Acta Geochimica最新文献

{"title":"Mafic and felsic magmatism in the Wadi Kalalat area, South Eastern Desert, Egypt: mineralogy, geochemistry and geodynamic evolution during the Neoproterozoic in the Nubian Shield","authors":"Adel A. Surour,&nbsp;Ahmed A. Madani,&nbsp;Mohamed A. El-Sobky","doi":"10.1007/s11631-023-00648-0","DOIUrl":"10.1007/s11631-023-00648-0","url":null,"abstract":"<div><p>In the south Eastern Desert of Egypt, two contrasting types of magmatism (mafic and felsic) are recorded in the Wadi Kalalat area, and form the Gabal El Motaghiarat and Gabal Batuga intrusions, respectively. The two intrusions post-dates ophiolitic and arc associations represented by serpentinite and metagabbro-diorite, respectively. The mafic intrusion has a basal ultramafic member represented by fresh peridotite, which is followed upward by olivine gabbro and anorthositic or leucogabbro. This mafic intrusion pertains to the Alaskan-type mafic–ultramafic intrusions in the Arabian–Nubian Shield (ANS) being of tholeiitic nature and emplaced in a typical arc setting. On the other hand, the Gabal Batuga intrusion comprises three varieties of fresh A-type granites of high K-calc alkaline nature, which is peraluminous and garnet-bearing in parts. A narrow thermal aureole in the olivine gabbro of the mafic intrusion was developed due to the intrusion of the Batuga granites. This results in the development of a hornfelsic melagabbro variety in which the composition changed from tholeiitic to a calc-alkaline composition due to the addition of SiO₂, Al₂O₃, alkalis, lithosphile elements (LILEs) such as Rb (70 ppm) and Y (28 ppm) from the felsic intrusion. Outside the thermal aureole, Rb amounts 2–8 ppm and Y lies in the range &lt; 2–6 ppm. It is believed that the Gabal Batuga felsic intrusion started to emplace during the waning stage of an arc system, with transition from the pre-collisional (i.e., arc setting) to post-collisional and within plate settings. Magma from which the Gabal Batuga granites were fractionated is high-K calc-alkaline giving rise to a typical post-collisional A-type granite (A₂-subtype) indicating an origin from an underplating crustal source. Accordingly, it is stressed here that the younger granites in the ANS are not exclusively post-collisional and within-plate but most likely they started to develop before closure of the arc system. The possible source(s) of mafic magmas that resulted in the formation of the two intrusions are discussed. Mineralogical and geochemical data of the post-intrusion dykes (mafic and felsic) suggest typical active continental rift/within-plate settings.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"43 1","pages":"150 - 173"},"PeriodicalIF":1.4,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135345282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemistry and mineral chemistry of the armoor granitoids, eastern dharwar craton: implications for the redox conditions and tectono-magmatic environment","authors":"A. Ajay Kumar,&nbsp;Ch. Ashok","doi":"10.1007/s11631-023-00647-1","DOIUrl":"10.1007/s11631-023-00647-1","url":null,"abstract":"<div><p>The mineralogical and geochemical characteristics of the K-rich granites from the Armoor granitic rocks in the northeastern portion of the Eastern Dharwar Craton (EDC) are presented. In order to understand its physicochemical conditions, the petrogenesis of the granitoid was explained from biotite chemistry and geochemical systematics. Studies of mineral chemistry expose that compositionally, K-feldspar and plagioclase in Armoor granite rocks range from An_0, Ab_3−5.9, Or_94−96.9 and An_{5−29, Ab71.9−94.9,} Or_0−1.5, respectively. The mineral chemistry of biotite crystals exhibits composition that varies from primary to re-equilibrated primary biotites. Although biotites from the Armoor granites generally exhibit an I-type trend, with calc-alkaline parental magma in a subduction setting. Biotite chemistry of granites displays magnetite (oxidized) series nature, which has oxygen fugacity (<i>f</i>O₂₎ = − 15.1 to − 16.7(log₁₀ bar), under high oxidizing conditions. Temperature and pressure estimates for the crystallization of Armoor granites based on biotite composition are T = 612–716 °C and 1.0−0.4 kbar, respectively. Geochemically, these rocks are metaluminous to slightly peraluminous and magnesian, with calc-alkaline potassium-rich granite. On the chondrite normalized REE diagram, the granites have positive europium anomalies; rich Sr/Y, (Dy/Yb)_N ratios and reduced Mg^#, Rb/Sr, Rb, Sr indicate that the melting of earlier rocks, crystal accumulation and residual garnet source formed at high pressures. The examined granites show that they are produced from the melting of crustal sources. Thus, the extensive analyses of the described Armoor granite suggest that they were produced by crust sources and developed under oxidizing conditions in subduction setting.