We show that the initial value problem associated to the dispersive
generalized Benjamin-Ono-Zakharov-Kuznetsov equation$$ u_t-D_x^\alpha u_{x}
- u_{xyy} = uu_x,\quad (t,x,y)\in\R^3,\quad 1\le \alpha\le 2,$$is locally
well-posed in the spaces Es, s\textgreaterα2−43,
endowed with the norm$|f|_{E^s} = |\langle
|\xi|^\alpha+\mu^2\rangle^s\hat{f}|_{L^2(\R^2)}.$As a consequence, we get the
global well-posedness in the energy space E1/2 as soon as
α\textgreater58. The proof is based on the approach of the short
time Bourgain spaces developed by Ionescu, Kenig and Tataru \cite{IKT} combined
with new Strichartz estimates and a modified energy.