Wreckage created by extremely destructive religious ceremony (6)
I believe the answer is:
debris
'wreckage' is the definition.
(I've seen this before)
'by extremely destructive religious ceremony' is the wordplay.
'by' means one lot of letters go next to another.
'extremely' means to remove the middle letters (only the extremes of the word are used).
'religious ceremony' becomes 'bris' (Bris is an example).
'destructive' with its centre removed is 'de'.
'de'+'bris' is 'DEBRIS'.
'created' is the link.
(Other definitions for debris that I've seen before include "Rubble, detritus" , "Scattered broken pieces, rubble" , "Rebids for rubble" , "Scattered wreckage" , "Rocky fragments" .)