Phosphorite deposits: A promising unconventional resource for rare earth elements

Shamim A. Dar; V. Balaram; Parijat Roy; Akhtar R. Mir; Mohammad Javed; M. Siva Teja

doi:10.1016/j.gsf.2025.102044

Geoscience Frontiers ›› 2025, Vol. 16 ›› Issue (3) : 102044 DOI: 10.1016/j.gsf.2025.102044

research-article

Phosphorite deposits: A promising unconventional resource for rare earth elements

Author information +

^aDepartment of Geology, Banaras Hindu University, Varanasi 221005 UP, India

^bCSIR-National Geophysical Research Institute (NGRI), Hyderabad 500 007, India

^cNational Centre for Polar and Ocean Research, Ministry of Earth Sciences, Goa 403804, India

^dDepartment of Earth Sciences, University of Kashmir, Srinagar 190006, India

^eDepartment of Geology, Acharya Nagarjuna University, Guntur 522510, India

^*E-mail address: sjshamim@bhu.ac.in (S.A. Dar).

Shamim A. Dar is currently working as an Assistant professor, at the Department of Geology, Banaras Hindu University (BHU), Varanasi, India. He did his Ph.D from Aligarh Muslim University, Aligarh, India, and his M.Sc and B.Sc from the University of Kashmir, Srinagar, J & K, India. Before, joining BHU, he worked as a lecturer in the higher education department of J & K for more than 05 years. He has published 21 research papers in SCI international and national journals and 02 book chap-ters. He is also a member of the governing council of the journal Indian Association of Sedimentologists. His area of specialization is sedimentary geochemistry, stable isotope geochemistry, economic geology, geoheritage, geotourism and geoparks. Presently he is guiding 06 Ph.D students and one postdoc in different fields of geology, fostering future leaders in geoscience.

V. Balaram is a former emeritus scientist at the Geo-chemistry Division of CSIR - National Geophysical Research Institute, Hyderabad, India. He authored over 340 SCI publications, which were cited ∼ 10,200 times (h-index 50, i-10 index 157), and guided 5 Ph.D. students. He has received several prestigious national and inter-national awards such as the ‘‘National Geoscience Award” from the Government of India, New Delhi (2000), represented India at the United Nations/IAEA Meeting at IAEA Headquarters in Vienna, Austria in 2022, included in Stanford University’s list of the ‘‘Top 2% of Scientists in the World” in 2020, 2021, 2022, 2023 & 2024, ‘‘The Academician Sazhin Medal 2024” from the State Atomic Energy Cor-poration, GIREDMET JSC, Moscow, Russia and "Geoscience Frontiers Highly Cited Author Award 2023" from the Geoscience Frontiers Journal (Elsevier, Beijing, China) presented to him at Curtin University, Kuching, Malaysia, in 2024 for his most referenced paper on REE published in 2019 with >1800 citations so far.

Parijat Roy is a senior scientist at National Centre for Polar and Ocean Research, Ministry of Earth Sciences. His research area is mainly focused in deep sea mineral exploration and in understanding the complex beha-viour of metals in hydrothermal circulation process in MORB’s. He is also involved in developing analytical protocols for the accurate determinations of metals in various types of geological samples.

Akhtar R. Mir serves as an Assistant Professor in the Department of Earth Sciences at the University of Kashmir, India, where he is making significant contri-butions to the field of Geology. He has published around 25 research papers in reputed journals. His research interests encompass petrology, geochemistry, and tec-tonics. In 2018, he was honoured with the prestigious ‘‘Smt. Ketharaju Venkata Subbamma-Sri. Subba Rao Medal” by the Indian Society of Applied Geochemists (ISAG) for his contributions to geochemistry applied to mineral resources. He has carried out geological field-works in Orisha, Ladakh, Kashmir, and Rajasthan. An inspiring mentor, he has guided numerous M.Sc. Geology students through both major and minor projects, nurturing the next generation of geoscientists.

Mohammad Javed is a research scholar (Ph.D. student) working under the supervision of Dr. Shamim Ahmad Dar at the Department of Geology, Banaras Hindu University, Varanasi, India. He has completed his Mas-ter’s and Bachelor’s degrees from the Department of Geology, Aligarh Muslim University, Aligarh, India. He has qualified CSIR-UGC JRF (AIR-21) in 2024, CSIR-NET in 2023, and also qualified GATE (2023, 2024) exami-nations. His research interests include sedimentary geochemistry, and economic ore deposits.

Matte Siva Teja is working as an Inspire Research Fel-low, at the Department of Science and Technology (DST) Government of India, at Acharya Nagarjuna University, Department of Geology. Currently, he is working on ‘‘Land Use, Land Cover, Mapping and Change Detection Analysis in and around Amaravathi Capital City, Andhra Pradesh, India” for his Ph.D.

Show less

History +

PDF (4617KB)

Abstract

The green energy transition relies heavily on critical metals, such as rare earth elements (REEs). However, their reserves are primarily focused in a few countries, such as China, which accounts for approximately 70% of global production. Hence, several countries are currently looking for alternative resources for REEs. Alternative REE resources in the supply chain include recycling of e-waste, industrial waste like red mud and phosphogypsum, coal ash, mine tailings, ocean floor sediments, and even certain types of sedimen-tary deposits like phosphorites where REEs are present in lower concentrations but at larger volumes compared to primary ore deposits which are becoming targets by REEs industry. Currently, several stud-ies are going on the development of eco-friendly REEs extraction technologies from phosphorite deposits. Consequently, advanced data analysis tools, such as Machine Learning (ML), are becoming increasingly important in mineral prospectivity and are rapidly gaining traction in the earth sciences. Phosphorite deposits are mainly used to manufacture fertilizers as these rocks are known for their significant phos-phorus content. Moreover, these formations are considered a prospective resource of REEs. The different types of phosphorite deposits such as continental, seamount, and ore deposits worldwide reported con-centrations of ∑REE upto 18,000 µg/g. Due to the augmented claim of REEs for various ultra-modern, and green technology applications that are required to switch over to a carbon-neutral environment, these phosphorite deposits have become an important target mostly because of their relatively higher content of REEs especially heavy rare earth elements (HREE). For example, Mississippian phosphorites reported ∑HREE 7,000 µg/g. To have a comprehensive understanding of the REEs potential of these phosphorite deposits which also include several Chinese phosphorite deposits, this study is undertaken to review the phosphorite deposits in the world and their REEs potential, in addition to some of the associated aspects such as applications and formation mechanisms for different types of phosphorite deposits such as igneous phosphate deposits, sedimentary phosphorite deposits, marine phosphorite deposits, cave phosphate deposits, and insular guano deposits. Other important aspects include their occurrences, types, geochemical characteristics, the REEs enrichment mechanisms, and various recovery methods adopted to recover REEs from different phosphorite deposits. The present review paper concludes that the recent studies highlight the global potential of phosphorite deposits to satisfy the increasing demand for REEs. Extracting REEs from phosphorite presents no significant technological or environmental difficul-ties, as long as radioactive elements are eliminated. In India, more comprehensive geological surveys, along with the advancement of new methods and evaluations, are required to locate phosphorite deposits with high concentrations of REEs.

Keywords

Phosphorite deposits / Phosphate phases / REE / Bioleaching / Extraction / Recovery

Cite this article

Download citation ▾

Shamim A. Dar, V. Balaram, Parijat Roy, Akhtar R. Mir, Mohammad Javed, M. Siva Teja. Phosphorite deposits: A promising unconventional resource for rare earth elements. Geoscience Frontiers, 2025, 16(3): 102044 DOI:10.1016/j.gsf.2025.102044

登录浏览全文

4963

注册一个新账户忘记密码

CRediT authorship contribution statement

Shamim A. Dar: Writing - review & editing, Writing - original draft, Visualization, Validation, Software, Resources, Project administration, Methodology, Investigation, Funding acquisition, Formal analysis, Data curation, Conceptualization. V. Balaram: Writing - review & editing, Writing - original draft, Visualization, Validation, Supervision, Software, Resources, Project administra-tion, Methodology, Investigation, Formal analysis, Data curation, Conceptualization. Parijat Roy: Supervision, Investigation, Concep-tualization. Akhtar R. Mir: Visualization, Validation, Supervision. Mohammad Javed: Methodology, Formal analysis, Data curation. M. Siva Teja: Visualization, Validation, Supervision, Conceptualization.

