High-resolution biostratigraphic and chemostratigraphic data from the Chenjiayuanzi section of the Doushantuo Formation in the Yangtze Gorges area, South China: Implication for subdivision and global correlation of the Ediacaran System

Acanthomorphic acritarchs of the Doushantuo Formation from an upper slope section in northwestern Hunan Province, South China, with implications for early–middle Ediacaran biostratigraphy

“…However, the two taxonomically distinct and biostratigraphically significant DPA assemblage zones established in the Yangtze Gorges area cannot be distinguished at Lujiayuanzi (Liu et al, 2013a(Liu et al, , 2014aMcFadden et al, 2009;Yin et al, 2011a;. The eponymous taxa of the two assemblage zones, Tianzhushania spinosa and Hocosphaeridium anozos, have not been recovered from the Lujiayuanzi section.…”

“…Ediacaran large acanthomorphic microfossils, known as Doushantuo-Pertatataka acritarchs (DPAs) (Narbonne et al, 2012;Zhou et al, 2001, have gained much attention in the past decades because of their importance in understanding Ediacaran biosphere and biostratigraphy Cohen et al, 2009;Golubkova et al, 2010;Grey, 2005;Liu et al, 2013aLiu et al, , 2014aMcFadden et al, 2009;Moczydłowska, 2015;Moczydłowska and Nagovitsin, 2012;Narbonne et al, 2012;Xiao et al, 1998Xiao et al, , 2014Xiao et al, , 2016. Currently available data from South China suggest that at least in the Yangtze Gorges area, DPAs appeared shortly after the termination of the Marinoan global glaciation , and disappeared at the horizon yielding a prominent carbon isotopic anomaly (EN3, likely equivalent to the Shuram excursion) in the middle Ediacaran Period (Liu et al, 2014a;Narbonne et al, 2012;Xiao et al, 2016), which represents one of the most pronounced negative carbon isotopic excursions in Earth history (Grotzinger et al, 2011) and has been considered as a potential chemostratigraphic tool for Ediacaran subdivision and global correlation .…”

“…Currently available data from South China suggest that at least in the Yangtze Gorges area, DPAs appeared shortly after the termination of the Marinoan global glaciation , and disappeared at the horizon yielding a prominent carbon isotopic anomaly (EN3, likely equivalent to the Shuram excursion) in the middle Ediacaran Period (Liu et al, 2014a;Narbonne et al, 2012;Xiao et al, 2016), which represents one of the most pronounced negative carbon isotopic excursions in Earth history (Grotzinger et al, 2011) and has been considered as a potential chemostratigraphic tool for Ediacaran subdivision and global correlation . However, biostratigraphic data from Russian Plate hint that DPAs may extend above the Shuram-equivalent horizon (Golubkova et al, 2015).…”

“…Phosphatized microfossils have been reported from many places on the Yangtze block, including Weng'an in central Guizhou Province Yuan and Hofmann, 1998;Zhang et al, 1998), Chadian in southern Shaanxi Province , Zhangcunping (McFadden et al, 2009, and references therein) and Baizhu (Zhou et al, 2001(Zhou et al, , 2004 in western Hubei Province, and Chaoyang in eastern Jiangxi Province (Zhou et al, 2002) ( from the Doushantuo chert nodules in the Yangtze Gorges areas of western Hubei Province (Liu et al, 2014b;Xiao, 2004b;Zhang et al, 1998;. Compared with the phosphatized assemblages that are mostly preserved in reworked clasts and restricted within specific phosphorite horizons, silicified DPAs are generally preserved in situ and thus have greater potential in Ediacaran acritarch biostratigraphy (Liu et al, 2013a(Liu et al, , 2014aMcFadden et al, 2009;. For example, in the Yangtze Gorges area, two acanthomorph assemblage zones have been recognized-the Tianzhushania spinosa assemblage zone in the lower Doushantuo Formation and the Hocosphaeridium anozos assemblage zone in the middle-upper Doushantuo Formation (Liu et al, 2013a(Liu et al, , 2014bMcFadden et al, 2009;Xiao et al, 2016;Yin et al, 2011a).…”

“…For example, in the Yangtze Gorges area, two acanthomorph assemblage zones have been recognized-the Tianzhushania spinosa assemblage zone in the lower Doushantuo Formation and the Hocosphaeridium anozos assemblage zone in the middle-upper Doushantuo Formation (Liu et al, 2013a(Liu et al, , 2014bMcFadden et al, 2009;Xiao et al, 2016;Yin et al, 2011a). The Tianzhushania spinosa assemblage zone is absent from early Ediacaran successions in many other continents such as Australia and Siberia (Grey et al, 2003;Liu et al, 2013aLiu et al, , 2014aMoczydłowska and Nagovitsin, 2012;Narbonne et al, 2012;Xiao et al, 2014). Currently available data indicate that acanthomorphs of the Hocosphaeridium anozos assemblage zone do not extend above the Shuram-equivalent negative carbon isotope excursion EN3 in South China (Liu et al, 2014a,b).…”