Ile shale is an organic-rich fine-grained sedimentary rock containing kerogen (a solit mixture o organic chemical compoonds) frae which liquid hydrocarbons, cried shale ile (nae tae be confused wi tight ile — crude ile occurring naturally in shales), can be produced. Shale ile is a substitute for conventional crude ile. Houiver, extracting shale ile frae ile shale is mair costly than the production o conventional crude ile baith financially an in terms o its environmental impact. Deposits o ile shale occur aroond the warld. A 2016 estimate o global deposits set the tot warld resoorces o ile shale equivalent o 6.05 trillion barrels (962 billion cubic metre) o ile.