A note on the differences between the sandstone and
carbonate tutorials
In carbonate rocks, the particles are dominantly biogenic, have a tremendous range of size, and can have shapes that are far from equant. Weirdly shaped biogenic particles can stack up to yield an amazing array of different pore-space arrangements. Thin-section-scale textures of limestones have more important variability than do textures at this scale in sandstones. So, it's simply not enough to look very closely at some fossil bit and say, "yep, that's an oyster!" You also need to step back and see what's going on around the oyster. Is the particle a part of a rounded and well-sorted grain assemblage, or is it part of a messy pile of other oysters, some whole and some broken, all encased in mud? Is it a beach rock or an oyster bank? In carbonate rocks you need to be able to see the grains in the proper context of the whole rock in order to really get the benefit of from your grain identification skills. Thus, the carbonate tutorial adopts an approach in which the images can be zoomed from a whole-thin section view, all the way down to individual grains.
"How to use this DVD".