GEOHERITAGE SITES
The Mountain has nine Geoheritage sites, with four of these being Geo-Cultural Heritage Places too. MAP
# 1 DEAD ISLAND
The peat soils of this shallow and sloped basin (misrepresented in Google Maps as a lake), in which have grown the most south-easterly alpine peats in Tasmania—up to a metre deep—represent thousands of years of life and are of international natural heritage significance.
# 2 THE ORGAN PIPES
A spectacular example of an exposed large-scale columnar dolerite “sill” whose fluted columns and deep couloirs start a kilometre above sea-level and stretch for over a kilometre from the southern-most University Buttress to the Northern Buttress. The inspiration of a hundred artists and graphic-designers, the goal for 500 different ascents. The Pipes are a cultural icon.
# 3 THE LOST WORLD CAVES
Beneath the mini–Organ Pipes of Mt Arthur is Lost World, and under it is a so-called pseudo karst boulder cave system. It is impressive, scary, and dangerous. It is not fully explored. We know it is the longest non-carbonate cave in Tasmania. Boulder caves developed in a dolerite column topple have passages in excess of 300 m long and 40 m deep. The site is the most extensive network of pseudokarst caves in Tasmania.
# 4 THE YELLOW CLIFFS
One of the highest and most extensive sandstone cliffs anywhere in Tasmania. In it are examples of rare wind-carved non-carbonate stalactites and stalagmites. A well developed, spectacular Triassic sandstone cliff complex, one of—if not the—highest and longest in the state (approximately 1 km long and 50 - 80 m high). Honeycomb weathering and overhangs are common at this unusual site
# 5 UN-GLACIATED MOUNTAINSIDES
The mountain is so close to the sea, and for tens of thousands of years the broad river which almost encircles it has tempered the temperature, even at the top of the mountain. It has prevented its freezing over and preserved its high-altitude landforms from the chill sawed gashes of glaciers. It is un-cut by ice. The most extensive high altitude periglacial terrane that has not otherwise been affected by glaciation (i.e. periglacial landforms unmodified by glaciation). The "Ploughed Field" periglacial block streams and the landforms and deposits produced by cold climate freeze/thaw processes which are now largely inactive, have produced many of the more striking landforms on Mount Wellington. The summit viewpoint overlooks the Derwent estuary, Frederick Henry Bay, Bruny Island and other geomorphological features of Hobart area (Criteria: A.1, D.1).
# 6 THE BOULDER FIELDS
The extensive fields and streams and standing and fallen tors on talus slopes, the potato fields, ski drifts, and toppling columns along the eastern escarpment, are numerous and have provoked awe and joy in every generation.
Darwin crossed the Potato Field in 1846. He described the hard, dark grey, lichen splotched tor shards as “common greenstone”, (today ‘dolerite’.) He found nothing that disrupted—indeed everything he found confirmed—his theory that lifeforms by some means or mechanism he could not explain, change over time. “All the Greenstone which crowns this mountain is of a very uniform character; it is rather coarse and contains crystals of Hornblende; it strongly affects the Magnetic needle; one side of the summit shows a large columnar structure; generally there is a grand accumulation of immense loose fragments.—I have as yet only mentioned the Trappean rocks incidentally, some as belonging to the first and more modern, others to the second series of strata. From my limited observations I have not been able to ascertain any difference in these Trappean rocks of two ages.—Indiscriminately over the country, we find ordinary Greenstone graduating into a granular kind which assumes a Syenitic appearance.”
# 7 THE ROCKING STONE
An enormous boulder just off the Ice House Track to The Pinnacle famous for its ability—on a plinth and balanced at an unlikely—to be rocked a few inches each way, making it the world’s heaviest walnut crush.
# 8 DISAPPEARING TARN
A very unusually tinted ephemeral natural pond which can suddenly arise in the boulder stream of Snake Plains Creek. It may reach up to six metres at its deepest point, but only after heavy rain, only to disappear almost as quickly as it appeared. Generally, of a coolish temperature. Winnowed solifluction colluvium with pseudokarst sinkhole depressions and underground drainage.
# 9 THE PURE WATERS
The purity of the waters of the Park are of outstanding significance for their role as wildlife habitat, as well as for the retention of nutrients and moisture; but also of course for the aesthetic value derived from their habit of falling and cascading over rocks. Nor must one leave out their potability.
# 10 RUNAWAY ROCK
Just below its junction with the Organ Pipes Track is a wondrous example of the power of nature in Runaway Rock. In 2014 a massive dolerite boulder became detached and hurtled down from higher up the mountain; coming to rest not far above the Pinnacle Road, just south of the Zig Zag Track, clearing a swathe in its path.
The Wellington Park Management Plan recognises three other sites:
FOSSIL SITES
Rare fossil reptiles and amphibians have been found in the area, one of them being closely related to fossil reptiles from India, South Africa and China.
COLLINS BONNET DOLERITE DYKE
Dolerite dyke intrudes dolerite sheet, now exposed as prominent ridge and extensive lineament, extending to Snug Tiers.