Present data on the detailed motions of actively forming folds and faults in thrust belts are inadequate to rigorously test between various models, but such data are difficult to obtain. This project will take advantage of the high rate of growth of the Taiwan arc-continent collision to study fold and thrust belt motion from the rapidly moving thrust front across the southern portion of the fold/thrust belt. GPS geodetic data combined with extensive seismic and drilling data are expected to result in three dimensional ground motion data over active folds and faults, new balanced sections and a calibration between geodetic results and standard geophysical hypocenter and focal mechanism solutions. These will be of considerable utility in evaluating the wedge model for thrust belt dynamics.