Islander to intone a critical review describing mineral deposit (11)

I believe the answer is:

singaporean

'islander' is the definition.
(someone from Singapore)

'intone a critical review describing mineral deposit' is the wordplay.
'intone' becomes 'sing'.
'critical review' becomes 'pan' (I've seen this in another clue).
'describing' means one lot of letters goes inside another (describe can mean to form the outline of).
'mineral deposit' becomes 'ore' (I've seen this before).
'pan' enclosing 'ore' is 'porean'.
'sing'+'a'+'porean'='SINGAPOREAN'

'to' acts as a link.

I've seen this clue in The Everyman puzzle in The Observer.

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