Robert J Newton

University of Leeds · School of Earth and Environment

The nature of the magma plumbing system of Large Igneous Provinces is still poorly understood. Among these exceptional magmatic events from Earth’s past, the end-Triassic Central Atlantic Magmatic Province (CAMP) and the end-Cretaceous Deccan Traps (Deccan) coincided in time with two of the most catastrophic biotic crises during the Phanerozoic. In...

The Permo-Triassic mass extinction was linked to catastrophic environmental changes and large igneous province (LIP) volcanism. In addition to the widespread marine losses, the Permo–Triassic event was the most severe terrestrial ecological crisis in Earth’s history and the only known mass extinction among insects, but the cause of extinction on la...

Phosphorus is generally considered the ultimate limiting nutrient for marine primary productivity over geological timescales and plays a key role in modulating several biogeochemical cycles. Most established methods for investigating P cycling do not provide direct evidence for water-column P concentrations, but recent work on carbonate associated...

The Minjera bauxites are the first analysed and mined bauxites in the world. They are a group of pyritised bauxites situated in northern Istria, developed during the subaerial exposure phase which marked a major part of the Late Cretaceous and Palaeocene in northern Istria. In this study, the morphology, petrography, mineralogy, geochemistry as wel...

Oceanic Anoxic Event 2 (OAE2) has been the focus of considerable research, but biogeochemical dynamics during the recovery from the carbon cycle disturbance largely remain unknown. Here, we present a high-resolution reconstruction of water column redox and nutrient cycling across the final stages of OAE2, in order to assess controls on the terminat...

Understanding the long-term variance of seawater sulfate concentrations ([SO 4 ²⁻ ] sw ) is critical to understanding the dynamic relationship between the sulfur, carbon, calcium, and oxygen cycles, and their influence on Earth's habitability. Here, we explore how [SO 4 ²⁻ ] sw has changed throughout the Phanerozoic, and its impact on other element...

Drilling for the International Continental Scientific Drilling Program (ICDP) Early Jurassic Earth System and Timescale project (JET) was undertaken between October 2020 and January 2021. The drill site is situated in a small-scale synformal basin of the latest Triassic to Early Jurassic age that formed above the major Permian-Triassic half-graben...

The early Toarcian of the Early Jurassic saw a long-term positive carbon-isotope excursion (CIE) abruptly interrupted by a significant negative excursion (nCIE), associated with rapid global warming and an oceanic anoxic event (T-OAE, ∼183 Ma). However, the detailed processes and mechanisms behind widespread ocean deoxygenation are unclear. Here, w...

Cambrian was a critical period in Earth's history, marked by rapid diversification of early animals and significant changes in oceanic conditions. Marine sediments, particularly carbonates, have been used to study variations in the global carbon cycle, seawater redox, weathering input, etc. In search of new archives of Cambrian paleo-seawater chemi...

The Pliocene-Recent is associated with many important climatic and paleoceanographic changes, which have shaped the biotic and abiotic nature of the modern world. The closure of the Central American Seaway and the development and intensification of Northern Hemisphere ice sheets had profound global impacts on the latitudinal and vertical structure...

Background We propose a method to identify inequity in access to emergency services and present a model to address inequity by siting additional facilities, recommending both quantity and location to decision makers. Methods We classify emergencies by the median income bracket of their ZIP code tabulation areas. We determine whether the proportion...

The Plio-Pleistocene is associated with many important climatic and paleoceanographic changes which have shaped the biotic and abiotic nature of the modern world. The closure of the Central American Seaway and the development and intensification of northern hemisphere icesheets had profound global impacts on the latitudinal and vertical structure o...

The early Toarcian Oceanic Anoxic Event (T-OAE, ~183 Ma) was characterized by marine deoxygenation and the burial of organic-rich sediments at numerous localities worldwide. However, the extent of marine anoxia and its impact on the sulfur cycle during the T-OAE is currently poorly understood. Here, stable sulfur isotopes of reduced metal-bound sul...

Warming-induced marine anoxia has been hypothesized as an environmental stressor for the end-Triassic mass extinction (ETME), but links between the spread of marine anoxia and the two phases of extinction are poorly constrained. Here, we report iron speciation and trace metal data from the Bristol Channel Basin and Larne Basin of the NW European ep...

