Gondwana Research最新文献

{"title":"Uncertainty and diversification: Analyzing the impact of energy-related and climate policy uncertainties on environmental degradation in the United States","authors":"Veli Yilanci ,&nbsp;Uğur Ursavaş ,&nbsp;Iftikhar Yasin","doi":"10.1016/j.gr.2025.02.017","DOIUrl":"10.1016/j.gr.2025.02.017","url":null,"abstract":"<div><div>This study examines the complex relationship between environmental degradation, energy-related uncertainty (EUI), climate policy uncertainty (CPU), and energy consumption diversification (ECD) in the United States from January 2001 to September 2022. Employing novel and robust econometric methods, including the Bootstrap ARDL Bounds test with smooth and sharp structural breaks, the Toda-Yamamoto causality test with a Fourier function, and partial wavelet coherency analysis, the study reveals a surprising negative relationship between both EUI and CPU with CO₂ emissions which suggests that uncertainties surrounding energy and climate policies may incentivize actors to adopt cleaner technologies and prioritize emission reduction strategies. However, the study also identifies a positive relationship between ECD and CO₂ emissions, highlighting the need for strategic diversification prioritizing renewable and low-carbon sources. These findings emphasize the critical role of clear, consistent, and sustained climate policies in fostering clean energy investment and mitigating environmental degradation.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"141 ","pages":"Pages 149-163"},"PeriodicalIF":7.2,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143528784","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":"Retrieving petrogenetic source, compositional diversity and tectono-magmatic scenario of Tethyan sediment-derived magmatic flare-up: A tale from petrochemical and multi-isotopic (Sr–Nd–B–Hf) systematics","authors":"Tehseen Zafar ,&nbsp;Shuguang Song ,&nbsp;Hafiz Ur Rehman ,&nbsp;Hamed Gamaleldien ,&nbsp;Abiola Oyebamiji ,&nbsp;Zaheen Ullah ,&nbsp;Umar Farooq Jadoon ,&nbsp;Muhammad Farhan ,&nbsp;Mohamed Zaki Khedr ,&nbsp;Irfan Maqbool Bhat ,&nbsp;Fatemeh Sepidbar ,&nbsp;Fatemeh Nouri ,&nbsp;Amjad Hussain ,&nbsp;Zahid Hussain ,&nbsp;Mabrouk Sami","doi":"10.1016/j.gr.2025.02.013","DOIUrl":"10.1016/j.gr.2025.02.013","url":null,"abstract":"<div><div>The Earth’s continental crust is predominantly composed of granitic rocks, yet the genesis of pure sediment-derived peraluminous granites (PGs) remains debated. This study investigates the Ordovician Mansehra granitic suite (ca. 476–483 Ma) from the northwestern Himalayas of Pakistan as an example of S-type granites, comparing them with global counterparts from Diancangshan-Ailaoshan (China), Tanggula-Damxung (Tibet), and Karamese (Turkey). Geochemical and isotopic data, including variable zircon εHf(t) values (−37.7 to + 12.6), enriched Sr isotope ratios ((⁸⁷Sr/⁸⁶Sr)i: 0.5678–0.7444), negative εNd(t) values (−13.4 to − 2.9), and a narrow δ¹¹B range (−15.4 ‰ to − 9.5 ‰), indicate that PGs formed through partial melting of heterogeneous, mature pelitic sources under shallow, low-pressure conditions in the lower–upper crust, with minimal mantle input. Heterogeneous Hf isotopic behavior reflects the disequilibrium melting of variable metasedimentary protoliths. Geochemical modeling highlights fluid-flux melting as the dominant process, except for the Tanggula granites, which exhibit characteristics of fluid-absent melting. Tectonically, the Mansehra PGs are interpreted as products of Proto-Tethyan oceanic subduction beneath northern Gondwana, formed through the disequilibrium melting of exhumed back-arc basin sediments. Slab break-off likely triggered asthenospheric upwelling, enhancing heat flux and driving anatexis and PG production. While global PGs represent different geodynamic evolutionary contexts, they predominantly display significant tectonic events rather than direct contributions to crustal growth. The Mansehra PGs, along with similar granites, record large-scale anatexis linked to collisional tectonics, providing critical insights into Earth’s geodynamic evolution.