Rare earth element geochemistry and tetrad effects of the Dalir phosphatic shales, northern Iran

Ree mobility and tetrad effects in bauxites an example from the Kanisheeteh deposit, NW Iran

“…This means that variation of Y/Ho ratio in geochemical processes reflects the prevailing physico-chemical conditions of depositional environment. Therefore, the non-CHARAC ratios and behavior of coherent elements such as Y and Ho can be interpreted by and/or attributed to tetrad effect feature in the geochemical processes (Abedini et al, 2017;Rezaei Azizi et al, 2017;Abedini et al, 2018b). The plots of Y/Ho ratios versus Y (Figure 6a) and Ho (Figure 6b individual tetrads and therefore all four elements are in the straight line connecting the first and fourth elements.…”

“…The second form of tetrad effect is characterized by a convex or M-shaped curve in their normalized REE distribution patterns indicating magmatic origin (e.g., granite) and associated evolved systems such as hydrothermal ore and gangue (e.g., fluorite) minerals (Kawabe, 1995;Haapala and Lukkari, 2005;Cao et al, 2013;Lee et al, 2013;Rezaei Azizi et al 2017). Finally, in the third form has both convex and concave (M-and W-shaped) curves which are commonly observed in natural glasses, phosphatic shale as well as in uranium, fluorine, and aluminum (bauxite) deposits (Takahashi et al, 2002;Minuzzi et al, 2008;Zhao et al, 2010;Rezaei Azizi et al, 2017;Abedini et al, 2017;Abedini et al, 2018b). The tetrad effect phenomenon can be used as a good geochemical indicator to assess various geological greenish cream, red, brownish red and dark red.…”

“…lanthanide effect (LTE) or double-double feature (Masuda and Ikeuchi, 1978) is tetrad one of the factors which controls the REE distribution and affects their behavior. Despite controversy on the origin of this phenomenon by some researchers (McLennan, 1994;Nakamura et al, 2007), the LTE has been widely applied as a new and good geochemical indicator to assess the geochemical processes involved during bauxite formation (Akagi et al, 1993;Broska et al, 2006;Chu et al, 2009;Cunha et al, 2012;Abedini et al, 2017;Rezaei Azizi et al, 2017;Abedini et al, 2018a).…”

“…Studies showed that three different forms of tetrad effect usually occur in the normalized REE distribution patterns. The first form has a concave or W-shaped curve which is mostly observed in the lowtemperature geological environments such as waters, limestone, marine sediments, and phosphorite (Masuda and Ikeuchi, 1978;Mazumdar et al, 2003;Yamamoto et al, 2004;Peretyazhko and Savina, 2010;Feng et al, 2014;Abedini et al, 2017). The second form of tetrad effect is characterized by a convex or M-shaped curve in their normalized REE distribution patterns indicating magmatic origin (e.g., granite) and associated evolved systems such as hydrothermal ore and gangue (e.g., fluorite) minerals (Kawabe, 1995;Haapala and Lukkari, 2005;Cao et al, 2013;Lee et al, 2013;Rezaei Azizi et al 2017).…”

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.…”