Declaration of competing interest

The authors declare that they have no known competing finan-cial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

The first author pays sincere thanks to the HOD, Department of Geology, B.H.U, Varanasi for providing the necessary facilities. Sha-mim A. Dar is highly thankful to the Anusandhan National Research Foundation (ANRF), Science and Engineering Research Board (SERB), Department of Science & Technology, Government of India for a start-up research grant (M-14/0599; Sanction order no. SRG/2022/001478) and Seed Grant under Institutions of Emi-nence (IoE), Banaras Hindu University (BHU) (Dev. Scheme No. 6031) for financial assistance. Dr. V. Balaram acknowledges the support of Dr. Prakash Kumar, Director, CSIR-National Geophysical Research, Hyderabad, India. Dr. Roy is thankful to the Director NCPOR, Goa for his kind support.

References

Publishing order | Descend order by publishing year | Descend order by cited within

[1]	Abouzeid, A.Z.M., 2008. Physical and thermal treatment of phosphate ores-An overview. Int. J. Mineral Proc. 85 (4), 59-84.

[2]	Ahmed, A.H., Aseri, A.A., Ali, K.A., 2022. Geological and geochemical evaluation of phosphorite deposits in northwestern Saudi Arabia as a possible source of trace and rare-earth elements. Ore Geol. Rev. 144, 104854. https://doi.org/10.1016/j.oregeorev.2022.104854.

[3]	Albaum, H.G., 1952. The role of phosphorus in the metabolism of plants. In: Wolterink L.F. (Ed.), The Biology of Phosphorus: East Lansing. Press, Michigan State Coll, pp. 37-75.

[4]	Alonso, E., Sherman, A.M., Wallington, T.J., Everson, M.P., Field, F.R., Roth, R., Kirchain, R.E., 2012. Evaluating rare earth element availability: a case with revolutionary demand from clean technologies. Environ. Sci. Tech. 46 (6), 3406-3414.

[5]	Altschuler, Z.S., Clarke Jr., R.S., Young, E.J., 1958. Geochemistry of uranium in apatite and phosphorite. U.S. Geol. Survey Prof. Paper 314-D, 45-90.

[6]	Amine, M., Asafar, F., Bilali, L., Nadifiyine, M., 2019. Hydrochloric acid leaching study of rare earth elements from moroccan phosphate. J. Chem. 2019, 675276. https://doi.org/10.1155/2019/4675276.

[7]	Armstrong, J., Parnell, J., 2024. Cycling of rare earth elements at the Precambrian-Cambrian boundary. Global Planet. Change 236, 104434. https://doi.org/10.1016/j.gloplacha.2024.104434.

[8]	Auer, G., Hauzenberger, C.A., Reuter, M., Piller, W.E., 2016. Orbitally paced phosphogenesis in Mediterranean shallow marine carbonates during the middle Miocene Monterey event. Geochem. Geophys. Geosyst. 17, 1492-1510.

[9]	Bai, Y., Zheng, S., Liu, N., Liu, Y., Wang, X., Qiu, L., Gong, A., 2024. The role of rare earths on steel and rare earth steel corrosion mechanism of research progress. Coatings 14, 465. https://doi.org/10.3390/coatings14040465.

[10]	Balaram, V., 2022. Rare earth element deposits: Sources, and exploration strategies. J. Geol. Soc. India 98, 1210-1216. https://doi.org/10.1007/s12594-022-2154-3.

[11]	Balaram, V., 2019. Rare earth elements: A review of applications, occurrence, exploration, analysis, recycling, and environmental impact. Geosci. Front. 10 (4), 1285-1303. https://doi.org/10.1016/j.gsf.2018.12.005.

[12]	Balaram, V., 2021. Current and emerging analytical techniques for geochemical and geochronological studies. Geol. J. 56 (5), 2300-2359. https://doi.org/10.1002/gj.4005.

[13]	Balaram, V., 2023a. Potential future alternative resources for Rare Earth Elements: Opportunities and challenges. Minerals 13, 425. https://doi.org/10.3390/min13030425.

[14]	Balaram, V., 2023b. Deep-sea mineral deposits as a source of critical metals for high-and green-technology applications. Mineral. Mineral Mater. 2 (5), 1-17. https://doi.org/10.20517/mmm.2022.1.

[15]	Balaram, V., Rahaman, W., Roy, P., 2022. Recent advances in MC-ICP-MS applications in the Earth, environmental sciences: Challenges and solution. Geosyst. Geoenviron. 1, 100010. https://doi.org/10.1016/j.geogeo.2021.100019.

[16]	Balaram, V., Santosh, M., Satyanarayanan, M., Srinivas, N., Gupta, H., 2024. Lithium: A review of applications, occurrence, exploration, extraction, recycling, analysis, and environmental impact. Geosci. Front. 15, 101868.

[17]	Benataya, K., Lakrat, M., Elansari, L.L., Mejdoubi, E., 2020. Synthesis of B-type carbonated hydroxyapatite by a new dissolution-precipitation method. materialstoday: PROCEEDINGS 31 (Suppl. 1), S83-S88. https://doi.org/10.1016/j.matpr.2020.06.100.

[18]	Benitez-Nelson, C.R., 2000. The biogeochemical cycling of phosphorus in marine systems. Earth-Sci. Rev. 51, 109-135.

[19]	Binnemans, K., Jones, P.T., Blanpain, B., Gerven, T.V., Pontikes, Y., 2015. Towards zero-waste valorisation of rare-earth-containing industrial process residues: a critical review. J. Clean. Prod. 99, 17-38. https://doi.org/10.1016/j.jclepro.2015.02.089.

[20]	Bishop, B.A., Robbins, L.J., 2024. Using machine learning to identify indicators of rare earth element enrichment in sedimentary strata with applications for metal prospectivity. J. Geochem. Expl. 258, 107388. https://doi.org/10.1016/j.gexplo.2024.107388.

[21]	Blatt, H., Tracy, R.J., 1996. Petrology. Freeman, New York, pp. 345-349.

[22]	Bonnot-Courtois, C., Flicoteaux, R., 1989. Distribution of rare-earth and some trace elements in Tertiary phosphorites from the Senegal Basin and their weathering products. Chem. Geol. 75, 311-328.

[23]	Bouabdallah, M., Elgharbi, S., Horchani-Naifer, K., Barca, D., Fattah, N., Férid, M., 2019. Chemical, mineralogical and rare earth elements distribution study of phosphorites from Sra Ouertane deposit (Tunisia). J. Afr. Earth Sci. 157, 1-8.

[24]	Briggs, D., Kear, A., 1993. Fossilization of soft tissue in the laboratory. Science 259 (5100), 1439.

[25]	Broom-Fendley, S., Siegfried, P.R., Wall, F., O’Neill, M., Brooker, R.A., Fallon, E.K., Pickles, J.R., Banks, D.A., 2021. The origin and composition of carbonatite-derived carbonate-bearing fluorapatite deposits. Mineral. Depos. 56, 863-884.

[26]	Brouziotis, A.A., Giarra, A., Libralato, G., Pagano, G., Guida, M., Trifuoggi, M., 2022. Toxicity of rare earth elements: An overview on human health impact. Front. Environ. Sci. 10, 948041. https://doi.org/10.3389/fenvs.2022.948041.

[27]	Buccione, R., Ameur-Zaimeche, O., Ouladmansour, A., Kechiched, R., Mongelli, G., 2024. Data-centric approach for predicting critical metals distribution: heavy rare earth elements in Cretaceous Mediterranean-type karst bauxite deposits, southern Italy. Geochem. 84, 126026.

[28]	Buccione, R., Kechiched, R., Mongelli, G., Sinisi, R., 2021. REEs in the North Africa P-bearing deposits, paleoenvironments, and economic perspectives: a review. Minerals 11, 214. https://doi.org/10.3390/min11020214.

[29]	Cate, A., Perozzi, L., Gloaguen, E., Blouin, M., 2017. Machine learning as a tool for geologists. Lead. Edge 36, 215-219. https://doi.org/10.1190/tle36030215.1.

[30]	Chen, Y., Li, F., Zhou, S., Zhang, X., Zhang, S., Zhang, Q., Su, Y., 2023. Bayesian optimization based random forest and extreme gradient boosting for the pavement density prediction in GPR detection. Construct. Build Mater. 387, 131564.