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"43 1","pages":"110 - 133"},"PeriodicalIF":1.4,"publicationDate":"2023-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135972973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 photosynthetic oxygen evolution does not exclude the important role and contribution of bicarbonate photolysis","authors":"Yanyou Wu,&nbsp;Shaogang Guo","doi":"10.1007/s11631-023-00649-z","DOIUrl":"10.1007/s11631-023-00649-z","url":null,"abstract":"<div><p>Photosynthesis is the most important biochemical reaction on Earth. It has co-evolved and developed with the Earth, driving the biogeochemical cycle of all elements on the planet and serving as the only chemical process in nature that can convert light energy into chemical energy. Some heavy oxygen isotopic (¹⁸O) labeling experiments have “conclusively” demonstrated that the oxygen released by photosynthesis comes only from water and are written into textbooks. However, it is not difficult to find that bicarbonate has never been excluded from the direct substrate of photosynthesis from beginning to end during the history of photosynthesis research. No convincing mechanism can be used to explain photosynthetic oxygen evolution solely from water photolysis. The bicarbonate effect, the Dole effect, the thermodynamic convenience of bicarbonate photolysis, the crystal structure characteristics of photosystem II, and the reinterpretation of heavy oxygen isotopic labeling (¹⁸O) experiments all indicate that the photosynthetic oxygen evolution does not exclude the important role and contribution of bicarbonate photolysis. The recently proposed view that bicarbonate photolysis is the premise of water photolysis, bicarbonate photolysis and water photolysis work together with a 1:1 (mol/mol) stoichiometric relationship, and the stoichiometric relationship between oxygen and carbon dioxide released during photosynthetic oxygen evolution is also 1:1, has excellent applicability and objectivity, which can logically and reasonably explain the precise coordination between light and dark reactions during photosynthesis, the bicarbonate effect, the Dole effect, the Kok cycle and the neutrality of water and carbon in nature. This is of great significance for constructing the bionic artificial photosynthetic reactors and scientifically answering the question of the source of elemental stoichiometric relationships in nature.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"43 1","pages":"174 - 179"},"PeriodicalIF":1.4,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135872800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 late Early-Paleozoic granitic magmatism in Northwestern Fujian, China: constraints on intraplate orogeny in the South China block","authors":"WanLi Gao,&nbsp;ZongXiu Wang","doi":"10.1007/s11631-023-00646-2","DOIUrl":"10.1007/s11631-023-00646-2","url":null,"abstract":"<div><p>The Early Paleozoic tectono-thermal event was a significant orogenic activity during the Phanerozoic era, which had a profound impact on the early crust of the South China Block (SCB) and established the foundation for later tectonic activity. The Wuyi-Yunkai orogenic belt in Southeastern China was extensively exposed to Early Paleozoic magmatism, the genetic mechanism of which remains controversial. To shed light on this issue, detailed petrological, geochemical, and zircon U–Pb–Hf isotopic studies were carried out on two granitoids, namely the Yuntongshan pluton and the Gaoqiao pluton, identified in the central Wuyishan. Zircon U–Pb chronology of the Yuntongshan and Gaoqiao bodies yielded ages of 437 ± 4 Ma (MSWD = 2.2) and 404 ± 2 Ma (MSWD = 12), respectively, indicating that they were emplaced during the Early Silurian and Early Devonian periods. These granitoids are primarily composed of biotite-granite and biotite-monzonitic-granites, with high concentrations of S_iO₂ (73.59–75.91 wt%), K₂O + Na₂O (8.31–8.73 wt%), and low contents of MgO, CaO, Cr, Ni. They are classified as high-K calc-alkaline and weakly metaluminous-strongly peraluminous S-type granites. These granitoids are enriched in light rare earth elements (LREEs) and