Journal ArticleDOI
Geochemistry of coastal sands of Eastern Mediterranean: The case of Nisyros volcanic materials
Ioannis Tzifas,Panagiotis Misaelides,Athanasios Godelitsas,P. Gamaletsos,Paraskevi Nomikou,A.G. Karydas,V. Kantarelou,A. Papadopoulos +7 more
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In this paper, the authors investigated the potential of coastal sand samples collected from the northern part of Nisyros volcanic island (Dodecanese, Greece) for their potential in strategic metals and compared with parental rocks of the island which are Quaternary volcanics with alternating lava flows, pyroclastic layers and lava domes and relevant materials located near granitoids of Northern Greece.Abstract:
Coastal sand samples collected from the northern part of Nisyros volcanic island (Dodecanese, Greece) were investigated for first time for their potential in strategic metals and compared with parental rocks of the island which are Quaternary volcanics with alternating lava flows, pyroclastic layers and lava domes and relevant materials located near granitoids of Northern Greece. The PXRD and SEM-EDS study of the sands revealed enhanced content of feldspars, Fe-Mn oxides, magnetite, tourmaline, pyroxenes, ilmenites, along with zircons, apatite and sulfide inclusions. The fresh hydrothermally deposited clayely material collected from the Nisyros caldera crater had a rather different mineralogical composition from the coastal one (alunite, anhydrite, opal-CT, quartz, kaolinite). UCC-normalized spidergrams indicated that the weathering processes contributed to accumulation of heavy minerals (mainly ilmenite), and strategic metals including V (1920 mg/kg) and Nb (245 mg/kg), in the coastal sand. The low REE concentration (ΣREE + Y = 240 mg/kg) could be attributed to the absence of REE-rich minerals. Moreover, the sands exhibit different geochemical patterns compared to the volcanic source rocks of the island, which are especially enriched in Large-Ion Lithophile Elements (LILE) and depleted in High Field Strength Elements (HFSE), such as Nb and Ta. On the other hand, the caldera material is enriched in volatile components, sulfur, chalcophile elements (Se, Bi, Hg, As, Pb) and Ba. Micro-XRF analyses of representative crystals showed that the high Nb content of the sands was associated with the Ti/Fe-rich phases (e.g. ilmenites). The geochemical composition of N Greece sands showed, because of their origin, enrichment not only in HFSE but also in REE. The study of the coastal heavy mineral sands originating from different geological environments of Greece provides information about the association of their mineral components with REE, other elements of economic interest (e.g. Co, Nb, Ta) and natural actinides. In addition, the study of the black sands of Nisyros island could be considered as a characteristic example of those from other parts of Hellenic Volcanic Arc (HVA) and other relevant Mediterranean regions.read more
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Journal ArticleDOI
Provenance discrimination between Atasta and Alvarado beach sands, western Gulf of Mexico, Mexico: Constraints from detrital zircon chemistry and U–Pb geochronology
John S. Armstrong-Altrin,Mayla A. Ramos-Vázquez,Ana C. Zavala-León,Patricia C. Montiel-García +3 more
Journal ArticleDOI
Textural and geochemical characteristics of late Pleistocene to Holocene fine-grained deep-sea sediment cores (GM6 and GM7), recovered from southwestern Gulf of Mexico
Abigail Anaya-Gregorio,John S. Armstrong-Altrin,María Luisa Machain-Castillo,Patricia C. Montiel-García,Mayla A. Ramos-Vázquez +4 more
TL;DR: In this article, the ages of two deep-sea sediment cores (GM6 and GM7) recovered in the southwestern Gulf of Mexico were investigated to infer their provenance and depositional condition.
Journal ArticleDOI
Foraminiferal assemblages, 14C ages, and compositional variations in two sediment cores in the western Gulf of Mexico
Mayla A. Ramos-Vázquez,John S. Armstrong-Altrin,María Luisa Machain-Castillo,Frank Raúl Gío-Argaez +3 more
TL;DR: Foraminifera species distribution, 14C ages, and geochemistry data of sediment cores GM33 and GM34 recovered from the southwestern Gulf of Mexico were investigated to infer the age, sedimentation rate, provenance, heavy metal contamination, and depositional environment as discussed by the authors.
Journal ArticleDOI
Mineralogical and geochemical characterization of the unconsolidated sands from the Mefou River terrace, Yaoundé area, Southern Cameroon
Ernest Mbale Ngama,Elisé Sababa,Elie Constantin Bayiga,Armel Zacharie Ekoa Bessa,Paul-Désiré Ndjigui,Paul Bilong +5 more
TL;DR: In this paper, nine sediment core samples from the right terrace of the Mefou River in the Yaounde area (southern Cameroon) were used to investigate the provenance and evolution of sediments.
Journal ArticleDOI
The Potential for REE and Associated Critical Metals in Coastal Sand (Placer) Deposits of Greece: A Review
TL;DR: In this paper, the distribution, abundance, and bulk geochemistry of rare earth elements (REEs) associated with placer deposits of Greece, and specifically with geologically young heavy mineral sand accumulations developed proximal to felsic plutonic source rocks.
References
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Book ChapterDOI
Composition of the Continental Crust
Roberta L. Rudnick,Shan Gao +1 more
TL;DR: In this paper, the present-day composition of the continental crust, the methods employed to derive these estimates, and the implications of continental crust composition for the formation of the continents, Earth differentiation, and its geochemical inventories are discussed.
Journal ArticleDOI
Trace element characteristics of graywackes and tectonic setting discrimination of sedimentary basins
Mukul R. Bhatia,Keith A.W. Crook +1 more
TL;DR: In this article, a large variation in trace element characteristics of graywackes of the Paleozoic turbidite sequences of eastern Australia show a large increase in light rare earth elements (La, Ce, Nd), Th, Nb and the Ba/Sr, Rb, Sr, La/Y and Ni/Co ratios.
Journal ArticleDOI
The geochemistry of shales, siltstones and sandstones of Pennsylvanian-Permian age, Colorado, USA : implications for provenance and metamorphic studies
TL;DR: In this paper, a series of shales and sandstones found near the source of the Sangre de Cristo, Belden, and Maroon Formations from central Colorado were examined petrographically and were analyzed for major and selected trace elements, including the REE.
Journal ArticleDOI
Evaluating rare earth element availability: a case with revolutionary demand from clean technologies
Elisa Alonso,Andrew M. Sherman,Timothy J. Wallington,Mark P. Everson,Frank R. Field,Richard Roth,Randolph Kirchain +6 more
TL;DR: Upper and lower bound usage projections for REE in automotive and wind applications were developed to evaluate the state of future REE supply availability and identify some key variables that could affect future rare earth markets and market behavior.