Remains of fires and mineral on land (6)
I believe the answer is:
ashore
'on land' is the definition.
(synonyms)
'remains of fires and mineral' is the wordplay.
'remains of fires' becomes 'ash' (I can't justify this - if you can you should believe this answer much more).
'and' is a charade indicator (letters next to each other).
'mineral' becomes 'ore' (ore is a kind of mineral).
'ash'+'ore'='ASHORE'
Can you help me to learn more?
(Other definitions for ashore that I've seen before include "Hoarse (anag)" , "Home for the sailor" , "Toward land from water" , "Off the boat" , "On(to) dry land" .)