Preprints
Filtering by Subject: Geochemistry
The Heavy Mineral Map of Australia Project: A Novel, Rapid, Automated Quantitative Mineralogy Workflow
Published: 2023-10-10
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics
The Heavy Mineral Map of Australia (HMMA) is the world’s first project aiming to define a continental heavy mineral baseline. It utilises a novel sample processing workflow and automated mineralogy techniques to rapidly generate and analyse mineralogical data from 1315 archived samples of catchment outlet sediments collected from 1186 catchments across the Australian continent. Heavy [...]
Coral geochemical response to uplift in the aftermath of the 2005 Nias-Simeulue earthquake
Published: 2023-10-07
Subjects: Environmental Indicators and Impact Assessment, Geochemistry, Geomorphology, Natural Resources and Conservation, Tectonics and Structure
On 28 March 2005, the Indonesian islands of Nias and Simeulue experienced a powerful Mw 8.6 earthquake and widespread co-seismic uplift and subsidence. In areas of coastal uplift (up to ~2.8 m), fringing reef coral communities were killed by exposure, while deeper corals that survived were subjected to habitats with altered runoff, sediment and nutrient regimes. Here we present time-series [...]
A shift in the Sr isotopic composition of the magmatic source triggering 2019 paroxysmal eruptions at Stromboli Volcano
Published: 2023-10-05
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics, Volcanology
The persistent volcanic activity of Stromboli Volcano, Aeolian Islands, Italy, is interrupted by paroxysmal eruptions on a decadal interval. In 2019, two strong paroxysms on July 3rd and August 28th, ended a more than a decade long period of regular strombolian activity. During normal strombolian activity the volcano erupts highly porphyritic scoria and lava (HP)20 with a shoshonitic basalt [...]
Novel observations of East Asian Summer Monsoon evolution during Glacial Termination II from Lake Suigetsu, Japan
Published: 2023-10-04
Subjects: Climate, Geochemistry
Glacial terminations offer a unique opportunity to examine how the East Asian Summer Monsoon (EASM) responds to rapid increases in global temperature and accompanying abrupt climatic reorganisation. Reconstructions from contrasting glacial terminations with differently evolving boundary conditions are of particular value to our understanding of deglacial EASM behaviours, e.g., Termination I (from [...]
Insights into deglacial East Asian Monsoon seasonality and inter-regional teleconnections from Lake Suigetsu, Japan
Published: 2023-10-04
Subjects: Climate, Geochemistry
The past evolution of the East Asian Monsoon (EAM) was affected by remote climate processes. However, there is uncertainty surrounding these teleconnections and their impact on each seasonal EAM mode during periods of rapid global change. Here we use the unique biannual precipitation patterns of central Japan to reconstruct winter and summer EAM evolution during the last glacial termination [...]
The contemporary stable isotope hydrology of Lake Suigetsu and surrounding catchment (Japan) and its implications for sediment-derived palaeoclimate records
Published: 2023-10-03
Subjects: Fresh Water Studies, Geochemistry, Hydrology, Meteorology
The Lake Suigetsu sediment cores exemplify a high-quality archive of palaeoclimatic change in East Asia during the past 150 ka. Robust interpretation of stable isotope-based proxy reconstructions from the Suigetsu cores can be aided by a greater understanding of the factors affecting the isotope composition of the lake and how it relates to that of precipitation. Here we use extended contemporary [...]
Combined genomic and imaging techniques show intense arsenic enrichment caused by detoxification in a microbial mat of the Dead Sea shore
Published: 2023-09-26
Subjects: Biogeochemistry, Environmental Microbiology and Microbial Ecology Life Sciences, Geochemistry, Paleobiology
Microbial mats and microbialites are essential tools for reconstructing early life and its environments. To better understand microbial trace element cycling, a microbial mat was collected from the sinkhole systems of the western shores of the Dead Sea, a dynamic environment exhibiting diverse extreme environments. Intense arsenic enrichment (up to 6.5 million times higher than current water [...]