[31]	Cherepanov, A.A., Berdnikov, N.V., Shtareva, A.V., 2019. Rare-earth elements and noble metals in phosphorites of the Gremuchy Occurrence, Lesser Khingan, Far East of Russia. Russian J. Pacific Geol. 13 (6), 585-593. https://doi.org/10.1134/s1819714019060022.

[32]	Chinkaka, E., Klinger, J.M., Davis, K.F., Bianco, F., 2023. Unexpected expansion of rare-earth element mining activities in the Myanmar-China border region. Remote Sens. 15, 4597. https://doi.org/10.3390/rs15184597.

[33]	Cohen, K.M., Finney, S.C., Gibbard, P.L., Fan, J.-X., 2013. The ICS international chronostratigraphic chart. Episodes 36 (3), 199-204.

[34]

Compton, J.S., Mallinson, D., Glenn, C.R., Filippelli, G., Follmi, K.B., Shields, G., Zanin, Y., 2000. Variations in the global phosphorus cycle. In: Glenn C.R., Prevot-Lucas L., Lucas J., (Eds.), Marine Authigenesis: From Global to Microbial. SEPM Society for Sedimentary Geology, Volume 66, pp. 21-33. https://doi.org/10.2110/pec. 00.66.

[35]	Cook, P.J., Shergold, J.H., 1984. Phosphorus, phosphorites and skeletal evolution at the Precambrian-Cambrian boundary. Nature 308, 231-236.

[36]	Costis, S., Mueller, K.K., Coudert, L., Neculita, C.M., Reynier, N., Blais, J.F., 2021. Recovery potential of rare earth elements from mining and industrial residues: A review and cases studies. J. Geochem. Expl. 221, 106699.

[37]	Cracknell, M.J., Reading, A.M., 2014. Geological mapping using remote sensing data: a comparison of five machine learning algorithms, their response to variations in the spatial distribution of training data and the use of explicit spatial information. Comput. Geosci. 63, 22-33.

[38]	Daessle, L.W., Carriquiry, J.D., 2008. Rare earth and metal geochemistry of Land and Submarine phosphorites in the Baja California Peninsula, Mexico. Marine Georesour. Geotech. 26, 240-349.

[39]	Dar, S.A., 2013. Geochemical and mineralogical studies of phosphorites and associated rocks in parts of Lalitpur district, Uttar Pradesh, India. Ph. D. Thesis (Unpublished), Department of Geology, Aligarh Muslim University, Aligarh, 35-54 pp.

[40]	Dar, S.A., Khan, K.F., Khan, S., Alam, M.M., 2015. Petromineralogical studies of the Paleoproterozoic phosphorites in the Sonrai basin, Lalitpur district, Uttar Pradesh, India. Nat. Resour. Res. 24 (3), 339-348.

[41]

Dar, S.A., Khan, K.F., Khan, S.A., Mir, A.R., Wani, H., Balaram, V., 2014. Uranium (U) concentration and its genetic significance in the phosphorites of the Paleoproterozoic Bijawar Group of the Lalitpur district, Uttar Pradesh, India. Arabian J. Geosci. 7 (6), 2237-2248. https://doi.org/10.1007/s12517-013-0903-8.

[42]

Dar, S.A., Khan, K.F., Mir, A.R., Komiya, T., Absar, N., Shuaib, M., Raza, W., 2025. Geochemical and C-O isotopic study of ∼2-1.9 Ga phosphate-bearing marine sedimentary rocks of the Sonrai Formation, Bijawar Group, Lalitpur district, UP, India: Implications for paleoredox, paleoclimate, and paleosalinity. Geosyst. Geoenviron. 4 (1), 100324.

[43]	Deer, W.A., Howie, R.A., Zussman, J., 1962. Rock-forming Minerals, Non-silicates. John Wiley & Sons, New York, p. 371.

[44]	Delaney, M.L., 1998. Phosphorus accumulation in marine sediments and the oceanic phosphorus cycle. Global Biogeochem. Cycle 12, 563-572.

[45]	Di, J., Ding, X., 2024. Complexation of REE in hydrothermal fluids and its significance on REE mineralization. Minerals 14, 531. https://doi.org/10.3390/min14060531.

[46]	Dramsch, J.S., 2020. 70 years of machine learning in geoscience in review. In: Moseley B., Krischer L. (Eds.),Machine Learning in Geosciences. Advances in Geophysics, Volume 61. pp.1-55.

[47]	Drummond, J.B., Pufahl, P.K., Porto, C.G., Carvalho, M., 2015. Neoproterozoic peritidal phosphorite from the Sete Lagoas Formation (Brazil) and the Precambrian phosphorus cycle. Sedimentology 62, 1978-2008.

[48]	Dumakor-Dupey, N.K., Arya, S., 2021. Machine learning-a review of applications in mineral resource estimation. Energies 14 (14), 4079.

[49]

Dushyantha, D., Ratnayake, N., Premasiri, R., Batapola, B., Panagoda, H., Jayawardena, C., Chandrajith, R., Ilankoon, I.M.S.K., Rohitha, S., Ratnayake, A.S., Abeysinghe, B., Dissanayake, K., Dilshara, P., 2023. Geochemical exploration for prospecting new rare earth elements (REEs) sources: REE potential in lake sediments around Eppawala Phosphate Deposit, Sri Lanka. J. Asian Earth Sci. 243, 105515. https://doi.org/10.1016/j.jseaes.2022.105515.

[50]	Elderfield, H., Pagett, R., 1986. Analytical chemistry in marine sciences rare earth elements in ichthyoliths: variations with redox conditions and depositional environment. Sci. Total Environ. 49 (IS), 175-197.

[51]	Elliott, R.B., 1973. The chemistry of gabbro/amphibolite transitions in south Norway. Contrib. Miner. Petrol. 38, 71-79.

[52]	Emsbo, P., McLaughlin, P.I., Breit, G.N., du Bray, E.A., Koenig, A.E., 2015. Rare earth elements in sedimentary phosphate deposits: Solution to the global REE crisis? Gondwana Res. 27 (2), 776-785. https://doi.org/10.1016/j.gr.2014.10.008.

[53]	Engle, M.A., Brunner, B., 2019. Considerations in the application of machine learning to aqueous geochemistry: origin of produced waters in the Northern U.S. Gulf Coast Basin. Appl. Comput. Geosci. 3, 100012. https://doi.org/10.1016/j.acags.2019.100012.

[54]	Esmaeiloghli, S., Tabatabaei, S.H., Hosseini, S., Deville, Y., Carranza, E.J.M., 2024. Blind source separation of spectrally filtered geochemical signals to recognize multi depth ore-related enrichment patterns. Math. Geosci. 56, 1255-1283. https://doi.org/10.1007/s11004-023-10101-w.

[55]	Felitsyn, S., Morad, S., 2002. REE patterns in latest Neoproterozoic-early Cambrian phosphate concretions and associated organic matter. Chem. Geol. 187, 257-265.

[56]

Ferhaoui, S., Kechiched, R., Bruguier, O., Sinisi, R., Kocsis, L., Mongelli, G., Bosch, D., Zaimeche, O.A., Laouar, R., 2022. Rare earth elements plus yttrium (REY) in phosphorites from the Tébessa region (Eastern Algeria): Abundance, geochemical distribution through grain size fractions, and economic significance. J. Geochem. Expl. 241, 107058. https://doi.org/10.1016/j. gexplo.2022.107058.

[57]	Filippelli, G.M., 1997. Controls on phosphorus concentration and accumulation in oceanic sediments. Mar. Geol. 139, 231-240.

[58]	Filippelli, G.M., 2008. The global phosphorus cycle: Past, present, and future. Elements 4, 89-95.

[59]

Filippelli, G.M., 2011. Phosphate rock formation and marine phosphorus geochemistry: The deep time perspective. Chemosphere 84, 759-766. Flicoteaux, R., Lucas, J., 1984. Weathering of phosphate minerals. In: Nriagu J.O., Moore P.B. (Eds.),Phosphate Minerals. Springer-Verlag Berlin, Heidelberg, pp. 292-317. https://doi.org/10.1007/978-3-642-61736-2_9.

[60]	Föllmi, K.B., 1996. The phosphorus cycle, phosphogenesis and marine phosphate-rich deposits. Earth Sci. Rev. 40 (1-2), 55-124.

