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The Permian–Triassic boundary (PTB) volcanic tuffs are widely distributed in the East Palaeo‐Tethys region, but their age and origin have been controversial. The Permian–Triassic deep‐water sediments in the northeastern margin of South China are favourable research objects, and we report new results from the PTB deep basin sediments in the Susong area, Anhui Province, in this paper. Two volcanic tuffs are found in the Zuoshan PTB in the Zuoshan section, and Laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) U–Pb zircon dating indicates that the upper and lower tuffs are 251.3 ± 1.7 Ma and 252.3 ± 2.1 Ma, respectively. The PTB age is 251.6 Ma according to a numerical interpolation method of the average deposition rate of the PTB. Fusulinids and non‐fusulinid foraminifers in the limestone overlying the lower tuff define the rock as end‐Permian. Zircon trace elements show that both tuffs are sourced from felsic volcanism in continental arc background, and their source magmas were derived from the continental crust. Zircons of PTB age from the upper tuff on the bottom of the Triassic have negative εHf(t) value from −8.02 to −3.75, and the Palaeo‐Mesoproterozoic two‐stage model ages of 1502–1780 Ma, showing that their source rocks were only derived from the remelting of the Palaeo‐Mesoproterozoic continental crust. The zircons from the lower tuff on the top of the Permian show two types, including negative εHf(t) values from −6.48 to −1.25 and Palaeo‐Mesoproterozoic two‐stage model ages of 1350–1679 Ma, and positive εHf(t) values from +3.98 to +10.15, and Neoproterozoic two‐stage model ages of 629–1023 Ma, indicating that their sources were derived from the reworking of the Palaeo‐Mesoproterozoic continental crust and early Neoproterozoic depleted mantle joined in juvenile crust growth in the northern margin of the South China Block at the beginning of the collision between the South China and North China blocks. The initial collision started no later than 252.3 Ma and developed significantly from east to west. [ABSTRACT FROM AUTHOR]

As one of the pioneer palaeontologists, Professor Zhuoting Liao has contributed his lifetime to promoting palaeontological and stratigraphical research in China for 60 years, and he passed away in the field excursion in South China on June 20, 2020. In his palaeontological career, Liao has worked on Late Palaeozoic to Mesozoic palaeontology and stratigraphy of almost all regions across China, and his interests have also extended to the Permian–Triassic (P‐Tr) boundary and mass extinction. He has worked on palaeontology, palaeobiogeography, biostratigraphy, tectonostratigraphy, and their implications in mineral and oil‐gas industries. Liao has established 22 new genera and 172 new species of brachiopods, and, together with his colleagues, proposed 11 new genera and 25 new species of echinoderms. He dedicated his lifetime to work on Late Palaeozoic palaeontology and stratigraphy of the previously remote and tectonically complex Xinjiang and adjacent regions, north‐west China, and established integrated stratigraphical frameworks for the Carboniferous to Permian strata, providing fundamental basis for mineral and hydrocarbon exploration in the poorly understood Central Asian terranes. In addition, he has mentored many young palaeontologists and stratigraphers in various ways. This volume assembles 30 papers addressing the Late Palaeozoic to Mesozoic palaeontology and stratigraphy of China and adjacent regions, which pays tribute to the achievement of Professor Zhuoting Liao. [ABSTRACT FROM AUTHOR]

This paper reports in situ U–Pb ages and Hf isotopic data on detrital zircons from Palaeozoic strata in central‐eastern Jilin Province, NE China, with the aim of constraining the timing of final closure of the Paleo‐Asian Ocean and the tectonic evolution of the eastern segment of the Central Asian Orogenic Belt (CAOB). Zircons from Middle to Late Permian Fanjiatun and Yangjiagou formations in central Jilin Province are characterized by four major groups of age populations (2.5–2.3 Ga, 1.9–1.7 Ga, 1.3–1.0 Ga, and Late Palaeozoic ages). The Paleo‐Mesoproterozoic and Cambrian zircons have positive εHf(t) values, suggesting that the source was mainly locally derived from the CAOB, whereas a lesser amount of Archean zircons with positive εHf(t) values, indicating that source from the North China Craton (NCC). The Phanerozoic zircons have both positive and negative εHf(t) values indicates that material from bidirectional provenances in the CAOB and the NCC. However, Late Permian Kaishantun Formation in eastern Jilin Province contain a single group of Phanerozoic zircons with positive εHf(t) values, distinct from known igneous zircons in the NCC, suggesting a local source. These observations, along with the results of previous studies on Middle–Late Permian igneous rocks in Jilin Province, indicate that the eastern segment of the Paleo‐Asian Ocean underwent the initial closure in central Jilin Province during the Middle Permian and the final closure in eastern Jilin Province in the Late Permian–Early Triassic. The detrital zircon geochronological data clearly record two stages of tectonic evolution and the scissor‐like closure model of the Paleo‐Asian Ocean in the eastern segment of the CAOB. [ABSTRACT FROM AUTHOR]

