Volcanism in South China during the Late Permian and its relationship to marine ecosystem and environmental changes

AbstractPermian–Triassic boundary (PTB) volcanic ash beds are widely distributed in South China and were proposed to have a connection with the PTB mass extinction and the assemblage of Pangea. However, their source and tectonic affinity have been highly debated. We present zircon U–Pb ages, trace-element and Hf isotopic data on three new-found PTB volcanic ash beds in the western Hubei area, South China. Laser ablation inductively coupled plasma mass spectrometry U–Pb dating of zircons yields ages of 252.2 ± 3.6 Ma, 251.6 ± 4.9 Ma and 250.4 ± 2.4 Ma for these three volcanic ash beds. Zircons of age c. 240–270 Ma zircons have negative εHf(t) values (–18.17 to –3.91) and Mesoproterozoic–Palaeoproterozoic two-stage Hf model ages (THf2) (1.33–2.23 Ga). Integrated with other PTB ash beds in South China, zircon trace-element signatures and Hf isotopes indicate that they were likely sourced from intermediate to felsic volcanic centres along the Simao–Indochina convergent continental margin. The Qinling convergent continental margin might be another possible source but needs further investigation. Our data support the model that strong convergent margin volcanism took place around South China during late Permian – Early Triassic time, especially in the Simao–Indochina active continental margin and possibly the Qinling active continental margin. These volcanisms overlap temporally with the PTB biocrisis triggered by the Siberian Large Igneous Province. In addition, our data argue that the South China Craton and the Simao–Indochina block had not been amalgamated with the main body of Pangea by late Permian – Early Triassic time.

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Modern lake sedimentary record of PAHs and OCPs in a typical karst wetland, south China: Response to human activities and environmental changes

Environmental Pollution ◽

10.1016/j.envpol.2021.118173 ◽

2021 ◽

pp. 118173

Author(s):

Cheng Cheng ◽

Tianpeng Hu ◽

Weijie Liu ◽

Yao Mao ◽

Mingming Shi ◽

...

Keyword(s):

South China ◽

Human Activities ◽

Environmental Changes ◽

Sedimentary Record

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A three-dimensional view on biodiversity changes: spatial, temporal, and functional perspectives on fish communities in the Baltic Sea

ICES Journal of Marine Science ◽

10.1093/icesjms/fsy027 ◽

2018 ◽

Vol 75 (7) ◽

pp. 2463-2475 ◽

Cited By ~ 3

Author(s):

Romain Frelat ◽

Alessandro Orio ◽

Michele Casini ◽

Andreas Lehmann ◽

Bastien Mérigot ◽

...

Keyword(s):

Baltic Sea ◽

Environmental Conditions ◽

Environmental Changes ◽

Temporal Dynamics ◽

Marine Ecosystem ◽

Fish Communities ◽

The Baltic Sea ◽

Functional Richness ◽

Holistic Understanding ◽

The Baltic

Abstract Fisheries and marine ecosystem-based management requires a holistic understanding of the dynamics of fish communities and their responses to changes in environmental conditions. Environmental conditions can simultaneously shape the spatial distribution and the temporal dynamics of a population, which together can trigger changes in the functional structure of communities. Here, we developed a comprehensive framework based on complementary multivariate statistical methodologies to simultaneously investigate the effects of environmental conditions on the spatial, temporal and functional dynamics of species assemblages. The framework is tested using survey data collected during more than 4000 fisheries hauls over the Baltic Sea between 2001 and 2016. The approach revealed the Baltic fish community to be structured into three sub-assemblages along a strong and temporally stable salinity gradient decreasing from West to the East. Additionally, we highlight a mismatch between species and functional richness associated with a lower functional redundancy in the Baltic Proper compared with other sub-areas, suggesting an ecosystem more susceptible to external pressures. Based on a large dataset of community data analysed in an innovative and comprehensive way, we could disentangle the effects of environmental changes on the structure of biotic communities—key information for the management and conservation of ecosystems.

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Influence of environmental changes on phytoplankton pattern in Daya Bay, South China Sea

Revista de biología marina y oceanografía ◽

10.4067/s0718-19572014000200011 ◽

2014 ◽

Vol 49 (2) ◽

pp. 323-337 ◽

Cited By ~ 4

Author(s):

Wu Mei-Lin ◽

Wang You-Shao ◽

Wang Yu-Tu ◽

Sun Fu-Lin ◽

Sun Cui-Ci ◽

...

Keyword(s):

South China Sea ◽

South China ◽

Environmental Changes ◽

Daya Bay ◽

China Sea

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Middle Permian (Roadian) gastropods from the Khao Khad Formation, Central Thailand: Implications for palaeogeography of the Indochina Terrane

Zootaxa ◽

10.11646/zootaxa.4766.1.1 ◽

2020 ◽

Vol 4766 (1) ◽

pp. 1-47 ◽

Cited By ~ 1

Author(s):

CHATCHALERM KETWETSURIYA ◽

BARAN KARAPUNAR ◽

THASINEE CHAROENTITIRAT ◽

ALEXANDER NÜTZEL

Keyword(s):

