Silicified glendonites in the Ediacaran Doushantuo Formation and their potential paleoclimatic implications

Transcription

1 GSA Data Repository Silicified glendonites in the Ediacaran Doushantuo Formation and their potential paleoclimatic implications Zhou Wang 1,2, Jiasheng Wang 1*, Erwin Suess 3,4, Guangzhe Wang 1, Can Chen 1, Shuhai Xiao 2* 1 State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, Wuhan , P. R. China 2 Department of Geosciences, Virginia Tech, Blacksburg VA 24061, USA 3 GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel 24148, Germany 4 College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis OR 97330, USA ANALYTICAL METHODS Samples were collected at the Bailu section ( N; E) near Zhangcunping in Hubei Province of South China (Fig. DR1). Petrographic thin sections and polished slabs were prepared for petrographic observations and elemental mapping on a Hitachi TEM3000 equipped with energy disperse spectroscopy. X-ray mocr-computed tomography (micro-ct) of glendonite-bearing drill core samples was 1

2 carried out using an ultra-high-resolution subsystem of the ACTIS scanner at the University of Texas High-Resolution X-ray CT Facility. Scan data were processed using CTAn and CTVox software for three-dimensional morphologic reconstruction of glendonites. The original CT scan data are available upon request from the authors. To prepare to carbon and oxygen isotope analyses, micro-drilled rock powders ( μg) were loaded on a Kiel IV equipment and allowed to react with anhydrous H 3 PO 4 for 220 seconds. CO 2 evolved from this reaction was analyzed on a Thermo-Finnigan MAT-253 mass spectrometer at China University of Geosciences to determine the isotopic compositions of carbonate carbon and oxygen. Isotopic results are expressed in the standard δ notation as per mil ( ) deviation from VPDB (Vienna Pee Dee Belemnite). Repeatedly analyses indicate that the analytical uncertainties were better than 0.1 (1σ) for both carbon and oxygen isotope compositions. The lack of correlation between δ 13 C and δ 18 O values (Fig. DR3), as well as the consistent δ 13 C profiles of the Doushantuo Formation at different sections, suggests that δ 13 C signatures were not strongly modified by post-depositional diagenesis. 2

3 Figure DR1. Geological maps and localities. (A) The Yangtze, Cathaysia, North China, and Tarim blocks in China. Red rectangle is magnified in (B). (B) Simplified paleogeographic map of the Yangtze Block during the Ediacaran Period, with study area (i.e., Huangling anticline) marked by a blue rectangle and the Weng an section marked by a green star. Modified from Jiang et al. (2011). (C) Simplified geological map of the Huangling anticline showing the location of the Jiulongwan, Baiguoyuan, and Bailu sections. Modified from Xiao et al. (2012). 3

4 Figure DR2. Field photographs. (A) Overview of the Bailu section. The zircon U-Pb ages of 614±9 Ma and 609±5 Ma are from the Zhangcunping area (Liu et al., 2009; Schmitz, 2012; Zhou et al., 2016). (B) Close-up view of (A), showing the contact between the lower phosphorite (unit 2) and the overlying middle dolostone with light gray chert concretions (unit 3). (C I) Close-up views of glendonite-bearing horizons in (A). (C) Stellate glendonite clusters with preferred stratigraphic orientation indicating upward growth (arrows). (D) Glendonites with preferred stratigraphic orientation (red arrow), coexisting with phosphatic chert nodules (white arrow) and lenses (yellow arrow). (E) Stellate glendonite clusters (yellow circle) on bedding surface. (F) Glendonite clusters with elongated pyramidal crystal (yellow ellipse) on bedding surface. (G) Stellate glendonite cluster (yellow circle) with crystals preferentially growing upward. (H I) Stellate glendonites (red arrows) and phosphatic chert nodules (yellow arrows) in a drill core sample. x*y marks bedding plane and z marks vertical direction. Twinning angles are marked with dotted lines. 4