large ion lithophile elements (LILEs) and depleted in heavy rare earth elements (HREEs) and high field strength elements (HFSEs) with arc affinity. The εHf(t) values of − 3.3 to − 15.4 with two-stage Hf model ages ranging from 2829 to 1644 Ma, combined with the presence of Neoproterozoic inherited zircons, suggest that the primary magma of these granitoids was derived from the partial melting of Neoproterozoic crust with a Paleoproterozoic crustal model age. These findings, combined with the spatio-temporal distribution of regional magmatism, reveal that the late Early-Paleozoic granitoids formed in the intraplate orogenic background originating from the subduction of the proto-Tethys Ocean and proto-Pacific Ocean around the margin of the east Gondwana supercontinent.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"43 1","pages":"134 - 149"},"PeriodicalIF":1.4,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135113421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 co-transport of Cd(II) and nZnO in saturated soil packed column: effects of ionic strength and pH","authors":"Min Liao,&nbsp;Guo Bin,&nbsp;Yixin Luo,&nbsp;Yuhao Zhang,&nbsp;Kangyou Hu,&nbsp;Xiongxiong Lu,&nbsp;Xiaomei Xie","doi":"10.1007/s11631-023-00645-3","DOIUrl":"10.1007/s11631-023-00645-3","url":null,"abstract":"<div><p>The rapid development and widespread use of ZnO nanoparticles (nZnO) in various industries have raised concerns about their potential environmental impact. Therefore, understanding the fate and role of nZnO in the natural environment is crucial for mitigating their hazardous effects on the environment and human safety. The purpose of the present study was to provide scientific support for understanding and eliminating the joint risk of nanoparticle and heavy metal pollution in the soil environment by revealing the co-transport characteristics of Cd(II) and ZnO nanoparticles (nZnO) in soil under different ionic strength (IS) and pH. The impacts of different IS and pH on the co-transport of Cd(II) and nZnO in a 20 cm long with an inner diameter of 2.5 cm acrylic column packed with 10 cm high soil samples were investigated in the present study. In the above system, a 500 μg L⁻¹ Cd(II) loaded nZnO suspension pulse with varying IS or pH was introduced into the soil column for leaching over 5 PVs, followed up by 5 PVs background solutions without nZnO. The IS was 1, 10, or 50 mM NaCl, with pH6, or the pH was 6, 7 or 8 with 1 mM NaCl. Meanwhile, Sedimentation experiments for nZnO, adsorption of Cd(II) on soil, and nZnO, DLVO theory calculation for the same background condition were conducted. The presence of nZnO significantly increased the mobility of Cd(II) as a result of its strong adsorption capacity for nZnO-associated Cd(II). However, with the increase of IS, the co-transport of nZnO and Cd(II) was decreased and the retention of nZnO in the soil column due to more nZnO attended to aggregate and sediment during the transport and the decrease in the adsorption capacity of nZnO for Cd(II) by competition of Na⁺. When pH was 6, 7, and 8, the co-transport of nZnO and Cd(II) increased with higher pH due to the lower electrostatic attraction between nZnO and soil under higher pH. Meanwhile, the DLVO theory was fitted to describe the above co-transport process of nZnO and Cd(II). More attention should be paid to the presence of nZnO on the migration of Cd(II) in the natural soil to control the potential risk of nanoparticles and heavy metals to the environment. The risk of co-transport of nZnO and Cd(II) might be controlled by adjusting IS and pH in the soil solution.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"43 1","pages":"97 - 109"},"PeriodicalIF":1.4,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134973376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Petrogenesis and tectonic implications of the Silurian adakitic granitoids in the eastern segment of the Qilian Orogenic Belt, Northwest China","authors":"Jiao-Long Zhao,&nbsp;Xiao-Jun Huang,&nbsp;Pei-Qing Hu,&nbsp;Zhen-Xi Yang,&nbsp;Ying Fan,&nbsp;Er-Teng Wang,&nbsp;Fu-Bo Yang,&nbsp;Jing-Yu Zhang","doi":"10.1007/s11631-023-00644-4","DOIUrl":"10.1007/s11631-023-00644-4","url":null,"abstract":"<div><p>Geodynamic mechanism responsible for the generation of Silurian granitoids and the tectonic evolution of the Qilian orogenic belt remains controversial. In this study, we report the results of zircon U–Pb age, and systematic whole-rock geochemical data for the Haoquangou and Liujiaxia granitoids within the North Qilian