[61]	Garnit, H., Bouhlel, S., Barca, D., Chtara, C., 2012. Application of LA-ICP-MS to sedimentary phosphatic particles from Tunisian phosphorite deposits: insights from trace elements and REE into paleo-depositional environments. Chem. Erde-Geochem. 72, 127-139.

[62]	Gerasimovsky, V.I., 1959. Geochemistry of rare earth elements. Int. Geol. Rev. 1 (12), 72-79.

[63]	German, C.R., Elderfield, H., 1990. Application of the Ce anomaly as a paleoredox indicator: the ground rules. Paleoceanography 5, 823-833.

[64]	German, C.R., Holliday, B.P., Elderfield, H., 1991. Redox cycling of rare earth elements in the suboxic zone of the Black Sea. Geochim. Cosmochim. Acta 55, 3553-3558.

[65]	Glenn, C.R., Follmi, K.B., Riggs, S.R., Baturin, G.N., Grimm, K.A., Trappe, J., 1994. Phosphorus and phosphorites: Sedimentology and environments of formation. Eclogae Geologicae Helvetica 87, 747-788.

[66]	Godet, A., Föllmi, K.B., 2021. Sedimentary Phosphate Deposits. In: In: Alderton, D., Elias S.A. (Eds.),Encyclopedia of Geology, Second Edition. Elsevier, pp. 922-930. https://doi.org/10.1016/B978-0-08-102908-4.00045-X.

[67]	Golroudbary, S.R., Makarava, I., Kraslawski, A., Repo, E., 2022. Global environmental cost of using rare earth elements in green energy technologies. Sci. Total Environ. 832, 155022. https://doi.org/10.1016/j.scitotenv.2022.155022.

[68]

Gong, X., Shengwei, W., Yong, X., Zhang, Z., He, S., Xie, Z., Xiao, J., Yang, H., Tan, Q., Huang, Y., Yang, Y., 2021. Enrichment characteristics and sources of the critical metal yttrium in Zhijin rare earth-containing phosphorites, Guizhou Province, China. Acta Geochimica 40 (3), 441-465. https://doi.org/10.1007/s11631-021-00460-8.

[69]

Gonzalez, F.J., Somoza, L., Hein, J.R., Medialdea, T., Leon, R., Urgorri, V., Reyes, J., Martın-Rubı J.A., 2016. Phosphorites, Co-rich Mn nodules, and Fe-Mn crusts from Galicia Bank, NE Atlantic: Reflections of Cenozoic tectonics and paleoceanography. Geochem. Geophys. Geosyst. 17, 346-374. https://doi.org/10.1002/2015GC005861.

[70]	Grandjean, P., Albarede, F., 1989. Ion probe measurement of rare earth elements in biogenic phosphates. Geochim. Cosmochim. Acta 53, 3179-3183.

[71]	Grandjean-Lecuyer, P., Feist, R., Albarede, F., 1993. Rare earth elements in old biogenic apatites. Geochim. Cosmochim. Acta 57, 2507-2514.

[72]

Graul, S., Kallaste, T., Pajusaar, S., Urston, K., Gregor, A., Moilanen, M., Ndiaye, M., Hints, R., 2023. REE + Y distribution in Tremadocian shelly phosphorites (Toolse, Estonia): Multi-stages enrichment in shallow marine sediments during early diagenesis. J. Geochem. Expl. 254, 107311. https://doi.org/10.1016/j.gexplo.2023.107311.

[73]

Graul, S., Monchal, V., Rateau, R., Joosu, L., Moilanen, M., Ndiaye, M., Hints, R., 2024. LA-ICP-MS imaging technique application on Estonian sedimentary phosphorites: Revealing REE enrichment stages and advanced ore characterisation. EGU General Assembly 2024. Vienna, Austria. https://doi.org/ 10.5194/egusphere-egu24-7319.

[74]

Gregory, D.D., Cracknell, M.J., Large, R.R., McGoldrick, P., Kuhn, S., Maslennikov, V.V., Baker, M.J., Fox, N., Belousov, I., Figueroa, M.C., Steadman, J.A., Fabris, A.J., Lyons, T.W., 2019. Distinguishing ore deposit type and barren sedimentary pyrite using laser ablation-inductively coupled plasma-mass spectrometry trace element data and statistical analysis of large data sets. Econ. Geol. 114, 771-786. https://doi.org/10.5382/econgeo.4654.

[75]	Grunsky, E.C., de Caritat, P., 2020. State-of-the-art analysis of geochemical data for mineral exploration. Geochem. Explor. Environ. Anal. 20, 217-232. https://doi.org/10.1144/geochem2019-031.

[76]	Habashi, 1985. The recovery of the lanthanides from phosphate rock. J. Chem. Technol. Biotechnol. 35 (1), 5-14. https://doi.org/10.1002/jctb.5040350103.

[77]	Haddad, F., Yazdi, M., Behzadi, M., Yakymchuk, C., Khoshnoodi, K., 2023. Mineralogy, geochemistry, and depositional environment of phosphates in the Pabdeh Formation, Khormuj anticline, SW of Iran. Environ. Earth Sci. 82 (18), 418.

[78]	Haley, B.A., Klinkhammer, G.P., McManus, J., 2004. Rare earth elements in pore waters of marine sediments. Geochim. Cosmochim. Acta 68, 1265-1279.

[79]

Haneklaus, N.H., Mwalongo, D.A., Lisuma, J.B., Amasi, A.I., Mwimanzi, J., Bituh, T., iric´ J., Nowak, J., Ryszko, U., Rusek, P., Maged, A., Bilal, E., Bellefqih, H., Qamouche, K., Brahim, J.A., Beniazza, R., Mazouz, H., Merwe, E.M.V.D., Truter, W., Kyomuhimbo, H.D., Wacławek, S., 2024. Rare earth elements and uranium in Minjingu phosphate fertilizer products: plant food for thought. Resour. Conserv. Recycl. 207, 107694. https://doi.org/10.1016/j.resconrec.2024.107694.

[80]	Haxel, G.B., Hedrick, J.B., Orris, G.J., 2002. Rare earth elements critical resources for high technology. U.S. Geological Survey, Fact Sheet, 087.

[81]	He, S., Xia, Y., Xiao, J., Gregory, D., Xie, Z., Tan, Q., Yang, H., Guo, H., Wu, S., Gong, X., 2022. Geochemistry of REY-enriched phosphorites in Zhijin Region, Guizhou Province, SW China: Insight into the origin of REY. Minerals 12, 408. https://doi.org/10.3390/min12040408.

[82]	He, Y., Ma, L., Liang, X., Li, X., Zhu, J., He, H., 2024. Resistant rare earth phosphates as possible sources of environmental dissolved rare earth elements: Insights from experimental bio-weathering of xenotime and monazite. Chem. Geol. 122186. https://doi.org/10.1016/j.chemgeo.122186.

[83]

Heggie, D.T., Skyring, G.W., O’Brien, G.W., Reimers, C., Herczeg, A., Moriarty, J.W., Burnett, W.C., Milnes, A.R., 1990. Organic carbon cycling and modern phosphorite formation on the east australian continental margin:an overview. In: Notholt A.J.G., Jarvis I. (Eds.),Phosphorite Research and Development. Geol. Soc. London Special Publ., pp. 87-117.

[84]	Hein, J.R., Koschinsky, A., Mikesell, M., Mizell, K., Glenn, C.R., Wood, R., 2016. Marine phosphorites as potential resources for heavy rare earth elements and yttrium. Minerals 6, 88. https://doi.org/10.3390/min6030088.

[85]	Hellal, F., El-Sayed, S., Zewainy, R., Amer, A., 2019. Importance of phosphate pock application for sustaining agricultural production in Egypt. Bull. Nat. Res. Centre 43, 11. https://doi.org/10.1186/s42269-019-0050-9.

[86]	Herwartz, D., Tutken, T., Munker, C., Jochum, K.P., Stoll, B., Sander, P.M., 2011. Timescales and mechanisms of REE and Hf uptake in fossil bones. Geochim. Cosmochim. Acta 75, 82-105.

[87]	Holser, W.T., 1997. Evaluation of the application of rare-earth elements to paleoceanography. Palaeogeogr. Palaeoclimatol. Palaeoecol. 132, 309-323.

