For the hell of it I decided to upload a bunch of the Cooper money photos to ChatGPT. I explained that it washed up on a beach originally in a bundle and asked what would be the cause of the edges looking that way.
Soil Acidity & Microbial Activity:
Paper currency buried underground is vulnerable to fungi, bacteria, and acidic soil.
These eat away at the cellulose fibers, starting from exposed edges.
That’s why the edges are more deteriorated—microbes attack from the outside in.
Water Damage (Floodplain or Tidal Influence):
Repeated wetting and drying cycles from a tidal area or seasonal flooding cause the paper to delaminate and rot unevenly.
Saltwater or brackish water could accelerate this if found near a coast or estuary.
Oxygen Deprivation (Partial Anaerobic Conditions):
In deeper soil or under dense sediment, oxygen is limited, slowing decomposition in the core of the bundle.
This can explain why some interior pieces might be more intact than the outer ones.
Compression from the Rubber Band:
The rubber band would have held the bundle together tightly for a time, protecting the inner bills slightly.
However, over time, rubber decays, and the band either breaks or fuses with the outer bills, sometimes leaving distinct discoloration or causing distortion.
Bills on the outside of the bundle would have taken the brunt of environmental damage.
Sediment Abrasion:
If the bundle was moved by floodwaters or a shifting riverbank, sand and silt could act like sandpaper, rounding and fraying the edges.
I then asked it if rolling along the bottom of the river could cause that damage....
Yes—rolling submerged along the bottom of a river could absolutely cause the rounded, scalloped edges you see in the image. In fact, that kind of mechanical erosion is one of the most plausible explanations for the distinctive damage pattern.
Here’s how that would work:
Constant Abrasion:
As the bundle tumbles or slides along the riverbed, it gets scraped by sand, gravel, and small rocks.
This slowly wears away the outer edges of the bills—just like how rocks in a river become smooth and rounded over time.
Edge-First Damage:
Since bills are thin and flexible, the edges are most exposed during tumbling.
Repeated folding, flapping, and scraping action causes the edges to fray, break, and wear away, creating those irregular, rounded contours.
Bundle Dynamics:
If the bills were still in a rubber band (even partially decayed), the bundle would roll and drag as a single unit, meaning the outer bills would absorb most of the damage.
Interior bills might remain more intact—especially if compressed.
Water Saturation and Fiber Breakdown:
Prolonged submersion softens the paper (cotton/linen blend), weakening its fibers.
This makes it more susceptible to tearing and abrasion, especially at the edges.
Combined with mechanical motion, this would produce rounded and lace-like damage—exactly what we see.
How Long Would It Take?
It would likely take weeks to months of tumbling in a moderately strong river current to cause this degree of damage.
A single storm event or spring flood could also loosen a buried bundle and send it rolling.