Fake.
The detail at the base of the Queens head is vastly different, even allowing for the wear.
Baz
As of the 31st of March 2010 there were an estimated 1.474 billion £1 coins in circulation, of which 43 million (2.94%) are estimated to be counterfeit (see "Conterfeiting"). [2]
That is in the UK Looking at the coin in the Photo I would say it was just well worn ,modern coinage deteriorates very quickly under ground , copper content of the coin show is about 70% rest is nickel and a bit of zinc, , I would think there are plenty of counterfeit coins where your at..