Thomas Wagner

Thomas Wagner
Heriot-Watt University · The Lyell Centre

About

253
Publications
40,864
Reads
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6,460
Citations
Citations since 2017
48 Research Items
2894 Citations
20172018201920202021202220230100200300400500600
20172018201920202021202220230100200300400500600
20172018201920202021202220230100200300400500600
20172018201920202021202220230100200300400500600
Additional affiliations
April 2005 - present
Newcastle University
Position
  • Professor of Earth System Sciences
April 2005 - December 2015
Newcastle University
Position
  • Professor (Full)
April 1994 - March 2005
Universität Bremen
Position
  • Professor (Assistant)

Publications

Publications (253)
Article
Full-text available
Mine water geothermal energy could provide sustainable heating, cooling and storage to assist in the decarbonisation of heat and achieving Net Zero carbon emissions. However, mined environments are highly complex and we currently lack the understanding to confidently enable a widespread, cost-effective deployment of the technology. Extensive and re...
Article
Full-text available
The early Toarcian Oceanic Anoxic Event (T-OAE) was associated with major climatic changes involving profound effects on the global carbon cycle. In this study, we present new carbon- and oxygen- isotope, CaCO3 and total organic carbon (TOC) records from two cores (Sogno and Gajum Cores) that recovered pelagic successions from north-western Tethys....
Article
Full-text available
Large‐scale atmospheric circulation patterns, such as the East Asian monsoon, have been proposed as possible feedbacks of the mid‐Pleistocene transition (MPT). Marine sediments of the Japan Sea (JS) record variations in the East Asian monsoon over long timescales and may be crucial for understanding of the MPT. To interpret these sediments correctl...
Article
Benthic foraminifera at Ocean Drilling Program (ODP) Hole 692B were studied to understand variations in oxygen and organic-matter fluxes in bottom waters during the Early Cretaceous. The upper Berriasian to lower Barremian black shales, characterized by high concentrations of total organic carbon (TOC) ranging between 1.3 and 18%, were deposited in...
Article
Full-text available
The Weissert Event ~133 million years ago marked a profound global cooling that punctuated the Early Cretaceous greenhouse. We present modelling, high-resolution bulk organic carbon isotopes and chronostratigraphically calibrated sea surface temperature (SSTs) based on an organic paleothermometer (the TEX86 proxy), which capture the Weissert Event...
Article
Full-text available
The Paleocene–Eocene Thermal Maximum (PETM) was a period of geologically-rapid carbon release and global warming ~56 million years ago. Although modelling, outcrop and proxy records suggest volcanic carbon release occurred, it has not yet been possible to identify the PETM trigger, or if multiple reservoirs of carbon were involved. Here we report e...
Preprint
Full-text available
Connecting tropical rainforests to larger rivers, tropical headwaters export large quantities of carbon and nutrients as dissolved organic matter (DOM), and are thus a key component of the global carbon cycle. This DOM transport is not passive, however; sunlight and microbial activity alter DOM concentrations and compositions, affecting riverine gr...
Article
Full-text available
Extensive black shale deposits formed in the Early Cretaceous South Atlantic, supporting the notion that this emerging ocean basin was a globally important site of organic carbon burial. The magnitude of organic carbon burial in marine basins is known to be controlled by various tectonic, oceanographic, hydrological, and climatic processes acting o...
Article
Full-text available
Quantification of risk to seal integrity in CCS, or gas extraction from hydraulic fracturing, is directly affected by the accessibility of organic pores within organic rich mudrocks. Knowledge of the host organic matter's mechanical properties, which are influenced by depositional environment and thermal maturity, are required to reduce operational...
Article
The Falkland Plateau is a key region for Early Cretaceous oceanography and climate, as its bathymetry controlled water mass and sediment exchange between the emerging South Atlantic and Southern Ocean basins. Changes in large-scale deep water circulation, induced by the evolution of marine gateways in the Falkland Plateau region, in turn, affected...
Article
Full-text available
Fine-grained sedimentary successions contain the most detailed record of past environmental conditions. High-resolution analyses of these successions yield important insights into sedimentary composition and depositional processes and are, therefore, required to contextualise and interpret geochemical data which are commonly used as palaeoclimate p...
Article
Marine anaerobic oxidation of ammonium (anammox) plays a central role in the nitrogen cycle of modern Oxygen Deficient Zones (ODZs). The newly developed bacteriohopanetetrol stereoisomer (BHT-x) biomarker for anammox, which is largely unaffected by early diagenesis, allows for the reconstruction of the presence and dynamics of past ODZs from the se...