[88]	Hong, J., Chengshi, G.A.N., Jie, L.I.U., 2019. Prediction of REEs in OIB by major elements based on machine learning. Earth Sci. Front. 26 (4), 45-54 (in Chinese with English abstract).

[89]	Hoshino, M., 2020. Potential of apatite for heavy rare earth resource. Chikyukagaku Geochem. 5, 29-59. https://doi.org/10.14934/chikyukagaku.54.29.

[90]	Howard, P., 1979. Phosphate. Econ. Geol. 74, 192-194.

[91]	Hu, B., Zeng, L.-P., Liao, W., Wen, G., Hu, H., Li, M.Y.H., Zhao, X.-F., 2022. The origin and discrimination of high-Ti magnetite in magmatic-hydrothermal systems: insight from machine learning analysis. Econ. Geol. 117, 1613-1627. https://doi.org/10.5382/econgeo.4946.

[92]	Ibrahim, B., Ahenkorah, I., Ewusi, A., Majeed, F., 2023. A novel XRF-based lithological classification in the Tarkwaian paleo placer formation using SMOTE-XGBoost. J. Geochem. Explor. 245, 107147.

[93]	Ibrahim, B., Majeed, F., Ewusi, A., Ahenkorah, I., 2022. Residual geochemical gold grade prediction using extreme gradient boosting. Environ. Chall. 6, 100421. Ismail, I.S., 2002. Rare earth elements in Egyptian phosphorites. China J. Geochem. 21, 19-28. https://doi.org/10.1007/BF02838049.

[94]	Jarvis, I., Burnett, W.C., Nathan, Y., Almbaydin, F.S.M., Attia, A.K.M., Castro, L.N., Flicoteaux, R., Hilmy, M.E., Husain, V., Qutawnah, A.A., Serjani, A., Zanin, Y.N., 1994. Phosphorite geochemistry: state-of-the-art and environmental concerns. J. Swiss Geol. Soc. 87, 643-700.

[95]	Jasinski, S.M., 2016. Mineral Commodity Summaries 2016. U.S. Geological Survey, pp. 124-125.

[96]	Jiang, X.-D., Sun, X.-M., Chou, Y.-M., Hein, J.R., He, G.-W., Fu, Y., Li, D., Liao, J.-L., Ren, J.-B., 2020. Geochemistry and origins of carbonate fluorapatite in seamount FeMn crusts from the Pacific Ocean. Mar. Geol. 423, 106135.

[97]	Jones, E.J.W., Bou Dagher-Fadel, M.K., Thirlwall, M.F., 2002. An investigation of seamount phosphorites in the Eastern Equatorial Atlantic. Mar. Geol. 183 (1-4), 143-162. https://doi.org/10.1016/S0025-3227(01)00254-7.

[98]	Jürjo, S., Oll, O., Lust, E., 2024. Yttrium separation from phosphorite extract using liquid extraction with room temperature ionic liquids followed by electrochemical reduction. Metals 14, 927. https://doi.org/10.3390/met14080927.

[99]	Kalvoda, J., Novak, M., Babek, O., Brzobohaty, R., Hola, M., Holoubek, I., Kanicky, V., Skoda, R., 2009. Compositional changes in fish scale hydroxylapatite during early diagenesis; an example from an abandoned meander. Biogeochemistry 94, 197-215.

[100]

Karpatne, A., Ebert-Uphoff, I., Ravela, S., Babaie, H.A., Kumar, V., 2019. Machine learning for the geosciences: challenges and opportunities. IEEE Trans. Knowl. Data Eng. 31, 1544-1554. https://doi.org/10.1109/TKDE.2018.2861006.

[101]

Kechiched, R., Laouar, R., Bruguier, O., Salmi-Laouar, S., Kocsis, L., Bosch, D., Foufou, A., Ameur-Zaimeche, O., Larit, H., 2018. Glauconite-bearing sedimentary phosphorites from the Tébessa region (Eastern Algeria): evidence of REE Enrichment and geochemical constraints on their origin. J. African Earth Sci. 145, 190-200.

[102]

Kechiched, R., Laouar, R., Bruguier, O., Kocsis, L., Laouar, S.S., Bosch, D., Zaimeche, D. A., Foufou, A., Larit, H., 2020. Comprehensive REE + Y and sensitive redox trace elements of Algerian phosphorites (Tébessa, eastern Algeria): A geochemical study and depositional environments tracking. J. Geochem. Expl. 208, 106396. https://doi.org/10.1016/j.gexplo.2019.106396.

[103]

Khan, K.F., Dar, S.A., Khan, S.A., 2012a. Geochemistry of phosphate bearing sedimentary rocks in parts of Sonrai block, Lalitpur District, Uttar Pradesh, India. Chemie Der Erde 72, 117-125. https://doi.org/10.1016/j. chemer.2012.01.003.

[104]

Khan, K.F., Dar, S.A., Khan, S.A., 2012b. Rare earth element (REE) geochemistry of phosphorites of the Sonrai area of Paleoproterozoic Bijawar basin, Uttar Pradesh, India. J. Rare Earths 30 (5), 507. https://doi.org/10.1016/S1002-0721(12)60081-7.

[105]

Khan, S., Dar, S.A., Khan, K.F., Shuaib, M., 2023. Rare earth element signatures of Paleoproterozoic Sallopat phosphorites of Aravalli Basin, India: implications for diagenetic effects and depositional environment. Acta Geochim. 42, 726-738. Khan, S.A., Khan, K.F., Dar, S.A., 2016. REE geochemistry of Early Cambrian phosphorites of Masrana and Kimoi blocks, Uttarakhand, India. Arab J. Geosci. 9, 456.

[106]

Kholodov, V.N., Butuzova, G.Y., 2001. Problems of iron and phosphorus geochemistry in the Precambrian. Lith. Mineral Resou. 36, 339-352.

[107]

Klein, C., 2005. Some Precambrian banded iron-formations (BIFs) from around the world: their age, geologic setting, mineralogy, metamorphism, geochemistry, and origin. Am. Mineral. 90, 1473-1499.

[108]

Koritnig, S., 1978. Phosphorus. In: Wedepohl K.H. (Ed.), Handbook of Geochemistry. Springer, Berlin, Heidelberg, New York. Laouar, K., Laouar, R., Bruguier, O., Bosch, D., Kechiched, D., Bouhlel, S., Tlili, A.,2024.

[109]

Geochemistry of Bled El Hadba phosphorites (NE Algeria): Glauconitization process versus REE-enrichment. J. Geochem. Expl. 258, 107398. https://doi.org/10.1016/j.gexplo.2024.107398.

[110]

Laurino, J.P., Mustacato, J., Huba, Z.J., 2019. Rare earth element recovery from acidic extracts of Florida phosphate mining materials using chelating polymer 1-octadecene, polymer with 2,5-furandione, sodium salt. Minerals 9 (8), 477. https://doi.org/10.3390/min9080477.

[111]

Le Maitre, R.W., 2002. Igneous rocks. A classification and glossary of terms. Recommendations of the International Union of Geological Sciences Sub-commission on the Systematics of Igneous Rocks. Cambridge University Press, Cambridge, p. 236.

[112]

Lecuyer, C., Reynard, B., Grandjean, P., 2004. Rare earth element evolution of Phanerozoic seawater recorded in biogenic apatites. Chem. Geol. 204, 63-102.

[113]

Lee, J., Bazilian, M., Sovacool, B., Hund, K., Jowitt, S.M., Nguyen, T.P., Månberger, A., Kah, M., Greene, S., Galeazzi, C., Awuah-Offei, K., Moats, M., Tilton, J., Kukoda, S., 2020. Reviewing the material and metal security of low-carbon energy transitions. Renew. Sust. Energ. Rev. 124, 109789. https://doi.org/10.1016/j.rser.2020.109789.

[114]

Lei, J.J., Li, R.W., Cao, J., 2000. The Characteristics of black shale hosted concretionary phosphates and the mechanisms of microbes mediated phosphorus precipitation in Cambrian horizon on Yangtze platform. Scientia Geol. Sinica 35 (3), 277-287.

[115]

Li, L., Solana, C., Canters, F., Kervyn, M., 2017. Testing random forest classification for identifying lava flows and mapping age groups on a single Landsat 8 image. J. Volcanol. Geotherm. 345, 109-124.

