Geochemistry and origin of rare earth elements (REEs) in the Shengli River oil shale, northern Tibet, China

Elemental geochemistry of the early Jurassic black shales in the Qiangtang Basin, eastern Tethys: constraints for palaeoenvironment conditions

“…( a ) Generalized map, showing location of study area (modified from Fu et al ., ). ( b ) Simplified geological map of the Sewa area in the Qiangtang Basin, showing location of black‐shale section.…”

Geochemistry of Neoproterozoic limestones of the Shahabad Formation, Bhima Basin, Karnataka, southern India

“…REEs are relatively immobile during the post-depositional processes like diagenesis (Chaudhuri and Cullers, 1979) and metamorphism (Muecke et al, 1979). Earlier studies mentioned that the carbonate rocks have low REE concentrations (Goldberg et al, 1963;Haskin and Haskin, 1966;Tlig and M'Rabet, 1985), and the REE patterns in carbonate rocks are mainly influenced by depositional environment (Murray et al, 1990, Madhavaraju and Ramasamy, 1999 and diagenetic processes (Armstrong-Altrin et al, 2003;Fu et al, 2011;Morad et al, 2010;Scherer and Seitz, 1980;Schieber, 1988). REEs are considered as an indicator to identify the depositional environmental system such as widespread marine anoxia (Liu et al, 1988;Murray et al, 1991b), oceanic palaeo-redox conditions (Wang et al, 1986;Elderfield and Pagett, 1986;Liu et al, 1988;Kato et al, 2002), variations in surface productivity (Toyoda et al, 1990), proximity to source area (Murray et al, 1991b), lithology and diagenesis Murray et al, 1991b;Nath et al, 1992;Madhavaraju and Ramasamy, 1999;Armstrong-Altrin et al, 2003;Madhavaraju and Lee, 2009;Madhavaraju et al, 2010) and paleogeography and depositional models (e.g., Kamber and Webb, 2001;Kemp and Trueman, 2003).…”

Reflections of the geological characteristics of Cyprus in soil rare earth element patterns

“…Total concentrations typically increase due to mass loss during regolith formation, though there is a tendency for greater loss of HREEs (Gregorauskienė and Kad unas, 2006;Beyala et al, 2009). A number of studies have investigated the behaviour of REEs under chemical weathering and subsequent transportation of the dissolved and suspended REE fractions by separating various element-mineral associations using a combination of total and partial geochemical extractions (Sholkovitz and Szymczak, 2000;Leybourne and Johannesson, 2008;Galbarczyk-Gą siorowska, 2010;Fu et al, 2011). Aqua regia extractions in particular display similar chondrite-normalised trends to total REE patterns in weathered materials but with a pronounced positive Gd anomaly (Marmolejo-Rodríguez et al, 2007).…”