Thursday, June 24, 2010

A Not-So-Rotten Day at Rotten Point: Part I

Tuesday, June 22, was a day in the field that reminded us geologically oriented folks why we do this. Yes, it’s partly for the increased knowledge that may grow out of our daring to venture from behind our computer screens, travel long distances, and look at real rocks. But it’s also because of how it often leads to a satisfaction that comes with accepting what might come your way, as well as surpassing the mental and physical demands of field research. Yet to most people outside of geology and paleontology, our endeavors sometimes look like sheer madness. Oh well: their loss.

But before I relate some of the escapades of that memorable day, a brief review of the days immediately preceeding is needed to get readers up to date on the sequence of events. Field work resumed in the Otway Ranges (“Cretaceous West”) on Sunday, June 20, after a four-day break in Melbourne, during which my wife Ruth arrived from the U.S. This reentry to the field was a gentle one, though, as three of us (Tom Rich, Ruth, and me), during the drive back to Apollo Bay, were able to just pull up to a roadside parking lot, take a few steps down a boardwalk, and stroll across a flat marine platform near Skenes Creek, Victoria.

The “salad days” of field work in the Otways; Skenes Creek, with nothing but flat marine platform and a parking lot nearby. My wife Ruth, having arrived in Australia just the day before, is definitely enjoying this easy start, but has no inkling whatsoever of the next two days’ worth of field work, which let’s just say was almost the opposite of what you see here.

The main reason why we stopped at Skenes Creek is because the Cretaceous rocks here were rumored to hold dinosaur tracks. This idea started in the 1980s when a local resident spotted and photographed tracks there, then reported them in a letter sent to Tom, which even included a photograph of these important trace fossils. Ever since then, paleontological volunteers have come back looking for these tracks; alas, none have been spotted. This was my fourth time there, and I did no better than my predecessors, although I did note and photograph some probable invertebrate trace fossils while there. So back in the car, and it was a short drive to Apollo Bay, which was where we were staying.

The number in our field party increased to five on Monday, June 21, as geologist Michael (Mike) Hall (Monash University) and our local guide and local Greg Denney joined Tom, Ruth, and me. This was also the first day of the winter solstice in the Southern Hemisphere, and Ruth, having just arrived from the oppressive heat and humidity of summertime in Atlanta, Georgia, was reveling in the kinder temperatures of a seasonal flip.

Tha day, we all went to an outcrop west of Dinosaur Cove with the intention of figuring out its stratigraphy – the order and distribution of the sedimentary rocks – and the original sedimentary environments – how the sediments composing the rocks were deposited more than 100 million years ago there, whether by river channels, deltas, floodplains, or lakes. By the end of that field day (some of which was rather strenuous), we felt that this goal was achieved, and we knew much more about the sedimentary situations that led to the formation and preservation of the trace fossils there.

Stratigraphy and sedimentary environments can be studied in lovely places, for sure, and the Otways Ranges have a wealth of them.

So what about June 22 and its challenges? It began with our goal, which was to scout a sizeable outcrop at a place I had never seen, the inauspiciously named Rotten Point. Rotten Point is located immediately west of Dinosaur Cove, and consists of dramatic coastal cliffs and marine platforms, which are continually shaped by powerful waves from southwesterly blowing winds. In planning for this reconnaissance, Greg told us this site should be easy to access. We examined a map together, which seemed to back up his claim. We could drive on a dirt road through his property to a small parking spot near Dinosaur Cove, park the vehicle, then hike a short trail to the outcrop that led from the track for the Great Ocean Walk. As we might say in the U.S., “Piece of cake.”

This “cake,” however, came out looking far different from its picture on the box, which looked all glossy and perfect, its icing tempting and sweet. Moreover, the instructions for mixing the ingredients and baking the cake must have been translated into Chinese, then back into English, and translated again into Esperanto with perhaps a smattering of Pig Latin. The “clear” trail had changed into an overgrown one that wound down a steep slope to the outcrop, a common occurrence in a place where plants tend to grow if unhampered by grazing animals or defoliating humans. This was not so bad in itself, but once we traversed it and reached the outcrop, we found ourselves standing on a relatively small bit of Cretaceous sandstone, penned in by broad gaps in the marine platform to the east and west. There simply was not much rock for us to see here, especially when compared to what was just east of us. Moreover, my ichno-vision detected no trace fossils here, a sad state of affairs, indeed.

Hey, looks like more Cretaceous rocks over there, perhaps with some trace fossils. What, you don’t want to swim across? Why not – where’s your sense of adventure?

So if we were to really examine this site, we would have to go back up and turn to the east, then hike over to a ridge to circumvent a broad chasm filled with foamy and churning seawater. Once there, we could drop down next to the cliffs and further down to the marine platform, enabling us to examine the much larger amount of rock offered to us by most of Rotten Point.

Back up the trail we went, and with Greg leading the way, we plunged into the dense coastal scrub.

Greg Denney, doing his Australian version of Houdini by disappearing in the coastal scrub: now you see him, now you don’t.

After all, the shortest distance between two points is a straight line, and there was no other way to reach the outcrop short of evolving gills or wings (and who has the time or genes for that?). Fortunately, very little of this coastal greenery is lethal, or even mildly disagreeable, for that matter. So this became more of an exercise in patience as we struggled our way through the thick vegetation to the ridge.

Once we reached the ridge, a quick slide down a sandy slope led to another patch of coastal scrub, then an abrupt descent into an amphitheater of Cretaceous rock. We had made it.

The cove just west of Rotten Point, which perhaps means it could be called Rotten Point Cove, but I will just call, Helluva-Trip-In Cove.

But was it worth the trip, geologically and paleontologically speaking? Tune in for A Not-So-Rotten Day at Rotten Point: Part II, in the next entry…

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