanium (Ti), vanadium (V), chromium (Cr), and manganese (Mn)) under 50–200 °C and 3–5 MPa conditions relevant to sedimentary basins, and find that the hydrogenation reaction processes show apparent temperature dependence and can be efficiently promoted by pressure. Titanium exhibits a strong affinity for hydrogen, and its reaction with hydrogen is the largest among the four metals. The affinity of vanadium is second only to titanium. The affinity of chromium and manganese is at a similarly low level. As the temperature rises, the reaction quantity of titanium with hydrogen continues to increase; in contrast, the reaction quantity of vanadium and manganese with hydrogen shows a trend of first decreasing and then increasing; at 3 MPa, the reaction quantity of chromium with hydrogen shows a trend of first decreasing and then increasing, and at 5 MPa, the reaction quantity of chromium with hydrogen shows a trend of first increasing and then decreasing. After the in-situ hydrogenation experiments, combined XRD, ToF-SIMS, and NMR analysis on the quenched samples confirm the formation and stability of metal hydrides. Our study not only reveals the possibility of forming metal hydrides in sedimentary basins but also deepens our understanding of the metal-hydrogen interaction mechanism, providing a specific research basis for the formation of hydrides in shallow basins, which sheds light on the search for natural hydrides in sedimentary basins as a new energy source in the future.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 1","pages":"Article 102206"},"PeriodicalIF":8.9,"publicationDate":"2025-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526144","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}

{"title":"Changes in hydrological regime regulate POC export across permafrost-dominated Arctic River basins","authors":"Shiqi Liu ,&nbsp;Ping Wang ,&nbsp;Jingjie Yu ,&nbsp;Renjie Zhou ,&nbsp;Bing Bai ,&nbsp;Olga I. Gabysheva ,&nbsp;Natalia L. Frolova ,&nbsp;Sergey P. Pozdniakov","doi":"10.1016/j.gsf.2025.102208","DOIUrl":"10.1016/j.gsf.2025.102208","url":null,"abstract":"<div><div>Warming-driven acceleration of hydrological processes is altering the carbon cycle in permafrost-dominated Arctic regions, yet the underlying drivers remain unclear. This study analyzes ArcticGRO data (2003–2021) from six major Arctic rivers (Ob, Yenisei, Lena, Kolyma, Yukon, and Mackenzie) to investigate trends and spatial–temporal variations in riverine particulate organic carbon (POC). The annual POC flux from these six rivers, estimated using the Load Estimator (LOADEST), averaged 2.78 Tg. Only the Lena River showed a notable annual decrease in POC flux (−3.9%/yr, <em>p</em> &lt; 0.001) and concentration (−12%/yr, <em>p</em> &lt; 0.001), while the Yukon River exhibited increasing streamflow (+0.98%/yr, <em>p</em> &lt; 0.001) and POC flux (+3.2%/yr, <em>p</em> &lt; 0.001). POC flux variations were primarily governed by streamflow and POC concentration, with higher concentrations in spring floods period and lower during winter. Spatial differences were linked to drainage density (<em>Dd</em>) and forest coverage (<em>Fc</em>). The Yukon River basin, with a higher <em>Dd</em> of 0.2 km/km² and lower <em>Fc</em> approximately 24%, exhibits the highest POC concentrations (2.3 mg/L). In contrast, the Yenisei River basin has the lowest POC concentration (∼0.4 mg/L), along with a relatively low drainage density (<em>Dd</em> = 0.18 km/km²) and a high forest cover (<em>Fc</em> = 67%). Permafrost conditions constrained riverine POC export, with isotopic evidence indicating a shift from a carbon sink to a source, as POC carbon age increased by ∼ 200 to 1700 years (4%–68%) annually, peaking in winter (700–2500 years) after 2012. Rivers with lower permafrost coverage (e.g., Ob, Yenisei), exhibit higher winter POC fluxes contributions (10%–20%), while others contributed &lt; 5%, suggesting the role of permafrost degradation in winter carbon export. This study emphasizes the need to assess climate-driven hydrological shifts and permafrost thaw in shaping Arctic land-to-ocean carbon fluxes.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 1","pages":"Article 102208"},"PeriodicalIF":8.9,"publicationDate":"2025-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526176","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}

