Dioni I. Cendón

• PhD
• Group Leader at Australian Nuclear Science and Technology Organisation

This paper presents a continental scale interpretation of δ2H and δ18O in Australian precipitation, incorporating historical GNIP data at seven sites (1962-2002) and 8-12 years of new monthly data from 15 sites from 2003 to 2014. The more than doubling of stations and the significant time series duration allow for an improved analysis of Australian...

Groundwater is an important resource in arid and semi-arid regions and determining its residence times is critical for sustainable use. Radiocarbon (¹⁴C) is currently the primary geochemical tracer for determining residence times of regional groundwater systems. The analysis of ¹⁴C contents of dissolved inorganic carbon (DIC) became more straightfo...

The application of N fertilisers to enhance crop yield is common throughout the world. Many crops have historically been, or are still, fertilised with N in excess of the crop requirements. A portion of the excess N is transported into underlying aquifers in the form of NO3⁻, which is potentially discharged to surface waters. Denitrification can re...

Increasing concentrations of Rare Earth Elements (REE) plus yttrium (REY) are entering the environment due to human activities. The similar chemical behaviour across the whole REY, i.e. the lanthanide series (lanthanum to lutetium) and yttrium, allows their use as tracers, fingerprinting rock-forming processes and fluid-rock interactions in earth s...

Understanding the connection between aquifers, aquitards, and groundwater-dependant ecosystems remains a key challenge when developing a conceptual hydrogeological model. The aim of this study was to develop a systematic strontium isotope (87Sr/86Sr) fingerprinting framework of rocks and water within the sedimentary Surat and Clarence-Moreton basin...

Understanding inter-aquifer connectivity or leakage of greenhouse gases and groundwater to aquifers overlying gas reservoirs is important for environmental protection and social licence to operate. Australia's Great Artesian Basin (GAB) is the largest artesian groundwater system in the world with groundwater extracted for agriculture, livestock, mi...

Area, Australia, are an important regional environmental record representing at least the last two interglacials. Understanding the source and evolution of these sediments, both temporally and spatially, is an essential component of the site’s reconstruction. In this study, we evaluate this question using physical, mineralogical, elemental, and iso...

Wetlands process large amounts of carbon (C) that can be exported laterally to streams and rivers. However, our understanding of wetland inputs to streams remains unclear, particularly in tropical systems. Here we estimated the contribution of seasonal wetlands to the C pool of a lowland headwater stream in the Australian tropics. We measured disso...

The Piedmont basin (NW Italy) records a Messinian Salinity Crisis (MSC) succession including a selenite gypsum deposit assigned to the Primary Lower Gypsum (PLG, MSC stage 1). Strontium isotope ratios are in the range of the PLG deposits of the Mediterranean area. Sulfate isotope compositions of vertically oriented selenite gypsum beds, in the lowe...

The analysis of stable carbon isotopes is commonly used in Quaternary science to reconstruct the environmental conditions and vegetation contributions to sedimentary sequences. However, the measured  13 C signature of the total organic matter (OM) pool can also reflect other complexities within depositional environments. The peats of the Thirlmere...

Chemical analyses of 2,618 (1,640 new and 978 published) fluid inclusions in marine halite were used to define paleoseawater [Ca²⁺] and [SO2−4] over the past 550 million years (Myr). Three types of fluid inclusion brine chemistries were recognized based on measured [Ca²⁺] and [SO2−4]: (1) SO4-rich with [SO2−4] ≫ [Ca²⁺]; (2) Ca-rich with [Ca²⁺] ≫ [S...

Dado que las aguas subterráneas constituyen la mayor reserva de agua dulce líquida en el mundo, la presencia de diversos contaminantes en acuíferos es un tema alarmante. En los sectores rurales prevalecen las problemáticas relacionadas con la contaminación del agua por la implementación de las prácticas de la agricultura industrializada. Con relaci...

Strata-bound elemental sulfur deposits occur in different circum-Mediterranean Miocene sedimentary successions containing evaporites and high amounts of organic matter. It is widely known that bacterial sulfate reduction processes are the triggering mechanisms involved in the origin of hydrogen sulfide and the subsequent native sulfur. However, in...

The potential for connectivity between water supply aquifers and gas reservoirs raises community, government, and scientific concerns. Methane can occur naturally, making it difficult to determine whether water bore methane levels are being influenced by nearby gas operations. This poses a challenge in the Surat Basin, where coal seam gas productio...

