document: Iron ore delivered into China fell 8.3% on Monday after Beijing reported weak export data over the weekend.
  China is one of the biggest consumers of the commodity and there are concerns a slowdown in its economy may hurt demand and impact miners' profits.
  Shares of BHP Billiton, Rio Tinto and Glencore Xstrata all fell.
  Rio Tinto shares ended the day down by 5.7%, while BHP Billiton fell more than 4% on the Australian Securities Exchange.
  Fortescue Metals tumbled nearly 10% in Sydney on Monday.
  Mining stocks listed in London were also hurt, with Anglo American, Antofagasta and Glencore Xstrata all down by more than 2%.
  Recent demand for minerals like iron ore and copper has been driven in part by China's export boom, as well as government-led infrastructure spending.
  That has seen miners become increasingly dependent on China for growth.
  However, over the weekend, China reported a surprise 18.1% fall in exports for February, compared to the same month last year.
  A fall in China's steel futures also hurt mining shares because iron ore is a key ingredient in steel manufacture.
  Fears of slowing demand from China have added to slides in other commodity prices, like that of copper, which has dropped to its lowest level in more than seven months.
  China is the biggest buyer of the metal, which is used in electronics production and other manufacturing industries.
  "Any poor news from China is always going to hit short-term market sentiment, especially in the mining sector, and fears of slower growth will hit base metals," said Steven Mayne, director at IPR Capital.
summary: Shares in some of the world's biggest mining companies have been hit by a slump in the price of iron ore, amid fears of a slowdown in China's economy.