Deposits grand in rich deposits (6)
I believe the answer is:
lodges
'deposits' is the definition.
('lodge' can be a synonym of 'deposit')
'grand in rich deposits' is the wordplay.
'grand' becomes 'g' (G is short for grand as in a thousand).
'in' indicates putting letters inside.
'rich deposits' becomes 'lodes' (I've seen this in another clue).
'g' placed into 'lodes' is 'LODGES'.
(Other definitions for lodges that I've seen before include "Chalets" , "Gatekeepers' cottages" , "deposits" .)