Omnivariant Generalized Least Squares Regression: Theory, Geochronological Applications, and Making the Case for Reconciled Δ47 calibrations
Published: 2023-09-22
Subjects: Applied Mathematics, Earth Sciences, Geochemistry
Least-squares regression methods are mathematically powerful, conceptually and computationally simple, and widely used in many fields. However, none of the commonly-used flavors of least-squares regression, such as York regression or Generalized Least Squares (GLS), take into account the full set of covariances between all observed (x,y) values. Here we describe the Omnivariant Generalized Least [...]
Generation of LOMU type alkali basalts in East Asia by melting and melt metasomatism of the asthenospheric mantle by a Paleoproterozoic subducted slab component
Published: 2023-08-30
Subjects: Geochemistry, Geology, Volcanology
The origin of alkali basalts with distinctive time-integrated low U/Pb (low µ, LOMU) from East Asia is controversial due to the complex geochemical and tectonic signatures reported from this region. We report new data on the petrology and geochemistry of the Higashi-Matsuura and Kita-Matsuura alkali basalts from southwest Japan, which confirm the presence of a LOMU-type mantle component below the [...]
Lithium isotope constraints on the plumeworld hypothesis for the Marinoan Snowball Earth
Published: 2023-08-26
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics
The Snowball Earth hypothesis predicts that continental chemical weathering was curtailed substantially during but rebounded strongly after the Marinoan ice age some 635 million years ago. Defrosting the planet would result in a plume of fresh glacial meltwater with a different chemical composition than underlying hypersaline seawater, generating an onshore-offshore geochemical gradient. Here we [...]
Why is it critical to revisit significance and consequences of salt precipitation during CO2 injection?
Published: 2023-08-24
Subjects: Earth Sciences, Environmental Sciences, Geochemistry
Among the candidates for CO2 sequestration, deep saline aquifers are considered the best option because of their storage capacity and proximity to emission sources. Injection of large volumes (million tons scale) of supercritical CO2 into the geological formations causes evaporation of formation water near wellbores and precipitation of salt crystals inside the porous medium. CO2-induced salt [...]
Eocene (50-55 Ma) greenhouse climate recorded in nonmarine rocks of San Diego, CA, USA
Published: 2023-08-08
Subjects: Chemistry, Climate, Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Soil Science, Stratigraphy
Nonmarine rocks in sea cliffs of southern California store a detailed record of weathering under tropical conditions millions of years ago, where today the climate is much drier and cooler. This work examines early Eocene (~50-55 million-year-old) deeply weathered paleosols (ancient, buried soils) exposed in marine terraces of northern San Diego County, California, and uses their geochemistry and [...]
Tephra dispersal and composition reveal the explosive onset of a large basaltic fissure eruption: Timanfaya, Lanzarote, 1730–1736 CE
Published: 2023-08-03
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Stratigraphy, Volcanology
Basaltic fissure eruptions are chiefly characterized by sizable emissions of lava flows and volcanic gases, posing significant hazards. However, such eruptions may be punctuated by explosive episodes, which are comparatively poorly understood but may have important volcanic hazard and environmental implications. The 1730–1736 CE Timanfaya eruption on Lanzarote, Canary Islands, is a large basaltic [...]
Application of the authigenic 10Be/9Be dating to constrain the age of a long-lived lake and its regression in an isolated intermontane basin: The case of Late Miocene Lake Turiec, Western Carpathians
Published: 2023-07-31
Subjects: Earth Sciences, Geochemistry, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
The depositional record of intermontane basins provides a valuable archive of the temporal evolution of orogenic belts; their common isolated nature may, however, hinder the efficient usage of standard approaches to constrain the age of a basin fill. In this paper the authigenic 10Be/9Be dating method is employed and tested to construct an age model of the existence and regression of Lake Turiec, [...]
Estimating the silica content and loss-on-ignition in the North American Soil Geochemical Landscapes datasets: a recursive inversion approach
Published: 2023-07-28
Subjects: Geochemistry, Natural Resources and Conservation, Soil Science
A novel method of estimating the silica (SiO2) and loss-on-ignition (LOI) concentrations for the North American Soil Geochemical Landscapes (NASGL) project datasets is proposed. Combining the precision of the geochemical determinations with the completeness of the mineralogical NASGL data, we suggest a ‘reverse normative’ or inversion approach to calculate first the minimum SiO2, water (H2O) and [...]