from The Century Dictionary and Cyclopedia
- Of or pertaining to gross, as distinguished from microscopic, structure.
Sorry, no etymologies found.
As for the "author as scribe" thing: we may be talking past each other a bit, as you introduce the idea of variations on a microstructural level, while I was thinking more about a macrostructural matter.
Horodyski 1976a studied these stromatolites in great detail, describing three macrostructural varieties that occur in this horizon.