The Piedmont basin (NW Italy) records a Messinian Salinity Crisis (MSC) succession including a selenite gypsum deposit assigned to the Primary Lower Gypsum (PLG, MSC stage 1). Strontium isotope ratios are in the range of the PLG deposits of the Mediterranean area. Sulfate isotope compositions of vertically oriented selenite gypsum beds, in the lowe...

Hydrochemical data responds at a much slower rate to changes in groundwater conditions than does the propagation of hydraulic pressure, and therefore may provide more insight to groundwater flow paths. In low rank coal measures, where gas is biogenic, it is important to understand the fluid-rock and microbial interactions that affect the spatial an...

Large volume of evaporites were deposited during the Messinian Salinity Crisis (MSC) across the Mediterranean. These evaporites are currently outcropping on land and are interpreted by seismic profiles beneath the Mediterranean floor. Biostratigraphic, magnetostratigraphic and astrochronologic data recovered from sediments below and above outcroppi...

The analysis of stable carbon isotopes is commonly used in Quaternary science to reconstruct the environmental conditions and vegetation contributions to sedimentary sequences. However, the measured d 13 C signature of the total organic matter (OM) pool can also reflect other complexities within depositional environments. The peats of the Thirlmere...

In the urban environment, anthropogenic activities provide numerous potential sources of contamination, which can often lead to difficulties in identifying the processes impacting groundwater quality (natural and anthropogenic). This is particularly relevant at Wastewater Treatment Plants (WWTPs) that are often subject to changes in land use and co...

Catchment-scale recharge and water balance estimates are commonly made for the purposes of water resource management. Few catchments have had these estimates ground-truthed. One confounding aspect is that runoff and soil-water inputs commonly occur throughout the year; however, in climates with strong dry seasons, base flow can be directly sampled....

The widespread formation of organic rich sediments in south-east Australia during the Holocene (Marine Isotope Stage [MIS] 1) reflects the return of wetter and warmer climates following the Last Glacial Maximum (LGM). Yet, little is known about whether a similar event occurred in the region during the previous interglacial (MIS 5e). A 6.8 m sedimen...

The presence of contaminants in groundwater is matter of concern due to the aquifers constitute the major reserve of liquid fresh water of the world. The objective of this work was to assess the presence of atrazine in the unconfined aquifer and confined aquifer layers of the Marcos Juarez loessic plain linking with the regional hydrogeological mod...

Los sistemas acuíferos confinados (SAC) son utilizados para diferentes actividades en la provincia de Córdoba. Dado que la tasa de renovación de estos sistemas puede superar los miles de años, es necesario su estudio y manejo sustentable. El objetivo de este trabajo fue evaluar los aspectos hidrodinámicos, geoquímicos y de aptitudes de uso asociado...

River floodplains sustain irrigated agriculture worldwide. Despite generalised groundwater-level falls, limited hard data are available to apportion groundwater sources in many irrigated regions. In this paper, we propose a workflow based on: hydrochemical analysis, water stable isotopes, radiocarbon contents and multivariate statistical analysis t...

Quantitative multi-element analyses of single fluid inclusions in halite and other sedimentary minerals can provide information on the origin and chemical evolution of ancient surface waters on Earth. Integrated laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and cryogenic-scanning electron microscopy-energy dispersive spect...

The potential for Wastewater Treatment Plants (WWTPs) to cause adverse impacts to groundwater quality is a major global environmental challenge. Robust and sensitive techniques are required to characterise these impacts, particularly in settings with multiple potential contaminant sources (e.g. agricultural vs. site-derived). Stable (δ²HH2O, δ¹⁸OH2...

For the past two decades, the measurement of nitrous oxide (N2O) isotopocules – isotopically substituted molecules 14N15N16O, 15N14N16O and 14N14N18O of the main isotopic species 14N14N16O – has been a promising technique for understanding N2O production and consumption pathways. The coupling of non-cryogenic and tuneable light sources with differe...

The isotopic composition of groundwater can be a useful indicator of recharge conditions and may be used as an archive to infer past climate variability. Groundwater from two largely confined aquifers in south-west Australia, recharged at the northernmost extent of the westerly wind belt, can help constrain the palaeoclimate record in this region....

Fresh groundwater on barrier islands is affected by changing sea levels and precipitation variability due to climate change and is also vulnerable to anthropogenic processes, such as contamination and groundwater over-abstraction. Constraining groundwater mean residence times (MRTs) and flow paths is essential for understanding and managing these r...

