This article was downloaded by: [University of Tokyo] On: 17 November 2014, At: 16:21 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK Australian Journal of Earth Sciences: An International Geoscience Journal of the Geological Society of Australia Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/taje20 The correlation between macroscopic algae and metazoans in the Ediacaran: a case study on the Wenghui biota in northeastern Guizhou, South China Y. Wanga, Y. Wangb, W. Duc & X. Wangb a School of Resources and Environments, Guizhou University, Guiyang 550025, PR China b School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, PR China c Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153–8902, Japan Published online: 19 Sep 2014. To cite this article: Y. Wang, Y. Wang, W. Du & X. Wang (2014) The correlation between macroscopic algae and metazoans in the Ediacaran: a case study on the Wenghui biota in northeastern Guizhou, South China, Australian Journal of Earth Sciences: An International Geoscience Journal of the Geological Society of Australia, 61:7, 967-977, DOI: 10.1080/08120099.2014.956231 To link to this article: http://dx.doi.org/10.1080/08120099.2014.956231 PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. 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Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and- conditions TAJE_A_956231.3d (TAJE) (210£274mm) 01-10-2014 11:32 Australian Journal of Earth Sciences (2014) 61, 967À977, http://dx.doi.org/10.1080/08120099.2014.956231 The correlation between macroscopic algae and metazoans in the Ediacaran: a case study on the Wenghui biota in northeastern Guizhou, South China Y. WANG1*, Y. WANG2,W.DU3 AND X. WANG2 1School of Resources and Environments, Guizhou University, Guiyang 550025, PR China. 2School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, PR China. 3Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153À8902, Japan. After the Marinoan glaciation, macroscopic organisms thrived in the Yangtze Sea, South China, during the Ediacaran period. The Wenghui biota, which is found from the upper Doushantuo Formation black shales (>551 Ma) in northeastern Guizhou, South China, includes macroscopic algae, metazoans and ichnofossils. Most macroalgae in the Wenghui biota bear a holdfast to secure them onto seafloor and have a thallus of various lengths extending into the water column. This biota can be divided into Globusphyton, SectoralgaÀLongifuniculum, Cucullus, Beltanelliformis and BaculiphycaÀGesinella assemblages. A fossil-barren interval containing a thin layer of feldspathic sandstone separates the macroscopic organisms into two distinct parts. From the Globusphyton assemblage through the SectoralgaÀLongifuniculum assemblage to the Cucullus assemblage, metazoans show a positive correlation with the abundance and diversity of branching macroalgae at both metre and millimetre scales. Nevertheless, both Beltanelliformis and BaculiphycaÀGesinella assemblages, in which the number and diversity of macroscopic algae and metazoans, especially the shorter branching macroalgae, are obviously decreasing or even lacking, might be related to a special environment and a fragile ecosystem. In addition, the ratios of Ni/Co, U/Th and V/(V C Ni) display zigzagged profiles at millimetre scales indicating frequent redox fluctuations. Variations in macrofossils and trace elements at both millimetre and metre scales indicate that the oxygen content in the northeast Guizhou Sea fluctuated frequently during the middleÀlate Ediacaran period and the Wenghui biota possibly lived in the redox buffering zone. Moreover, the abundance and diversity of macroalgae, especially the branching macroalgae, could have significantly influenced the redox conditions in water column. The increase in oxygen may have improved the environment for the growth and reproduction of macroalgae and metazoans. KEY WORDS: metazoan, macroalga, Wenghui biota, Ediacaran, northeastern Guizhou, South China. INTRODUCTION in the Yangtze Sea during the Ediacaran period (Figure 1). Although there are still debates on