scholarly journals Sedimentology and chemostratigraphy of the terminal Ediacaran Dengying Formation at the Gaojiashan section, South China

2019 ◽  
Vol 156 (11) ◽  
pp. 1924-1948 ◽  
Author(s):  
Huan Cui ◽  
Shuhai Xiao ◽  
Yaoping Cai ◽  
Sara Peek ◽  
Rebecca E. Plummer ◽  
...  
Keyword(s):  
South China ◽  
Temporal Variations ◽  
Shaanxi Province ◽  
Seawater Chemistry ◽  
Evolutionary Innovation ◽  
Aragonite Crystal ◽  
Dengying Formation ◽  
Peritidal Facies ◽  
Bilaterian Animal ◽  
High Alkalinity

AbstractThe terminal Ediacaran Dengying Formation (c. 551.1–538.8 Ma) in South China is one of two successions where Ediacara-type macrofossils are preserved in carbonate facies along with skeletal fossils and bilaterian animal traces. Given the remarkable thickness of carbonate-bearing strata deposited in less than 12.3 million years, the Dengying Formation holds the potential for construction of a relatively continuous chemostratigraphic profile for the terminal Ediacaran Period. In this study, a detailed sedimentological and chemostratigraphic (δ13Ccarb, δ18Ocarb, δ13Corg, δ34Spyrite, and 87Sr/86Sr) investigation was conducted on the Dengying Formation at the Gaojiashan section, Ningqiang County of southern Shaanxi Province, South China. Sedimentological results reveal an overall shallow-marine depositional environment. Carbonate breccia, void-filling botryoidal precipitates and aragonite crystal fans are common in the Algal Dolomite Member of the Dengying Formation, suggesting that peritidal facies were repeatedly karstified. The timing of karstification was likely early, probably soon after the deposition of the dolomite sediments. The presence of authigenic aragonite cements suggests high alkalinity in the terminal Ediacaran ocean. Geochemical analysis of micro-drilled samples shows that distinct compositions are registered in different carbonate phases, which should be considered when constructing chemostratigraphic profiles representative of true temporal variations in seawater chemistry. Integrated chemostratigraphic data suggest enhanced burial of organic carbon and pyrite, and the occurrence of extensive marine anoxia (at least in the Gaojiashan Member). Rapid basinal subsidence and carbonate accumulation during a time of elevated seawater alkalinity and increased rates of pyrite burial may have facilitated the evolutionary innovation of early biomineralizing metazoans.

scholarly journals Chemo- and biostratigraphy of the Gaojiashan section (northern Yangtze platform, South China): a new Pc-C boundary section

Fossil Record ◽  
2015 ◽  
Vol 18 (2) ◽  
pp. 105-117 ◽  
Author(s):  
A. Gamper ◽  
U. Struck ◽  
F. Ohnemueller ◽  
C. Heubeck ◽  
S. Hohl
Keyword(s):  
Shallow Water ◽  
South China ◽  
Shaanxi Province ◽  
Cambrian Explosion ◽  
Local Perturbation ◽  
Data Set ◽  
Carbonate Carbon ◽  
Dengying Formation ◽  
Isotope Record ◽  
Ediacaran Fauna

Abstract. The widespread, terminal Ediacaran Dengying Formation (~ 551–~ 542 Ma) of South China hosts one of the most prominent negative carbonate carbon isotope excursions in Earth's history and thus bears on the correlation of the Precambrian–Cambrian boundary worldwide. The dominantly carbonate strata of the Dengying Formation are largely studied for their unique preservation of its terminal Ediacaran fauna but their geochemical context is poorly known. This study presents the first high-resolution stable isotope record (δ13C, δ18O) of calcareous siliciclastic shallow-water deposits of the Gaojiashan section (Shaanxi Province). The section includes (in ascending order) the Algal Dolomite Member, the Gaojiashan Member and the Beiwan Member of the Dengying Formation. Our data record a major δ13Ccarb negative excursion to −6 ‰ in the uppermost Gaojiashan Member which is comparable in shape and magnitude to the global Precambrian–Cambrian boundary negative δ13C excursion. Our data set is consistent with a "shallow-water anoxia" scenario which is thought to contribute to the "Cambrian explosion". The stratigraphic occurrence of Cloudina and a large negative δ13C excursion suggest that the Precambrian–Cambrian boundary is located near the top of the Gaojiashan Member and, consequently, that overlying carbonates and dolomites of the Beiwan Member are of earliest Cambrian age. Thus the Gaojiashan section may represent a new shallow-water section spanning the Precambrian–Cambrian boundary. Although bio- and chemostratigraphic data support this novel interpretation, we cannot exclude the possibility that the key excursions may represent a local perturbation indicating a restricted-basin environment.