The general objective of the research is to assess the recharge areas, water dynamics, water chemistry, residence times and water age in local and regional aquifers (unconfined and confined) and their link with surface and atmospheric waters in the province of Córdoba In Marcos Juarez plain the work is being developed in order to elucidate relation...

The riverine export of carbon is expected to be driven by changes in connectivity between source areas and streams. Yet we lack a thorough understanding of the relative contributions of different water sources to the dissolved carbon flux, and of the way these contributions vary with seasonal changes in flow connectivity. Here we assess the tempora...

Abstract. For the past two decades, the measurement of N₂O isotopocules – isotopically substituted molecules ¹⁴N¹⁵N¹⁶O, ¹⁵N¹⁴N¹⁶O and ¹⁴N¹⁴N¹⁸O of the main isotopic species ¹⁴N¹⁴N¹⁶O – has been a promising t...

Fishermans Bend is an urban redevelopment precinct situated on the Yarra River estuary in Melbourne, Australia. Understanding the hydrogeological system is important for characterising the impacts from legacy contamination and for monitoring the effects of urbanisation on groundwater flow systems and quality. Stable isotopes of water (δ¹⁸O, δ²H) an...

Identifying the source of methane (CH4) in groundwater is often complicated due to various production, degradation and migration pathways, particularly in settings where there are multiple groundwater recharge pathways. This study demonstrates the ability to constrain the origin of CH4 within an alluvial aquifer that could be sourced from in situ m...

This paper examines the distributions of several anthropogenic radionuclides (239+240Pu, 241Am, 137Cs, 90Sr, 60Co and 3H) at a legacy trench disposal site in eastern Australia. We compare the results to previously published data for Pu and tritium at the site. Plutonium has previously been shown to reach the surface by a bath-tubbing mechanism, fol...

The Lorca and Fortuna basins are two intramontane Neogene basins located in the eastern Betic Cordillera (SE Spain). During the Late Tortonian ‐ Early Messinian, marine and continental evaporites precipitated in these basins as a consequence of increased marine restriction and isolation. Here we show a stratigraphic correlation between the evaporit...

Fresh groundwater on barrier islands is affected by changing sea levels, groundwater use and precipitation variability due to climate change. These systems are also vulnerable to contamination and groundwater over-abstraction. Constraining groundwater mean residence times (MRT) and flow paths are essential for understanding and managing these resou...

Groundwater δ18O record of paleorecharge and climate for the last 35ka in south-west Western Australia

Quaternary sand dunes and underlying Pliocene-Oligocene materials host the key groundwater resources that provide the only source of drinking water for a large proportion of Maputo district (Mozambique). This resource is at risk due to potential over exploitation, pollution and salinization. Few hydrogeochemical studies have been conducted in the r...

Catchment-scale hydrological and hydrogeological investigations commonly conclude by finding that particular stream reaches are either gaining or losing; they also often assume that the influence of bedrock aquifers on catchment water balances and water quality is insignificant. However, in many cases, such broad findings are likely to oversimplify...

Documenting the sources and residence times of water that contributes to streamflow is important for understanding processes in river catchments. The residence times of bank storage and return flow and its influence on river water chemistry in the upper Barwon River of southeast Australia were investigated using stable (¹⁸O, ²H, and ¹³C) and radioa...

Understanding the sources and transit times of water that generates streamflow in headwater streams is important for understanding catchment functioning. This study determines the water sources and transit times in first-order streams from a temperate rainforest in the Otway Ranges, southeast Australia. Comparison of the major ion geochemistry of s...

The Messinian Salinity Crisis (MSC) led to deposition of one of the youngest saline giant on Earth. The increasing restriction of the connections between the Mediterranean, the Atlantic Ocean and the freshwater Paratethyan basins resulted in the deposition of massive amounts of evaporites (gypsum, anhydrite, halite and potash salts) in shallow marg...

The interaction between surface water and groundwater in clay-rich fluvial environments can be complex and is generally poorly understood. Airborne electromagnetic surveys are often used for characterizing regional groundwater systems, but they are constrained by the resolution of the method. A resistivity imaging survey has been carried out in the...

Research activities of the Spanish Working Group of the International Geosciences Program (2013-2016) are located in places where wetlands are dependent on groundwater: Las Tablas de Daimiel (Ciudad Real), Laguna de Fuente de Piedra (Málaga) and the coastal wetlands of the Sagunto-Castellón area. In these areas, the studies are focused on the hydro...