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"141 ","pages":"Pages 164-179"},"PeriodicalIF":7.2,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143547083","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":"Jurassic picritic and potassic mafic dyke swarms in eastern China: Evidence for thermal erosion of the lithospheric mantle during Paleo-Pacific subduction","authors":"Wenjia Wang ,&nbsp;Shuguang Song ,&nbsp;Chao Wang ,&nbsp;Mark B. Allen ,&nbsp;Lifei Zhang ,&nbsp;Xiaowei Li ,&nbsp;Li Su","doi":"10.1016/j.gr.2025.02.012","DOIUrl":"10.1016/j.gr.2025.02.012","url":null,"abstract":"<div><div>Paleo-Pacific subduction significantly impacted the structure and nature of the mantle in Eastern China. However, the thermal structure of the supra-subduction-zone mantle during the early stage of the Paleo-Pacific subduction has not been well constrained. Here, we present an integrated study involving field investigation, petrology, and geochemistry on two types of Jurassic (168–155 Ma) mafic dyke swarms in Western Liaoning, North China Craton (NCC), to trace the properties of the NCC mantle during the Jurassic. The picritic dyke swarms, trending NNW (330°–350°), show OIB-like geochemical signatures, with high mantle potential temperatures (Tp) ranging from 1498 ± 52°C to 1535 ± 56°C. These picritic dyke swarms are derived from high-degree of partial melting of the asthenospheric mantle by a hot and hydrous asthenospheric melts rising from the mantle transition zone above the subducted slab. In contrast, the Jurassic potassic mafic dyke swarms, trending NNW (325°–345°), were formed by partial melting of the metasomatized lithospheric mantle during the upwelling of the asthenospheric melts. We conclude that thermal erosion would be a major factor in the destruction of the lithospheric mantle beneath the NCC in the early stage of the Paleo-Pacific plate subduction.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"141 ","pages":"Pages 135-148"},"PeriodicalIF":7.2,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143518931","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":"Carboniferous-Permian magmatism in western section of the North Qaidam, northern Tibet Plateau: Response to the spatio-temporal evolution of the Paleo-Tethys Ocean","authors":"Panlong Wang ,&nbsp;Yongjun Li ,&nbsp;Yujun Zhuang ,&nbsp;Pingyang Gu ,&nbsp;Gaoxue Yang ,&nbsp;Fenghao Duan ,&nbsp;Jianye Zhang ,&nbsp;Wei Li ,&nbsp;Nanhe Peng ,&nbsp;Qian Wang ,&nbsp;Hai Li","doi":"10.1016/j.gr.2025.02.007","DOIUrl":"10.1016/j.gr.2025.02.007","url":null,"abstract":"<div><div>The origin of Late Paleozoic igneous rocks in the North Qaidam (NQ) remains controversial. This study presents comprehensive geochronological, geochemical, and isotopic data on the igneous rocks in western section of the NQ. The chronological results indicate that the Yanchangbeishan (YC) hornblende gabbro was formed at <em>ca.</em> 254 Ma; the Xiaosaishitengshan (XS) gabbro, biotite quartz-diorite, monzogranite, and andesite were formed at <em>ca.</em> 318 Ma, <em>ca.</em> 259 Ma, <em>ca.</em> 252 Ma, and <em>ca.</em> 271 Ma, respectively; and the Dasaishitengshan (DS) gabbro, tonalite, and biotite monzogranite were formed at <em>ca.</em> 268 Ma, <em>ca.</em> 272 Ma, and <em>ca.