Latitude -30.273546, Longitude 150.164137
Located in the North West Region of NSW, nearest town Narrabri
Source: National Parks and Wildlife Service
Mt Kaputar National Park is a rugged island wilderness, towering high above the surrounding Western Plains. It's the footprint left behind by a series of volcanic eruptions that moved across this area between 17 and 21 million years ago (m.y.a). Millions of years of erosion have carved this volcanic pile into the Nandewar Range, with its dramatic landscape of lava terraces, volcanic plugs and ring dykes.
Twenty-one million years ago, part of the Indo-Australian tectonic plate drifted over a 'hot spot' (see article "The effect of the mantle hotspot on Eastern New South Wales" on this website under "General Geological Information"). As a result of a surface weakness, molten rock surged up from below the earth's surface and, over a period of approximately four million years, this molten rock gradually formed the Nandewar volcano. This activity appears to have occurred in two key areas. The first was centred over present day Killarney Gap. The second, occurring later, began to build up around what is now Mt Kaputar.
When we think of volcanoes, we tend to imagine the typical cone shape blasting ash and rock into the air. The Nandewar volcano was different: a shield volcano with gently sloping sides rising to a height of over 2100 metres, it was also 50 kilometres wide and erupted over 400 cubic kilometres of lava.
Nandewar's lava flows consist of interspersed layers and various intrusions of basalt and another lava type, trachyte. Trachyte is harder than the surrounding rock. Over time, various layers of lava have eroded at different rates, producing a great variety of dramatic landscape features. Although still impressive, the volcanoes we see now are dwarfs compared to the giants they were before. Today, the Nandewar volcano is barely recognisable. Seventeen million years of wind, rain and ice have sculpted the vast volcanic dome, revealing the magnificent landscape now preserved as Mt Kaputar National Park.
As you wander through the park's majestic forests, it's hard to imagine that this was once a deadly place bereft of life. The story of Kaputar and everything visible there today is inextricably linked to volcanoes. Kaputar's ferocious past has resulted in a landscape dominated by deep narrow valleys, steep ridges and cliff-edged lava terraces.
The highest point in the park is Mt Kaputar itself, at 1510m above sea level (ASL). Twelve other named peaks exceed the winter snowline of 1200m ASL. Narrabri by contrast, located on the very edge of the Western Plains, is just 230m ASL. Most of the walks and look-outs in the park are associated with prominent and spectacular geological features. You'll be rewarded with breathtaking views and an insight into the history of this remarkable landscape. Kaputar Plateau, Mount Dowe, Mount Grattai and Lindsay Rock Tops are all excellent examples of ancient trachyte lava terraces. In other places, lava terraces have been carved up by erosion, leaving behind flat-topped flow remnants, such as at Governor, Euglah Rock, Camel's Hump and Castle Top.
Kaputar Plateau, Mount Dowe, Mount Grattai and Lindsay Rock Tops are all excellent examples of ancient trachyte lava terraces. In other places, the lava terraces have been carved up by erosion, leaving behind flat-topped flow remnants, such as at Governor, Euglah Rock, Camel's Hump and Castle Top.
One of the most prominent peaks in central Kaputar is the solitary shape of Ningadhun, which is a remnant of a much larger flow of trachyte lava that has been cut away and isolated from the rest of the park.
Mount Yulludunida is not a volcanic crater, but a feature known as a ring dyke. A ring dyke typically forms when an underground pool of hot molten rock drains away. The pool's roof then collapses, forming cracks. Molten volcanic rock is then squeezed through the cracks to form dykes, which are roughly circular. As the softer rock eroded the hard volcanic dyke rock on the sides remained.
The four processes involved in forming a ring Dyke are illustrated below
You can walk up the side of Mount Yulludunida to the summit. It is located just off Kaputar Road and the track head is at Green Camp. It's a hard, steep minimum 3 hour - 4km return walk and not for the faint hearted or unfit. There are approximately 260 steps to negotiate to reach the end of the track before the rocky outcrop. When you reach the rocky outcrop there is no marked trail and you will need to scramble over rocks to reach the summit. Piles of rock have been left in various places, indicating the easiest ascent route. There are no safety fences so be careful where you walk. Also be mindful of weather changes: when we walked the track it was warm and sunny at the base and yet it hailed at the summit. Once the rocky outcrop is wet it is very slippery. Information on the park's walking tracks, camping, and other facilities is available from National Parks and Wildlife Service Office, First floor, 1/100 Maitland St, Narrabri or look at www.nationalparks.nsw.gov.au/
There is plenty of accommodation in Narrabri, but book early as the town is located near some large mining projects and accommodation can be booked out on some days.