Abstract
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In the Shoalhaven River Gorge, in the eastern Lachlan Fold Belt, the Ordovician quartz���turbidite succession (Adaminaby Group) is affected by one major phase of deformation with northerly trending, gently plunging, upright, close to tight folds (F1) characterised by a range in half wavelengths up to 3 km. Several anticlinoria and synclinoria are developed and folds occur in at least four orders; these characteristics are consistent with buckling occurring at several scales and are controlled by the thickness of competent units in the multilayered succession. F1 folding is thick���skinned in style with the whole crust probably having been affected by deformation. D1 occurred during the Silurian to Middle Devonian interval and was associated with crustal thickening and the shallowing of depositional environments over time. Locally, F1 is overprinted by south���southeast���trending, steeply to moderately inclined F2 that reorients F1 to recumbent attitudes. D2 is of Early to Middle Carboniferous age. Both deformations are related to convergence in an intra���arc to backarc region and occurred inboard of a subduction zone, remnants of which occur in the New England Fold Belt. �� 1998 Taylor & Francis Group, LLC.