Data for: Three-Dimensional Morphometry of Ooids in Oolites: a new tool for more accurate and precise paleoenvironmental interpretation

The prevalence of ooids in the stratigraphic record, and their association
with shallow-water carbonate environments, make ooids an important
paleoenvironmental indicator. Recent advances in the theoretical
understanding of ooid morphology, along with empirical studies from Turks
and Caicos, Great Salt Lake, and The Bahamas, have demonstrated that the
morphology of ooids is indicative of depositional environment and
hydraulic conditions. To apply this knowledge from modern environments to
the stratigraphic record of Earth history, researchers measure the size
and shape of lithified ooids on two-dimensional surfaces (i.e., thin
sections or polished slabs), often assuming that random 2D slices
intersect the nuclei and that the orientation of the ooids is known. Here
we demonstrate that these assumptions rarely are true, resulting in errors
of up to 35% on metrics like major axis length. We present a method for
making 3D reconstructions by serial grinding and imaging, which enables
accurate measurement of the morphology of individual ooids within an
oolite, as well as the sorting and porosity of a sample. We also provide
three case studies that use the morphology of ooids in oolites to extract
environmental information. Each case study demonstrates that 2D
measurements can be useful if the environmental signal is large relative
to the error from 2D measurements. However, 3D measurements substantially
improve the accuracy and precision of environmental interpretations. This
study focuses on oolites, but errors from 2D measurements are not unique
to oolites; this method can be used to extract accurate grain and porosity
measurements from any lithified granular sample. The data files consist of
2 3D models of segmented oolites in .raw format and 2 corresponding image
stacks in .tif format.