LATERAL VARIATION IN THE GEOMORPHOLOGY OF A PLEISTOCENE ROCKY COASTLINE AT KALBARRI, WESTERN-AUSTRALIA

The junction of the Indian Ocean with Kalbarri National Park and adjac ent townsite of Kalbarri in Western Australia exhibits two spectacular rocky coastlines. One is the modern setting with its broad rock platf orms and towering sea cliffs eroded in the red Bird Sandstone (Siluria n) capped by pale sandstones and shales (Triassic, Cretaceus). The oth er is an approximately 100,000 year-old Pleistocene rocky shoreline wi th a wide variety of deposits preserved unconformably against the Silu rian sandstone. Over a short distance of 8 km along the water front, f ive very different geomorphological features may be observed in a cont inuum associated with the same ancient rocky coastline. The include: r iver-mouth bar, cobble pocket beach, intertidal abrasion platform with tidal pools, drowned paleovalley, and neptunian dikes in massive sea cliffs. A typical intertidal fauna with turbinid and patellid gastropo ds if fossilized. These deposits richly illustrate a range of conditio ns through which rocky shores are incorporated into the geologic recor d. They are described herein as a new rock unit named the Chinaman's R ock Member, attributed to the basal Tamala Limestone.