orogenic belt and the Qilian Block, respectively, to constrain their petrogenesis, and the Silurian tectonic evolution of the Qilian orogenic belt. Zircon U–Pb ages indicate that the Haoquangou and Liujiaxia intrusions were emplaced at 423 ± 3 Ma and 432 ± 4 Ma, respectively. The Haoquangou granodiorites are calc-alkaline, while the Liujiaxia granites belong to the high-K calc-alkaline series. Both are peraluminous in composition and have relatively depleted Nd isotopic [ε_Nd(t) = (− 3.9 – + 0.6)] characteristics compared with regional basement rocks, implying their derivation from a juvenile lower crust. They show adakitic geochemical characteristics and were generated by partial melting of thickened lower continental crust. Post-collisional extensional regime related to lithospheric delamination was the most likely geodynamic mechanism for the generation of the Haoquangou granodiorite, while the Liujiaxia granites were generated in a compressive setting during continental collision between the Qaidam and Qilian blocks.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"43 1","pages":"72 - 86"},"PeriodicalIF":1.4,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135885247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solubility of water in bridgmanite","authors":"Wenhua Lu,&nbsp;Yuan Li","doi":"10.1007/s11631-023-00642-6","DOIUrl":"10.1007/s11631-023-00642-6","url":null,"abstract":"<div><p>Water in Earth’s mantle plays a critical role in both geodynamic and surficial habitability. Water in the upper mantle and transition zone is widely discussed, but less is known about the water in the lower mantle despite it constituting over half of Earth’s mass. Understanding the water storage in Earth’s lower mantle relies on comprehending the water solubility of bridgmanite, which is the most abundant mineral both in the lower mantle and throughout Earth. Nevertheless, due to limited access to the lower mantle, our understanding of water in bridgmanite mainly comes from laboratory experiments and theoretical calculations, and a huge controversy still exists. In this paper, we provide a review of the commonly employed research methods and current findings concerning the solubility of water in bridgmanite. Potential factors, such as pressure, temperature, compositions, etc., that influence the water solubility of bridgmanite will be discussed, along with insights into future research directions.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"42 6","pages":"998 - 1006"},"PeriodicalIF":0.0,"publicationDate":"2023-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11631-023-00642-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50015089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemistry, zircon U–Pb geochronology, and Hf isotopes of S-type granite in the Baoshan block, constraints on the age and evolution of the Proto-Tethys","authors":"Jianjun Zhang,&nbsp;Chuanlong Mou,&nbsp;Chendong Liu,&nbsp;Yong Zhang,&nbsp;Ting Chen,&nbsp;Hualiang Li","doi":"10.1007/s11631-023-00639-1","DOIUrl":"10.1007/s11631-023-00639-1","url":null,"abstract":"<div><p>Geochemistry, zircon U–Pb geochronology, and Hf isotope data for the Early Paleozoic granites in the Baoshan Block reveal the Early Paleozoic tectonic evolution of the Proto-Tethys. The samples are high-K, calc-alkaline, strongly peraluminous rocks with A/CNK values of 1.37–1.46, are enriched in SiO₂, K₂O, and Rb, and are depleted in Nb, P, Ti, Eu, and heavy rare earth elements, which indicates the crystallization fractionation of the granitic magma. Zircon U–Pb dating indicates that they formed in ca. 480 Ma. The Nansa granites have ε_Hf(t) values ranging from − 16.04 to 4.36 with corresponding T^C_DM ages of 2.10–0.81 Ga, which suggests the magmas derived from the partial melting of ancient metasedimentary with minor involvement of mantle-derived components. A synthesis of data for the Early Paleozoic igneous rocks in the Baoshan block and adjacent (Tengchong, Qiangtang, Sibumasu, Himalaya, etc.) blocks indicates that these blocks were all aligned along the proto-Tethyan margin of East Gondwana in the Early Paleozoic. The Early Paleozoic S-type granites from Nansa were generated in a high-temperature and low-pressure (HTLP) extensional tectonic setting, which resulted from Andean-type orogeny instead of the final assembly of Gondwana or crustal extension in a non-arc environment. In certain places, an expanding environment may exist in opposition to the tectonic backdrop of the lithosphere's thickening and shortening, leading the crust to melt and decompress, mantle-derived materials to mix, and a small quantity of peraluminous granite to emerge.