Only two days remain before traveling to Melbourne, Australia, a 24-hour journey that starts in Atlanta, Georgia and connects (mercifully briefly) through Los Angeles, California before flying across The Big Pond to Oz. In Melbourne, I will meet with friends who will help me to begin what I’ve dubbed The Great Cretaceous Walk.
And just what is meant by “The Great Cretaceous Walk”? Well, the “great” part of this label is not applied out of grandiose expectations for what might happen, but partially refers to “The Great Ocean Road,” a drive along the Victoria coast west of Melbourne that is often rated one of the most spectacular in the world. One of the reasons why this drive is regarded with such awe is because of the extensive seacliffs and marine platforms that line the shore where the Bass Strait meets the mainland of Australia. Similarly, a 104-km (65-mi) long trail that winds from Apollo Bay to The Twelve Apostles, an iconic string of seastacks, was given the name “The Great Ocean Walk.”
OK, that’s the “Great” part. What about the “Cretaceous” part? Most of the rocks composing this vista west of Melbourne fall within the Early Cretaceous Period, a geological time unit that spans from 145 to 100 million years ago. Rivers and lakes formed these rocks about 110 million years ago, with their sediments dumped during many summers of a polar climate (more about that “polar climate” in future entries). Geologists and paleontologists refer collectively to these rocks as the Otway Group, named after Cape Otway in that region. In the Otway Group are the remains of dinosaurs, mammals, turtles, fish, clams, insects, crayfish, and plants, painting a picture of what lived in these rivers and lakes then. Most importantly, from my skewed perspective, these rocks also hold the echoes of past behavior, preserved as burrows, tracks, and other vestiges called trace fossils. These are what will be sought on this walk, and these (I am confident) are what will be found.
But only half of the story told by the Great Cretaceous Walk is in these rocks west of Melbourne. Melbourne is nearly equidistant between two great Cretaceous coastal outcrops: those of the Otway Group, and those of the Strzelecki Group to the east. These rocks are slightly older, at around 115-120 million years old, with the “slightly” modifier as a geological conceit along the lines of “what’s a few million years between friends?” Still, these rocks are in the Early Cretaceous Period, too, and these also contain bits and pieces of some of the earliest known mammals of Australia, as well as dinosaurs and many other animals. In fact, one of the best sites in the world for polar dinosaurs is at Flat Rocks, where the Dinosaur Dreaming dig takes place every year, starting in 1994.
The “Walk” part is fairly straightforward: I plan to walk along this coast. And wherever Cretaceous rocks and their trace fossils might be, I plan to document these and their locations. The current plan is to start in the east and walk to the west, but like all field-based work, I expect that plan will change somewhere along the way. Regardless, I will be walking a lot. (And yes, you might apply the expression “walkabout” to this endeavor.)
But for now, preparations for travel, the travel itself, and recovery from that travel will need to happen before that first step is taken on the Cretaceous rocks of Victoria. This is where my Australian friends Tom Rich, Pat Vickers-Rich, Lesley and Gerry Kool, Dave Pickering, Mike and Naomi Hall, Mike Cleeland, and many others will prove invaluable as my “support group” in this project, especially once I arrive in Oz. Wish us luck!
The next entry will ask (and answer) the question: how did the Great Cretaceous Walk come about? See you then!