Field investigations across the northern Variscan margin have revealed the 3-dimensional geometry of thrust displacements and thrust growth. Thrusts in the orogenic belt have developed as isolated structures whereby displacement will be maximum at the centre of the fault, decreasing to zero at the tip-line. Where changes in dip are incorporated into the model displacement will not conform to the theoretical model. The cumulative-slip model best-fits data from immature thrusts with low aspect ratios. The data indicate that with increasing thrust maturity the dimensions of the fault changes. The predicted growth law of thrusts indicates a power-law exponent (k) of 1.0< in the relationship D=cSk. In these cases it results in lateral elongation of thrusts with respect to displacement and dip-dimension. Cumulative displacement profiles indicate displacement on thrusts decreases rapidly at the tips and away from the fault centre, a function of (k) values 1.0<.In isolated thrusts regions of extension and compression are formed around the fault. In these areas strain is accommodated by changes in bed thickness principally layer-parallel shortening and vertical extension of beds, veining and folding. Increasing fault maturity leads to the interaction of thrusts forming a mechanically, geometrically or kinematically linked thrust system. Thrust linkage is achieved by the physical linkage of fault planes or by displacement transfer in relay zones. Displacement transfer is aided by folding, back-thrusting and splay faulting in the overlapping zone between faults. Displacement gradients in these areas will be high.Palaeostress analysis of thrust orientations reveals two distinct compressive phases recorded in the South Wales Coalfield. The computed sigma 1 trajectories reveal an initial phase of N-S compression. In the second phase sigma 1 trajectories indicate E-W compression, in places reactivating E-W striking thrusts as strike-slip and oblique-slip ramps. The dextral rotation of NW-SE trending normal faults to N-S orientations was coeval with Variscan compression, illustrated by the spread of thrust orientations in the Coal Measures of the north-crop. Progressive rotation of thrusts and normal faults indicates that dextral transpression was active throughout the late Variscan