Sulphur isotope stratigraphy of drill cuttings and stratigraphic correlation of Permian-Triassic evaporites

The stratigraphy of the European late Permian-Triassic commonly lacks chronostratigraphic constraint due to the scarcity of diagnostic fossils for biostratigraphy. This is particularly true for the United Kingdom, and as a result, stratigraphic correlation within and between sedimentary basins is primarily reliant on lithostratigraphy. Evaporitic sulphate can be used to develop time series of δ34Sevap data that can be utilised for stratigraphic correlation. However, the availability of continuous drillcore is limited, whilst drill cuttings are commonly acquired but are widely overlooked for stable isotope stratigraphy. We derive a δ34Sevap record from drill cuttings from the southern North Sea Basin, and successfully correlate it with an equivalent published δ34Sevap record from a continuous drillcore in the Cleveland Basin, Yorkshire, United Kingdom. We have chosen seven points in the δ34Sevap records for stratigraphic correlation, defining eight packages of isotopically distinct coeval strata. This is significant, as the ubiquity of drill cuttings presents the opportunity to derive δ34Sevap curves with high geospatial resolution. Equivalent gamma ray logs were used for correlation and compared with the δ34Sevap curves. The correlations agree relatively well, however, the δ34Sevap correlation permits the development of more robust chronostratigraphic constraints. Specifically, the δ34Sevap records constrain the age of the Bunter Shale and Bunter Sandstone in the western Southern North Sea to the latest Permian. This has significant implications for understanding the stratigraphy and palaeogeographic evolution of United Kingdom Permian-Triassic sedimentary basins, and may have economic implications, since the Bunter Sandstone is being considered as a potential reservoir for CO2 storage in the United Kingdom sector

Nitrogen isotopes in herbaria document historical nitrogen sewage pollution in the Mersey Estuary, England

A macroalgae (seaweed) herbarium nitrogen isotope (δ15N) record is produced for the River Mersey and Liverpool South Docks (England) between 1821 and 2018. A modern macroalgae δ15N record was also produced from September 2022. The herbaria δ15N record shows a stark difference from 1821 to the present. Lower δ15N in the early 1800s is attributed to agricultural and raw sewage pollution. From 1970 to the present the herbaria samples record very elevated δ15N values – peaking in 1978 at +31‰. The 1989 Water Act and privatisation of water companies in the UK had limited impact on the herbarium δ15N record but indicated a dominance of sewage nitrogen in the River Mersey. Macroalgae δ15N has become even more elevated since the last herbaria sample in 2013. The herbaria and modern data record some of the highest seaweed δ15N values (and therefore, sewage nitrogen pollution) recorded to date. This study highlights a novel use of herbaria macroalgae to document past changes in nitrogen pollution in estuarine environments. More poignantly it highlights that the River Mersey – Mersey Estuary is heavily polluted with sewage nitrogen and requires immediate action to resolve this environmental issue

An 80-million-year sulphur isotope record of pyrite burial over the Permian–Triassic

Despite the extensive use of sulphur isotope ratios (δ34S) for understanding ancient biogeochemical cycles, many studies focus on specific time-points of interest, such as the end-Permian mass extinction (EPME). We have generated an 80 million-year Permian–Triassic δ34Sevap curve from the Staithes S-20 borehole, Yorkshire, England. The Staithes δ34Sevap record replicates the major features of the global curve, while confirming a new excursion at the Olenekian/Anisian boundary at ~ 247 million years ago. We incorporate the resultant δ34Sevap curve into a sulphur isotope box model. Our modelling approach reveals three significant pyrite burial events (i.e. PBEs) in the Triassic. In particular, it predicts a significant biogeochemical response across the EPME, resulting in a substantial increase in pyrite burial, possibly driven by Siberian Traps volcanism. Our model suggests that after ~ 10 million years pyrite burial achieves relative long-term stability until the latest Triassic

Intrashelf basin record of redox and productivity changes along the Arabian margin of Neo-Tethys during Oceanic Anoxic Event 1a

