The dynamical behavior of two-dimensional arrays of slider blocks is considered. The blocks are pulled across a frictional surface by a constant-velocity driver; the blocks are connected to the driver and to each other by springs. Only one block is allowed to slip at a time and its displacement can be obtained analytically; the system is deterministic with no stochastic inputs. Studies of a pair of slider blocks show that they exibit periodic, limit-cycle, or choatic behavior depending upon parameter values and initial conditions. Studies of large, two-dimensional arrays of blocks show self-organized criticality. Positive Lyapunov exponents are found that depend upon the stiffness and size of the array.