Hii shiloh, it is indeed the oldest metal find from this specific field. Otherwise it has produced mainly stone implements like axe heads or bladesfrom the Neolithic (stone age), dating between 5200 to 4000 BC.
Other fields nearby produce mainly roman and celtic finds.
Hi shaun7,
Today this brooch was the only medieval metal find, last week I found a nice medeival silver penny dated 1190/91 AD. The only other really old metal find was a roman bronze coin, either from Domitian (81-96 AD) or Trajan (98-117 AD). Three other coins (copper pennies) date between 1875 and 1925