Trace and rare earth element geochemistry of Jurassic mudstones in the northern Qaidam Basin, northwest China

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

“…Redox conditions of black‐shale formation were determined by analysis of some geochemical indicators. Several trace elements are known to be enriched in anoxic sediments, such as U, Ni, Zn, Mo, Cu, Co, V and Cr (Calvert and Pedersen, ; Arthur and Sageman, ; Gavshin and Zakharov, ; Yuri et al ., ; Hetzel et al ., ; Cao et al ., ). As shown in Figure , the early Jurassic black‐shale samples from the Qiangtang Basin are enriched in Ni, Zn, Cu, V and Cr in comparison with UC, whereas U and Mo exhibit a slightly lower content than their UC values.…”

Mineralogy and geochemistry of Late Permian coals from the Donglin Coal Mine in the Nantong coalfield in Chongqing, southwestern China

“…Moreover, the ratio of Sr/Ba is another effective index for depositional environment, with a value higher than 1 indicative of marine water influence (Cao et al, 2012;Dai et al, 2013a;Li et al, 2013;Wang, 1996). All Donglin coals bear Sr/Ba ratios higher than 1 (Table 5), with the exception of two samples DL-4-2 and DL-4-11, further suggesting the influence of brackish water during coal accumulation.…”

Rare earth elements in surface soils of the Davarzan area, NE of Iran

“…So, it is crucial to define the geochemical relation of different lithologies and derived soils. For this reason, the study of soil chemistry derived from various rocks has increased in recent years (e.g., Etame et al, 2009;Long-Jiang et al, 2009;Cao et al, 2012). The soils that developed on serpentinite and ultramafic rocks have high concentrations of chromium (Cr) and nickel (Ni) which could be a potential risk for the environment (Hseu, 2006;Oze et al, 2008).…”