  We study the generalized Chaplygin gas (GCG) scenario in a modified gravity
approach. That is, we impose that our universe has a pure dust configuration,
and allow for a modification of gravity that yields a GCG specific scale factor
evolution. Moreover, assuming that this new hypothetical gravity theory obeys a
generalization of Birkhoff's law, we determine the Schwarzschild-like metric in
this new modified gravity. We also study the large scale structure formation in
this model. Both the linear and non-linear growth are studied together with the
growth of the velocity fluctuation in the linear perturbation theory. We
compare our results with those corresponding to the $\Lambda$CDM model and
discuss possible distinguishable features.