Discussion of ‘First finds of problematic Ediacaran fossil Gaojiashania in Siberia and its origin’

2010 ◽  
Vol 148 (2) ◽  
pp. 329-333 ◽  
Author(s):  
Yaoping Cai ◽  
Hong Hua ◽  
Andrey Yu. Zhuravlev ◽  
José Antonio Gámez Vintaned ◽  
Andrey Yu. Ivantsov
Keyword(s):  
South China ◽  
Yunnan Province ◽  
North China ◽  
Guizhou Province ◽  
Shaanxi Province ◽  
Qinghai Province ◽  
Autonomous Region ◽  
Dengying Formation ◽  
Ningxia Hui Autonomous Region ◽  
Southern Shaanxi

Y. Cai & H. Hua comment: Zhuravlev, Gámez Vintaned & Ivantsov (2009) reported the problematic Ediacaran fossil Gaojiashania annulucosta in Siberia and they considered that this is the first find of Gaojiashania outside China, since Gaojiashania had previously only been reported from the Gaojiashan Member of the middle Dengying Formation in the Ningqiang area, southern Shaanxi Province, South China. However, we believe that the so-called Siberian Gaojiashania was mis-identified, and what was described as Gaojiashania annulucosta by Zhuravlev, Gámez Vintaned & Ivantsov (2009) is more appropriately ascribed to Shaanxilithes ningqiangensis, another problematic Ediacaran fossil that has also been known from the Gaojiashan Member in Shaanxi Province of South China (Chen, Chen & Lao, 1975; Xing et al. 1984), as well as the stratigraphically equivalent Taozichong Formation in Guizhou Province (Hua, Chen & Zhang, 2004) and the Jiucheng Member (Dengying Formation) in Yunnan Province of South China (Zhu & Zhang, 2005), the Zhoujieshan Formation in Qinghai Province (Shen et al. 2007), and the Zhengmuguan Formation in Ningxia Hui Autonomous Region of North China (Shen et al. 2007).

Characteristics and temporal variations of near-bottom currents near the Dongsha Island in the northern South China Sea

2019 ◽  
Vol 38 (4) ◽  
pp. 80-89
Author(s):  
Dawei Li ◽  
Zexun Wei ◽  
Yonggang Wang ◽  
Shujiang Li ◽  
Tengfei Xu ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
Northern South China Sea ◽  
Temporal Variations ◽  
Bottom Currents ◽  
China Sea

ACloudina-like fossil with evidence of asexual reproduction from the lowest Cambrian, South China

2017 ◽  
Vol 154 (6) ◽  
pp. 1294-1305 ◽  
Author(s):  
JIAN HAN ◽  
YAOPING CAI ◽  
JAMES D. SCHIFFBAUER ◽  
HONG HUA ◽  
XING WANG ◽  
...  
Keyword(s):  
Asexual Reproduction ◽  
South China ◽  
Fossil Record ◽  
Tube Wall ◽  
Shaanxi Province ◽  
Branching Structures ◽  
Southern Shaanxi ◽  
Wall Construction ◽  
Evolutionary Continuity ◽  
Evolutionary Fate

AbstractThe earliest fossil record of animal biomineralization occurs in the latest Ediacaran Period (c. 550 Ma).CloudinaandSinotubulitesare two important tubular taxa among these earliest skeletal fossils. The evolutionary fate ofCloudina-type fossils across the Ediacaran–Cambrian transition, however, remains poorly understood. Here we report a multi-layered tubular microfossilFeiyanella manicagen. et sp. nov. from a phosphorite interval of the lowest Cambrian Kuanchuanpu Formation, southern Shaanxi Province, South China. This newly discovered fossil is a conical tube with a ‘funnel-in-funnel’ construction, showing profound morphological similarities toCloudinaandConotubus. On the other hand, the outer few layers, and particularly the outermost layer, ofFeiyanellatubes are regularly to irregularly corrugated, a feature strikingly similar to the variably folded/wrinkled tube walls ofSinotubulites. TheFeiyanellatubes additionally exhibit two orders of dichotomous branching, similar to branching structures reported occasionally inCloudinaand possibly indicative of asexual reproduction. Owing to broad similarities in tube morphology, tube wall construction and features presumably indicative of asexual reproduction,Cloudina, Conotubus, Sinotubulitesand the here describedFeiyanellamay thus constitute a monophyletic group traversing the Ediacaran–Cambrian boundary. The tube construction and palaeoecological strategy ofFeiyanellaputatively indicate evolutionary continuity in morphology and palaeoecology of benthic metazoan communities across the Ediacaran–Cambrian transition.

Yangtziramulus zhanginew genus and species, a carbonate-hosted macrofossil from the Ediacaran Dengying Formation in the Yangtze Gorges area, South China

2009 ◽  
Vol 83 (4) ◽  
pp. 575-587 ◽  
Author(s):  
Bing Shen ◽  
Shuhai Xiao ◽  
Chuanming Zhou ◽  
Xunlai Yuan
Keyword(s):  
South China ◽  
Life Forms ◽  
Black Shales ◽  
Benthic Organism ◽  
New Genus And Species ◽  
Additional Material ◽  
Fine Grained ◽  
Dengying Formation ◽  
Ecological Complexity ◽  
Siliciclastic Rocks

