Structural geometry and controls on basement-involved deformation in the northern Flinders Ranges, Adelaide Fold Belt, South Australia

In the northern Flinders Ranges, Neoproterozoic and Cambrian sedimentary ro cks were deformed and variably metamorphosed during the ca 500 Ma Cambro-Or dovician Delamerian Orogeny. Balanced and restored structural sections acro ss the northern Flinders Ranges show shortening of about 10-20%. Despite th e presence of suitable evaporitic detachment horizons at the basement-cover interface, the structural style is best interpreted to be Thick-skinned in volving basement with only a minor proportion of the overall shortening acc ommodated along stratigraphically controlled detachments. Much of the contr actional deformation was localised by the inversion of former extensional f aults such as the Norwest and Paralana Faults, which both controlled the de position of Neoproterozoic cover successions. As such, both faults represen t major, long-lived structures which effectively define the present boundar ies of the northern Flinders Ranges with the Gawler Craton to the west and the Curnamona Craton to the east. The most intense deformation, which resul ted in exhumation of the basement along the Paralana Fault to form the Mt P ainter and Babbage Inliers, coincides with extremely high heat flows relate d to extraordinarily high heat-production rates in the basement rocks. High heat flow in the northern Flinders Ranges suggests that the structural sty le not only reflects the pre-Delamerian basin architecture but is also a co nsequence of the reactivation of thermally perturbed, weakened basement.