Article
Full-text available
Calcareous and siliceous microorganisms are common components of mudrocks, and can be important in terms of stratigraphy and environmental interpretation. In addition, such microorganisms can have a significant ‘after life’, through post-mortem alteration, and represent a potential source of additional information about the diagenetic and deformati...
Article
Understanding the mechanical response of coal to CO2 injection is necessary to determine the suitability of a seam for carbon capture and underground storage (CCUS). The bulk elastic properties of a coal or shale, which determine its mechanical response, are controlled by the elastic properties of its individual components, i.e. macerals and minera...
Article
Full-text available
Mudrocks are highly heterogeneous in terms of both composition and fabric, with heterogeneities occurring at the submicron to centimetre plus scale. Such heterogeneities are relatively easy to visualise at the micron-scale through the use of modern scanning electron microscopy (SEM) techniques, but due to their inherent fine grain size, can be diff...
Preprint
Full-text available
Abstract. Extensive black shale deposits formed in the Early Cretaceous South Atlantic, supporting the notion that this emerging ocean basin was a globally important site of organic carbon burial. The magnitude of organic carbon burial in marine basins is known to be controlled by various tectonic, oceanographic, hydrological, and climatic processe...
Article
Organic carbon burial is an important driver of carbon cycle and climate dynamics on geological and shorter time scales. Ocean basins emerging during the Early Cretaceous break-up of Gondwana were primary sites of organic carbon burial, implying that their tectonic and oceanographic evolution may have affected trends and perturbations in global cli...
Poster
Full-text available
This project combines black shale dissolved organic matter (DOM) leaching with microcosm experiments under controlled conditions. The aim is to determine the abundance and nature of DOM, its availability for microbiological degradation and quantify produced gases (CO2, methane).
Conference Paper
Full-text available
One of the defining characteristics of contourite systems is the marked cyclicity in grain-size and related sediment properties. This property led to the definition of the bi-gradational contourite sequence (C1-C5) as the standard facies model for mixed grade mud/sand contourites. Drilling in the Gulf of Cadiz during IODP 339 recovered over 4.5 km...
Poster
Since 2017, we investigated iDOM in tropical and temperate rivers across Amazonia and Scotland using the next-generation liquid chromatography organic carbon detection – organic nitrogen detection system utilised by Pereira et al. (2014). Monthly sampling of rivers including the Cree, the Clyde and the Forth show evidence for iDOM mobilisation, but...
Article
Full-text available
The Kimmeridge Clay Formation (KCF) is a laterally extensive, total-organic-carbon-rich succession deposited throughout northwest Europe during the Kimmeridgian–Tithonian (Late Jurassic). It has recently been postulated that an expanded Hadley cell, with an intensified but alternating hydrological cycle, heavily influenced sedimentation and total o...
Presentation
We investigated the riverine carbon exports from a two headwater peatland environments in the UK, and examined the potential uncertainty of quantification due to the role of optically “invisible” dissolved organic matter (iDOM). Importantly, our work captured compositional changes of riverine DOM in during an exceptionally dry period and compared t...
Article
Full-text available
Sediment samples from the Gulf of Alaska (GOA, IODP Expedition 341, Site U1417) have been analyzed to understand present and past diagenetic processes that overprint the primary sediment composition. No Sulfate-Methane Transition Zone (SMTZ) was observed at the zone of sulfate depletion, but a >200 m thick sulfate- and methane-free sediment interva...
Article
Full-text available
Muds deposited in large-scale epicontinental seaways provide deep insights into palaeoclimates, biogeochemical cycles, sedimentation processes, and organic carbon burial during exceptionally warm periods throughout the Phanerozoic. Temporal changes can be monitored at single locations but the key, larger-scale oceanographical and related biogeochem...
Conference Paper
Expanded successions of marine black shale provide important proxy records to test climatic teleconnections across ocean basins and paleo-latitudes. The causal and generic relationships controlling the timing, composition, and internal variability of marine organic carbon (OC)-rich shale over large distances and during variable global climate state...
Article
Full-text available
The Kimmeridge Clay Formation (KCF) is a laterally extensive, total organic carbon-rich succession deposited throughout Northwest Europe during the Kimmeridgian–Tithonian (Late Jurassic). Here we present a petrographic and geochemical dataset for a 40 metre-thick section of a well-preserved drill core recovering thermally-immature deposits of the K...