</em> 282 Ma, respectively. The Lu-Hf isotopic results show that the ε_Hf(t) values of YC hornblende gabbro, XS andesite, and DS gabbro and tonalite are + 1.21 to + 9.53, +9.01 to + 15.70, +0.05 to + 4.71, and − 5.43 to − 1.93, respectively. Among them, XS gabbro (high-alumina) and andesite, and YC gabbro (high-magnesium) exhibit significant depletions in Nb, Ta, and Ti, similar to island arc magmas, which formed by partial melting of depleted lithospheric mantle metasomatized by slab fluids to varying degrees. DS gabbro (high-Nb) shows slight depletions in Nb, Ta, and Ti, resembling intraplate rift basic rocks, and resulting from low-degree partial melting of depleted mantle wedge metasomatized by slab melts. XS biotite quartz-diorite, monzogranite, and DS biotite monzogranite have high SiO₂ (63.69–76.85 wt%) contents and low Mg^# values (28–43), classified as I-type granites, formed by partial melting of juvenile crust. DS tonalite (high Ba-Sr) shows depletions in Nb, Ta, and Ti, originating from the lithospheric mantle metasomatized by slab-derived fluids and undergoing extensive fractional crystallization. By integrating the results of this study with published work regarding the igneous rocks in the NQ, we propose a new tectonic evolution model involving Zongwulong Paleo-Tethys Ocean subduction slab roll-back and subduction zone retreat for the Late Paleozoic in the NQ.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"141 ","pages":"Pages 265-288"},"PeriodicalIF":7.2,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610711","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":"Decoding cycling and enrichment of boron and associated lithium in waters of the Tibetan Plateau with boron isotopes","authors":"Yu Zhang ,&nbsp;Hongbing Tan ,&nbsp;Zhiwei Shi ,&nbsp;Fei Xue ,&nbsp;Xiying Zhang ,&nbsp;Huiying Ma","doi":"10.1016/j.gr.2025.02.006","DOIUrl":"10.1016/j.gr.2025.02.006","url":null,"abstract":"<div><div>The Tibetan Plateau (TP), which has various water bodies exhibiting extreme enrichment of boron (B), lithium (Li) and other elements, is a unique and cost-effective supplier of B and Li globally. However, the sources and enrichment mechanisms of these elements remain disputed. Herein, big data on B isotopes and geochemistry were compiled to reveal cycling and enrichment of B and associated Li in the complex mountain-basin systems of the TP. Various water bodies on the TP show remarkably high B and Li concentrations compared with the global average levels. B and Li are supernormally enriched or even mineralized in some salt lakes, oilfield brines, and geothermal systems. Water with high B concentrations exhibits simultaneous ¹¹B depletion. The spatial patterns of B-Li concentrations and δ¹¹B values are characterized by a westward increase and a southward decrease, respectively. The mechanisms of B and Li cycling and enrichment, from source to sink, on the TP can be summarized as follows: 1) Slab subduction and following continental collisions induced partial melting of the mid-lower crust, resulting in late-stage highly differentiated crust-derived magma upwelling and invasion into the mid-upper crust. Hot springs thereby maintain an efficient release of abnormally abundant B and Li from magmatic fluids to the surface through deep geothermal circulation. 2) In the eastern and southeastern TP, Massive degassing of mantle fractions prevails along large strike-slip faults. B and Li enriched from mantle- or crust-derived fluids can reach the surface via local volcanism. 3) Water-rock interaction and weathering trigger further activation, mobilization, and enrichment of B and Li in water. The aforementioned geological processes supply constantly deep-source B and Li to rivers and groundwater as cold-hot springs. Eventually, B and Li are fed into the lake basin jointly with supergene processes; after prolonged evaporation-concentration, excellent B-Li-rich salt lake resources are formed.