The widespread development of Permian/Triassic boundary microbialites is a key biosedimentary response to the mass extinction event. The microbial communities that precipitated these structures remain, however, poorly resolved. Here, we report abundant columnar microfossils from five Permian‐Triassic successions in South China. Four phases of the microfossil life cycle are recorded: baeocytes, juvenile column, mature column, and baeocyte‐splitting, which are interpreted as Pleurocapsales (cyanobacterial clade that reproduces by multiple fission). The great thickness (up to 13 m) of these microbial deposits and Raman spectrum analysis indicate a strong calcification capacity of the Pleurocapsales. Pronounced peaks of Mg/(Mg + Ca) ratios from microbialite and distinct Mg‐enrichment in microfossils indicate that Pleurocapsales blooms may also have facilitated dolomitization of the microbialites. Common occurrence, strong biomineralization capacity, baffling framework, and the close association with carbonate minerals suggest that Pleurocapsales were key constructors of post‐extinction microbialites. Plain Language Summary: As a biosedimentary response to the end‐Permian mass extinction, the widespread occurrence of microbialites has attracted increasing levels of interests from geologists worldwide. However, the major constituents of microbial communities that constructed the microbialites have long been disputed. Our new study describes morphological features, growth direction and reproduction characteristic of columnar microfossils obtained from the microbialites, and all characteristics indicate that these microfossils are assignable to a type of photosynthesizing bacteria, known as Pleurocapsales cyanobacteria. Both biomineralization and dolomitization of these Pleurocapsales are evaluated based on in‐situ observations and geochemical analyses. The new results show that the cluster‐branching morphologies, together with common occurrence and strong calcification capacity indicate that Pleurocapsales were key constructors of the microbialites. High Mg/(Mg + Ca) ratios coinciding with the microbialites and Mg‐enrichment in the microfossils suggest that the Pleurocapsales may have catalyzed dolomitization of the microbialites after the end‐Permian mass extinction. Key Points: Four phases of a microbe life cycle are recognized from fossils within microbialites reflecting Pleurocapsales asexual reproductionCommon occurrence and baffling framework indicate that Pleurocapsales cyanobacteria are important in constructing microbialitesPleurocapsales cyanobacteria were an important component of microbialite calcification and magnesium enrichment [ABSTRACT FROM AUTHOR]

Heat stroke is a serious heat‐related health outcome that can eventually lead to death. Due to the poor accessibility of heat stroke data, the large‐scale relationship between heat stroke and meteorological factors is still unclear. This work aims to clarify the potential relationship between meteorological variables and heat stroke, and quantify the meteorological threshold that affected the severity of heat stroke. We collected daily heat stroke search index (HSSI) and meteorological data for the period 2013–2020 in 333 Chinese cities to analyze the relationship between meteorological variables and HSSI using correlation analysis and Random forest (RF) model. Temperature and relative humidity (RH) accounted for 62% and 9% of the changes of HSSI, respectively. In China, cases of heat stroke may start to occur when temperature exceeds 36°C and RH exceeds 58%. This threshold was 34.5°C and 79% in the north of China, and 36°C and 48% in the south of China. Compared to RH, the threshold of temperature showed a more evident difference affected by altitude and distance from the ocean, which was 35.5°C in inland cities and 36.5°C in coastal cities; 35.5°C in high‐altitude cities and 36°C in low‐altitude cities. Our findings provide a possible way to analyze the interaction effect of meteorological variables on heat‐related illnesses, and emphasizes the effects of geographical environment. The meteorological threshold quantified in this research can also support policymaker to establish a better meteorological warning system for public health. Plain Language Summary: The impact of extreme heat events on population has become of urgent public health concern. In China, the real mortality and morbidity data are not publicly available and data of some diseases are not enough recorded. Thus, it is difficult to build a solid relationship between heat strokes and meteorological variables in large spatial scale. Internet search data, highly correlated with real heat stoke cases, was adopted as a new data set in our research instead of the heat‐related morbidity data to investigate the relationship between heat strokes and multiple meteorological variables. According to Random forest model, temperature and relative humidity (RH) were identified as the most important factor, which mainly affected the severity of heat strokes. We quantified the meteorological threshold that affected the severity of heat strokes as well. Heat strokes may start to occur when temperature exceeds 36°C and RH exceeds 58% in China. The temperature of this threshold is higher in the south or low‐latitude region or coastal region of China. This work provides new insights for health research and help to timely alert the public in adverse weather conditions. Key Points: Internet search data could help to evaluate the health impact in large scale to address the data shortageIncreasing temperature and relative humidity (RH) led to sharply increased heat stroke, particularly when maximum temperature exceeds 36°C and RH exceeds 58%Meteorological threshold was affected by geographical factors like altitude, latitude and distance from ocean [ABSTRACT FROM AUTHOR]

