BEDROCK-SCULPTURING BY TSUNAMI, SOUTH COAST NEW-SOUTH-WALES, AUSTRALIA

Bedrock-sculpturing resulting in s-forms is associated with catastroph ic flooding in near- and subglacial environments produced by flow velo cities approximating 10 m s(-1). These velocities can also be produced by extreme tsunami generated by submarine landslides or comet impacts with oceans. Repetitive tsunami events during the late Holocene have overwashed headlands along the New South Wales south coast and produce d two suites of bedrock-sculptured terrain. At the smaller scale, s-fo rms similar to muschelbruche, v-shaped grooves, and sichelwannen have developed on upslopes while broad potholes, flutes, and transverse tro ughs have formed on headland crests. Cavitation features consisting of sinuous grooves, impact marks, drill holes, and cavettos appear more ubiquitously. At the larger scale stripped ramps, large potholes, casc ade channels and canyon-like features have been generated. Six flow ph enomena: Mach-stem waves, letting, vortex impingement, horseshoe vorti ces, helical flow, and multiple vortex formation are all involved, eit her singly or in combination with each other, in the creation of bedro ck-sculptured features and terrain. Tsunami-sculptured terrain undoubt edly has a global distribution whose extent requires further investiga tion.