Virtual_shell

A dataset containing data used to test the ShellChron functions.
Generated using the code in "Generate_Virtual_shell.r" in <code>data-raw</code>

datasets

Takes as input a stable oxygen isotope (d18O) profile measured in growth direction (D)
through a shell + uncertainties in both variables (d18O_err & D_err). It then models the seasonality
in the d18O record by fitting a combination of a growth and temperature sine wave to year-length chunks of
the data (see Judd et al., (2018) <doi:10.1016/j.palaeo.2017.09.034>). This modeling is carried out along a sliding window through the data and yields estimates of
the day of the year (Julian Day) and local growth rate for each data point. Uncertainties in both modeling
routine and the data itself are propagated and pooled to obtain a confidence envelope around the age of
each data point in the shell. The end result is a shell chronology consisting of estimated ages of shell
formation relative to the annual cycle with their uncertainties. All formulae in the package serve this
purpose, but the user can customize the model (e.g. number of days in a year and the mineralogy of the
shell carbonate) through input parameters.

Niels de Winter

ShellChron

Builds Chronologies from Oxygen Isotope Profiles in Shells

Virtual_shell function

A data frame with 80 rows and 5 variables:<dl class="dl-horizontal">
<dt>D</dt><dd>Depth, in \(\mu\)m along the virtual record</dd>
<dt>d18Oc</dt><dd>stable oxygen isotope value, in permille VPDB</dd>
<dt>D_err</dt><dd>Depth uncertainty, in \(\mu\)m</dd>
<dt>d18Oc_err</dt><dd>stable oxygen isotope value uncertainty, in permille VPDB</dd>
<dt>YEARMARKER</dt><dd>"1" marking year transitions</dd>
...
</dl>

Format

Virtual input data for ShellChron — Virtual_shell

A data frame with 80 rows and 5 variables:<dl class='dl-horizontal'>
<dt>D</dt><dd>Depth, in \(\mu\)m along the virtual record</dd>
<dt>d18Oc</dt><dd>stable oxygen isotope value, in permille VPDB</dd>
<dt>D_err</dt><dd>Depth uncertainty, in \(\mu\)m</dd>
<dt>d18Oc_err</dt><dd>stable oxygen isotope value uncertainty, in permille VPDB</dd>
<dt>YEARMARKER</dt><dd>"1" marking year transitions</dd>
...
</dl>

Virtual_shell: Virtual input data for ShellChron

Description

Usage

Arguments

Format