Quasilocal Energy-Momentum for Geometric Gravity Theories
  From a covariant Hamiltonian formulation, using symplectic ideas, we obtain covariant quasilocal energy-momentum boundary expressions for general gravity theories. The expressions depend upon which variables are fixed on the boundary, a reference configuration and a displacement vector field. We consider applications to Einstein's theory, black hole thermodynamics and alternate spinor expressions. 
Chiang-Mei Chen, James M. Nester and Roh Suan Tung