The purpose of this spreadsheet is to provide the community of trace element partitioning experimentalists some structure for the data we produce.
Those of you who do other types of experiments will note that it bears a strong resemblance to the older LEPR templates. That is not an accident. We have
benefited greatly from their experience, yet we are presented with a number of unique problems when dealing with experiments on the partitioning
of trace elements. In addition, as we look forward, we are attempting to build a structure that will allow a wide range of data types to be included
in the future LEPR and traceDs resources.
As you work on the transcription of the data, remember that it is most important that we have as many experiments included in the database as possible.
If you find that you do not have all of the details listed in the template, it is still important that you include as much of the information as possible.
ASK FOR HELP BEFORE GETTING FRUSTRATED - We suggest that you read through this README, then go to each tab and look at the instructions attached
to the cell headings ("hover" your mouse over the red triangle). You wiill then be more efficient at transcribing your data into the chosen form.
traceDs will include only experimental determinations of partition coefficients (e.g. not phenocryst/matrix). In addition, only those studies where
there is both data on major and trace element composition of the phases. In addition, there must be information on the basic experimental conditions.
This includes the parameters temperature, pressure, experimental apparatus, analytical method, capsule material and time (that goes for LEPR also).
The database is designed for the inclusion of details on the temperature trajectory, multiple determinations of the same element by different techniques
(e.g. Ti by EMP and ICP) and for the inclusion of multiple analyses of the same phase from the same experiment (as opposed to use of an average of
multiple analyses). Further, supplemental data and images may be attached to provide details of the experiments.
The basic structure of this spreadsheet mirrors the structure of the data. Specifically, we have tabs for the reference (e.g. where was the data published?),
for the laboratories in which the work was done (experiments, major elements, trace elements etc); the experimental conditions including the bulk
composition of the starting mixture. Finally, we have tabs for each phase present in the experiment. For example, if you generate an experiment that
contains glass (liquid), clinopyroxene and plagioclase, there will be a tab for each phase. The experimental phase compositions are tied together by their
experimental name. When the data is submitted for addition to the database, a unique identifier will be given to that experiment. However, that will be
done by the Earthchem data group and is only really important for the internal consistency of the whole database.
Within this template, there are explanations attached as comments to the headers. Therefore, if you have questions about what is meant by "SiO2standard"
in the Bulk sheet, you can slide your cursor over the header and get a brief description. In that case, it is the identification of the lab where the chemical
the SiO2 content of the starting material was determined (which may or may not be the saime as the "lab_id" where the experiment was performed).
The "standard" ids for different species and the "lab_id" are identified by numbers, with the key provided in the Lab IDs tab.
Lab IDs:
This is a list of laboratories where most of the partitioning work has been done over the past 40 years. However, the list is not exaustive. If one of the labs
you worked in is not listed, either consult with the data entry group at EarthChem, or simply add a lab description to your submission.
Reference:
This is where you place the full reference for the publication that describes the details of the experiments. No data resource can include everything that
you published regarding any set of experiments. In addition, this information will be downloaded with the data when individuals use the database, and will
allow them to accurately cite your papers when they write their manuscript. Please include a DOI (if possible), as well as links to any supplementary data
tables.
Experiment:
This tab includes the experimental conditions. If you need details on what is to be added in each column, check the comments. Temperature can be added
as multiple components, listed in chronological order. T1 represents the first heating increment (if one was used). An example would be the temperature
of homogenization together with the time it was held at. T2 represents the next temperature, and trajectory represents the rate at which the experiment
transitioned between T1 and T2. The basic spreadsheet only includes two temperatures. However, additional increments may be added (e.g. T3, T4) as
needed in order to fully describe the time temperature pattern. Information on the phases includes both those which were fully analyzed, as well as those
that were not, but which may be important for a full understanding of the run products (or as material for future analysis).
Bulk:
This tab is for the bulk composition of the starting material as well as the mode of the experiment. The mode may also be included in the information for
each phase (see tooltip in the Bulk tab). Compositional information for the starting composition should include all the major elements as well as the trace
elements. Each element should have the method of analysis identified as well as the error and units (e.g. wt % or ppm). Information on the standard used
for that element should be added if known. At present, this represents a place holder where we can add the ID number for the laboratory at which the
analysis was done.
If the name of the sheet (or the row for the optional horizontal format) is just "Bulk" then it is assumed that the composition is for the starting material and
modes are for the experimental products. Occasionally the modes of the starting material or bulk composition of the run products are reported. To enter
these data make separate "Bulk (starting material)" and/or "Bulk (run products)" tabs to distinguish. See the Phase(s) vocab tabs for more details.
Phase composition tabs:
The template will support two different formats. In the first format, each phase will have it own tab. If one looks at the Liquid tab, you will see that the
information is compiled vertically for each experiment. The Phase (copy and rename as needed) tab needs to be duplicated for each of the other phases
present and relabeled to the full name of the phase (see phase vocab). Because this is predominantly a mineral/melt database, most contributions will
include a tab for the liquid - often described in the papers as glass. The phase names should be selected from the list of phases we have provided in the
Phase(s) vocab tabs in this template (the abbreviations are used for the "phases" column on the Experiment tab). It is important that the name for the
experiment is the same in each tab. That consistent name is what allows connection of the disparate parts of the whole. Mode represents the phase
proportions, and the structure of the compositional data should be similar to that for the bulk composition.
The second option is to include all the compositional information on all phases in one tab. This is laid out in the optional Phases (optional horizontal) tab.
As noted above, this structure allows for the inclusion of all the individual analyses collected for a specific phase. Therefore, the database may include
5 analyses of the glass, 10 of the clinopyroxene, 6 for olivine for the same experiment - all with the same experiment name. Ultimately we will add spatial
information on each analysis. However, the existing data do not have that level of detail. For those of you who are using this sheet as a template for current
experiments or for supplements to submitted manuscripts, we strongly encourage you to publish all of your analyses - not just averages. This is why we have
included a column for analysis number. As noted in the comment in the header, this refers to the number of the analysis. However, note that there is only
one column for each analysis. That means that you need to correlate the analyses collected by different analytical techniques. This information is critical
for our understanding of issues such as "mixed" analyses - for example where glass and mineral phases were hit simultaneously during analysis.
If one only has average analyses, that column may remain blank - or one may enter the number of analyses used in the average in the next column.
Restricted vocabulary
In order for the database to connect the components of the experiments, and for the search function to work properly, it is important that we use a
consistent set of descriptors and abbreviations. These are provided in the tabs "Device vocab, Capsule vocab, Phase group, Phases vocab, techique vocab
and Units vocab". Before you construct and/or submit your spreadsheet please review and apply these sets of restricted vocabulary (including how to enter
analyses that are below the detection limit).
IMPORTANT FINAL NOTE
The structure of this spreadsheet is based on different tabs for different phases. In order for different phases from single experiments to be linked, the
experiment name (or index) must be identical. However, upload template will also support the use of a single tab that contains all the phase compositions.
To use that option, use the Phases (optional horizontal) tab as a template. For obvious reasons, if you chose that option, you must make sure that each line
contains the name of the phase in a separate column.