Sunday, October 31, 2010

Cretaceous Worlds of Queensland: Part I

Way back in June 2010, after completing nearly a month of field excursions exploring the Cretaceous rocks of Victoria, Australia, I had adjusted to a daily routine of expectations. These were, in no particular order: difficult access, high coastal cliffs, thick brush, dangerous waves, slippery rocks, lots of walking (and looking), and only a few trace fossils at the end of each day to show for all of this effort. Here is an artistic rendering of what it felt like out there most days:

Claude Monet’s Gros Temp à Étretat [Rough Weather at Étretat], 1883, in the National Gallery of Victoria, looking oddly familiar to me after lots of field work on the Victoria coast during their winter. I’m the one trying to hold onto my hat.

Another realization gained from field work in Victoria is that fossil bones are rare there. In all of our walking along the coast and scrutinizing more than 100 km (60+ miles) of coastline, Tom Rich (Museum of Victoria) and I did not find a single piece of bone. This hard-earned insight made me appreciate all the more the exceptional nature of those places in the Victoria with abundant bones. Moreover, the bones that have been found came at a considerable cost, especially in terms of human labor (see Dinosaur Cove for an example).

Dave Pickering, a curator and fossil preparator at the Museum of Victoria, who has a bone to pick with you. And as small as this bone is, it could have taken a few hundred hours of prospecting in the Cretaceous rocks of Victoria before someone found it, followed by yet more hours of preparation. Next time you see Dave or any volunteer who looks for fossils on the Victoria coast, please buy them a beer or its monetary equivalent.

Now, for anyone who is used to literary tricks of the trade in journalism or other forms of story-telling, you probably see a set-up here, where I give you one premise – the Cretaceous of Victoria – then shatter it by wielding the exact opposite situation – the Cretaceous of Queensland. Yes, that’s right, the old “compare-and-contrast” device, which is right up there with the “overcoming incredible odds, only to succeed through hard work and moral fortitude” Horatio Alger story.

(Incidentally, the realist in me enjoys puncturing such stories by pointing out that Horatio Alger was actually Horatio Alger, Jr., a second-generation Harvard man, who probably had the hired help pulling up his bootstraps for him. Fortunately for American literature, Mark Twain, a contemporary of Alger, had satirical responses to such stories: “Poor Little Stephen Girad” and “The Story of the Good Little Boy”), when he wasn’t already writing about trace fossils (specifically, fossil tracks of giant ground sloths).

American satirist Mark Twain, who had little tolerance for Horatio Alger, Jr.'s stories, and occasionally reported on possible trace fossils made by giant ground sloths, or, alternatively, Nevada legislators and Old Silurian asses, with the distinction purposefully blurred. Photo from Wikipedia Commons.

So I plead guilty to falling into the cliché of contrasts, but only partially. As befits a continent that straddles three time zones and about 30° of latitude – from Tasmania to tropical Queensland – Australia is teeming with environmental and geological contrasts. When you travel from the southern part of mainland Australia (Victoria) to the northern part (Queensland), some differences are expected, and indeed there are many.

Australia’s a country and a continent, mate. Image from Google Maps and modified by me.

For example, the Cretaceous of Queensland is often represented by: wide, flat areas; deeply eroded rocks with few actual outcrops; and no nearby ocean waves. (Or at least, not now. Go back 100 million years, then yes.) So this is indeed remarkably different from paleontological explorations in the slightly older Cretaceous rocks of Victoria, and requires a bit of an attitude adjustment one going from one to the other.

The outback of central Queensland (top) versus the Victoria coast (bottom). Spot any differences? Photo on top is by Ruth Schowalter, who was driving shotgun at the time.

Nonetheless, the human-perceived differences of conducting field work in Queensland versus Victoria largely end there. Paleontologists still have to work very hard to find bones or trace fossils in the Cretaceous of Queensland, just like in Victoria, although it definitely requires a different kind of effort. And even though rocks in this region of Australia have yielded some significant fossils through the years (especially in the past few years), you still need to have the right search images for finding them, and lots of human labor to recover and prepare them. More about that aspect will be discussed in future entries, and we will especially the logistical differences between finding and handling a leg bone of a small juvenile ornithopod dinosaur, versus that of an adult sauropod.

No rugged individualism is allowed when you find sauropod limb bones in the Cretaceous of Queensland. Rather, mateship is encouraged and necessary. “Gorgeous George” of the Australian Age of Dinosaurs (AAOD) Centre near Winton for scale (more about him and his mates at the AAOD later).

Perhaps what is most remarkable about paleontology in Queensland, though, is how much it has suffused into the outback culture there in just the past few decades. For example, despite more than 30 years of intensive research on dinosaurs and other fossils from the Cretaceous of Victoria, Australia’s “Dinosaur Trail” is located in Queensland. The three outback towns of Hughenden, Winton, and Richmond roughly define a triangle containing rocks rich with Cretaceous fossils, marine and terrestrial, comprised of plants, invertebrate animals, and vertebrate animals. Another outback town with a good collection of Cretaceous fossils to see is in Boulia. For younger fossils, hailing from the mere Cenozoic Era, there is also the city of Mt. Isa. These fossils are from the world-famous Riversleigh deposit, holding geologically younger and exquisitely preserved body fossils of marsupials from the Oligocene through the Miocene Epochs, from about 25-15 million years ago.

So upcoming entries will be about those places in Queensland and their fossils, told from the perspective of a Yank paleontologist, a stranger in an even stranger land, yet one that was very friendly, had many fantastic fossils to see, and (most importantly) no shortage of beer.