Xiaolin Zhang

University of Science and Technology of China | USTC

The Cryogenian Sturtian and Marinoan Snowball Earth glaciations bracket a nonglacial interval during which Demosponge and green-algal biomarkers first appear. To understand the relationships between environmental perturbations and early animal evolution, we measured sulfur and mercury isotopes from the Datangpo Formation from South China. Hg enrich...

Large magnitude and rapid negative carbon isotope (δ ¹³ C) excursions (CIEs) in the Triassic-Jurassic boundary (TJB) interval have been proposed as critical evidence for the hypothesis that the emplacement of Central Atlantic Magmatic Province (CAMP) has triggered global carbon cycle perturbations and the end-Triassic mass extinction (ETE). However...

The Serpukhovian (mid-Carboniferous) mass extinction has been ranked fifth among the major Phanerozoic biodiversity crises, based on its ecological impact. Global cooling and environmental deterioration driven by the late Paleozoic ice age (LPIA) have been invoked as potential drivers of the Serpukhovian extinction; however, the underlying killing...

Globally, Late Permian to Early Triassic carbonate rocks record several pronounced positive and negative C-isotope excursions, indicating a dramatic reorganization of the global carbon cycle. These C-isotopic anomalies provide important constraints on environmental changes that occurred during the end-Permian extinction and the subsequent delayed b...

Multiple observations have shown that widespread oceanic anoxia may have played an important role in the end-Permian mass extinction and delayed biotic recovery in the Early Triassic. However, it has not been reached a consensus on the temporal and spatial changes in oceanic redox conditions at that time. Chromium (Cr) isotopes have been widely use...

The Silurian-Devonian interval is an essential period in Earth history for witnessing the rise of sarcopterygian fishes and terrestrial vascular plants. In addition to its implication in global stratigraphic correlation, the precise location of the Silurian-Devonian boundary (SDB) in East Yunnan closely relates to the minimal and maximal estimated...

We present new high-resolution carbonate carbon isotope data (δ¹³Ccarb) from four sections in the Yangtze Platform, South China, ranging in age from Tremadocian to early Katian. The data have five distinct characteristics: 1) A prominent δ¹³Ccarb increase from −2.79‰ to 0.13‰ at the base of the Ordovician within the Tremadocian Cordylodus angulatus...

The Smithian negative C-isotope excursion was one of the major perturbations of the global carbon cycle following the end-Permian mass extinction event. Profound oceanographic and biological changes occurred during the Smithian, but the mechanism driving the negative C-isotope excursion and its links with marine environmental and biotic changes rem...

The end-Permian mass extinction (EPME) was the most severe extinction event in the past 540 million years, and the Siberian Traps large igneous province (STLIP) is widely hypothesized to have been the primary trigger for the environmental catastrophe. The killing mechanisms depend critically on the nature of volatiles ejected during STLIP eruptions...

The emergence and proliferation of metazoan lineage in the Ediacaran Period is commonly hypothesized to reflect an increase in the oxygen content of marine environments. However, recent studies suggest that the Ediacaran oceanic redox conditions were spatially heterogeneous and temporally dynamic. In this study, we report high-resolution pyrite S-i...

We report the temporal and spatial C-isotopic variations of carbonate (δ¹³Ccarb) and organic carbon (δ¹³Corg) spanning the Permian-Triassic transition at the Xiakou and Chaotian sections in South China. The C-isotope data from the two sections show two episodes of δ¹³Ccarb decrease. However, in contrast to most of the C-isotopic records of the Phan...

Volcanic eruptions are thought to be a key driver of rapid climate perturbations over geological time, such as global cooling, global warming, and changes in ocean chemistry. However, identification of stratospheric volcanic eruptions in the geological record and their causal link to the mass extinction events during the past 540 million years rema...

Several prominent negative carbon isotope (δ¹³C) excursions are observed during the Ediacaran-Cambrian (E-C) transition, reflecting large perturbations of the carbon cycle in the ocean–atmosphere system. These negative δ¹³C excursions have been linked to dramatic paleoenvironmental changes and been widely used as regional and global chemostratigrap...