Very few macroscopic soft-bodied Ediacaran fossils are hosted in carbonates; most of them are preserved as casts and molds in siliciclastic rocks or as carbonaceous compressions in black shales. This taphonomic bias limits our capability to fully understand the diversity and paleoecology of macroscopic Ediacaran life forms. Previous reports have shown that the upper Ediacaran Dengying Formation in South China and Khatyspyt Formation in Siberia contain macroscopic soft-bodied fossils preserved in bituminous limestone; thus they have the potential to expand our knowledge about the Ediacaran biosphere. However, the biogenecity of the Dengying fossils described in Xiao et al. (2005) has been questioned. In this paper, we provide additional material and arguments in support of the biogenecity of these fossils, which are formally described asYangtziramulus zhanginew genus and species.Yangtziramulus zhangiconsists of a branching system with a central axis and tubes on both sides. The tubes appear to be distally open.Yangtziramulus zhangiis interpreted as a flat-lying benthic organism, as indicated by the mutual avoidance relationship among densely clustered individuals.Yangtziramulus zhangifinds few morphological analogs among modern organisms, but it is broadly similar to several macroscopic Ediacaran forms. Its morphological and ecological complexity is inconsistent with a microbial interpretation.Yangtziramulus zhangiis typically covered by a thin veneer of fine-grained silts, suggesting that it was probably smothered and killed by an episodic flux of silty sediments (event deposits). Its tube walls are replaced with early diagenetic calcspars.

A new modular palaeopascichnid fossil Curviacus ediacaranus new genus and species from the Ediacaran Dengying Formation in the Yangtze Gorges area of South China

2017 ◽  
Vol 154 (6) ◽  
pp. 1257-1268 ◽  
Author(s):  
BING SHEN ◽  
SHUHAI XIAO ◽  
CHUANMING ZHOU ◽  
LIN DONG ◽  
JIEQIONG CHANG ◽  
...  
Keyword(s):  
South China ◽  
New Genus ◽  
Three Dimensional ◽  
Internal Anatomy ◽  
Carbonate Facies ◽  
New Genus And Species ◽  
Modular Organisms ◽  
Dengying Formation ◽  
Body Construction ◽  
Phylogenetic Affinities

AbstractNon-biomineralizing Ediacaran macrofossils are rare in carbonate facies, but they offer valuable information about their three-dimensional internal anatomy and can broaden our view about their taphonomy and palaeoecology. In this study, we report a new Ediacaran fossil, Curviacus ediacaranus new genus and species, from bituminous limestone of the Shibantan Member of the Dengying Formation in the Yangtze Gorges area of South China. Curviacus is reconstructed as a benthic modular organism consisting of serially arranged and crescent-shaped chambers. The chambers are confined by chamber walls that are replicated by calcispars, and are filled by micritic sediments. Such modular body construction is broadly similar to the co-occurring Yangtziramulus zhangii and other Ediacaran modular fossils, such as Palaeopascichnus. The preservation style of Curviacus is similar to Yangtziramulus, although the phylogenetic affinities of both genera remain unresolved. The new fossil adds to the diversity of Ediacaran modular organisms.

scholarly journals The Ediacaran frondose fossil Arborea from the Shibantan limestone of South China

2020 ◽  
Vol 94 (6) ◽  
pp. 1034-1050 ◽  
Author(s):  
Xiaopeng Wang ◽  
Ke Pang ◽  
Zhe Chen ◽  
Bin Wan ◽  
Shuhai Xiao ◽  
...  
Keyword(s):  
New Species ◽  
South China ◽  
Type Species ◽  
Microbial Mats ◽  
Width Ratio ◽  
General Morphology ◽  
Dengying Formation ◽  
Length Width

AbstractBituminous limestone of the Ediacaran Shibantan Member of the Dengying Formation (551–539 Ma) in the Yangtze Gorges area contains a rare carbonate-hosted Ediacara-type macrofossil assemblage. This assemblage is dominated by the tubular fossil Wutubus Chen et al., 2014 and discoidal fossils, e.g., Hiemalora Fedonkin, 1982 and Aspidella Billings, 1872, but frondose organisms such as Charnia Ford, 1958, Rangea Gürich, 1929, and Arborea Glaessner and Wade, 1966 are also present. Herein, we report four species of Arborea from the Shibantan assemblage, including the type species Arborea arborea (Glaessner in Glaessner and Daily, 1959) Glaessner and Wade, 1966, Arborea denticulata new species, and two unnamed species, Arborea sp. A and Arborea sp. B. Arborea arborea is the most abundant frond in the Shibantan assemblage. Arborea denticulata n. sp. resembles Arborea arborea in general morphology but differs in its fewer primary branches and lower length/width ratio of primary branches. Arborea sp. A and Arborea sp. B are fronds with a Hiemalora-type basal attachment. Sealing by microbial mats and authigenic cementation may have played an important role in the preservation of Arborea in the Shibantan assemblage. The Shibantan material of Arborea extends the stratigraphic, ecological, and taphonomic ranges of this genus.UUID: http://zoobank.org/554f21da-5f09-4891-9deb-cbc00c41e5f1

Sign in / Sign up

Export Citation Format

Share Document