5 Figure DR3. Lithostratigraphy, carbonate δ 13 C chemostratigraphy, and δ 13 C carb δ 18 O carb crossplots. The zircon U-Pb ages of 614 ± 9 Ma and 609 ± 5 Ma are from the Zhangcunping area (Liu et al., 2009; Schmitz, 2012; Zhou et al., 2016). Orange line represent a five-point-average curve of the δ 13 C profile in units 3 8. See Table DR1 for data. 5

6 Table DR1. Carbonate carbon and oxygen isotope data, reported as deviation from VPDB. Samples in bold are dolomicritic matrix of glendonite-bearing specimens. Sample δ 13 C δ 18 O Height (m) Lithology SL-Z Silicified dolomicritic matrix SL-Z Silicified dolomicritic matrix SL-Z Dolostone SL-Z Dolostone SL-Z Dolostone SL-Z Dolostone SL-Z Dolostone SL-Z Phosphorite SL-Z Phosphorite SL-Z Phosphorite SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Phosphorite SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Phosphorite SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone 6

7 SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone 7

8 SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Calcareous mudstone SL-Z Argillaceous dolostone SL-Z Argillaceousdolostone SL-Z Dolostone with shale interbeds SL-Z Dolostone with shale interbeds SL-Z Dolostone with shale interbeds SL-Z Dolostone with shale interbeds SL-Z Dolostone with shale interbeds SL-Z Dolostone with shale interbeds SL-Z Dolostone with shale interbeds SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone 8

9 SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Calcareous mudstone SL-Z Argillaceousdolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z-138-B Argillaceous dolostone SL-Z Calcareous mudstone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Argillaceous dolostone SL-Z Dolostone with shale interbeds SL-Z Dolostone with shale interbeds SL-Z Dolostone with shale interbeds SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Dolostone with shale interbeds SL-Z Dolostone with shale interbeds SL-Z Massive dolostone SL-Z Dolostone with shale interbeds SL-Z Dolostone with shale interbeds SL-Z Dolostone with shale interbeds SL-Z Dolostone with shale interbeds SL-Z Dolostone with shale interbeds SL-Z Massive dolostone SL-Z Dolostone with shale interbeds SL-Z Dolostone with shale interbeds 9

10 SL-Z Dolostone with shale interbeds SL-Z Dolostone with shale interbeds SL-Z Dolostone with shale interbeds SL-Z Dolostone with shale interbeds SL-Z Dolostone with shale interbeds SL-Z Massive dolostone SL-Z Massivedolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone SL-Z Massive dolostone BL-08 Roadcut Massive dolostone BL-09 Roadcut Massive dolostone BL-11 Roadcut Massive dolostone BL-12 Roadcut Massive dolostone BL-13 Roadcut Massive dolostone BL-14 Roadcut Massive dolostone BL-16 Roadcut Massive dolostone REFERENCES CITED Jiang, G., Shi, X., Zhang, S., Wang, Y., and Xiao, S., 2011, Stratigraphy and paleogeography of the Ediacaran Doushantuo Formation (ca Ma) in South China: Gondwana Research, v. 19, p , doi: /j.gr

11 Liu, P., Yin, C., Gao, L., Tang, F., and Chen, S., 2009, New material of microfossils from the Ediacaran Doushantuo Formation in the Zhangcunping area, Yichang, Hubei Province and its zircon SHRIMP U-Pb age: Chinese Science Bulletin, v. 54, p , doi: /s Schmitz, M.D., 2012, Appendix 2 Radiometric ages used in GTS2012, in Gradstein, F., Ogg, J., Schmitz, M. D., and Ogg, G., eds., The Geologic Time Scale 2012: Boston, Elsevier, p Xiao, S., McFadden, K.A., Peek, S., Kaufman, A.J., Zhou, C., Jiang, G., and Hu, J., 2012, Integrated chemostratigraphy of the Doushantuo Formation at the northern Xiaofenghe section (Yangtze Gorges, South China) and its implication for Ediacaran stratigraphic correlation and ocean redox models: Precambrian Research, v , p Zhou, C., Li, X.-H., Xiao, S., Lan, Z., Ouyang, Q., Guan, C., and Chen, Z., 2016, A new SIMS zircon U-Pb date from the Ediacaran Doushantuo Formation: age constraint on the Weng'an biota: Geological Magazine, v. in press. 11