Changes in oceanic chemical conditions are frequently invoked as a primary driver of biodiversification and mass extinction events in Earth history. During the Ediacaran–Cambrian transition, two major biological events, including the extinction of the Ediacaran biota and the Cambrian explosion, occurred approximately coincident with perturbations o...

The middle Cambrian (Cambrian Series 3) Drumian carbon isotope excursion (DICE) represents a pronounced negative carbon isotopic excursion, and has been proposed as a key chemostratigraphic marker for identifying the base of Cambrian Drumian Stage and global correlation. However, the precise interbasinal correlation of the DICE to the South China r...

In this study, we report multiple S-isotopic data (δ³⁴S and Δ³³S) of sedimentary pyrite in Early to Late Ordovician sections from South China. The results reveal two distinct groups of negative Δ³³S anomalies during the Dapingian and Sandbian to Early Katian stages, which coincide with two faunal turnover events. The negative Δ³³S values reflect th...

It is assumed that the potential intensity of tropical cyclones (TC) will increase with rising global temperature. The western North Pacific is one of the three principal TC centers, but TC records from the region are scarce and sometimes controversial. Here we present grain‐size distributions and element contents of sediment cores from the East Ch...

Remarkable carbonate carbon isotope (δ¹³Ccarb) excursions accompanied by invariant organic carbon isotope (δ¹³Corg) values have been observed in many late Neoproterozoic successions. This decoupled relationship between δ¹³Ccarb and δ¹³Corg in the Precambrian differs from most Phanerozoic records which have been substantially imprinted by aqueous ph...

The timing of the Holocene summer monsoon maximum (HSMM) in northeastern China has been much debated and more quantitative precipitation records are needed to resolve the issue. In the present study, Holocene precipitation and temperature changes were quantitatively reconstructed from a pollen record from the sediments of Tianchi Crater Lake in nor...

Neoproterozoic cap carbonates formed in the immediate aftermath of a global glaciation event (“Snowball Earth”) [1]. Accumulation of atmospheric CO2 during the glaciation led to higher erosion rates, higher Ca input into the oceans and cap carbonate precipitation [2]. Cap carbonates are typically thinly laminated and contain varying amounts of sili...

Significance Anomalous sulfur isotopic compositions preserved in sedimentary rocks older than ∼2.5 billion years have been widely interpreted as the products of UV photolysis of sulfur dioxide in an anoxic atmosphere and used to track the history of primitive Earth and evolution of early life. In this study, we present strong observational evidence...

There is a controversy regarding the timing of the onset of the Holocene optimum (HO) in the Huai River Basin in eastern China, reflecting the scarcity of well-dated high-resolution sedimentary records in the region. In this study we validate the time-transgressive onset of the HO in the East Asian Monsoon (EAM) region and update a regression model...

We employed a novel approach using the bipolar and tropical distributions of bivalves to track the northward drift of the Indian Plate. The Kimmeridgian–Tithonian Retroceramus, Tithonian Anopaea and Buchia, and Aptian–Cenomanian Aucellina were mainly restricted to areas poleward of 30°N and 30°S, but middle Oxfordian–latest Cretaceous rudist bivalv...

The Upper Cambrian Steptoean Positive Carbon Isotope Excursion (SPICE, ca. 497 to 493 Ma) is characterized by a globally observed positive δ¹³C excursion of ~4‰ to 6‰. Late Cambrian strata of South China, consisting of thick carbonate rocks with an excellent fossil record, provide key sedimentary successions for characterizing the SPICE and underst...

The Yangtze platform of South China preserves relatively continuous strata of the Ediacaran Period and has been one of the key areas to explore Neoproterozoic Earth history. In this study, high-resolution carbon isotope (δ¹³C) and oxygen isotope (δ¹⁸O) data of 701 samples were reported for sedimentary rocks spanning the entire Ediacaran Period usin...

Low nitrogen isotopic compositions (δ¹⁵N) have been reported in deposits from the proto-North Atlantic and western Tethys during Oceanic Anoxic Event 2 (OAE2) at the Cenomanian-Turonian (C-T) transition. It has been proposed that the low δ¹⁵N values may have resulted from enhancement of N2 fixation and/or incomplete assimilation of the upwelled amm...

