[yarcob]

Classic archaeology is all about layers. When excavating, a lot of effort is made to determine where one layer starts and where a layer ends. You can often tell eg. by soil color or other hints.

So yes, dredging up the ground destroys all context, and you get finds that are very hard to date (carbon dating and other scientific methods have limited precision if you don't have any reference points)

On the other hand, I guess you take what you can get, and archaeologists often work with finds like that. A farmer might accidentally have dug up some roman coins on their field, or people with metal detectors may find some clothing pins (not sure of the correct english word) or something. These people may also not be eager to tell you where they found it (farmers really don't want excavations on their fields)

[BurningFrog]

You can also make an argument to wait with the underwater exploration a few decades until better tools have been developed.

[macintux]

The dredging wasn’t done by the archaeologists. They’re just taking advantage of it.

[BurningFrog]

Thanks.

I should have read the article before commenting.

[vmh1928]

Another archeological project based on the spoil from uncontrolled construction excavation of a historical site is The Sifting Project.

https://en.wikipedia.org/wiki/Temple_Mount_Sifting_Project

[timeon]

> people with metal detectors may find some clothing pins (not sure of the correct english word) or something. These people may also not be eager to tell you where they found it

And often just sell it straight on black market.

[soperj]

Clothes pins is I think the word you're looking for.