The first lecture I attended on Geology at Queensland University was delivered by Professor Bryan on the Grand Canyon.
The landscape is geologically young, being carved within just the last 6 m.y. when the East Pacific Rise intercepted the coast of California and uplifted the Basin and Range blocks to form the Rockies.
Three “Granite Gorges” in the bottom of the canyon expose crystalline rocks formed during the early-to-middle Proterozoic Era (late Precambrian). They were originally deposited as sediments and lava flows, and were intensely metamorphosed about 1,750 million years ago. Magma rose into the rocks, cooling and crystallising into granite, and welded the region to the North American continent.
Rocks exposed in the Grand Canyon range in age from 1840 million years old (m.y), to 270 m.y. The 3,500 feet walls of sedimentary rock display a largely undisturbed cross section of the Earth’s crust extending back some two billion years.
Vigorous cutting by the snow-fed Colorado River carved the Canyon and widening is held in check by the region’s dry climate.
Kaibab Bright Angel Loop
I visited the south rim of the Grand Canyon in 1996. I was aged 73 at the time and had a replaced left hip and two replaced knees. I started from the South Kaibab Trailhead down the Kaibab Trail with a stout walking staff. The steps were over one foot (30 cm) deep and I continued until I reached the terrace in the Tonto Group at a depth of about 3,000 feet. On the way I was passed by a train of mules carrying those who preferred to do their sight-seeing the easy way. I turned left on to the loop trail (shown in purple on the sketch above) to take me across to Indian Gardens, another five miles and on this last stretch I ran out of water. When I arrived at Indian Gardens, I lay on a bench exhausted and dehydrated and Kath poured water over me and then had lunch. We climbed back up the Bright Angel Trail which is a fairly gentle climb on a path with no steps in the midst of a thunderstorm with hail the size of golf balls. I slept well that night..
Gunung Mulu National Park Sarawak
Gunung Mulu Gunung National Park in Sarawak, Malaysia is a stunning World Heritage site inscribed for both the enormity and magnificence of its limestone caves and for its enormous biodiversity. At 52,865 hectares Mulu is about a third the size of Fraser Island yet it has tremendous biodiversity. It has daunting biodiversity of both plants andanimals. It list 3,500 vascular plants alone. That is at least five times as many plant species as found on Fraser Island). I was surprised to see Angiopteris evecta growing right outside the HQ offices. The stunning and enormous limestone caves (Deer Cave has a roof 300 metres above the floor and you could fly a 747 into it) hold an inestimable number of bats (several million).
However it wasn’t the World Heritage values that made such an impression on me but the superb and sustainable management that the Malaysian authorities have established there.
- There we no cars allowed in Mulu. People have to walk although they can take a longboat ride on a river to visit some sites up-river. The only motor vehicles I saw in the park were small motorcycles for staff to take their children to school.
- The walkways are wide and substantial. I estimate that this Borneo park must have had at least 5 or 6 kms of boardwalk or proper paths that I walked on to get to the great World Heritage caves. In fact we didn’t walk anywhere in Mulu that wasn’t on a substantial boardwalk or concrete path.
- We stayed in accommodation provided by the Park. We did three tours — Two cave tours and the 500 metre long tree tops walk. All required a guide accredited by the park. All were local indigenous Penans and they we very good
- Although the park currently is reported to attract only 35,000 visitors annually. That accords with what we saw, about 100 per day with most visitors spending 2-3 days there as we did. Yet this developing country, Malaysia, has installed an infrastructure that shames the paltry or non-existent Queensland efforts to protect the integrity of Fraser Island.
Having visited more than 50 World Heritage sites I was most impressed to observe just how this country was able to manage and present a great National Park so sustainably and in a way that makes the management of Fraser Island, the World Heritage site I am most familiar with shameful. A comparison of the photos of the two sites shows just what a contrast there is and yet the Queensland Government refuses to explore the options for people movers and has failed to develop adequate boardwalks on Fraser Island that would make visitation more sustainable.
How can Malaysia do so much so well for 35,000 visitors annually and Queensland that reaps the financial rewards and kudos for 350,000 visitors to Fraser Island fail to do enough to stop the degradation there? Worse, why are the Queensland and Australian Governments so indifferent to the degradation occurring on Fraser Island?
Photos from Gunung National Park
Mulu World Heritage Values
Mulu Park Head Quarters
Mulu Park Tracks between Caves
Mulu Park Discovery Centre
Mulu Park Deer Cave
Mulu Park Tree Top Walk