[116]

Li, Z., Xie, Z., He, D., Deng, J., Zhao, H., Li, H., 2021. Simultaneous leaching of rare earth elements and phosphorus from a Chinese phosphate ore using H3PO4. Green Proc. Synt. 10, 258-267. https://doi.org/10.1515/gps-2021-0023.

[117]

Lindsay, J.J., Hughes, H.S.R., Yeomans, C.M., Andersen, J.C.Ø., McDonald, I., 2021. A machine learning approach for regional geochemical data: Platinum-group element geochemistry vs geodynamic settings of the North Atlantic Igneous Province. Geosci. Front. 12, 101098. https://doi.org/10.1016/j.gsf.2020.10.005.

[118]

Linnen, R.L., Samson, I.M., Williams-Jones, A.E., Chakhmouradian, A.R., 2014. Geochemistry of the rare-earth element, Nb, Ta, Hf, and Zr deposits. In: Holland H.D., Turekian K.K. (Eds.),Treatise on Geochemistry. Elsevier, pp. 543-568. https://doi.org/10.1016/B978-0-08-095975-7.01124-4.

[119]

Maallah, R., Chtaini, A., 2018. Bacterial electrode for the oxidation and detection of phenol. Pharm Anal Acta 9, 580. https://doi.org/10.4172/2153-2435.1000580. März, C., Riedinger, N., Sena, C., Kasten, S., 2018. Phosphorus dynamics around the sulphate-methane transition in continental margin sediments: Authigenic apatite and Fe(II) phosphates. Marine Geol. 404, 84-96. https://doi.org/10.1016/j.margeo.2018.07.010.

[120]

Masoud, A.M., Ammar, H., Elzoghby, A.A., Agamy, H.H.E., Taha, M.H., 2024. Rare earth elements adsorption from phosphoric acid solution using dendrimer modified silica gel as well as kinetic, isotherm, and thermodynamic studies. J. Rare Earths, in press. https://doi.org/10.1016/j.jre.2024.06.012.

[121]

Mazumdar, A., Banerjee, D.M., Schidlowski, M., Balaram, V., 1999. Rare-earth elements and stable isotope geochemistry of early Cambrian chert-phosphorite assemblages from the Lower Tal formation of the Krol Belt (Lesser Himalaya, India). Chem. Geol. 156, 275-297. https://doi.org/10.1016/S0009-2541(98) 00187-9.

[122]

McArthur, J.M., Walsh, J.N., 1984. Rare earth geochemistry of phosphorites. Chem. Geol. 47, 191-220.

[123]

Mills, M.M., Ridame, C., Davey, M., La Roche, J., Geider, R.J., 2004. Iron and phosphorus co-limit nitrogen fixation in the eastern tropical North Atlantic. Nature 429, 292-294.

[124]

Morad, S., Felitsyn, S., 2001. Identification of primary Ceanomaly signatures in fossil biogenic apatite: implication for the Cambrian oceanic anoxia and phosphogenesis. Sediment. Geol. 143, 259-264.

[125]

Mustapha, S.O., Olatunji, A.S., Ajay, F.F., Isibor, R.A., 2022. Mineralogy and geochemistry of some phosphate deposits for possible rare earth elements mineralization potentials within Sokoto Basin, Northwestern Nigeria. Indian J. Sci. Tech. 15 (46), 2570-2578. https://doi.org/10.17485/IJST/v15i46.1603.

[126]

Nash, W.P., 1984. Phosphate minerals in terrestrial igneous and metamorphic rocks. In: Nriagu J.O., Moore P.B. (Eds.),Phosphate Minerals. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-61736-2_6.

[127]

Nathan, Y., 1984. The mineralogy and geochemistry of phosphorites. In: Nriagu J.O., Moore P.B. (Eds.),Photosphate Minerals. Springer, Berlin, Heidelberg, pp. 275-291. https://doi.org/10.1007/978-3-642-61736-2_8.

[128]

Nelson, G.J., Pufahl, P.K., Hiatt, E.E., 2010. Paleoceanographic constraints on Precambrian phosphorite accumulation, Baraga Group, Michigan, USA. Sediment. Geol. 226, 9-21.

[129]

Notholt, J.G.A., 1991. African phosphate geology and resources: A bibliography, 1979-1988. J. Afr. Earth Sci. 13, 543-552.

[130]

O’Brien, H., Heilimo, E., Heino, P., 2015. The Archean Siilinjärvi carbonatite complex. In: Maier, W.D., Lahtinen, R., O’Brien, H. (Eds.),Mineral Deposits of Finland. Elsevier, pp.327-343.

[131]

O’Brien, G., Heggie, D., 1988. East Australian continental margin phosphorites. EOS 69 (1), 1-2. https://doi.org/10.1029/88EO00007.

[132]

Och, L.M., Shields-Zhou, G.A., 2012. The Neoproterozoic oxygenation event: Environmental perturbations and biogeochemical cycling. Earth- Sci. Rev. 110, 26-57.

[133]

Palache, C., Berman, H., Frondel, C., 1951. Dana’s System of Mineralogy. John Wiley & Sons, New York, p. 1124.

[134]

Papadopoulos, A., Tzifas, I.T., Tsikos, H., 2019. The potential for REE and associated critical metals in coastal sand (placer) deposits of Greece: A review. Minerals 9, 469. https://doi.org/10.3390/min9080469.

[135]

Papineau, D., 2010. Global biogeochemical changes at both ends of the Proterozoic: Insights from phosphorites. Astrobiology 10, 201. https://doi.org/10.1089/ast.2009.0360.

[136]

Parker, R.J., 1971. The petrography and major element geochemistry of phosphorite nodule deposits on the Agulhas Bank, South Africa. South Afr. Narl. Comm. Oceanogr. Res., Mar Geol. Prog. Bull. Univ. Cape Town 2, 92-94.

[137]

Parsa, M., 2021. A data augmentation approach to XGboost-based mineral potential mapping: an example of carbonate-hosted ZnPb mineral systems of Western Iran. J. Geochem. Explor. 228, 106811.

[138]

Paytan, A., McLaughlin, K., 2007. The oceanic phosphorus cycle. Chem. Rev. 107, 563-576.

[139]

Ptácek, P., 2016. Phosphate rocks. In: Ptacek P. (Ed.), Apatites and Their Synthetic Analogues - Synthesis, Structure, Properties and Applications. Intech Open, London. https://doi.org/10.5772/62214.

[140]

Pufahl, P.K., 2010. Bioelemental sediments. In: James N.P., Dalrymple R.W. (Eds.),Facies Models. 4th ed. Geological Association of Canada, pp. 477-503.

[141]

Pufahl, P.K., Grimm, K.A., 2003. Coated phosphate grains: proxy for physical, chemical, and ecological changes in seawater. Geology 31, 801-804.

[142]

Pufahl, P.K., Groat, L.A., 2016. Sedimentary and igneous phosphate deposits: Formation and exploration: An invited paper. Econ. Geol. 112, 483-516.

[143]

Pufahl, P.K., Hiatt, E.E., 2012. Oxygenation of the Earth’s ocean atmosphere system: a review of physical and chemical sedimentological responses. Marine Petro. Geol. 32, 1-20.

[144]

Rasmussen, B., 1996. Early-diagenetic REE-phosphate minerals (florenctite, gorceixite, crandallite, and xenotime) in marine sandstone: a major sink for oceanic phorous. J. Sci. 296, 601-632.

[145]

Raudsep, R., 2008. Estonian georesources in the European context. Est. J. Earth Sci. 57, 80.

[146]

Reynard, B., Lecuyer, C., Grandjean, P., 1999. Crystal-chemical controls on rare-earth element concentrations in fossil biogenic apatites and implications for paleoenvironmental reconstructions. Chem. Geol. 155, 233-241.

[147]

Ritterbush, S.W., 1978. Marine resources and the potential for conflict in the South China Sea. In: Fletcher Forum of World Affairs 1983-2000, pp. 64-85.

[148]

Roshdy, O.E., Haggag, E.A., Masoud, A.M., Bertau, M., Haneklaus, N., Pavón, S., Hussein, A.E.M., Khawassek, Y.M., Taha, M.H., 2023. Leaching of rare earths from Abu Tartur (Egypt) phosphate rock with phosphoric acid. J. Material Cycles Waste Manage. 25, 501-517.

