from Wiktionary, Creative Commons Attribution/Share-Alike License.
- adjective geology, of soil Of
fluviatile, marineor lacustrineorigin.
- adjective chemistry Of or pertaining to fluvic acid.
Sorry, no etymologies found.
The rivers of the region are black-water rivers, characterized by their typically low concentration of electrolytes and the dark brown color of the water due to the fluvic acids.