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"141 ","pages":"Pages 120-134"},"PeriodicalIF":7.2,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437595","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":"A review of Mesozoic geodynamic evolution of the North Makran (SE Iran): A tale of a Neo-Tethyan ocean vanished due to two coexisting subduction zones","authors":"Edoardo Barbero ,&nbsp;Luca Pandolfi ,&nbsp;Morteza Delavari ,&nbsp;Asghar Dolati ,&nbsp;Emilio Saccani ,&nbsp;Maria Di Rosa ,&nbsp;Michele Marroni","doi":"10.1016/j.gr.2025.01.016","DOIUrl":"10.1016/j.gr.2025.01.016","url":null,"abstract":"<div><div>This paper presents a synthesis of the geological features of each tectonic unit of the North Makran (SE Iran), integrating results of multidisciplinary analyses, including structural and stratigraphic studies, petrographic and geochemical analyses, thermobarometric studies, as well as biostratigraphic and geochronological dating. This wealth of data forms the basis for a novel geodynamic model of the Jurassic − Eocene evolution of the Neo-Tethys realm, which evolved between the Arabian Plate and the Lut Block. The features of the North Makran tectonic units support the existence of a mid-ocean ridge setting during the Jurassic – Early Cretaceous. Contrary to previous interpretations, the data from these tectonic units suggests a single oceanic basin separating the Arabian and Lut continental margins, without the interposition of a microcontinental block. In the Early Cretaceous, subduction initiation is recorded by volcanic arc assemblages accommodating the convergence between the Arabian Plate and Lut Block. The nucleation of an intra-oceanic subduction marked the separation of the North Makran Ocean from the Neo-Tethys. The Late Cretaceous was characterized by plume-related magmatism and the onset of the convergence in the North Makran Ocean, inducing its subduction beneath the Lut Block. This subduction is recorded by volcanic arc assemblage and high pressure and low-temperature metamorphism within a subduction complex. Meanwhile, intra-oceanic subduction persisted within the Neo-Tethys, accompanied by a subduction complex and arc magmatism. The final closure of the North Makran Ocean occurred during the Late Cretaceous –Late Paleocene with the progressive amalgamation of the two subduction complexes and the deformation of the interposing oceanic lithosphere. This study suggests that the subduction of a seamount chain in the North Makran Ocean played a key role in the shortening and closure of this basin. This research emphasizes the importance of considering multiple factors in understanding the tectonic evolution of the Neo-Tethys realm.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"141 ","pages":"Pages 74-101"},"PeriodicalIF":7.2,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420499","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":"Reactionary interaction of upper mantle minerals with SiC at 6 GPa and 1100–1500 °C: Implication for moissanite appearance in ophiolitic peridotite and other uncommon natural environments","authors":"K.D. Litasov ,&nbsp;A. Shatskiy ,&nbsp;A.V. Arefiev ,&nbsp;H. Kagi","doi":"10.1016/j.gr.2025.02.005","DOIUrl":"10.1016/j.gr.2025.02.005","url":null,"abstract":"<div><div>Experiments were carried out on the interaction of mantle rocks and minerals with SiC at 6 GPa and 1100–1500 °C. Fine powders of natural peridotites and eclogites from kimberlites with the addition of 10 wt% SiC, as well as monomineralic powders and crystals of chromite, olivine, and garnet, were used as starting materials. The experiments were carried out on a 1500-ton multianvil press. In all experiments, the reduction of silicates and chromite was observed with an increase in the magnesium number (Mg#=100 Mg/(Mg + Fe)) of minerals to 97–100 % and the precipitation of metallic phases − alloys in the Fe-Ni and Fe-Si-Cr systems. The most pronounced reactions occurred at 1500 °C. Equilibrium was not reached in all the studied systems even after 72 h of annealing at 1300 °C. Instead, reaction rims were formed on mineral grains and finely dispersed iron alloys were precipitated throughout the volume of crystals. The reaction between SiC and chromite was fastest. The Mg# of chromite changed from 57 (in the initial chromite) to 80–94 %. It was