Understanding pathways of recharge to alluvial aquifers is important for maintaining sustainable access to groundwater resources. Water balance modelling is often used to proportion recharge components and guide sustainable groundwater allocations. However, it is not common practice to use hydrochemical evidence to inform and constrain these models...

Documenting the location and magnitude of groundwater recharge is critical for understanding groundwater flow systems. Radioactive tracers, notably ¹⁴C, ³H, ³⁶Cl, and the noble gases, together with other tracers whose concentrations vary over time, such as the chlorofluorocarbons or sulfur hexafluoride, are commonly used to estimate recharge rates....

The Canning Basin is the largest sedimentary basin in Western Australia and is located in one of the most cyclone prone regions of Australia. Despite its importance as a future resource, limited groundwater data is available for the Basin. The main aims of this paper are to provide a detailed understanding of the source of groundwater recharge, the...

It has been widely acknowledged that environmental literacy can provide a strong foundation for future environmental responsiveness, as well as help in the transition towards more sustainable societies and healthy living. According to environmentalists and social scientists, behavioural intentions to sustainable consumption and lifestyle among citi...

This study demonstrates the importance of the conceptual hydrogeological model for the estimation of groundwater recharge rates in an alluvial system interconnected with an ephemeral or intermittent stream in south-east Queensland, Australia. The losing/gaining condition of these streams is typically subject to temporal and spatial variability, and...

The residence times of groundwater and chloride and the processes contributing to the development of saline (total dissolved solids (TDS) up to 45,379 mg/L) groundwater within the Barwon River Catchment of southeast Australia were investigated using major ion, stable isotope (δ¹⁸O, δ²H, and δ¹³C) and radioactive isotope (³H, ¹⁴C, ³⁶Cl) geochemistry...

Geochemical and microbiological indicators of methane (CH4) production, oxidation and migration processes in groundwater are important to understand when attributing sources of gas. The processes controlling the natural occurrence of CH4 in groundwater must be understood, especially when considering the potential impacts of the global expansion of...

The influence of mountain front recharge on the water balance of alluvial valley aquifers located in upland catchments of the Condamine River basin in Queensland, Australia, is investigated through the development of an integrated hydrogeological framework. A combination of three-dimensional (3D) geological modelling, hydraulic gradient maps, multi...

Groundwater sources supply fresh drinking water to almost half of the World's population and are a main source of water for irrigation across world. Characterization of groundwater resources, surfacegroundwater interactions and their link to the global water cycle and modern global change are important themes in hydrogeological research, whereas li...

Geochemical and microbiological indicators of methane (CH4) production, oxidation and migration processes in groundwater are important to understand when attributing sources of gas. The processes controlling the natural occurrence of CH4 in groundwater must be understood, especially when considering the potential impacts of the global expansion of...

The Macquarie Marshes (NSW, Australia) cover approximately 200 square km of the Macquarie River flood-plains. The marshes are one of the largest remaining inland semi-permanent wetlands in south-eastern Australia. Diversity of fauna and flora has decreased in the wetlands while the flood-drought cycles controlling these ecosystems have been affecte...

Abstract

Here, we present a terrestrial multi-proxy record of Late Quaternary environmental changes in the southern Iberian Peninsula covering approximately 30 ka. This sedimentary record originates from a saline playa lake (Laguna de Fuente de Piedra) hosted within a complex geological setting dominated by Triassic claystones and evaporites, Jurassic carbo...

A major limitation to the assessment of catchment transit time (TT) stems from the use of stable isotopes or chloride as hydrological tracers, because these tracers are blind to older contributions. Yet, accurately capturing the TT of the old water fraction is essential, as is the assessment of its temporal variations under non-stationary catchment...

A multi-layered coastal aquifer in southeast Australia was assessed using environmental isotopes, to identify the origins of salinity and its links to palaeo-environmental setting. Spatial distribution of groundwater salinity (electrical conductivity values ranging from 0.395 to 56.1mS/cm) was examined along the coastline along with geological, iso...

Coal seam gas (CSG) production can have an impact on groundwater quality and quantity in adjacent or overlying aquifers. To assess this impact we need to determine the background groundwater chemistry and to map geological pathways of hydraulic connectivity between aquifers. In south-east Queensland (Qld), Australia, a globally important CSG explor...

Reconstructions of Quaternary climate are often based on the isotopic content of paleo-precipitation preserved in proxy records. While many paleo-precipitation isotope records are available, few studies have synthesized these dispersed records to explore spatial patterns of late-glacial precipitation δ18O. Here we present a synthesis of 86 globally...