Poster
Full-text available
The Jurassic stratigraphic succession of the Lombardy Basin (Southern Alps) is part of the southern Tethys passive continental margin. A Late Triassic-Early Jurassic rifting phase resulted in regional bathymetric differentiation vis-à-vis deep basins and structural highs. Outcrops of Jurassic sections at Colle di Sogno remain undisturbed, and inclu...
Conference Paper
Full-text available
An advanced method for pyritic and organic sulphur quantification in organic rich sediments was developed using a Rock-Eval which was designed for sulphur quantification in addition to carbon quantification (Rock-Eval S). This new method involves data processing of parameters obtained via Rock-Eval S analysis of rock samples. It was applied to sedi...
Conference Paper
Organic and inorganic geochemical investigations were carried out on samples of Kimmeridge Clay from Yorkshire, UK, to examine the Fe-S-C dynamics that created them. These samples have variable bulk and molecular compositions reflecting differing redox conditions, inputs of iron, and organic matter quantity/quality (TOC up to 18wt%, Type I-II/III k...
Article
Mudrocks are highly heterogeneous in a range of physical and chemical properties, including: porosity and permeability, fissility, colour, particle composition, size, orientation, carbon loading, degree of compaction, and diagenetic overprint. It is therefore important that the maximum information be extracted as efficiently and completely as possi...
Article
Full-text available
Tropical forests are global climate regulators through their interaction with hydrological and biogeochemical cycles. Despite extensive research on deforestation in South America and its global impact, the role of the largely intact Guiana Shield forests, north of the Amazon, has not yet been considered as part of this climate system. We use a regi...
Conference Paper
Full-text available
An advanced method for pyritic and organic sulphur quantification was developed using a Rock-Eval 6 adapted for sulphur quantification in addition to carbon (Rock-Eval 6S). It consists in data processing of sulphur parameters obtained via Rock-Eval 6S analysis of a rock sample. This Rock-Eval 6S method for pyritic and organic sulphur quantification...
Article
Methane and CO2 are climatically active greenhouse gases (GHG) and are powerful drivers of rapid global warming. Comparable to the Arctic, the tropics store large volumes of labile sedimentary carbon that is vulnerable to climate change. However, little is known about this labile carbon reservoir, in particular the behaviour of high methane–produci...
Article
Full-text available
It is well established that greenhouse conditions prevailed during the Cretaceous Period (~ 145–66 Ma). Determining the exact nature of the greenhouse-gas forcing, climatic warming and climate sensitivity remains, however, an active topic of research. Quantitative and qualitative geochemical and palaeontological proxies provide valuable observation...
Article
This study reviews and synthesises existing information generated within the SCOPSCO (Scientific Collaboration on Past Speciation Conditions in Lake Ohrid) deep drilling project. The four main aims of the project are to infer (i) the age and origin of Lake Ohrid (Former Yu-goslav Republic of Macedonia/Republic of Albania), (ii) its regional seismot...
Article
Visual inspection (optical microscope point counting) and silica abundance show that laminated shale from the Late Cretaceous of Colombia contains high levels of detrital quartz silt and sand particles. Closer examination using the charge contrast imaging (CCI) technique, however, illustrates that much of the quartz is authigenic micro-quartz, and...
Article
Full-text available
During the Cretaceous major episodes of oceanic anoxic conditions triggered large scale deposition of marine black shales rich in organic carbon. Several oceanic anoxic events (OAEs) have been documented including the Cenomanian to Turonian OAE 2, which is among the best studied examples to date. This study reports on a large limestone body that oc...
Article
The role of mountain evolution on local climate is poorly understood and potentially underestimated in climate models. One prominent example is East Africa, which underwent major geodynamic changes with the onset of the East African Rift System (EARS) more than 250 Myr ago. This study explores, at the regional East African scale, a molecular approa...
Article
Visual inspection (optical microscope point counting) and silica abundance show that laminated shale from the Late Cretaceous of Colombia contains high levels of detrital quartz silt and sand particles. Closer examination using the charge contrast imaging (CCI) technique, however, illustrates that much of the quartz is authigenic micro-quartz, and...
Article
The role of mountain evolution on local climate is poorly understood and potentially underestimated in climate models. One prominent example is East Africa, which underwent major geodynamic changes with the onset of the East African Rift System (EARS) more than 250 Myr ago. This study explores, at the regional East African scale, a molecular approa...
