By Daily Mail Reporter PUBLISHED: 18:39 EST, 3 October 2012 | UPDATED: 02:05 EST, 4 October 2012 Oil tycoon T. Boone Pickens and his fourth wife Madeleine are filing for divorce after seven years of marriage. The separation is amicable although the couple are 'saddened' by the split, according to Pickens' spokesman. Boone Pickens, an Oklahoma native, has made $1.2billion from oil drilling and corporate takeovers. The 84-year-old tycoon and philanthropist has become a vocal advocate for alternative energy in recent years. Luxury lifestyle: Texas oil billionaire T. Boone Pickens has split with wife Madeleine after seven years of marriage
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T. Boone Pickens married widow Madeleine, 65, at her Californian home
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Mrs Pickens, an animal rights activist, was previously married to Gulfstream Aerospace founder Allen Paulson
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Couple had homes in exclusive Preston Hollow suburb of Dallas where George W Bush is a neighbor
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Pickens, who is worth $1.2bn, has been married three times before
He had planned to build the world's largest wind farm in @placeholder but put plans on hold during the economic turn-down.