The 17O correction parameters below are used to compute
δ13C, δ18O,
and raw clumped-isotope Δ values from working-gas δ values
(computational details in
Daëron et al., 2016).
Working Gas Composition Settings
Based on carbonate standards analyzed in each session
Requires that each session includes one or more samples with
non-empty Nominal_d13C_VPDB and Nominal_d18O_VPDB
fields.
Remember to define a suitable (18O/16O) acid fractionation factor below.
Explicitly defined in the raw data
Bulk composition of the WG must be explicitly defined in each line of the raw data,
using fields d13Cwg_VPDB and
d18Owg_VSMOW.
Carbon-13 Standardization Settings
No standardization
Only rely on working gas composition to constrain δ13C values.
Single-point standardization (shift all δ13C values by a constant offset)
Requires that each session includes one or more samples with a non-empty
Nominal_d13C_VPDB field.
Two-point standardization (apply affine transformation to δ13C values)
Requires that each session includes two or more samples with a non-empty
Nominal_d13C_VPDB field.
It is critical that these values cover a large enough range to avoid gross extrapolation errors.
Oxygen-18 Standardization Settings
No standardization
Only rely on working gas composition to constrain δ18O values.
Single-point standardization (shift all δ18O values by a constant offset)
Requires that each session includes one or more samples with a non-empty
Nominal_d18O_VPDB field.
Remember to define a suitable (18O/16O) acid fractionation factor below.
Two-point standardization (apply affine transformation to δ18O values)
Requires that each session includes two or more samples with a non-empty
Nominal_d18O_VPDB field.
It is critical that these values cover a large enough range to avoid gross extrapolation errors.
Remember to define a suitable (18O/16O) acid fractionation factor below.
Acid Fractionation Settings
Only used for computing WG composition based on carbonate standards
and for single-point or two-point δ18O standardization.
Δ47 Standardization Settings
In the text box below, specify the “true” Δ47 values and sample names of anchors,
separated by a single tab character (one line per anchor).
Pooled regression model taking unknowns into account
Independent models for each session only taking anchors into account
Raw Data Input
Each line corresponds to a single analysis. Fields are tab-delimited.
The first line must correspond to field names.
The required fields are:
a sample identifier (Sample),
and the working-gas delta values d45, d46, d47.
For each analysis you may also (optionally) specify
a unique analysis identifier (UID) and/or
an identifier for the analytical session (Session).
Independently known oxygen-17 anomalies may be provided as D17O
(in ‰ relative to VSMOW, with the λ value specified above), and are assumed to be zero otherwise.
Working-gas deltas d48 and d49 may also be
specified (treated as NaN otherwise). Other optional fields are
d13Cwg_VPDB, d18Owg_VSMOW (see “Working Gas Composition Settings” above),
Nominal_d13C_VPDB, and Nominal_d18O_VPDB
(see “Carbon-13 Standardization”, “Oxygen-18 Standardization”, “Working Gas Composition” settings above).
About
ClumpyCrunch is an open-source
application built on
Flask and
D47crunch v0.6.2dev1,
using the standardization methods described by
Daëron (in prep.).
ClumpyCrunch retains no records of your analytical data after you close your browser window.
All questions/suggestions are welcome and should be directed at
Mathieu Daëron.