Extreme enrichment of polymetallic Ni–Mo–PGE–Au in Lower Cambrian black shales of South China: An Os isotope and PGE geochemical investigation

Marine redox variations and nitrogen cycle of the early Cambrian southern margin of the Yangtze Platform, South China: Evidence from nitrogen and organic carbon isotopes

“…Presumably, because of the rapidity of this sea level rise, lower Cambrian units across much of South China are condensed with only a few centimeters thickness in the deeper water realms (Goldberg et al, 2007;Schütter, 1998;Steiner et al, 2001Steiner et al, , 2007. Related to this condensation, a polymetallic enrichment layer occurs sporadically in the lower portion of this transgressive black shale along a NE-striking 1600 km belt, which can be used as a correlation marker Och et al, 2013;Zhu et al, 2003), but mineable ore layer is usually less than half meters in thickness and exposed only within Guizhou and Hunan provinces (Jiang et al, 2006(Jiang et al, , 2007. The deposit formed under sulfidic depositional conditions although the origin of the metal enrichment has proven controversial (Jiang et al, 2006;Lehmann et al, 2007;Steiner et al, 2007).…”

Geochemistry of major and trace elements and Pb–Sr isotopes of a weathering profile developed on the Lower Cambrian black shales in central Hunan, China

“…As such, black shales usually have a high content of organic carbon and sulphides and are important hosts for a remarkable array of ore metals such as Co, Ni, V, U, Mo, Mn, P, and PGE (platinum group elements) (e.g., Horan et al, 1994;Mao et al, 2002;Peng et al, 2005;Jiang et al, 2006Jiang et al, , 2007a. Because of their high organic carbon and sulphide contents, black shales are susceptible to alteration when exposed, and thus mining in shales throughout the world has accelerated the weathering of these sedimentary rocks.…”

REE and trace element patterns from organic-rich rocks of the Ediacaran–Cambrian transitional interval

“…80 m thick Yuanjia section, and the approximately 120 m thick Lijiatuo section consist of black chert of the Liuchapo Formation, overlain by gray to black shales of the Niutitang Formation. The base of the Niutitang Formation is defined by a horizon rich in phosphatic nodules and a sulfide layer enriched in Ni-Mo-PGEs (Pan et al, 2004;Jiang et al, 2007;Lehmann et al, 2007;Wille et al, 2008). The upper parts of the sections contain mainly gray to black shales rich in sponge spicules .…”

“…Numerous studies have centered on the fossil record, the sedimentology, and the geochemistry of this period (Richard, 1998;Wu et al, 1999a, b;Yang et al, 2003;Yang et al, 2004;Xiao et al, 2005;Tribovillard et al, 2006;Goldberg et al, 2007;Jiang et al, 2007;Lehmann et al, 2007;Schröder and Grotzinger, 2007;Zhu et al, 2007;Guo et al, 2007a, b;Ishikawa et al, 2008;Sawaki et al, 2008;Wille et al, 2008;Guo et al, 2013;Ishikawaa et al, 2013;Pi et al, 2013;Xu et al, 2013;Feng et al, 2014;Och et al, 2015;Wang et al, 2015). Anoxic to euxinic conditions have been proposed for the early Cambrian based on the widespread deposition of black shales, the enrichment of certain redox-sensitive trace metals such as Mo, Ni, and PGE (Pt-group elements), and the prominent negative shifts in the isotopic evolution of C (lower δ…”