Redox variations across the Permian‐Triassic boundary (PTB) have long been debated, especially during the proliferation of PTB microbialites. Here, we report redox fluctuations across the PTB to evaluate links between the two based on pyrite framboid analysis from basin to platform settings in South China. During the end‐Permian extinction, abundant framboids indicate a widespread anoxia that was likely a direct cause of extinction. In the earliest Triassic (Hindeodus parvus conodont zone), pyrite framboids were absent in ramp to basin and shallow, nonmicrobialite platform sections. In contrast, the coeval microbialites yield abundant framboids indicative of dysoxia. The fact that framboids were only confined to PTB microbialites and absent in other habitats indicates that microbe bloom may have stimulated dysoxic watermass and triggered the framboid growth within microbe aggregates. Thus, microbialites were not built in reducing settings, but instead, microbial proliferation caused local, dysoxia within shallow oxygenated platforms after the extinction. Plain Language Summary: The widespread occurrence of microbialites immediately after the end‐Permian extinction has attracted interest about their formation conditions. Microbialites are generally believed to be formed during microbial bloom in reducing conditions linked to the mass extinction. However, the cause‐and‐effect relationship between microbe bloom and reducing states of seawater has long been disputed. Our new results based on analyses of 17,306 pyrite framboid diameters and morphologies derived from various Permian‐Triassic boundary sections in South China show that microbialite formation (microbial bloom) was not triggered by reducing waters upwelled from deeper water masses, instead, it caused local, dysoxic areas within oxygenated platforms after the end‐Permian crisis. Key Points: A total of 17,306 pyrite framboids are analyzed in size and morphology from the Permian‐Triassic boundary beds of 26 sections, South ChinaFramboids were absent in ramp to basin and shallow, nonmicrobialite platforms after the extinction, but occurred in coeval microbialitesMicrobe bloom/microbialite growth was not triggered by reducing condition, but stimulated dysoxic water mass and triggered framboid growth [ABSTRACT FROM AUTHOR]

A large number of fossil woods were preserved in the Permian–Triassic sequences in the Junggar Basin of Xinjiang Uygur Autonomous Region. These wood fossils provide a lot of palaeoenvironmental information of the Junggar Basin during the Permian–Triassic transition. Here, we describe the fossil woods collected from the base of the Olenekian Shaofanggou Formation in Dalongkou Anticline. Anatomically, these wood remains closely resemble Junggaropitys dalongkouensis, but they lack growth rings and rays are higher. Thus, we suggest identifying them as J. cf. dalongkouensis. The growth pattern shows that J. cf. dalongkouensis is evergreen and developed under warm and humid environments. However, the data of geochemistry, palaeosol and certain sedimentary features reveal a dry climate. Thus, we speculate that the Olenekian Junggar Basin contained gallery forests in the arid environment. [ABSTRACT FROM AUTHOR]

A silicified trunk, Zhuotingoxylon liaoi Wan, Yang, Wang, Liu et Wang gen. et sp. nov., is described from the uppermost part of Guodikeng Formation in South Taodonggou section, Turpan–Hami Basin, Xinjiang Uygur Autonomous Region, northwestern China. It is characterized by a solid pith, endarch primary xylem and pycnoxylic wood. The pith is composed of parenchyma and sclereids. Radial walls of primary xylem tracheids have spiral and scalariform thickenings. Secondary xylem consists of thick‐walled tracheids and parenchymatous rays. Uniseriate rounded pits with oval apertures are distributed on radial tracheidal walls separately. Cell walls of rays are homogeneous and smooth. Rays are 1–10 cells high in tangential section. Cross‐field pits are cupressoid. There are 1–4 bordered pits with slit‐like to oval apertures in each cross‐field. Based on the anatomical features of the pith and xylems, it is proposed that the new stem has a coniferous affinity. The new fossil stem adds to the knowledge of vascular plant diversity close to the Permian–Triassic boundary. [ABSTRACT FROM AUTHOR]

Volcanism represented by the Permian–Triassic boundary (PTB) volcanic ash beds in South China plays a vital role in the PTB mass extinction. However, the probable provenance of the PTB volcanic ashes has not been exactly identified until now. In this study, the geochemical analysis was conducted on newly found five volcanic ash beds from the Mao'ershan and Tielukou sections in the northern part of the Yangtze platform. Volcanic ashes geochemistry indicates a felsic nature and negative Eu anomalies. Zircons selected from the five ash beds yield LA‐ICP‐MS U–Pb ages varying from ca. 255 to 248 Ma, and εHf(t) values of −8.6 to 1.1, which indicates the earlier stage volcanic ash beds in Mao'ershan are likely derived from mantle material and partial melting of crustal rocks, and the later stage volcanic ash beds in Tielukou are derived largely from ancient crustal rocks. Combined with previous U–Pb ages, εHf(t) values, trace elements of zircons, and geological setting, the PTB volcanic ash beds probably drift from the Jomda–Weixi volcanic belt in Sanjiang region of SE Asia, and that are represented by the volcanic rocks in Misha regions, eastern margin of the Lanping Basin. New data and discussion on the provenance of the PTB volcanic ashes provide important implications for the trigger of PTB mass extinction. [ABSTRACT FROM AUTHOR]