the macro- After the Marinoan global glaciation (or the Nantuo gla- organismal classification, many researchers have ciation in China), global warming during the Ediacaran À Downloaded by [University of Tokyo] at 16:21 17 November 2014 reported that metazoans had emerged in the middle late may be an important condition for the development of Ediacaran period (Chen et al. 1994b, 2000; Ding et al. 1996; macroscopic organisms. In the Yangtze Block, South Xiao et al. 2002; Wang et al. 2007b, 2008, 2009, 2010, 2011; China, abundant macroscopic organisms were reported Wang & Wang 2008, 2011; Tang et al. 2008, 2011; Zhu et al. in Chinese Ediacaran macrobiotas, including the Lan- 2008). tian biota from the lower Lantian Formation in south- The carbonaceous compressions from the upper ern Anhui (e.g. Chen et al. 1994a; Tang et al. 1997; Yuan Doushantuo Formation in northeastern Guizhou were et al. 2011), the Miaohe biota from the upper Doushantuo reported first by Zhao et al. (2005) and named as the Wen- Formation in western Hubei (e.g. Zhu & Chen 1984; Chen ghui biota by Wang et al. (2007a). Wang et al. (2007a, b, & Xiao 1991, 1992; Chen et al. 1994b; Ding et al. 1996; Xiao 2008), Wang & Wang (2008, 2011), Tang et al. (2008) and et al. 2002) and the Wenghui biota from the upper Doush- Zhu et al. (2008) systemically described the macroscopic antuo Formation in northeastern Guizhou (e.g. Wang algae and metazoans in this biota. Based on fossil collec- et al. 2005, 2007a, 2008, 2009, 2011; Tang et al. 2009). These tion of the Wenghui biota at metre scales, Wang et al. Ediacaran macrobiotas, which are dominated by macro- (2011) reported the temporal sequences of assemblages. scopic algae, imply that macroscopic organisms thrived This paper discusses the relationship between *Corresponding author: [email protected] Ó 2014 Geological Society of Australia TAJE_A_956231.3d (TAJE) (210£274mm) 01-10-2014 11:32 968 Y. Wang et al. Figure 1 Distribution of the Chinese Eidacaran macrobiotas in the Yangtze Block, South China. (a) Tectonic outline showing the location of Yangtze Block in China; and (b) paleogeographic reconstruction of the Yangtze Block during the early Edia- caran period (modified from Jiang et al. 2011). macroscopic algae and metazoans in the Wenghui biota Macroscopic algae and metazoans at millimetre to metre scales. The abundance and diver- The macroscopic algae are the dominant fossils in the sity of macroscopic algae can influence the depositional Wenghui biota and can be morphologically divided into redox conditions, which in turn may affect the growth the (thallus- and filament-) branching macroalgae, the and reproduction of metazoans. unbranching macroalgae, the coin-shaped macroalgae and the macroalgal holdfasts. The thallus-branching THE WENGHUI BIOTA macroalgae include Anomalophyton zhangzhongyini Chen et al. 1994b (Figure 3a, b), Doushantuophyton line- The Wenghui biota includes macroscopic algae, metazo- area Chen in Chen & Xiao 1991 (Figure 3c), D. rigidulum ans and ichnofossils, and is found in the upper Doushan- Chen in Chen et al. 1994a (Figure 3d), Enteromorphites tuo Formation black shales in Wenghui Village, siniansis Zhu & Chen 1984 (Figure 3e), Jiangkouphyton Jiangkou County, northeastern Guizhou Province, guizhouensis Wang et al. 2007a (Figure 3f, g), Miaohephy- southern China (265000700N, 1090102000E). In the Wenghui ton bifurcatum Chen in Chen & Xiao 1991 (Figure 3h), section, the Doushantuo Formation is about 71 m thick, Wenghuiphyton erecta Wang et al. 2007a (Figure 3i, j), overlying the Nantuo Formation diamictite and underly- Zhongbaodaophyton crassa Chen et al. 1994b (Figure ing the bedded cherts of the Liuchapo Formation. It com- 3k, l) and Z. robustus Wang et al. 2007a (Figure 3m). The prises dolostones in the lower part (cap carbonate), filament-branching macroalgae include Globusphyton dolostones and shaly dolostones with black shales in the lineare Wang et al. 2007a (Figure 3n, o), Longifuniculum middle part, and black shales with abundant carbona- dissolutum Steiner et al. 1992 (Figure 3p, q), Sectoralga Downloaded