A pronounced positive δ¹³C excursion in the Hirnantian Age has been documented globally, reflecting large perturbations of carbon cycling in the Late Ordovician oceans. Increased organic-carbon burial or enhanced carbonate weathering during glacioeustatic sea-level regression has been proposed to account for this anomalous C-isotope excursion. To t...

The Wa'ergang section in South China has been proposed as a potential Global Stratotype Section and Point (GSSP) for the base of Stage 10, the uppermost stage of the Cambrian System. In this study, high-resolution C-isotopic compositions are reported and we identified three large negative δ ¹³ C excursions, namely N1, N2 and N3, at Wa'ergang. The N...

Significance To understand how most life on Earth went extinct 250 million years ago, we used multiple sulfur isotopes to investigate redox chemistry changes in the Panthalassic Ocean, comprising ∼85–90% of the contemporaneous global ocean. The S-isotopic anomalies from Canada and Japan provide evidence for the timing of the onset of euxinia and mi...

The organic carbon isotope (δ13Corg) curve for ~1.7-km-thick mid-Cretaceous strata of the Chaqiela section in Gamba area, southern Tibet is presented in this study. C-isotopic chemostratigraphic correlation combined with biostratigraphic constraints show that the Chaqiela section spans early Aptian through early Campanian period, and that almost al...

Three continuous cores acquired in the Sihetun area of Liaoning Province, famous for feathered non-avian dinosaurs of the Jehol Biota, reveal the stratigraphic and facies relationships of the divisions of the Early Cretaceous Yixian and underlying ?Jurassic-Early Cretaceous Tuchengzi formations. Based on these cores, we propose a modified lithostra...

Multiple sulfur isotopes (S-32, S-33, S-34, and S-36) measured on pyrites from the Penglaitan section, the Global Stratotype Section and Point (GSSP) for the Guadalupian-Lopingian Series boundary, and from the auxiliary Tieqiao section in South China show a sulfur isotope signal of negative and positive delta S-34 with negative Delta S-33. We sugge...

The Wonoka-Shuram Anomaly represents the largest negative carbon isotope excursion recognized in the geologic record and is associated with the emergence and diversification of metazoan life ca. 580 million years ago (Ma). The origin of the anomaly is highly debated, with interpretations ranging from primary to diagenetic, each having unique and po...

Significance Geological records of paleoclimate provide the only constraints on Solar System orbital solutions extending beyond the ∼50-Ma limit imposed by chaotic diffusion. Examples of such constraints are coupled high and low latitude, Triassic–Jurassic (∼198–202 Ma) sedimentary cyclicity in coal-bearing outcrops from the ∼60° N-paleolatitude Ju...

The Early Cretaceous ostracod fauna in western Liaoning is divided into eight successive ostracod assemblages. These assemblages have provided information about age constraint of relevant nonmarine Early Cretaceous strata: Yixian Formation-Hauterivian to Barremian, probably up to Aptian; Jiufotang Formation-Barremian to Aptian; Fuxin Formation-Apti...

The brackish-water bivalve WaagenopernaTokuyama, 1959 is reported from the Lower Jurassic Badaowan Formation at four localities, along the southern margin and western margin of the Junggar Basin. Taphonomic features recorded in the field indicate that it occurs in autochthonous or parautochthonous assemblages. The autecology of Waagenoperna therefo...

Pan, Y., Sha, J., Fürsich, F.T., Wang, Y., Zhang, X. & Yao, X. 2011: Dynamics of the lacustrine fauna from the Early Cretaceous Yixian Formation, China: implications of volcanic and climatic factors. Lethaia, Vol. 45, pp. 299–314. The taphonomy and palaeoecology of the famous Lower Cretaceous Jehol biota of northeastern China are two of its least r...

: The Triassic–Jurassic (Tr–J) boundary marks a major extinction event, which (∼200 Ma) resulted in global extinctions of fauna and flora both in the marine and terrestrial realms. There prevail great challenges in determining the exact location of the terrestrial Tr–J boundary, because of endemism of taxa and the scarcity of fossils in terrestrial...