The stable carbon isotopic values were reported as [delta]-notation in per mil ([per thousand]) relative to the Vienna Pee Dee Belemnite
(VPDB) standard with a measurement precision for [[delta].sup.13] C of [+ or -]0.5[per thousand].
is tritium unit, and PDB and pmc are, respectively, Pee Dee Belemnite
and percentage of modern carbon.
For [sup.13]C/[sup.12]C, the reference material is the carbonate from a fossil belemnite
from Pee Dee Formation (Farquhar et al.
Both whole otoliths were ground to a fine powder, and isotopic ratio mass spectrometry was used for isotopic analysis of carbonates with Vienna Pee Dee Belemnite
limestone as the standard.
The international standard for carbon is a limestone found in a geological formation called Pee Dee, North Carolina, USA, whose abbreviation is PDB (Pee Dee Belemnite
), and has [sup.13]C / [sup.12]C (R) molar ratio of 0.01124.
d%oPDB (Pee Dee Belemnite
) is the unit determining the [sup.13]C[O.sub.2] content within the total pool of the exhaled carbon dioxide relative to the international standard of the [sup.13]C:[sup.12]C isotope proportion--the calcium carbonate of the fossil Belemnitella of the cretaceous Pee Dee formation is South Carolina (USA).
Where R is the molar ratio of heavy to light isotope ([13.sup.C]/[12.sup.C] and [15.sup.N]/[14.sup.N]) of the sample or the international standard V-PDB (Vienna Pee Dee Belemnite
) reference for [delta][13.sup.C] and atmospheric [N.sub.2] reference for [delta][15.sup.N].
Comparison of the recorded changes in seawater palaeo-temperature, using the [delta][sup.18.O.sub.bel] from diagenetically screened belemnite
calcite as a proxy, and the [delta][sup.18.O.sub.bel] records obtained in several European sections has allowed the characterization of several climatic intervals probably of global extent (Gomez et al, 2016).
The data were expressed in [delta][sup.13]C notation, in relation to the Pee Dee Belemnite
(PDB) an international standard, with analyses deviation at the order of 0.2[per thousand] and calculated by the equation:
[C.sub.3] plants have a typical isotopic range of values between -25[per thousand] and -35[per thousand] with an average around -27 [+ or -] 2%; hence, in every 1,000 atoms there are 27 fewer [sup.13]C atoms than in the international standard Vienna Pee Dee Belemnite
The test results are given in the Pee Dee Belemnite
(PDB) standard; the test temperature and humidity were 25[degrees]C and 60%, respectively.
O padrao utilizado para o carbono e uma rocha fossil conhecida como PDB (Pee Dee Belemnite
), enquanto o padrao utilizado para nitrogenio e o ar atmosferico.
The results are reported as delta percent ([DELTA]%) versus the PeeDee Belemnite
(PDB) reference standard.
The values of [[delta].sup.13][C.sub.org] are expressed in standard delta notation relative to the Vienna Pee Dee Belemnite
9 -- -- 10 -197 Mixed 11 -162 Thermogenic 12 -- -- Notes: VPDB = Vienna Pee Dee Belemnite
; VSMOW = signal strength or other sample problems.