This study has significantly advanced our understanding of the origin of groundwater recharge in a semi-arid zone region of the Darling River catchment, Australia. The generally accepted hypothesis in arid zone environments in Australia that river water forms the primary groundwater recharge source has proven difficult to monitor. This is due to th...

A major limitation to the accurate assessment of streamwater transit time (TT) stems from the use of stable isotopes or chloride as hydrological tracers, because these tracers are blind to older contributions. Also, while catchment processes are highly non-stationary, the importance of temporal dynamics in older water TT has often been overlooked....

In areas of potential coal seam gas (CSG) development, understanding interactions between coal-bearing strata and adjacent aquifers and streams is of highest importance, particularly where CSG formations occur at shallow depth. This study tests a combination of hydrochemical and isotopic tracers to investigate the transient nature of hydrochemical...

An understanding of hydrological processes is vital for the sustainable management of groundwater resources, especially in areas where an aquifer interacts with surface water systems or where aquifer interconnectivity occurs. This is particularly important in areas that are subjected to frequent drought/flood cycles, such as the Cressbrook Creek ca...

Previous analyses of past climate changes have often been based on site-specific isotope records from speleothems, ice cores, sediments and groundwaters. However, in most studies these dispersed records have not been integrated and synthesized in a comprehensive manner to explore the spatial patterns of precipitation isotope changes from the last i...

The Kulumadau deposit represents an intermediate-sufidation epithermal gold deposit (3.8 Mt at 2.3g/t, Ag:Au = 1). Mineralisation is primarily confined to hydrothermal breccias within preexisting fault zones, where it is disseminated throughout a hydrothermal matrix comprising chlorite-quartz-adularia-illite-I/S clays-calcite-pyrite. The host seque...

Reconstructions of Quaternary climate are often based on the isotopic content of paleo-precipitation preserved in proxy records. While many paleo-precipitation isotope records are available, few studies have synthesized these dispersed records to explore spatial patterns of late-glacial precipitation δ18O. Here we present a synthesis of 86 globally...

Multiple tracer-element and isotope approaches were applied at a 1960s-era low-level radioactive waste burial site located in the Lucas Heights area on the southwest urban fringe of Sydney, Australia. The site is situated among other municipal and industrial (solid and liquid) waste disposal sites causing potential mixing of leachates. Local rainfa...

Understanding the behaviour and variability of environmental tracers is important for their use in estimating groundwater discharge to rivers. This study utilizes a multi-tracer approach to quantify groundwater discharge into a 27 km upland reach of the Gellibrand River in southwest Victoria, Australia. Ten sampling campaigns were conducted between...

Knowledge of groundwater residence times and recharge locations is vital to the sustainable management of groundwater resources. Here we investigate groundwater residence times and patterns of recharge in the Gellibrand Valley, southeast Australia, where outcropping aquifer sediments of the Eastern View Formation form an "aquifer window" that may r...

Knowledge of groundwater residence times and recharge locations are vital to the sustainable management of groundwater resources. Here we investigate groundwater residence times and patterns of recharge in the Gellibrand Valley, southeast Australia, where outcropping aquifer sediments of the Eastern View Formation form an "aquifer window" that may...

Groundwater residence time in the Kulnura–Mangrove Mountain aquifer was assessed during a multi-year sampling programme using general hydrogeochemistry and isotopic tracers (H2O stable isotopes, δ13CDIC, 3H, 14C and 87Sr/86Sr). The study included whole-rock analysis from samples recovered during well construction at four sites to better characteris...

An understanding of hydrological processes is vital for the sustainable management of groundwater resources, especially in areas where an aquifer interacts with surface water systems or where aquifer-interconnectivity occurs. This is particularly important in areas that are subjected to frequent drought/flood cycles, such as the Cressbrook Creek ca...

The residence time of groundwater within 50 m of the Tambo River, South East Australia, has been estimated through the combined use of 3H and 14C. Groundwater residence times increase towards the Tambo River which implies a gaining river system and not increasing bank storage with proximity to the Tambo River. Major ion concentrations and δ2H and δ...

The residence time of groundwater within 50 m of the Tambo River, South East Australia, has been estimated through the combined use of 3H and 14C. Groundwater residence times increase towards the Tambo River which implies a gaining river system and not increasing bank storage with proximity to the Tambo River. Major ion concentrations and δ2H and δ...