Filtering by Subject: Geochemistry
Published: 2021-02-24
Subjects: Earth Sciences, Geochemistry, Geology, Tectonics and Structure
Forearc basins preserve the geologic record relating strictly to arc magmatism. The provenance of forearc sediment can be used to differentiate periods of crustal growth, accretion, and destruction, enhanced magmatism, advancing and retreating subduction slabs, delamination, etc. All these tectonic events systems predict differing degrees of sedimentary reworking of the older forearc units. [...]
Published: 2021-02-18
Subjects: Earth Sciences, Geochemistry, Other Earth Sciences, Physical Sciences and Mathematics, Volcanology
The flow of high-temperature and compositionally-enriched material between mantle plumes and nearby spreading centres influences up to 30% of the global mid-ocean ridge system and represents a significant, but currently unconstrained, flux of volatiles out of the mantle. Here we present new analyses of H2O, F, Cl and S in basaltic glass chips from an archetypal region of plume-ridge interaction, [...]
Published: 2021-02-10
Subjects: Geochemistry, Geology, Tectonics and Structure
Late Quaternary coral growth ages from uplifted coastal regions, such as marine terraces and associated palaeoshorelines, are an essential tool used to derive tectonic and fault controlled uplift and deformation rates, and thus contribute to seismic hazard analysis and constrain past global sea levels. Fossil coral growth ages are assessed for reliability based upon whether the δ234Ui (or [...]
Published: 2021-02-01
Subjects: Earth Sciences, Environmental Sciences, Geochemistry, Geology, Numerical Analysis and Scientific Computing, Statistics and Probability, Volcanology
Minerals exhibit zoning patterns that can be related to changes in the environment in which they grew. Using statistical methods that have been designed to segment optical images, we have developed a procedure to segment zonation within minerals and correlate these zones between multiple crystals using elemental maps. This allows us to quantify the complexity and variability of chemical zoning [...]
Published: 2021-02-01
Subjects: Biogeochemistry, Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Monitoring, Geochemistry, Geology, Geomorphology, Geophysics and Seismology, Glaciology, Multivariate Analysis, Oil, Gas, and Energy, Other Earth Sciences, Paleobiology, Paleontology, Sedimentology
Ordination is the name given to a group of methods used to analyze multiple variables without preceding hypotheses. Over the last few decades the use of these methods in Earth science in general, and notably in analyses of sedimentary sources, has dramatically increased. However, with limited resources oriented towards Earth scientists on the topic, the application of ordination analysis is at [...]
Published: 2021-02-01
Subjects: Earth Sciences, Geochemistry, Geology, Stratigraphy, Volcanology
Establishing a quantitative link between magmatic processes occurring at depth and volcanic eruption dynamics is essential to forecast the future behaviour of volcanoes, and to correctly interpret monitoring signals at active centres. Chemical zoning in minerals, which captures successive events or states within a magmatic system, can be exploited for such a purpose. However, to develop a [...]
Published: 2021-01-24
Subjects: Biogeochemistry, Cosmochemistry, Earth Sciences, Geochemistry, Geology, Geomorphology, Geophysics and Seismology, Paleobiology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure, Volcanology
Earth's mantle undergoes convection on million-year timescales as heat is transferred from depth to the surface. Whilst this flow has long been linked to the large-scale horizontal forces that drive plate tectonics and supercontinent cycles, geologists are increasingly recognising the signature of convection through transient vertical motions in the rock record, known as "dynamic topography". A [...]
Published: 2021-01-21
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geomorphology, Physical Sciences and Mathematics, Soil Science
First described over 120 years ago in Brazil, Amazonian Dark Earths (ADEs) are expanses of dark soil that are exceptionally fertile and contain large quantities of archaeological artefacts. The elevated fertility of the dark and often deep A horizon of ADEs is widely regarded as an outcome of pre-Columbian human influence1. Controversially, in their recent paper Silva et al.2argue that the higher [...]
Published: 2021-01-16
Subjects: Earth Sciences, Geochemistry, Geophysics and Seismology, Volcanology
Geophysical and petrological probes are key to understanding the structure and the thermochemical state of active magmatic systems. Recent advances in laboratory analyses, field investigations and numerical methods have allowed increasingly complex data-constraint models with new insights into magma plumbing systems and melt evolution. However, there is still a need for methods to quantitatively [...]
Published: 2021-01-13
Subjects: Geochemistry
Crystal cargoes of oceanic basalts often preserve records of mantle-derived chemical variability that are erased from their carrier melts by magma mixing. However, the impacts of mixing between similarly primitive but chemically variable magmas remain poorly understood despite ubiquitous evidence of chemical variability in primary melt compositions and chemical disequilibrium in erupted crystal [...]
Published: 2020-12-13
Subjects: Biogeochemistry, Climate, Geochemistry, Oceanography and Atmospheric Sciences and Meteorology, Paleobiology
For most of the Phanerozoic Eon, Earth’s woody vegetation has been dominated by C3 plants – predominantly gymnosperms - with angiosperms only emerging as the dominant plant group as CO2 declined during the Cenozoic (66 Ma onward). At present, differences in carbon isotope discrimination (Δ13C) between angiosperm and gymnosperm plants are relatively small (2–3 ‰), but an increasing body of [...]
Published: 2020-12-08
Subjects: Earth Sciences, Geochemistry, Geology, Physical Sciences and Mathematics, Planetary Geochemistry, Planetary Geology, Planetary Sciences, Volcanology
Thermodynamics has been fundamental to the interpretation of geologic data and modeling of geologic systems for decades. However, more recent advancements in computational capabilities and a marked increase in researchers’ accessibility to computing tools has outpaced the functionality and extensibility of currently available modeling tools. Here we present VESIcal (Volatile Equilibria and [...]
Published: 2020-12-02
Subjects: Biogeochemistry, Climate, Earth Sciences, Geochemistry, Physical Sciences and Mathematics, Speleology
The temperate region of Western Europe underwent dramatic climatic and environmental change during the last deglaciation. Much of what is known about the terrestrial ecosystem response to deglacial warming stems from pollen preserved in sediment sequences, providing information on vegetation composition. Other ecosystem processes, such as soil respiration, remain poorly constrained over past [...]
Published: 2020-11-30
Subjects: Earth Sciences, Geochemistry
The computational costs associated with coupled reactive transport simulations are mostly due to the chemical subsystem: replacing it with a pre-trained statistical surrogate is a promising strategy to achieve decisive speedups at price of small accuracy losses and thus to extend the scale of problems which can be handled. We introduce a hierarchical coupling scheme in which ``full [...]
Published: 2020-11-21
Subjects: Biogeochemistry, Computer Sciences, Databases and Information Systems, Earth Sciences, Environmental Sciences, Geochemistry, Geology, Geomorphology, Hydrology, Other Computer Sciences, Other Earth Sciences, Soil Science
Data sharing benefits the researcher, the scientific community, and most importantly, the public by enabling more impactful analysis of data and greater transparency in scientific research. However, like many other scientists, the low-temperature geochemistry (LTG) community has generally not developed protocols and standards for publishing, citing, and versioning datasets. This paper is the [...]