[149]

Rychkov, V.N., Kirillov, E.V., Kirillov, S.V., Semenishchev, V.S., Bunkov, G.M., Botalov, M.S., Smyshlyaev, D.V., Malyshev, A.S., 2018. Recovery of rare earth elements from phosphogypsum. J. Clean. Prod. 196, 674-681. https://doi.org/10.1016/j.jclepro.2018.06.114.

[150]

Safhi, A.M., Amar, H., El-Berdai, Y., El-Ghorfi, M., Taha, Y., Hakkou, R., Benzaazoua, M., 2022. Characterizations and potential recovery pathways of phosphate mines waste rocks. J. Clean. Prod. 374, 134034. https://doi.org/10.1016/j.jclepro.2022.134034.

[151]

Santosh, M., Groves, D.I., Yang, C.X., 2024. Habitable planet to sustainable civilization: Global climate change with related clean energy transition reliant on declining critical metal resources. Gondwana Res. 130, 220-233. https://doi.org/10.1016/j.gr.2024.01.013.

[152]

Saporetti, C.M., da Fonseca, L.G., Pereira, E., de Oliveira, L.C., 2018. Machine learning approaches for petrographic classification of carbonate-siliciclastic rocks using well logs and textural information. Appl. Geophys. J. 155, 217-225.

[153]

Sasmaz, A., Sasmaz, B., Soldatenko, Y., El Albani, A., Zhovinsky, E., Kryuchenko, N., 2023. Geochemical evidence of Ediacaran phosphate nodules in the Volyno-Podillya-Moldavia Basin, Ukraine. Minerals 13, 539. https://doi.org/10.3390/min13040539.

[154]

Sassi, B.A., Zaïer, A., Joron, J.L., Treuil, M., 2005. Rare Earth elements distribution of tertiary phosphorites in Tunisia. Miner. Depos. Res. 2, 1061-1064.

[155]

Schenau, S.J., Slomp, C.P., De Lange, G.J., 2000. Phosphogenesis and active phosphorite formation in sediments from the Arabian Sea oxygen minimum zone. Mar. Geol. 169, 1-20.

[156]

Schnitzler, N., Ross, P.S., Gloaguen, E., 2019. Using machine learning to estimate a key missing geochemical variable in mining exploration: application of the random forest algorithm to multi-sensor core logging data. J. Geochem. Explor. 205, 106344. https://doi.org/10.1016/j.gexplo.2019.106344.

[157]

Sengupta, D., Van Gosen, B., 2016. Placer-type rare earth element deposits. In: Verplanck P., Hitzman M. (Eds.),Reviews in Economic Geology, vol 18. Society of Economic Geologists, Littleton, CO, USA, pp. 81-100. https://doi.org/10.1130/abs/2016AM-279551.

[158]

Seredin, V.V., 2010. A new method for primary evaluation of the outlook for rare earth element ores. Geol. Ore Deposits 52, 428-433.

[159]

Shaban, A.M., 2016. A Review on Phosphate Deposits. American University of Beirut, p. 45. She, Z., Strother, P., McMahon, G., Nittler, L.R., Wand, J., Zhang, J., Sang, L., Ma, C., Papineau, D., 2013. Terminal Proterozoic cyanobacterial blooms and phosphogenesis documented by the Doushantuo granular phosphorites I: In situ microanalysis of textures and composition. Precambrian Res. 235, 20-35.

[160]

Shields, G., Stille, P., 2001. Diagenetic constraints on the use of cerium anomalies as palaeoseawater redox proxies: an isotopic and REE study of Cambrian phosphorites. Chem. Geol. 175, 29-48.

[161]

Sholkovitz, E.R., Landing, W.M., Lewis, B.L., 1994. Ocean particle chemistry: the fractionation of rare earth elements between suspended particles and seawater. Geochim. Cosmochim. Acta 58, 1567-1579.

[162]

Silva Santos, V., Gloaguen, E., Louro, H.A.V., Blouin, M., 2022. Machine learning methods for quantifying uncertainty in prospectivity mapping of magmatic-hydrothermal gold deposits: a case study from Juruena Mineral, Northern Mato Grosso, Brazil Province. Minerals 12 (8), 941. https://doi.org/10.3390/min12080941.

[163]

Skhurram, S.J., Shahida, W., Siddique, N., Shakoor, R.A., Tufail, M., 2010. Measurement of rare earth elements in Kakul phosphorite deposits of Pakistan using instrumental neutron activation analysis. J. Radioanaly. Nuclear Chem. 284 (2), 397-403. https://doi.org/10.1007/s10967-010-0469-9.

[164]

Skorovarov, J.I., Kosynkin, V.D., Moiseev, S.D., Rura, N.N., 1992. Recovery of rare earth elements from phosphorites in the USSR. J. Alloys Compounds 180 (1-2), 71-76.

[165]

Slansky, M., 1986. Geology of Sedimentary Phosphates. North Oxford Academic Publisher Ltd., Oxford, pp. 19-35. Slomp, C.P., Van Cappellen, P., 2007. The global marine phosphorus cycle: sensitivity to oceanic circulation. Biogeosci. 4, 155-171.

[166]

Slomp, C.P., Epping, E.H.G., Helder, W., Raaphorst, W.V., 1996. A key role for iron-bound phosphorus in authigenic apatite formation in North Atlantic continental platform sediments. J. Marine Res. 54, 1179-1205.

[167]

Stammeier, J.A., Hippler, D., Nebel, O., Leis, A., Grengg, C., Mittermayr, F., Kasemann, S.A., Dietzel, M., 2019. Radiogenic Sr and stable C and O isotopes across Precambrian-Cambrian transition in marine carbonatic phosphorites of Malyi

[168]

Karatau (Kazakhstan)-Implications for paleo-environmental change. Geochem. Geophy. Geosyst. 20, 3-23. https://doi.org/10.1029/2018GC007767.

[169]

Sun, D., Fan, C., Guo, W., Zhao, L., Zhan, X., Hu, M., 2024. Study of new CGSP-P series phosphate matrix reference materials for LA-ICP-MS. Geostand. Geoanal. Res. 48 (3), 677-695.

[170]

Tahar-Belkacem, N., Ameur-Zaimeche, Q., Kechiched, R., Ouladmansour, A., Heddam, S., Wood, D.A., Buccione, R., Mongelli, G., 2024. Machine learning models to predict rare earth elements distribution in Tethyan phosphate ore deposits: Geochemical and depositional environment implications. Geochemistry 84 (4), 126128. https://doi.org/10.1016/j.chemer.2024.126128.

[171]

Tan, H.M.R., Huang, X.W., Qi, L., Gao, J.F., Meng, Y.M., Xie, H., 2022. Research progress on chemical composition of apatite: Application in petrogenesis, ore genesis and mineral exploration. Acta Petrol. Sinica 38 (10), 3067-3084.

[172]

Taylor, S.R., McLennan, S.M., Armstrong, R.L., Tarney, J., 1981. The composition and evolution of the continental crust: Rare earth element evidence from sedimentary rocks: discussion. Philosoph. Transact. B 301 (1461), 398-399. https://doi.org/10.1098/rsta.1981.0119.

[173]

U.S. Geological, Survey, 2021. Rare Earth Statistics. In: Kelly T.D., Matos G.R., (Eds.), Historical Statistics for Mineral and Material Commodities in the United States:U.S. Geological Survey Data Series 140; US Geological Survey. Reston, Virginia, USA, 2014.

[174]

Vadakkepuliyambatta, S., Roy, P., Ingole, B.S., Raju, K.A.K., Kurian, P.J., Meloth, T., 2024. Potential of deep-sea mineral resources for the blue economy. Current Sci. 126, 1-8.

[175]

Valetich, M., Zivak, D., Spandler, C., Degeling, H., Grigorescu, M., 2022. REE enrichment of phosphorites: An example of the Cambrian Georgina Basin of Australia. Chem.Geol. 588,120654.https://doi.org/10.1016/j.

[176]

chemgeo. 2021. 120654. van der Zee, C., Slomp, C.P., van Raaphorst, W., 2002. Authigenic P formation and reactive P burial in sediments of the Nazare´ canyon on the Iberian margin (NE Atlantic). Mar. Geol. 185, 379-392.

[177]

Van Gosen, B.S., Verplanck, P.L., Long, K.R., Gambogi, J., Robert, R., Seal, I.I., 2014. The rare-earth elements: vital to modern technologies and lifestyles. Fact Sheet. 2014, 3078

[178]

Wang, J., Qiao, Z., 2024. Study on the material source and enrichment mechanism of REE-rich phosphorite in Zhijin, Guizhou. Sci. Rep. 14, 6474. https://doi.org/10.1038/s41598-024-57074-2.

