Latitude -35.353094, Longitude 150.479822
Located in the Shoalhaven Region of NSW, nearest town Ulladulla
Source: Tour leader geologist Phil Smart
Ulladulla's coastal location in the far south of the Sydney Basin makes it geologically unique and gives the site unrivalled potential as a scientific and educational resource. The quality of preservation and abundance of Permian marine invertebrate fossils in the ~270Ma old Wandrawandian Siltstone have long been recognised by geologists. In the 1960s, the fossils in the horizontal strata of the wave-cut rock platforms at Ulladulla were studied and a number of new bivalve species were identified.
The rock platforms remained an untapped scientific and educational resource visited only by a few university and school groups until the Guided Fossil Walk was successfully introduced in 2009.
This very attractive harbourside site was chosen for the Guided Fossil Walk because it is a wonderful natural educational resource and its location beside the Princes Highway made it so easily accessible.
The abundant fossils are typical of a Permian cold water fauna and include twenty species of Echinoderms, mostly Crinoid (sea lilies); Bryozoans, mostly Fenestellid (sea fans); Brachiopods, chiefly spiny Productids and Spiriferids; Molluscs, mainly Bivalves; and Gastropods; solitary Rugose horn corals, and a branching colonial coral which are rare. Some bioturbated (reworking of sediment by organisms) horizons display a range of trace fossils including burrows, tracks and feeding trails. Plant fossils are also preserved in this shallow near-shore marine deposit as pieces of carbonized wood.
The horizontal strata bordering the Harbour offer much more than just the abundant fossils. In an easy 500m walk across the wave-cut platform, guided Fossil Walk participants are exposed to:- a diverse array of angular to rounded metamorphic and igneous drop stones a tessellated pavement that is far more extensive than the heritage listed one at Eagle Hawk Neck in Tasmania; stellate and rosette clusters of glendonite crystals mostly found as sharp moulds; carbonate cannon-ball shaped concretions built around fossil shell, glendonite or drop stone nuclei; a ~3m thick folded and faulted seismite that has horizontal strata immediately above and beneath it; an undercut sea-cliff behind a boulder beach which lies adjacent to a typical sandy beach. These highly visible geological features which are considered spectacular by almost all of the Walk participants form the basis of discussions on a range of topics including:- fossilization; moulds and casts; palaeoclimates and Permian glaciation on Gondwana; age and significance of the prominent 60° and 330° joint directions; and the geological processes resulting in the present day harbour landscape.
More information and a list of scheduled Guided Fossil Walks can be found on the website www.gondwanacoastfossilwalk.com.au. To make a booking contact the Ulladulla Visitor Centre phone (02) 4455 1269