Schemes regarding stones in rock layers? (10)
I believe the answer is:
stratagems
'schemes' is the definition.
(stratagem is a kind of scheme)
'regarding stones in rock layers?' is the wordplay.
I cannot quite see how this works, but
'stones' could be 'st' (I've seen this in other clues) and 'st' is present in the answer.
'rock' could be 'gem' and 'gem' is present in the answer.
The remaining letters 'ratas' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for stratagems that I've seen before include "Plans" , "Manoeuvres" .)