At a Memorial Day cookout, I met a young, Tasmanian rock climber, Josh Thomas. As with many of us leading a geolifestyle, the conversation soon turned to rocks! Here are Thomas’ top three locales for appreciating Tasmania’s geo-sites combined with my takes on these areas’ geology. 🦘
Sharon Lyon
Editor, GeoLifestyle
Cataract Gorge, Launceston
Sanjay Dura/ Shutterstock.com
Cataract Gorge is a river gorge located on the outskirts of the city of Launceston. It's a top tourist attraction in northern Tasmania for its natural beauty and history.
Cataract Gorge geology: The Cataract Gorge formed when the South Esk River changed course about 15 million years ago, redirected by lava flows.
The river eroded at the intersection of two faults: the Basin Road Fault and a second, unnamed fault. The South Esk River leads into the Tamar River at King’s Bridge.
The gorge features steep cliffs in the heavily fractured dolerite, rock columns, waterfalls, plunge pools, and cascades.
The area’s natural look shifted dramatically more than 100 years ago due to swamp clearing, tree planting, and even the use of dynamite.
Cultural heritage: The gorge is on Stoney Creek Nation lands. It has been occupied for at least 42,000 years, and Aboriginal stories describe stone boulders as sentinels or ancestors transformed into the landscape.
Trip tips: At Cataract Gorge, you can…
Walk along the King’s Bridge–Cataract Walk—a historic trail along the north bank
Ride the world’s longest single-span chairlift
Swim in the First Basin’s pool
Ride the funicular railway, take a boat cruise, or tour the interpretive museum at the decommissioned Duck Reach Power Station
Look for the free-roam peacocks and wallabies at the Victorian Cliff Grounds Garden.
Thomas’ take: “The gorge has cliffs for many different rock-climbing levels. After a day at the gorge, whether you are climbing or just sight-seeing, be sure to eat at Cataract on Paterson, which features local Tasmanian food.”
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Coles Bay is a small, scenic village on Tasmania’s east coast, about two hours from Launceston. It sits inside Freycinet National Park, which extends north-south along the Freycinet Peninsula. The peninsula is framed by the Hazards, a dramatic granite mountain range.
Area geology: The Freycinet Peninsula is geologically unique in Tasmania, contrasting with the more widespread Jurassic dolerite and Precambrian quartzite.
The peninsula is dominated by Devonian-age granite (395–368 million years old), which was emplaced during the Tabberabberan Orogeny. The granite is rich in orthoclase feldspar, giving the Hazards Range its distinctive pink-red hue.
The granite exhibits “onion skin” weathering (exfoliation), creating smooth, rounded, dome-like forms and large boulders.
Wineglass Bay, a crescent-shaped bay on the eastern side of the peninsula, is known for its white sand beaches. The beaches are formed from white quartz derived from the erosion of the granite.
Easy: The Isthmus Track to Hazards Beach is a flat, coastal bushwalk to a less-crowded beach.
Moderate: Walk to Wineglass Bay Lookout, a two-hour roundtrip trek with views of the bay.
Strenuous: Climb up Mt. Amos, thehighest peak in the Hazards.
Excursions:
Water: Venture into the waves for sea kayaking, windsurfing, swimming, or fishing.
Off-road: Try quad biking or a four-wheel drive tour.
Wildlife spotting:
While beach walking or kayaking, look for Southern Right and Humpback whales, Bottlenose dolphins, and Australian Fur Seals. On land, look for wallabies, echidnas, and possums.
On a night walk, you may see the elusive wombat, pademelon, or Tasmanian Devil.
Thomas’ take: “On the way to Freycinet, stop at Lost Falls near Lake Leake for a short walk to see the falls and Lost Pools below. Be aware: they get their name because they disappear during the dry season. Then, taste a glass of premium Pinot Noir at Devil’s Corner Vineyard. Be sure to climb their lookout tower for spectacular views. For lunch, visit Freycinet Marine Farm for fresh oysters, mussels, or southern rock lobster caught that morning.”
Tasman Peninsula
Devaka Seneviratne/Shutterstock.com
The Tasman Peninsula along the southeast coast of Tasmania combines unique geological history, dramatic coastal landforms, and rich biodiversity. Tasman National Park encompasses 40 square miles on the peninsula and is known for its towering dolerite sea cliffs.
Area geology: Permian and Triassic (298–201 million years old) rocks underlay sandstone, siltstone, limestone, and coal.
Magma intruded into these rocks in the Jurassic, forming sheets and columns of the dolerite that are now visible as dramatic cliffs and pillars.
Faulting during the early Cenozoic (66 million years ago) created rift valleys and uplifted zones.
Sea levels rose around 10,000 years ago, creating the current drowned coastline with sea cliffs, caves, and sea stacks.
Landforms: The Tasman Peninsula hosts a myriad of spectacular erosional coastal landforms.
At Eaglehawk Neck—an isthmus connecting the peninsula to the mainland—observe natural, tile-like patterns known as Tessellated Pavement. On an intertidal rock platform, this unusual feature formed by jointing and erosion in the Permian siltstone and sandstone.
At Waterfall Bay, a picturesque waterfall drops directly into the ocean. Trails connect Eaglehawk Neck to Waterfall Bay and beyond, offering views of geological features.
The Tasman Arch is the remnant of a collapsed sea cave roof, formed by wave erosion exploiting vertical joints.
Devils Kitchen is a deep-sea gorge formed from collapsed sea caves and tunnels.
At Cape Pillar, there are towering dolerite columns up to 1,000 feet tall.
Remarkable Cave is a tunnel-like sea cave at the contact between dolerite and sandstone, notable for its shape resembling Tasmania.
Wildlife: The peninsula is home to the endangered Swift Parrot and Forty-spotted Pardalote, as well as Wedge-tailed Eagles and Tasmanian Sea Eagles.
Little Fairy Penguins also nest along the coast.
Humpback and Southern Right whales migrate through the area from May to September.
Rock climbing: Cliffs and tall, narrow dolerite sea stacks such as the Totem Pole and Candlestick are major climbing destinations. No bolting is allowed.
Thomas’ take: “Stop for oysters at Get Shucked Oysters. Harvested that morning, they could not be fresher. Not an oyster fan? Taste the local beer and cheese at Bruny Island Cheese Co.”
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