shown that at 6 GPa, SiC reacted quickly with minerals and mantle rocks to form metal phases, high-magnesian silicates, and chromite. This means that they cannot be in equilibrium, as was previously stated for ophiolite peridotite and chromitite, and volcanic rocks such as basalts and kimberlites. The kinetic relationships indicate that a few millimeter grains of SiC can survive in the fluid-free mantle during subduction-exhumation only in cold environments below 700–800 °C. We believe that SiC in most natural rocks is related to anthropogenic contamination. In rare cases, which should be carefully documented, moissanite may have a natural terrestrial origin related to very localized events of formation of highly reduced hydrogen-bearing fluids.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"141 ","pages":"Pages 102-119"},"PeriodicalIF":7.2,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429079","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":"Recent increase in soil moisture levels concerning climate variability in the karst region of southwest China using wavelet coherence and multi-linear regression","authors":"Azfar Hussain ,&nbsp;Huizeng Liu ,&nbsp;Jianhua Cao ,&nbsp;Hui Yang ,&nbsp;Abolfazl Rezaei ,&nbsp;Pei Wang ,&nbsp;Qukan Luo ,&nbsp;Mengxia Zhou ,&nbsp;Zhong Liang","doi":"10.1016/j.gr.2025.02.002","DOIUrl":"10.1016/j.gr.2025.02.002","url":null,"abstract":"<div><div>Classifying climate-induced variations in soil moisture (SM) is vital in the face of climate change to enhance vegetation restoration and decrease rocky desertification in karst areas. In this paper, the Monotonic Mann-Kendall and Sen’s Slope test are used to assess the changes in SM and regional climatic variables from 1981 to 2019 across the karst region of southwest China (KRSC) using the ERA5 SM at 0–7, 7–28 and 28–100 cm. By utilizing wavelet coherence and multi-linear regression (MLR), we assess the association of SM with local climatic factors and teleconnections. Our findings indicate increased SM, NDVI, temperature (TMP), and precipitation (PCP) from 2002 to 2019 in the KRSC. The combined variance of the first and second EOF for 0–7, 7–28, and 28–100 cm showed 55 %, 52 %, and 44 %, respectively. The findings revealed a dominant influence of PCP and sensible heat fluxes (SHF) in SM for 8–120 months (∼1–10 years) periodic cycles, whereas the teleconnections showed consistent patterns in karst and non-karst regions. For integrated factors, PCP + actual evapotranspiration (AET), NDVI + SHF and long-wave radiation (LWR) + SHF showed mean significant coherences between 0.70 and 0.80, whereas ENSO + PDO + NAO (0.71–0.76) explained high coherence in comparison to other combinations. The karst SM showed a significant correlation with PCP (0.63–0.89), LWR (0.59–0.77), and SHF (0.76–0.95), while non-karst exhibited a significant correlation with ENSO (0.07–0.49), PDO (0.16–0.41) and PNA (0.10–0.38) in all seasons. The MLR identified PCP, SHF and LWR as the leading influencing variables in the karst region, whereas PCP and LWR showed more influence in the non-karst region for 0–7 cm. Our findings give valuable insights regarding sustainable SM management to promote vegetation and reduce rocky desertification.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"141 ","pages":"Pages 40-54"},"PeriodicalIF":7.2,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143376839","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":"Spatial and temporal distribution, fate, and potential health risks of microplastics in urban indoor air","authors":"Liyuan Peng ,&nbsp;Na Zheng ,&nbsp;Qirui An ,&nbsp;Xiaoqian Li ,&nbsp;Siyu Sun ,&nbsp;Yunyang Li ,&nbsp;Jingze Yu ,&nbsp;Fan Shao ,&nbsp;Yingxi Qiu ,&nbsp;Shuyue Zhang","doi":"10.1016/j.gr.2025.01.015","DOIUrl":"10.1016/j.gr.2025.01.015","url":null,"abstract":"<div><div>The growing awareness of microplastics (MPs) in indoor residential environments