Evidence for early extension in the Malbon Group is preserved in a series of high-angle normal faults, which displace the massive quartzites of the lower Mitakoodi Quartzite on the eastern limb of the Duck Creek Anticline, Mitakoodi Culmination. The crests of half-graben tilt-blocks have been eroded, and the hangingwall sequences adjacent to faults commonly include a conglomerate horizon that contains clasts of the underlying lithologies. Two locally angular unconformities associated with this faulting are described: the Upper Mitakoodi Unconformity (at the base of the upper Mitakoodi Quartzite) and the Overhang Jaspilite Unconformity (at the base of the Overhang Jaspilite). Inversion of this extensional architecture during the Isan Orogeny resulted in the buttressing of the weaker phyllites and conglomerate of the upper Mitakoodi Quartzite, against the massive and more competent quartzites of the lower Mitakoodi Quartzite, the resultant strain partitioning effecting the development of a complex array of fold styles and axial-planar cleavage orientations, which wrap around the footwall buttresses. Variations in fold and cleavage orientations are interpreted to reflect the influence of a pre-existing extensional architecture during a single shortening event, rather than invoking multiple folding events with different shortening directions.