Latitude -30.90, Longitude 152.12
Located in the New England Region of NSW, nearest towns Armidale and Walcha
Source: National Parks and Wildlife Service Plan of Management
Source: Field Geology of NSW Branagan & Packham
Oxley Wild Rivers National Park, part of the Gondwana Rainforests of Australia World Heritage Area features rare dry rainforest, dramatic gorges and waterfalls, extensive wilderness areas, wild and scenic rivers and an amazing array of wildlife. It is a landscape which has been defined by its geology which has resulted in steep, deep gorges and when running, fast flowing rivers. Much of the land is difficult to access which has prevented early agricultural development although early miners found ways to mine in difficult terrain.
From evidence found in the area the Dunghutti Aboriginal people's territory is thought to have extended over the entire Macleay River valley including the Oxley Wild Rivers National Park. The Dunghutti were comprised of six to eight dialect groups, two of which, the Nulla-Nulla and the Conderang, occupied the upper catchment of the Macleay River system. Above the river valleys, the Anaiwain tribal group occupied the Tablelands.
John Oxley was the first European to visit the New England region. In September 1818 he passed near the southern edge of what is now Oxley Wild Rivers National Park whilst returning from an expedition along the Macquarie River in inland NSW.
The New England Fold Belt has been subject to intermittent uplifts interspersed with erosion from fast running streams draining the New England tableland, resulting in the deeply dissected landscape of the area. Landscapes include: - The eastern margins of the large flat to undulating New England Tablelands. Remnant, isolated sections of the former eastward extent of the tablelands, including the Front Tableland, Paradise Tablelands and Carrai Plateau.
The Great Escarpment, a spectacular landform feature along the eastern edge of the tablelands that extends from northern Queensland to southern Victoria. Westward erosion of the tablelands by the Macleay River system has created the spectacular gorges of the Oxley Wild Rivers National Park area. Depth of the gorges approach 600 metres in several places. Waterfalls or cascades are characteristic of many of the streams as they plunge over the Great Escarpment. Drops exceeding 100 metres are common and the largest single drop is 240m at Wollomombi Falls.
Steep hillslopes and deep valleys with a complex drainage pattern cover most of the area east of the Great Escarpment. Small areas of alluvial landforms occur along the valley floors but are uncommon until the Macleay River flows out of the upper gorges. Elevation ranges from 200m above sea level at Georges Creek to 1,294m at Baynes Mountain. This gradient exerts a major influence on climate and therefore on plant and animal communities.
The park lies within two major structural subdivisions of the New England Foldbelt, being the: - Tablelands Complex, which outcrops in the western parts of Oxley Wild Rivers National Park and is composed of metamorphosed sediments and volcanics; - Nambucca Slate Belt, a series of often intensively deformed metamorphosed sandstones, siltstones, conglomerates and tuffs exposed in the eastern sections and in the gorges.
Each of these structural subdivisions is bounded by major faults and intruded by granites of the New England Batholith (a batholith is a large emplacement of igneous intrusive rock that forms from cooled magma deep in the Earth's crust) and numerous small associated batholiths (plutons) that caused contact metamorphism of the original sediments and volcanics.
During the Late Permian, a large granitoid pluton intruded the sediments as part of the larger New England Batholith. This pluton is termed Carrai adamellite, and consists of granodiorite, monzonite and leuco-granite. Carrai adamellite is centred on Feltons Knob (1190m), dominates its surrounds and is located in the adjacent Carrai National Park, accessed by Cochrane Road.
Limestone deposits within the Kunderang Brook catchment have given rise to a number of relatively small caves and other features, referred to as the Kunderang Brook Karst System. Little is known of the extent and values of the karst system and associated landscape. A total of 17 caves have been recorded. The caves are poorly decorated and remote, and most are infrequently visited.
There is a derelict open cut gold and antimony mine outside Oxley Wild Rivers National Park on the steep sides of the Chandler River valley at Halls Peak.