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"43 1","pages":"40 - 58"},"PeriodicalIF":1.4,"publicationDate":"2023-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135644103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Facies development and sedimentology of the Middle Miocene carbonates of the Raghama Formation, northeastern Saudi Arabia","authors":"Mansour H. Al-Hashim,&nbsp;Abdelbaset S. El-Sorogy,&nbsp;Meshal Wadani","doi":"10.1007/s11631-023-00643-5","DOIUrl":"10.1007/s11631-023-00643-5","url":null,"abstract":"<div><p>Ragahama Formation comprises a siliciclastic continental deposits followed by marine carbonates, representing prograding alluvial fans from adjacent high hinterlands seaward into lagoons and fringing reef environments. The present work aimed to document the facies development and sedimentology of the Raghama carbonates exposed along the eastern coastal plain of the Red Sea, northwestern Saudi Arabia. Four stratigraphic sections were measured and sampled (D1–D4) and thin sections and major and trace element analyses were prepared and applied for petrographic and geochemical approaches. The carbonates were subdivided into three successive fore-reef, reef-core, and back-reef depositional facies. Sandy stromatolitic boundstone, microbial laminites, dolomitic ooidal grainstone, bioclastic coralline algal wackestone, sandy bioclastic wackestone, and coral boundstones were the reported microfacies types. Petrographic analysis reveals that the studied carbonates were affected by dissolution, dolomitization, and aggrading recrystallization, which affects both the original micrite matrix and grains or acts as fracture and veinlet filling leading to widespread vuggy and moldic porosity. No evidence of physical compaction, suggesting rapid lithification and recrystallization during early diagenesis and prior to substantial burial and intensive flushing by meteoric waters. Most of the original microstructure of corals were leached and destructed. This is indicated by the higher depletion in Sr and Ca levels and increase in Mg, Na, Fe, and Mn levels, especially in section D1, in comparison with the worldwide carbonates.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"43 1","pages":"87 - 96"},"PeriodicalIF":1.4,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135696041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distribution, health and ecological risk assessments of trace elements in Nigerian oil sands","authors":"Odunayo T. Ore,&nbsp;Festus M. Adebiyi","doi":"10.1007/s11631-023-00641-7","DOIUrl":"10.1007/s11631-023-00641-7","url":null,"abstract":"<div><p>The Nigerian oil sands represent the largest oil sand deposit in Africa, yet there is little published information on the distribution and potential health and ecological risks of trace elements in the oil resource. In the present study, we investigated the distribution pattern of 18 trace elements (including biophile and chalcophile elements) as well as the estimated risks associated with exposure to these elements. The results of the study indicated that Fe was the most abundant element, with a mean concentration of 22,131 mg/kg while Br had the lowest mean concentration of 48 mg/kg. The high occurrence of Fe and Ti suggested a possible occurrence of ilmenite (FeTiO₃) in the oil sands. Source apportionment using positive matrix factorization showed that the possible sources of detected elements in the oil sands were geogenic, metal production, and crustal. The contamination factor, geo-accumulation index, modified degree of contamination, pollution load index, and Nemerow pollution index indicated that the oil sands are heavily polluted by the elements. Health risk assessment showed that children were relatively more susceptible to the potentially toxic elements in the oil sands principally via ingestion exposure route (HQ &gt; 1E-04). Cancer risks from inhalation are unlikely due to CR &lt; 1E-06 but ingestion and dermal contact pose severe risks (CR &gt; 1E-04). The high concentrations of the elements pose serious threats due to the potential for atmospheric transport, bioaccessibility, and bioavailability.</p></div>","PeriodicalId":7151,"journal":{"name":"Acta Geochimica","volume":"43 1","pages":"59 - 71"},"PeriodicalIF":1.4,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135696332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}