Article
Petroleum source rocks are strongly enriched in organic carbon (OC), and their trace metal (TM) contents often reach low-grade ore levels. The mechanisms leading to these coenrichments are important for understanding how extreme environmental conditions support the formation of natural resources. We therefore studied organic-rich Eocene marls and l...
Poster
Full-text available
Poster presented by the supervisor of the project, T. Wagner, to the GRC Conference, evidencing the difficulties of obtaining palaeo-redox conditions from organic proxies in the high thermally mature samples, and identifying how inorganic proxies could fill this information gap.
Article
New climate simulations using the HadCM3L model with a paleogeography of the Late Jurassic [155.5 Ma], and proxy-data corroborate that warm and wet tropical-like conditions reached as far north as the UK sector of the Jurassic Boreal Seaway [~35oN]. This is associated with a northern hemisphere Jurassic Hadley cell and an intensified subtropical je...
Article
During the Cretaceous greenhouse, episodes of widespread ocean deoxygenation were associated with globally occurring events of black shale deposition. Possibly the most pronounced of these oceanic anoxic events (OAE's) was the Cenomanian–Turonian OAE2 (∼94 Ma). However, although certain redox sensitive trace metals tend to be preferentially sequest...
Article
Full-text available
We present elemental, lipid biomarker and, in the supplement, compound-specific isotope (δ13C, δ2H) data for soils and leaf litter collected in the catchment of Lake Ohrid (Albania, Macedonia), as well as macrophytes, particulate organic matter and sediments from the lake itself. Lake Ohrid provides an outstanding archive of continental environment...
Chapter
Full-text available
Data
To reconstruct the cycling of reactive phosphorus (P) in the Bering Sea, a P speciation record covering the last ~ 4 Ma was generated from sediments recovered during Integrated Ocean Drilling Program (IODP) Expedition 323 at Site U1341 (Bowers Ridge). A chemical extraction procedure distinguishing between different operationally defined P fractions...
Article
Full-text available
The Cretaceous period (~145–65 m.y. ago) was characterized by intervals of enhanced organic carbon burial associated with increased primary production under greenhouse conditions. The global consequences of these perturbations, oceanic anoxic events (OAEs), lasted up to 1 m.y., but short-term nutrient and climatic controls on widespread anoxia are...
Article
Full-text available
The Congo River basin drains the second largest area of tropical rainforest in the world, including a large proportion of pristine wetlands. We present the bacteriohopanepolyol (BHP) inventory of a suite of tropical soils and, from comparison with published data, propose some initial ideas on BHP distribution controls. Strong taxonomic controls on...
Article
We present elemental, lipid biomarker and compound-specific isotope (δ13C, δ2H) data for soils and leaf litter collected in the catchment of Lake Ohrid (Albania, Macedonia), as well as macrophytes, particulate organic matter and sediments from the lake itself. Lake Ohrid provides an outstanding archive of continental environmental change of at leas...
Article
Full-text available
Minerals stabilize organic carbon (OC) in sediments, thereby directly affecting global climate at multiple scales, but how they do it is far from understood. Here we show that manganese oxide (Mn oxide) in a water treatment works filter bed traps dissolved OC as coatings build up in layers around clean sand grains at 3%w/wC. Using spectroscopic and...
Conference Paper
Full-text available
Tropics play a key role in the atmospheric circulation, partly responsible for the variations of climatic conditions, as they are a major source of heat and water vapour on Earth. Thus, improving our knowledge on past temperature fluctuations and hydrological regimes in these areas may allow to better constrain the driving forces controlling climat...
Conference Paper
Full-text available
Long chains n-alkanes are components of terrestrial plant leaf waxes that are ubiquitously found in geological archives. They have been extensively used to track environmental and ecological variations in the past, notably changes in vegetation communities. Recent analytical developments led to the possibility of measuring their deuterium to hydrog...
Poster
Poster with first results from a basic strategy implemented in order to estimate the non-affected-by-maturity, i.e. immature, parameters of Cretaceous source rocks (HI, TOC). Background data consisted on Rock Eval and quantitative petrographic analyses.
Article
Full-text available
We use first field-based observations of precipitation and river isotopic chemistry from a three-year study (2009-2011) in rainforest and nearby savannah in central Guyana at the northern rim of the Amazon rainforest to establish the quality of modelled or remotely-sensed datasets. Our 3 years of data capture a reduced rainfall regime in 2009 and a...