New Species ◽

Shallow Water ◽

South China ◽

New Genus ◽

Middle Permian ◽

Late Permian ◽

Gastropod Species ◽

Late Palaeozoic ◽

Central Thailand

A new Permian gastropod assemblage from the Roadian (Middle Permian) Khao Khad Formation, Saraburi Group (Lopburi Province, Central Thailand) which is part of the Indochina Terrane, has yielded one of the most diverse Permian gastropod faunas known from Thailand. A total of 44 gastropod species belonging to 30 genera are described herein, including thirteen new species and one new genus. The new genus is Altotomaria. The new species are Bellerophon erawanensis, Biarmeaspira mazaevi, Apachella thailandensis, Gosseletina microstriata, Worthenia humiligrada, Altotomaria reticulata, Yunnania inflata, Trachydomia suwanneeae, Trachyspira eleganta, Heterosubulites longusapertura, Platyzona gradata, Trypanocochlea lopburiensis and Streptacis? khaokhadensis. Most of the species in the studied assemblage represent vetigastropods (35.6%) and caenogastropods (26.7%) and most of the species belong to Late Palaeozoic cosmopolitan genera. The studied faunas come from shallow water carbonates that are rich in fusulinids, followed by gastropods, ostracods, bivalves and brachiopods. The gastropod assemblage from the Khao Khad Formation shares no species with the gastropod assemblages from other Permian formations in Thailand, the Tak Fa Limestone and the Ratburi Limestone. However, it is similar to the Late Permian gastropod faunas from South China of the Palaeo-Tethys, therefore it suggests that the Indochina Terrane was not located far from South China.

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On the consistency of MODIS chlorophyll $a$ products in the northern South China Sea

Biogeosciences ◽

10.5194/bg-11-269-2014 ◽

2014 ◽

Vol 11 (2) ◽

pp. 269-280 ◽

Cited By ~ 22

Author(s):

S. L. Shang ◽

Q. Dong ◽

C. M. Hu ◽

G. Lin ◽

Y. H. Li ◽

...

Keyword(s):

South China Sea ◽

Chlorophyll A ◽

South China ◽

Environmental Changes ◽

Northern South China Sea ◽

Optical Data ◽

Coastal Zones ◽

Data Set ◽

Study Region ◽

China Sea

Abstract. Chlorophyll a (Chl) concentrations derived from satellite measurements have been used in oceanographic research, for example to interpret eco-responses to environmental changes on global and regional scales. However, it is unclear how existing Chl products compare with each other in terms of accuracy and consistency in revealing temporal and spatial patterns, especially in the optically complex marginal seas. In this study, we examined three MODIS (Moderate Resolution Imaging Spectroradiometer) Chl data products that have been made available to the community by the US National Aeronautics and Space Administration (NASA) using community-accepted algorithms and default parameterization. These included the products derived from the OC3M (ocean chlorophyll three-band algorithm for MODIS), GSM (Garver–Siegel–Maritorena model) and GIOP (generalized inherent optical properties) algorithms. We compared their temporal variations and spatial distributions in the northern South China Sea. We found that the three products appeared to capture general features such as unique winter peaks at the Southeast Asian Time-series Study station (SEATS, 18° N, 116° E) and the Pearl River plume associated blooms in summer. Their absolute magnitudes, however, may be questionable in the coastal zones. Additional error statistics using field measured Chl as the truth demonstrated that the three MODIS Chl products may contain high degree of uncertainties in the study region. Root mean square error (RMSE) of the products from OC3M and GSM (on a log scale) was about 0.4 and average percentage error (ε) was ~ 115% (Chl between 0.05–10.41 mg m−3, n = 114). GIOP with default parameterization led to higher errors (ε = 329%). An attempt to tune the algorithms based on a local coastal-water bio-optical data set led to reduced errors for Chl retrievals, indicating the importance of local tuning of globally-optimized algorithms. Overall, this study points to the need of continuous improvements for algorithm development and parameterization for the coastal zones of the study region, where quantitative interpretation of the current Chl products requires extra caution.

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Are Late Permian carbon isotope excursions of local or of global significance?

Geological Society of America Bulletin ◽

10.1130/b31996.1 ◽

2019 ◽

Vol 132 (3-4) ◽

pp. 521-544 ◽

Cited By ~ 5

Author(s):

Borhan Bagherpour ◽

Hugo Bucher ◽

Torsten Vennemann ◽

Elke Schneebeli-Hermann ◽

Dong-xun Yuan ◽

...

Keyword(s):

Carbon Isotope ◽

South China ◽

Sea Water ◽

Equatorial Position ◽

Late Permian ◽

Terrestrial Organic Matter ◽

Triassic Boundary ◽

Atmospheric Propagation ◽

Isotope Record ◽

Permian Triassic Boundary

Abstract We present a new, biostratigraphically calibrated organic and inorganic C-isotope record spanning the basal Late Permian to earliest Triassic from southern Guizhou (Nanpanjiang basin, South China). After fluctuations of a likely diagenetic overprint are removed, three negative carbon isotope excursions (CIEs) persist. These include a short-lived CIE during the early Wuchiapingian, a protracted CIE ending shortly after the Wuchiapingian–Changhsingian Boundary, and a third CIE straddling the Permian–Triassic boundary. Comparison of our new C-isotope record with others from the same basin suggests that influences of local bathymetry and of the amount of buried terrestrial organic matter are of importance. Comparison with other coeval time series outside of South China also highlights that only the negative CIE at the Permian–Triassic boundary is a global signal. These differences can be explained by the different volumes of erupted basalts between the Late Permian Emeishan and the younger Siberian large igneous provinces and their distinct eruptive modalities. Emeishan volcanism was largely submarine, implying that sea water was an efficient buffer against atmospheric propagation of volatiles. The equatorial position of Emeishan was also an additional obstacle for volatiles to reach the stratosphere and benefit from an efficient global distribution. Consequently, the local significance of these CIEs calls into question global correlations based on C-isotope chemostratigraphy during the Late Permian. The timing of the Late Permian Chinese CIEs is also not reflected in changes in species diversity or ecology, unlike the sudden and global Permian–Triassic boundary crisis and subsequent Early Triassic upheavals.

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