The biotic, environmental, climatic, oceanic, and sea-level perturbations during the Early Aptian Oceanic Anoxic Event (OAE) 1a have been extensively documented from both deep- and shallow-marine deposits worldwide. However, there has been relatively little comparative assessment of the simultaneous interplay among organic carbon burial, redox conditions, terrigenous output, and productivity, leading to a lack of precise constraints on these relationships. Here, we use analyses of stable carbon isotopes (δ13Corg, δ13Ccarb, and Δ13C), total organic carbon (TOC), detrital proxies (Al, Si, Ti, K), redox-sensitive (RSTE: U, V, Mo) and productive-sensitive (PSTE: P, Cu, Ni) trace elements from a continuous, predominantly carbonate succession of the Kazhdumi Intrashelf Basin to evaluate the culprits for the OAE1a-associated changes in bottom-water oxygenation, organic-rich layer formation, and biotic shifts along the Arabian margin of the Neo-Tethys. Concentrations of Al-normalized RSTE and TOC values indicate that the bottom water conditions ranged from oxic prior to and at the onset of the OAE 1a (carbon-isotope segments C2 to basalmost C4 sensu Menegatti et al., 1998), to anoxic-suboxic but not euxinic (Mo 100 m), continental-margin basins during major oceanic perturbations

Trans-Atlantic correlation of Late Cretaceous high-frequency sea-level cycles

Previous studies of Cretaceous sedimentary rocks have used multi-proxy correlation methods to suggest eustatic change, modulated by the c. 400 kyr long eccentricity rhythm. Although numerous authors have inferred eustatic changes on shorter timescales, none have demonstrated synchronous sea-level changes in separate basins on different plates, thousands of kilometres apart. Our study integrates basin-scale, three-dimensional sequence architecture, molluscan biostratigraphy, and carbon-isotope chemostratigraphy to demonstrate synchronous sea-level changes in upper Turonian to lower Coniacian shallow-marine clastic successions in the Western Canada Foreland Basin, and the Bohemian Cretaceous Basin. Depositional sequences in both basins are plotted in a common time domain using an astronomically calibrated age model, allowing direct comparison. In both basins, at least seven major transgressive events can be shown to be synchronous within the limits of combined biostratigraphic and chemostratigraphic resolution. ‘Major’ and ‘minor’ sequences of late Turonian age appear to have been paced, respectively, by the long (c. 400 kyr) and short (c. 100 kyr) eccentricity cycles. In contrast, early Coniacian sequences evidence pacing by the c. 38 kyr obliquity rhythm. Stratal architecture suggests that sequences developed in response to eustatic changes of c. 14–20 m at average rates ranging 0.08 to >1.3 m/kyr. At a time of ‘warm greenhouse’ climate, sea-level change of this magnitude and timescale may not be explicable entirely as a result of thermal- and aquifer-eustasy, and hence glacio-eustasy may also have been a contributing factor

A new subsurface record of the Pliensbachian–Toarcian, Lower Jurassic, of Yorkshire

Here, we describe the upper Pliensbachian to middle Toarcian stratigraphy of the Dove’s Nest borehole, which was drilled near Whitby, North Yorkshire, in 2013. The core represents a single, continuous vertical section through unweathered, immature Lower Jurassic sedimentary rocks. The thickness of the Lias Group formations in the Dove’s Nest core is approximately the same as that exposed along the North Yorkshire coast between Hawsker Bottoms and Whitby. The studied succession consists of epeiric-neritic sediments and comprises cross-laminated very fine sandstones, (oolitic) ironstones, and argillaceous mudstones. Dark argillaceous mudstone is the dominant lithology. These sediments were deposited in the Cleveland Basin, a more subsident area of an epeiric sea, the Laurasian Sea. We present a set of geochemical data that includes organic carbon isotope ratios (δ13Corg) and total organic carbon (TOC). The δ13Corg record contains a negative excursion across the Pliensbachian–Toarcian boundary and another in the lower Toarcian that corresponds to the Toarcian Oceanic Anoxic Event (T-OAE). Below the T-OAE negative excursion, δ13Corg values are less13C-depleted than above it. We find no evidence of a long-term δ13 Corg positive excursion. TOC values below the T-OAE negative excursion are lower than above it. Sedimentary evidence suggests that, during much of the Pliensbachian–Toarcian interval, the seafloor of the Cleveland Basin was above storm wave-base and that storm-driven bottom currents were responsible for much sediment erosion, transport, and redeposition during the interval of oceanic anoxia. The abrupt shifts observed in the δ13Corg record (lower Toarcian) are likely to reflect the impact of erosion by storms on the morphology of the δ13C record of the T-OAE

