Writedown of Zanaga in the Glencore Accounts31 Oct 2020 13:37
In the 2014 Glencore accounts there was an impairment charge of $489 million, taken against the Congo iron ore project due to the decision to slow down development. It is unclear if this is the entire balance sheet value (which was $ 365 million in the 2012 Xstrata Accounts), but I suspect it is.
(copy of my posing here 15/6/2018).