The end-Triassic mass extinction (ETME) was associated with intensified deep-water anoxia in epicontinental seas and mid-depth waters, yet the absolute oxygenation state in the shallow ocean is uncharacterized. Here we report carbonate-associated iodine data from the peritidal Mount Sparagio section (Southern Italy) that documents the ETME (~ 200 M...

Past major biological turnovers are coeval to large injections of CO2 into the atmosphere–ocean system that are often linked to the emplacement of Large Igneous Provinces. The impact of these CO2 pulses on ecosystems is however different at different times, and this difference is contingent on the initial boundary conditions. Here, we show how dela...

The climatic and environmental impact of exclusively volcanic CO2 emissions is assessed during the main effusive phase of the Central Atlantic Magmatic Province (CAMP), which is synchronous with the end-Triassic mass extinction. CAMP volcanism occurred in brief and intense eruptive pulses each producing extensive basaltic lava flows. Here, CAMP vol...

The Early Jurassic is an important interval characterized by several global carbon-isotope (δ13C) perturbations. Although the δ13C records are becoming better documented during this time interval, we have a relatively poor understanding of the associated long-term environmental and climatic changes. In order to decipher these events, we here presen...

The Ediacaran Period was characterised by major carbon isotope perturbations. The most extreme of these, the ∼570 Ma Shuram/DOUNCE (Doushantuo Negative Carbon isotope Excursion) anomaly, coincided with early radiations of benthic macrofauna linked to a temporary expansion in the extent of oxygenated seawater. Here we document an earlier negative ex...

The early Toarcian (~183 Ma) was characterized by a prominent volcanism-induced warming event associated with a massive addition of ¹²C-enriched carbon to the ocean-atmosphere system. This warming likely contributed to marked ocean deoxygenation during this time, giving the event its name: the early Toarcian oceanic anoxic event (T-OAE). Although t...

Exceptional magmatic events coincided with the largest mass extinctions throughout Earth’s history. Extensive degassing from organic-rich sediments intruded by magmas is a possible driver of the catastrophic environmental changes, which triggered the biotic crises. One of Earth’s largest magmatic events is represented by the Central Atlantic Magmat...

In 2020, California required San Francisco to consider equity in access to resources such as housing, transportation, and emergency services as it re-opened its economy post-pandemic. Using a public dataset maintained by the San Francisco Fire Department of every call received related to emergency response from January 2003 to April 2021, we calcul...

Extinction rates in the modern world are currently at their highest in 66 million years and are likely to increase with projections of future climate change. Our knowledge of modern-day extinction risk is largely limited to decadal-centennial terrestrial records, while data from the marine realm is typically applied to high-order (> 1 million year)...

Extinction rates in the modern world are currently at their highest in 66 million years and are likely to increase with projections of future climate change. Our knowledge of modern-day extinction risk is largely limited to decadal-centennial terrestrial records, while data from the marine realm is typically applied to high-order (> 1 million year)...

The Mozambique continental margin experienced large variations in sedimentation rates, primarily due to re-routing of sediment deposition from the Zambezi River during the last glacial-Holocene transition. As changes in sediment accumulation and organic matter deposition impose a strong control on the formation of authigenic minerals in the sedimen...

The Carnian Pluvial Episode (Late Triassic) was a time of global environmental changes and possibly substantial coeval volcanism. The extent of the biological turnover in marine and terrestrial ecosystems is not well understood. Here, we present a meta-analysis of fossil data that suggests a substantial reduction in generic and species richness and...

The role of ocean anoxia as a cause of the end-Triassic marine mass extinction is widely debated. Here, we present carbonate-associated sulfate d34S data from sections spanning the Late Triassic–Early Jurassic transition, which document synchronous large positive excursions on a global scale occurring in ~50 thousand years. Biogeochemical modeling...

Carbon and oxygen isotopes (δ13C and δ18O) in tree rings are widely used to reconstruct palaeoclimate variables such as temperature during the Holocene (12 thousand years ago - present), and are used increasingly in deeper time. However, their use is largely restricted to arboreal trees, which excludes potentially important data from prostrate tree...