A Land of Plenty? Colonial Diet in Rural New Zealand

Colonial New Zealand was built on the ideal of creating better lives for settlers. Emigrants came looking to escape the shackles of the class-system and poor conditions in Industrial Revolution period Britain. Colonial propaganda claimed that most emigrants achieved their aims, but the lives the colonists actually experienced upon reaching New Zealand remain relatively unexplored from a biosocial perspective. In this paper we present a pilot study of stable isotope results of bone collagen from seven adults interred in the St. John’s Cemetery (SJM), Milton, New Zealand (ca. AD 1860–1900). We interpret the diet at Milton and broadly compare our isotopic results with contemporaneous samples from Britain. We show that, like contemporary Britain, the diet of our studied individuals was focused on C3 crops and terrestrial meat sources. Despite higher ????15N values in contemporary UK populations (which can simplistically be interpreted as indicative of higher meat intake), consideration of different local baselines makes it likely that this New Zealand population had relatively similar levels of meat intake. Interestingly marine resources did not form an important part of the Milton diet, despite the site's proximity to the ocean, hinting at the possible stigmatisation of local resources and the development of a European New Zealand (pākehā) food identity

Carbon, nitrogen and sulphur isotope data of archaeological fish and mammal bone collagen from Lithuania

Until relatively recently, stable sulphur isotope analysis of bone collagen was seldom undertaken in bioarchaeological research. With increasing frequency, its application has proven useful in reconstructing palaeodiets and palaeoecologies, as well as identifying potential migration and mobility patterns. Here, sulphur (δ34S) isotope analysis, together with carbon (δ13C) and nitrogen (δ15N), was performed on six fish and 34 mammal bone collagen samples from 14 prehistoric sites in Lithuania dating from the Late Mesolithic (ca. 7000–5000 cal BC) to the Late Bronze Age (ca. 1100–500 cal BC). We present the first δ34S data from Lithuania, including coupled δ13C and δ15N data, offering a crucial dataset for future research to explore spatial and temporal variability in the region and beyond

A Meeting In The Forest: Hunters And Farmers At The Coneybury ‘Anomaly’, Wiltshire

The Coneybury ‘Anomaly’ is an Early Neolithic pit located just south-east of Stonehenge, Wiltshire. Excavations recovered a faunal assemblage unique in its composition, consisting of both wild and domestic species, as well as large quantities of ceramics and stone tools, including a substantial proportion of blades/bladelets. We present a suite of new isotope analyses of the faunal material, together with ancient DNA sex determination, and reconsider the published faunal data to ask: What took place at Coneybury, and who was involved? We argue on the basis of multiple lines of evidence that Coneybury represents the material remains of a gathering organised by a regional community, with participants coming from different areas. One group of attendees provided deer instead of, or in addition to, cattle. We conclude that the most likely scenario is that this group comprised local hunter-gatherers who survived alongside local farmers

Fluvial organic carbon cycling regulated by sediment transit time and mineral protection

Rivers transfer terrestrial organic carbon (OC) from mountains to ocean basins, playing a key role in the global carbon cycle. During fluvial transit, OC may be oxidized and emitted to the atmosphere as CO2 or preserved and transported to downstream depositional sinks. The balance between oxidation and preservation determines the amount of particulate OC (POC) that can be buried long term, but the factors regulating this balance are poorly constrained. Here, we quantify the effects of fluvial transit on POC fluxes along an ~1,300 km lowland channel with no tributaries. We show that sediment transit time and mineral protection regulate the magnitude and rate of POC oxidation, respectively. Using a simple turnover model, we estimate that annual POC oxidation is a small percentage of the POC delivered to the river. Modelling shows that lateral erosion into POC-rich floodplains can increase POC fluxes to downstream basins, thereby offsetting POC oxidation. Consequently, rivers with high channel mobility can enhance CO2 drawdown while management practices that stabilize river channels may reduce the potential for CO2 drawdown