  Recent downward revision of solar heavy-element abundances using
three-dimensional atmospheric model has introduced serious discrepancies
between standard solar models and helioseismic inferences about solar
structure. In this paper, we investigate the possibility of determining the
heavy-element abundances using helioseismic inversion techniques with the hope
of providing an independent estimate. We use the adiabatic index, Gamma_1
(logarithmic partial derivative of pressure with respect to density at constant
entropy) as a probe to examine the effects of the total heavy-element
abundance, as well as the effects due to the abundance of individual elements.
Our inversion results show that the new, lower, abundance increases the
discrepancy between the Sun and the solar models.