{"title":"The Messinian halite facies: Insights into halite crystallisation and depositional environments using geochemical, petrographic and fluid inclusion studies","authors":"Mara Cipriani ,&nbsp;Alessandra Costanzo ,&nbsp;Martin Feely ,&nbsp;Adriano Guido ,&nbsp;Massimo D’Antonio ,&nbsp;Giovanni Vespasiano ,&nbsp;Sandro Donato ,&nbsp;Giuseppe Cianflone ,&nbsp;Giuseppe Maruca ,&nbsp;Carmine Apollaro ,&nbsp;Francesca Alessandro ,&nbsp;Francesco Perri ,&nbsp;Rocco Dominici","doi":"10.1016/j.gsf.2025.102207","DOIUrl":"10.1016/j.gsf.2025.102207","url":null,"abstract":"<div><div>The Crotone Basin (Calabria, Southern Italy) is a representative area in the Italian peninsula where Messinian halite deposits preserve three distinct crystal facies: (i) <em>banded</em> composed of cumulate halite and mud-rich interlayers, (ii) <em>white</em> consisting of bottom-growth crystals with chevron fabrics, and (iii) <em>transparent</em> made up of massive, optically pure crystals. The transparent facies appears to be undocumented in other Mediterranean Messinian basins, offering new perspective on halite crystallisation under variable environmental conditions. Microscopic observations (optical and scanning electron microscopy), supported by high-resolution 3D imaging through synchrotron-based X-ray microtomography, revealed a lack of pervasive recrystallisation in all facies, enabling the non-destructive visualisation of internal fabrics and inclusions. These methods provided critical insights into halite growth dynamics and the environmental conditions prevailing during deposition.</div><div>Microthermometric data indicated that all halite crystals precipitated from a NaCl-MgCl₂-H₂O salt-water system under extreme evaporative conditions, with fluid salinity exceeding 340 ‰ – 360 ‰ and a distinct brine temperature for each facies (∼35 °C in the banded, ∼45 °C in the white, and ∼ 20 °C in the transparent). Strontium isotope ratios (⁸⁷Sr/⁸⁶Sr) placed halite formation within the TG14-TG12 interval (ca. 5.61 – 5.55 Ma), with progressively increasing values from banded to transparent facies, suggesting enhanced continental input and brine dilution in the later stages of deposition.</div><div>Organic matter was detected both in primary fluid inclusions and within the halite lattice, particularly in the white and transparent facies. Raman spectroscopy and UV-epifluorescence revealed amorphous organic compounds, including carotenoids and aliphatic functional groups such as methyl and methylene, which are commonly associated with microbial activity. These findings suggested that organic-rich brines may have played an active role in crystal nucleation and growth dynamics. The chemical immaturity and heterogeneous distribution of organic compounds imply a combination of autochthonous microbial input and episodic allochthonous influx, pointing to complex organic-mineral interactions during halite formation.</div><div>The coexistence of three petrographically distinct halite facies within a confined area, each linked to specific environmental and geochemical conditions, supports the view that halite precipitation was modulated by fluctuations in hydrological balance, brine composition, and organic matter availability. These data contribute to a better understanding of the environmental and geochemical processes that controlled evaporite deposition during the Messinian Salinity Crisis.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 1","pages":"Article 102207"},"PeriodicalIF":8.9,"publicationDate":"2025-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145576765","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}

{"title":"The missing late Cretaceous magmatic arc in the Arabia-Eurasia collision zone (NW Iran): constraints from zircon geochronology, Hf isotopes, and geochemistry","authors":"Ali Mohammadi ,&nbsp;Hadi Shafaii Moghadam ,&nbsp;Amaneh Kaveh-Firouz ,&nbsp;Anna Lechmann ,&nbsp;Fulong Cai ,&nbsp;Lin Ding","doi":"10.1016/j.gsf.2025.102205","DOIUrl":"10.1016/j.gsf.2025.102205","url":null,"abstract":"<div><div>The Late Cretaceous magmatic evolution of northwestern (NW) Iran reveals a previously unrecognized continental arc system, the Azerbaijan Continental Magmatic Arc, herein termed the Azerbaijan Continental Magmatic Arc, which is largely obscured by subsequent tectonic overprinting, erosion, and basin burial. Integration of new zircon U-Pb ages, Lu-Hf isotopic data, and whole-rock geochemical compositions from volcanic and plutonic rocks in the Misho, Sufian, Moro, Amand, Vanyar, and Iskandar regions identifies a subduction-related arc system distinct from the Sanandaj–Sirjan and Urumieh–Dokhtar magmatic belts. The ∼ 101–97 Ma gabbros and granodiorites record <em>ε</em>_Hf(<em>t</em>) values from + 9.8 to −7.2, reflecting variable mantle and crustal inputs. Arc-like trace-element patterns, including LREE enrichment and subduction-related anomalies, together with structural alignments along the Siah Cheshmeh–Khoy–Misho–Tabriz Fault (SKMT), indicate arc magmatism contemporaneous with transpressional deformation. The magmatic series evolved from juvenile tholeiitic to enriched shoshonitic compositions, tracking increasing crustal assimilation and slab rollback. This flare-up event represents a transient phase of Neo-Tethyan subduction, later overprinted by Eocene intrusions of the Urumieh–Dokhtar Magmatic Arc. Collectively, these results highlight the cryptic preservation of continental arcs and propose that the SKMT Fault marks a concealed suture accommodating Late Cretaceous arc migration and back-arc basin development in NW Iran.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 1","pages":"Article 102205"},"PeriodicalIF":8.9,"publicationDate":"2025-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526175","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}