Log of Tasmania Field Course
Today we left the confines of Hobart and began our road trip out into the bush. Over the next week we will engage the wilderness of Tasmania's World Heritage Site, the rugged West Coast Range, and the wind swept West Coast, the NW region and Bass Strait coast, and the cave regions of north central Tasmania. Our first destination was the Valley of the Giants, huge swamp gum trees (Eucalyptus elegans) which are the tallest hardwood trees (and flowering plants) in the world. We were not to be disappointed as we made our way to Russell Falls (in Mt Field National Park) and the Styx River State forest.
Figure 17: View of Russell Falls and surrounding rain forest of the Mt. Field National Park. The falls are formed over the bedding of the Fern Tree Mudstone, a late Permian sequence of shales, siltstones, and pebbly sandstones (photo by Kim Roe).
Figure 18: View of one of the giant trees, Swamp Gum or Mountain Ash (photo by Kim Roe).
We left the comfort of our accommodations at Giant's Table and drove the longest trek of our entire journey to the West Coast Town of Strahan. During this day trip we crossed into the true wilderness of the World Heritage Site and viewed some of the most distinctive flora and landscapes that any of us have seen.
Figure 19: View of Mt. Hobhouse across the King William Plains from the A10 Highway to Queenstown, just after Derwent Bridge. The wetlands in the foreground abound with sharp button grass, moss and cushion plants while the gum trees are scattered or clumped on higher ground, the slopes of the Mtns. before us are the last remnants of the Gondwana rocks (dolerite) before we hit the King William Range and the folded and thrusted terrain of western Tasmania. The vista is one of a parkland or broken savannah, yet ice crusts are in the water pockets on either side of us and we can see snow on the highest peaks to the north of us (the Cheyne Range). View is looking west, in late morning sun.
Figure 20: Taylor Burt ('08) joined us for the field excursion to the west and northwest coast and here he stands in awe of the West Coast Range, a suite of quartzite, conglomerate, volcanic, and carbonate rocks of Cambrian and Ordovician age.
We awoke to the amazing blue skies over the Hentey Beach and Dunes, with a clear view of the Southern Ocean to our west and the distant ranges of the NW Tasmania coast. Usually even in summer this coast is shrouded in fog and with pounding surf. It is the largest sand dune complex on the coast of Tasmania, expansive, sand, drift wood, and with the cool smell of eucalyptus. We could not have wanted for a better start to our second week in Tasmania.
Fig 21: Taylor Burt joined our group for this part of the journey and he is pictured here with the rest of the “mob” on the far left.
Fig 22: composite view of the extensive Hentey Beach, looking toward the north.
We traveled to Mt Cradle National Park and planned our various treks for the next day. Again good weather followed us to the park, were for at least a few minutes the summit of Cradle Mtn. was free of cloud, but not snow.
Day 10 was our biggest adventure of the trip as we planned three different hikes for three groups (each of different skill level and experience).
Fig 23: The ascent to Cradle Mountain includes a long gentle walk across the quartzite plains, an extensive moorland and alpine tundra like zone dominated by scrubby Nothofagus, cushion plants, and diverse lichens. Here the high peaks are still obscured in the clouds above and behind the plateau of quartzite.
Fig 24: This composite view of the Cradle Mountain Valley still has no view of the mountain but it gives a good sense of the nature of the alpine wilderness before us, Pandani trees (look like palms), King Billy Pines, and Snow Gums dominate the foreground but the distance is endless cushion plants that cover the low hills of glacial moraine. The deposits of glacial detritus were dumped at the terminus of the large ice cap that covered this area 15,000 years ago, part of the global Late Pleistocene glaciation.
Fig. 25: Katheryn Doran amongst the snow gums and button grass of the glacial moraine complex, as we descend from the high plateau. Shades of green, gold, and blue mix in low tones and hues, creating a surreal landscape of color.
We left Cradle Mountain National Park and headed into State Forest which quickly turned into an alternating patchwork of clear fell (clear cut) and tree plantations. The older plantings are still of the Monterey Pine (an introduced species) but the newer plantings are of native gum trees.
Fig. 26: Here the four amigos attack the glacial stones of the Wynyard Tillite, a glacial deposit of 230 million years deposited by a vast ice sheet that covered the ancient landmass of Tasmania along with Antarctica and the rest of Australia. It is best exposed here in the Helleyer Gorge area (a protected patch of rain forest amongst clear fell all around) and the seashore near Wynyard, our destination for the night.