Deposits sent south including US coin (9)

I believe the answer is:

sediments

'deposits' is the definition.
('sediment' can be a synonym of 'deposit')

'sent south including us coin' is the wordplay.
'south' becomes 's' ('S' can be a synonym of 'south').
'including' is an insertion indicator.
'us coin' becomes 'dime' (I've seen this before).
'sent'+'s'='sents'
'sents' going around 'dime' is 'SEDIMENTS'.

I've seen this clue in The Times.

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