  Cold fronts are sharp surface brightness discontinuities characterized by a
jump in gas temperature accompanied by a decline in X-ray surface brightness
such that the gas pressure remains continuous across the front and, thus, these
structures differ from bow shocks. Models suggest that cold fronts can be
generated by external mechanisms involving the accretion of a subsystem with a
remnant "cold core". However, internal mechanisms can also create cold fronts,
such as gravitational scattering of subclumps or cD oscillation around the
bottom of the potential well. These competing models for their formation can be
discriminated through the measurements of the SN Type contamination across the
front, which in turn can be determined from metal abundance ratios as measured
from an ensemble of elements. Here we present the preliminary results of such
analysis using a sample of clusters observed with Chandra.
