Rare earth element geochemistry and tetrad effects in fluorites: A case study from the Qahr-Abad deposit, Iran

Lanthanide tetrad effect in limestone: a tool to environment analysis of the Ruteh Formation, NW Iran.

“…The concave or W-shape tetrad effect phenomenon is indicative of low temperature deposits such as marine carbonates, underground waters, phosphorites, phosphatic shales, cherts, low temperature hydrothermal deposits (Kawabe, 1996;Akagi et al, 2004;Feng et al, 2011;Feng et al, 2014;Abedini et al, 2017). In addition, recent studies indicate that concave form of the tetrad effect phenomenon can be attributed to distribution of REE in seawaters, diagenetic processes, and REEcomplexation (Minami et al, 1998;Cunha et al, 2012).…”

“…effect phenomenon are not very clear (Censi et al, 2007;Monecke et al, 2007;Inoue et al, 2009). But, based on recent investigations, some geochemicallybased models such as mineral phases during fractional mineralization, complexes in solutions, fluid-rock interaction, weathering, and hydrothermal alteration have been proposed by many researchers (Pan, 1997;Monecke et al, 2007;Badanina et al, 2010;Feng et al, 2011;Wu et al, 2011;Nardi et al, 2012;Abedini et al, 2017;Rezaei Azizi et al, 2017). Generally, during igneous activities such as fractional mineralization and interaction of rising hydrothermal fluids with rocks along the channelways (faults and/or fractures), and complexing with ligands in hydrothermal systems are distinguished by convex (M-shape) tetrad effect curves in normalized REE distribution patterns (McLennan, 1994;Irber, 1999;Monecke et al, 2007).…”

“…Convex shapes (M -like) in the normalized REE patterns are indicative of igneous and related systems such as hydrothermal activities, alteration and evolution processes (Irber, 1999;Monecke et al, 2007;Cao et al, 2013;Lv et al, 2018;Yang et al, 2018). In contrast, concave shapes (W-like) are mostly observed in low-temperature deposits such as marine sediments, limestones, cherts, phosphatic shales, and underground waters (Masuda et al, 1987;Akagi et al, 2004;Rossi et al, 2011;Feng et al, 2014;Abedini et al, 2017). Another form of tetrad effect is known as co-existence of both convex and concave tetrad effect shapes in the same normalized REE distribution patterns such as Tono uranium deposit in Japan, volcanic glasses, ferromanganese nodules and Terra Rossa in China, porphyric rocks in Transbaikalia, cryolites in Pitinga of Brazil, fluorite deposit, phosphatic shales, and titanium-rich bauxites…”

“…Despite their similar geochemical and CHARAC behavior, these elements show many irregular curves in their normalized distribution patterns have been reported from various depositional environments. This is related to non-CHARAC behaviors of REE such as lanthanides tetrad effect (Censi et al, 2007;Yasnygina and Rasskazov, 2008;Peretyazhko and Savina, 2010;Feng et al, 2011;Nardi et al, 2012;Cao et al, 2013;Lee et al, 2013;Abedini et al, 2017;Rezaei Azizi et al, 2017;Abedini et al, 2018). This phenomenon for the first time, labeled as 'tetrad effect', 'zigzag', 'kinked', and/or 'double-double' (Lee et al, 1994;Kawabe, 1995), reflects a unique characteristic of normalized REE distribution patterns which was reported for the first time in the aqueous extraction of rare earth elements studies in natural materials (Fidelis and Siekierski, 1966;Peppard et al, 1969).…”

REE Tetrad Effect as a Powerful Indicator of Formation Conditions of Karst Bauxites: A Case Study of the Shahindezh Deposit, NW Iran

“…as a new geochemical/mathematical-based tool to interpret irregular curves in normalized REE distribution patterns in a wide range of deposits (Kawabe, 1995;Lee et al, 1994;Irber, 1999;Jahn et al, 2001;Broska et al, 2006;Feng et al, 2011;Cunha et al, 2012;Nardi et al, 2012;Cao et al, 2013;Lee et al, 2013;Duc-Tin and Keppler, 2015;Abedini et al, 2017;Rezaei Azizi et al, 2017;Abedini et al, 2018a). Lee et al (1994) went on to suggest that the zigzag pattern of normalized REE patterns are indicative of an imperfect tetrad effect phenomenon in geochemical systems.…”