[179]

Wang, Z.Y., Fan, H.R., Zhou, L., Yang, K.F., She, H.D., 2020. Carbonatite-related REE deposits: An overview. Minerals 10, 965. https://doi.org/10.3390/min10110965.

[180]

Warren, J.K., 2010. Evaporites though time:tectonic and eustatic controls in marine and nonmarine deposites. Earth Sci. Rev. 98 (3/4), 217-268.

[181]

Watkins, R.T., Nathan, Y., Bremner, J.M., 1995. Rare earth elements in phosphorite and associated sediment from the Namibian and South African continental shelves. Mar. Geol. 129, 111-128.

[182]

Woolley, A.R., Kempe, D.R.C., 1989. Carbonatites:nomenclature, average chemical compositions and element distribution. In: Bell K. (Ed.), Carbonatites, Genesis and Evolution. Unwin Hyman, London, pp. 1-14.

[183]

Wright, J., Schrader, H., Holser, W.T., 1987. Paleoredox variations in ancient oceans recorded by rare earth elements in fossil apatite. Geochim. Cosmochim. Acta 51, 631-644.

[184]

Wu, S., Yang, H., Fan, H., Xia, Y., Meng, Q., He, S., Gong, X., 2022. Assessment of the effect of organic matter on rare earth elements and yttrium using the Zhijin Early Cambrian phosphorite as an example. Minerals 12, 876. https://doi.org/10.3390/min12070876.

[185]

Wu, C., Yuan, Z., Bai, G., 1996. Rare earth deposits in China. In: Jones A.P., Wall F., Williams C.T. (Eds.),Rare Earth Minerals-Chemistry, Origin and Ore Deposits. Chapman and Hall, New York, pp. 281-310.

[186]

Xing, J., Jiang, Y., Xian, H., Yang, W., Yang, Y., Niu, H., He, H., Zhu, J., 2024. Rare earth element enrichment in sedimentary phosphorites formed during the Precambrian-Cambrian transition, Southwest China. Geosci. Front. 15, 101766. https://doi.org/10.1016/j.gsf.2023.101766.

[187]

Xiong, C., Xie, H., Wang, Y., Wang, C., Li, Z., Yang, C., 2024. Microdistribution and mode of rare earth element occurrence in the Zhijin rare earth element-bearing phosphate deposit, Guizhou, China. Minerals 14, 223. https://doi.org/10.3390/min14030223.

[188]

Xiqiang, L., Hui, Z., Yong, T., Yunlong, L., 2020. REE geochemical characteristic of apatite: implications for ore genesis of the Zhijin Phosphorite. Minerals 10, 1012. https://doi.org/10.3390/min10111012.

[189]

USGS, 2024. U.S. Geological Survey, Mineral Commodity Summaries. January 2024.

[190]

Yahorava, V., Bazhko, V., Freeman, M., 2016. Viability of phosphogypsum as a secondary resource of rare earth elements. In: IMPC 2016:XXVIII International Mineral Processing Congress Proceedings at Quebec.

[191]

Yang, H.Y., Xiao, J.F., Hu, R.Z., Xia, Y., He, H.X., 2020. Formation environment and metallogenic mechanism of Weng’an phosphorite in the early Sinian. J. Palaeogeog. 22 (5), 929-946.

[192]

Yang, H., Xiao, J., Xia, Y., Xie, Z., Tan, Q., Xu, J., He, S., Wu, S., Liu, X., Gong, X., 2021. Phosphorite generative processes around the Precambrian-Cambrian boundary in South China: An integrated study of Mo and phosphate O isotopic compositions. Geosci. Front. 12, 101187. https://doi.org/10.1016/j.gsf.2021.101187.

[193]

Yang, H.Y., Zhao, Z.F., Fan, H.F., Zeng, M., Xiao, J.F., Liu, X.Q., Wu, S.W., Chao, J.Q., Xia, Y., 2023. Fe-(oxyhydr)oxide participation in REE enrichment in early Cambrian phosphorites from South China: Evidence from in-situ geochemical analysis. J. Asian Earth Sci. 259, 105910. https://doi.org/10.1016/j.jseaes.2023.105910.

[194]

Yang, X.S., Salvador, D., Makkonen, H.T., Pakkanen, L., 2019. Phosphogypsum processing for rare earths recovery-A review. Nat. Resour. 10, 325-336. https://doi.org/10.4236/nr.2019.109021.

[195]

Ye, M., Zhu, L., Li, X., Ke, Y., Huang, Y., Chen, B., Yu, H., Li, H., Feng, H., 2023. Estimation of the soil arsenic concentration using a geographically weighted XGBoost model based on hyperspectral data. Sci. Total Environ. 858, 159798.

[196]

Yerkebulan, R., Perizat, A., Ulzhalgas, N., 2023. Enrichment of low-grade phosphorites by the selective leaching method. Green Proc. Synth. 12 (1), 20228150. https://doi.org/10.1515/gps-2022-8150.

[197]

Yin, X., Martineau, C., Demers, I., Basiliko, N., Fenton, N.J., 2021. The potential environmental risks associated with the development of rare earth element production in Canada. Environ. Rev. 29, 354-377. https://doi.org/10.1139/er-2020-0115.

[198]

Young, R.A., 1975. Some aspects of crystal structural modeling of biological apatites. In: Physico-Chime et Cristallographie Des Apatites D’interet Biologique. C. N. R. S, Paris, pp. 21-40.

[199]

Yuan, W., Liu, G.D., Luo, W.B., Li, C.Z., Xu, L.M., Niu, X.B., Ai, J.Y., 2016. Species and formation mechanism of apatites in the 7(th) member of Yanchang Formation organic-rich shale of Ordos Basin, China. Nat. Gas Geosci. 27 (8), 1399-1408.

[200]

Yu, L.M., Liu, M.X., Dan, Y., Said, N., Wu, J.-H., Ming-Cai, H., Zou, H., 2023. The origin of Ediacaran phosphogenesis event: New insights from Doushantuo Formation in the Danzhai phosphorite deposit, South China. Ore Geol. Rev. 152, 105230.

[201]

Zanin, Yu.N., Zamirailova, A.G., 2007. Trace elements in supergene phosphorites. Geochem. Int. 45 (8), 758-769.

[202]

Zaremotlagh, S., Hezarkhani, A., 2017. The use of decision tree induction and artificial neural networks for recognizing the geochemical distribution patterns of LREE in the Choghart deposit, Central Iran. J. African Earth Sci. 128, 37-46.

[203]

Zhang, B., Li, M., Li, W., Jiang, Z., Khan, U., Wang, L., Wang, F., 2021a. Machine learning strategies for lithostratigraphic classification based on geochemical sampling data: a case study in area of Chahanwusu River, Qinghai Province, China. J. Cent. South Univ. 28, 1422-1447.

[204]

Zhang, P., Zhang, Z., Yang, J., Cheng, Q., 2023a. Machine learning prediction of ore deposit genetic type using magnetite geochemistry. Nat. Resour. Res. 32 (1), 99-116.

[205]

Zhang, W., He, Y., Wang, L., Liu, S., Meng, X., 2023b. Landslide susceptibility mapping using random forest and extreme gradient boosting: A case study of Fengjie, Chongqing. Geol. J. 58 (6), 2372-2387.

[206]

Zhang, Z., Jiang, Y., Niu, H., Xing, J., Yan, S., Weng, Q., Zao, X., 2021b. Enrichment of rare earth elements in the early Cambrian Zhijin phosphorite deposit, SW China: Evidence from francolite micro-petrography and geochemistry. Ore Geol. Rev. 138, 104342. https://doi.org/10.1016/j.oregeorev.2021.104342.

[207]

Zhou, J., Yu, W., Wei, W., Yang, M., Du, Y., 2023. Provenance and tectonic evolution of bauxite deposits in the Tethys: perspective from random forest and logistic regression analyses. Geochem. Geophys. Geosyst. 24, e2022GC010745.

[208]

Zuo, R., Wang, J., Xiong, Y., Wang, Z., 2021. The processing methods of geochemical exploration data: past, present, and future. Appl. Geochem. 132, 105072.