Glen Rose Carbon and Oxygen Stable Isotope data - Godet et al
Description
This file include carbon and oxygen isotope data for samples of the Albian Glen Rose Formation from central and west Texas. Results were obtained using a IRMS, as described in the Methods section of the manuscript.
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Steps to reproduce
A set of slabs was cut and polished for stable isotope analysis at the UTSA Chemical Hydrology and Mass Spectrometry Laboratory. A microscope-mounted drill assembly was used to mill points of interest per slab (e.g., matrix, spar, fossils, or ichnofossils). For highly homogenous samples, the same carbonate phase (usually micrite) was sampled 2 or 3 times to test reproducibility of results. The resulting powdered samples were collected, weighed (ca. 0.120 mg) and subsequently transferred into a sealed Exetainer®, which was completely flushed with helium gas before four drops of 100% phosphoric acid were introduced into each and reacted at 70° C in an oven for one hour to produce CO2 from carbonates for the purpose of stable C and O isotopic analysis (e.g., McCrea, 1950). The CO2 was collected via a Thermo-Gasbench II and transferred to a Thermo-Finnagan Delta +XP. The stable carbon and oxygen isotope ratios are reported in the delta (δ) notation as the per mil (‰) deviation relative to the Vienna Pee Dee Belemnite standard (VPDB) using internally calibrated standards and the international standard, and external reproducibility is reported as ± 0.1 ‰ via repeated analyses of an internal standard (Sundance Fm Belemnites).