Publikationsdatum:
2022-12-16
Beschreibung:
Abstract
Beschreibung:
The ratio of 18O to 16O in cherts and other chemical sediments has increased by about 15‰ over geological time, but the cause of this increase is debated. Here, we provide a 1D sediment-column model designed to investigate the role of diagenesis, and specifically the heat flow through marine sediments, in setting the chert oxygen isotope ratios. The model simulates the transformation of amorphous silica (opal-A) to crystalline quartz via an intermediate phase by using a silicon mass balance that is driven by the kinetics and thermodynamics of silica phase dissolution and (re)precipitation. The model demonstrates that heat flow through marine sediments influences the rate, and therefore depths, temperatures, and oxygen isotope compositions, at which cherts form. The implication is that because global heat flow from the solid Earth has decreased through geological time, heat flow is an important contributing factor to the long-term trend in chert oxygen isotope composition.
The model is provided as a set of Matlab scripts (".m" files) and assorted input datasets provided as standard plain text files. The model is described in full in the manuscript "Chert oxygen isotope ratios are driven by Earth's thermal evolution" by Michael Tatzel, Patrick J. Frings, Marcus Oelze, Daniel Herwartz, Nils K. Lünsdorf, and Michael Wiedenbeck, and in the online Supporting Information associated with the manuscript. Once downloaded and unzipped, the files should be added to the local Matlab search path. The parameters of interest can be changed in the first few lines of 'chertKineticModel.m'. No other files need to be opened or modified. These files have been tested in Matlab R2020a running on Mac OS X 12.2.1 and in Matlab R2022b on Mac OS X 12.6.1.
Beschreibung:
Other
Beschreibung:
Licence: MIT License (https://opensource.org/licenses/MIT)
Copyright © 2022 Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
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The software is provided "as is", without warranty of any kind, express or
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authors or copyright holders be liable for any claim, damages or other
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out of or in connection with the software or the use or other dealings in the
software.
Schlagwort(e):
Chert
;
EARTH SCIENCE 〉 OCEANS 〉 MARINE SEDIMENTS 〉 DIAGENESIS
;
EARTH SCIENCE 〉 PALEOCLIMATE 〉 OCEAN/LAKE RECORDS 〉 OXYGEN ISOTOPES
;
EARTH SCIENCE 〉 PALEOCLIMATE 〉 PALEOCLIMATE RECONSTRUCTIONS 〉 SEA SURFACE TEMPERATURE RECONSTRUCTION
;
EARTH SCIENCE 〉 SOLID EARTH 〉 GEOTHERMAL DYNAMICS 〉 GEOTHERMAL TEMPERATURE 〉 TEMPERATURE GRADIENT
Materialart:
Model
,
Model
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