stems from their pervasive presence and potential health risks. MPs were collected from living rooms and bedrooms, and their accumulation in the lungs of residents in three urban cities during summer and winter was assessed. The abundance of MPs at ≤ 2.5 μm and ≤ 10 μm was determined (Changchun: 713 ± 477 and 4239 ± 2420, Xingtai: 1003 ± 726 and 3781 ± 2070, Guangzhou: 492 ± 479 and 2446 ± 903, item/m³/day). Nearly 50 % of the total abundance of MPs discovered in this study were ≤ 10 μm in size. Considerable differences in MPs abundance were observed between summer and winter (<em>p</em> &lt; 0.01). The quantity of MPs in residential settings correlated with lifestyle choices and ventilation time (<em>p</em> &lt; 0.05). Fragments represented the primary shape of MPs (45 % – 68 %), with polyamide (PA; 5 % – 35 %) and polycarbonate (PC; 5 % – 33 %) being the predominant polymers. Indoor uptake of MPs in lungs varied by age group. Adults had the highest intake, followed by teenagers and older individuals, while children had the lowest intake. Children and adults were estimated to intake 530 – 2060 and 1046 – 4068 items/day of MPs, respectively. Additionally, living rooms and bedrooms exhibited medium to extreme hazards according to the pollutant loading index (PLI) and polymer hazard index (PHI) assessments. This study deepens our understanding of MPs pollution in urban indoor air, raises awareness of the health risks to lungs associated with MPs exposure, and provides data to support these findings.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"141 ","pages":"Pages 1-12"},"PeriodicalIF":7.2,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372090","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":"Pre-Himalayan crustal evolution in the northern margin of India: Implications from zircon U–Pb, Hf and O isotope study of Chhota Shigri granitoids, Himachal Himalaya, Northwest India","authors":"Waikhom Nongdon ,&nbsp;Bidyananda Maibam ,&nbsp;Pankaj Kumar ,&nbsp;Yoann Gréau ,&nbsp;Jasper Berndt ,&nbsp;Stephen Foley ,&nbsp;Atul Kumar Singh ,&nbsp;Deeksha Khandelwal","doi":"10.1016/j.gr.2025.02.001","DOIUrl":"10.1016/j.gr.2025.02.001","url":null,"abstract":"<div><div>A systematic geochemical, geochronological (U−Pb), and isotopic study (Lu−Hf and O) of zircons from the northern margin of India has been carried out to understand the pre-Himalayan crustal evolution along the area. The rocks were characterized as granitoid and yielded two significant age peaks: 1018–715 Ma and 516–476 Ma, with sparse inherited cores of Paleoproterozoic to Archean ages, defining two major magmatic events (Tonian and Cambro-Ordovician) in the NW Himalaya. While Tonian ages are preserved in the zircon cores, the rims and numerous whole grains record the younger Cambro-Ordovician event. The Tonian zircon cores display εHf values ranging from –5.9 to +8.3, indicating both juvenile mantle-derived and recycled crustal sources. The Tonian zircon cores yield single-stage Hf model (T_DM) ages of 1.66–1.19 Ga and δ¹⁸O values of 5.75–10.88‰, suggesting that Tonian granitoids formed from mixed sources comprising juvenile material, recycled ancient crust and δ¹⁸O-rich supracrustal components. The Cambro-Ordovician zircons yielded εHf values from –27.4 to –4.0 and single-stage Hf model (T_DM) ages of 2.16–1.21 Ga, demonstrating extensive reworking of both Neoproterozoic crust and ancient crust occurred during the Cambro-Ordovician magmatism. Their elevated δ¹⁸O values (8.05–11.35‰) further support widespread crustal remelting with substantial incorporation of δ¹⁸O-rich supracrustal materials. These evidence the preservation of supercontinent (Rodinia) components within the NW Himalaya.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"141 ","pages":"Pages 55-73"},"PeriodicalIF":7.2,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420498","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}