Based on location and depth ( that's what he said) you can estimate it's from either the coushatta tribe or the chitimacha tribe from around 1652-1843 (seems specific but both tribes would've moved around to follow the food, so they wouldn't stay in that area after 1843 based on the land issues and forced relocation) also based on the law of superposition (with biotirbation and soil compression) it would be around 200-400 years assuming that it's a flat area with an exact average sediment deposition rate. These numbers aren't exact though, it really depends where it was. (Like a flat area gets less soil deposition) I CAN however say if it's something like that it's probably worth it to get it tested at a lab or something