An Elegant Solution for Archaeology

While it's clear what's been shown of Archeology thusfar isn't a fully fleshed out mechanic, I still find the idea really interesting. It appears that currently; players would use brushes to excavate dirt, gravel, and other sediment. This raises some obvious concerns- such as how the ability to gradually wear down layers would affect terrain, or how so many blocks would have to have some sort of new loot table system. 

Instead, I propose the addition of a couple of new blocks that can specifically be mined by a Brush to produce artifacts. For want of a better term, I'll call them 'Disturbed' Blocks. (In that there's something in them. Not in that the blocks themselves are disturbing.) Hence, Disturbed Dirt, Disturbed Stone, and Disturbed Deepslate; in order from most common to rarest.

Disturbed blocks look similar to their Undisturbed counterparts, but can be spotted pretty easily if you know what you're looking for. Silk Touch can mine the block itself, but any other tool collects the Undisturbed variant if it's mined. Archaeological sites could still be added, and would feature lots of Disturbed Blocks nearby, or piled up for your convenience.

When you use a brush on a Disturbed Block, however, you can get loot, artifacts- or just junk like Flint, Bones, or Sticks; With rarer disturbed blocks obviously dropping rarer things. (Brushes could also be enchanted to better their odds, or simply increase the amount they obtain.)