  In this paper we study graded Bourbaki ideals. It is a well-known fact that
for torsionfree modules over Noetherian normal domains, Bourbaki sequences
exist. We give criteria in terms of certain attached matrices for a
homomorphism of modules to induce a Bourbaki sequence. Special attention is
given to graded Bourbaki sequences. In the second part of the paper, we apply
these results to the Koszul cycles of the residue class field and determine
particular Bourbaki ideals explicitly. We also obtain in a special case the
relationship between the structure of the Rees algebra of a Koszul cycle and
the Rees algebra of its Bourbaki ideal.