Oxygen deprivation and hydrogen sulfide toxicity are considered potent kill mechanisms during the mass extinction just before the Permian–Triassic boundary (~251.9 million years ago). However, the mechanism that drove vast stretches of the ocean to an anoxic state is unclear. Here, we present palaeoredox and phosphorus speciation data for a marine...

Records suggest that the Permo–Triassic mass extinction (PTME) involved one of the most severe terrestrial ecosystem collapses of the Phanerozoic. However, it has proved difficult to constrain the extent of the primary productivity loss on land, hindering our understanding of the effects on global biogeochemistry. We build a new biogeochemical mode...

Large Igneous Province eruptions coincide with many major Phanerozoic mass extinctions, suggesting a cause-effect relationship where volcanic degassing triggers global climatic changes. In order to fully understand this relationship, it is necessary to constrain the quantity and type of degassed magmatic volatiles, and to determine the depth of the...

The Early Toarcian was characterised by the eruption of the Karoo-Ferrar large igneous province (LIP), rapid global warming, significant perturbations in the global carbon cycle, the development of widespread anoxia known as the Early Toarcian Oceanic Anoxic Event (T-OAE) and a biotic crisis in the marine realm known as the Early Toarcian Mass Exti...

The Early Toarcian was characterised by the eruption of the Karoo-Ferrar large igneous province (LIP), rapid global warming, significant perturbations in the global carbon cycle, the development of widespread anoxia known as the Early Toarcian Oceanic Anoxic Event (T-OAE) and a biotic crisis in the marine realm known as the Early Toarcian Mass Exti...

Flood basalt volcanism represented by the Kalkarindji Province(Australia) is temporally associated with a trilobite mass extinction at the Cambrian Series 2 – Series 3 boundary, providing one of the oldest potential links between volcanism and biotic crisis in the Phanerozoic. However, the relative timing of flood basalt volcanism (Kalkarindji Prov...

The shell material of marine benthic bivalves provides a sensitive archive of water chemistry immediately above the sediment–water interface, which in turn is affected by sedimentary geochemistry and redox reactions. Sulfate has a major controlling effect on sedimentary carbon cycling, particularly the processes of methane production and oxidation,...

The apparent lag between the first permanent rise of atmospheric oxygen to appreciable levels and oxygenation of the deep ocean has focused efforts in deciphering the evolution of seawater chemistry across the Proterozoic Eon (2.5–0.542 Ga). It is generally accepted that from ∼1.85 Ga oxic shallow marine waters were widespread while the deep ocean...

Eutrophication is a globally significant challenge facing freshwater ecosystems and is closely associated with anthropogenic enrichment of phosphorus (P) in the aquatic environment. Phosphorus inputs to rivers are usually dominated by diffuse sources related to farming activities and point sources such as waste water treatment works (WwTW). The lim...

Shell-bound organic matter (SBOM) is present in the shells of biomineralizing organisms and can act as an isotopic proxy for nutrition. Stable isotope analysis of SBOM generally requires its isolation from the mineral component of the shell, and this study shows that various shell removal techniques (cation exchange resin, ethylenediaminetetraaceti...

One of the most expanded records to contain the final fortunes of ammonoid cephalopods is within the López de Bertodano Formation of Seymour Island, James Ross Basin, Antarctica. Located at ~65º South now, and during the Cretaceous, this sequence is the highest southern latitude onshore outcrop containing the Cretaceous–Paleogene (K–Pg) transition....

It is generally accepted that wide stretches of the world's oceans turned anoxic during the Permian-Triassic transition. Although it is often invoked that these anoxic regions experienced an extreme redox state signified by free hydrogen sulfide in the water column (euxinia), recent studies employing iron speciation suggest that some regions were a...

The Cretaceous–Paleogene (K–Pg) mass extinction event 66 million years ago led to large changes to the global carbon cycle, primarily via a decrease in primary or export productivity of the oceans. However, the effects of this event and longer-term environmental changes during the Late Cretaceous on the global sulfur cycle are not well understood....