I am looking for reference giving the original definition of prime cycles of coherent sheaves on noetherian scheme. Was it in EGA? I googled, but could not find proper reference.
Thanks in advance
I am looking for reference giving the original definition of prime cycles of coherent sheaves on noetherian scheme. Was it in EGA? I googled, but could not find proper reference. Thanks in advance 


EGA IV$_4$, 3.1.1 for any quasicoherent sheaf on any (pre)scheme: the commutative algebra definition on stalks. So one needs 3.1.2 and 3.1.3 there to get useful alternative formulations of this definition in the locally noetherian case. You can find it by looking for "Point associe" or "Cycle premier associe a un Module" in the index, or "Cycles premiers associes a un Module" in the Table of Contents (only 8 volumes to try...). 