Travel approximately 19 kilometres east along Waterfall Way towards Dorrigo from Armidale and take the turn-off to Metz (on your right, south side of road). Turn into Chinamens Gully Road and then turn immediately into Martyn Street, travel to the end to locate the Metz Gorge Lookout. There is a picnic table and primitive toilet at the lookout.
Here you will find outcrops of dark cherty slaty greywacke (a variety of sandstone generally characterised by its hardness, dark colour, and poorly sorted angular grains of quartz, feldspar, and small rock fragments). Part of the silicification (impregnate with silica) of this rock is caused by contact metamorphism by the intruding Hillgrove Plutonic Suite (a body of intrusive igneous rock).
Looking down the gorge you will see the remains of the 1887 Bakers Creek gold mine, smelter chimney and mine dump. A twenty head crushing plant was installed to extract ore and the mine proved to be very profitable in its early stages. The reefs contained quartz accompanied by slate with the mineralisation in the quartz deposited during the cooling of the nearby Permian granite. The early miners dealt with access to the mine by constructing an 810m long tramway which inclined up to 43° and led up the steep gorge to the town of Hillgrove. The rail trucks were lowered over the first drop by an engine until the weight of the rail truck counter balanced another rail truck from below and pulled it up the rail. When sufficient momentum was reached by the descending rail truck a robust breaking system slowed the trucks progress down the gorge. Remnants of the tramway can still be seen on the side of the gorge.
Travel to Bakers Creek Falls lookout via Chinamans Gully Road. At northern end, turn right onto Old Hillgrove Road, look for the track to the lookout on the southern side of the road about 500m along. These falls are usually dry unless there has been recent rain. Dark varieties of the Hillgrove Plutonic Suite crop out here. The granite has strong jointing characteristics contributing to the headway retreat of the river bed caused by erosion after the uplift of the New England Plateau about 66 million years ago. Look south down the gorge and note the change to metamorphic rocks as seen at the Metz lookout.
Hillgrove was established in 1884 principally to mine antimony and gold. In 1895 it became the first town to be supplied with power by means of hydro-electricity which operated from Gara Gorge to the west. Difficulties with mining and dropping metal prices saw the town decline in the early 20th century. There are some relics and old buildings still standing including the school now used to house the Hillgrove Rural Life and Industry Museum. Presently, mining is undergoing resurgence with several companies mining tungsten, gold and antimony.
Travel to Hillgrove and turn right into Wood Street, follow it past a garbage dump and to a lookout near a small dam. At the lookout the eastern side of the gorge is composed of granite and the western side metamorphosed Sandon beds. The contact can be recognised a few hundred metres to the west of the lookout, on the eastern side of the gorge. Return to Waterfall Way and travel east until you see the turn off to Wollomombi Gorge and Falls.
The Wollomombi Gorge must be the most impressive of the gorges. It hosts two spectacular waterfalls, the Wollomombi Falls 260m drop, and the Chandler Falls; both can be viewed from Wollomombi lookout. You get a good view of the gorge from Edgars lookout. The gorge has been formed by the cutting back action of the waterfalls and rivers. This can be observed by looking at the Wollomombi Falls which appear to sprout from the side of the cliff. The rocks at this location are tightly folded and faulted Palaeozoic slates. There is bush camping at this location with gas BBQs, picnic tables and toilets for disabled.
There are many gorges in this park including Gara Gorge, Dangars Gorge and Falls; both accessed from Armidale, and Apsley Falls and Gorge accessed from Walcha.
If you wish to investigate the geology of this area purchase Field Geology of New South Wales, authors Branagan & Packham. This book describes detailed geological excursions and can be purchased online or by post phone (02) 4931 6666 www.dpi.nsw.gov.au/aboutus/resources/bookshop
The park is best explored via the scenic drive along the Waterfall Way which runs between Bellingen and Armidale. Alternately, via the Oxley Highway which runs from Walcha to Port Macquarie.