2004 GPS Western Australia Trip

By Division of Geological and Planetary Sciences

August 12-31, 2004

Photo galleries

Thursday-Saturday, August 12-14: Flying into Broome

We left LAX Thursday evening from terminal 4, the American Airlines terminal. Everything got through security all right, though Cody was called back because his Brunton compass set off the alarms with a petroleum smell. The plane flight in to Broome was successfully uneventful, with no passports or connections lost. Unfortunately, the flight was sold out, so we were packed in like sardines. (Joe and Koseki, in contrast, flew in from Osaka, and the flight was nearly empty; they slept stretched out over 4 seats each.) The only slow down for the main group occurred when Bob was briefly held up at Australian customs, as he was carrying Joe's wooden camping cots, which Joe had neglected to clean before packing. Arriving at the correct Caravan Park on our second try, we enjoyed a dinner of local fare in local restaurants and sunset on the beach. Broome was rather full, as their annual horse racing event coincided with our arrival.

Sunday, August 15, 2004: Gibb River Road

We spent the morning at the beach, until the car rental place opened at 10 am. Shopping lasted until early afternoon, when we finally got on the road despite a dead battery, which we swapped for a spare. About an hour into our journey, we stopped briefly to investigate the giant termite mounds, about a meter high, which litter the landscape like tombstones. We also took a closer look at one of the huge boab trees that grow in the area. Kyle and Francis retrieved a fruit from the tree, about 15 cm long, white, in a brown pod. The flavor was similar to tamarind, but the texture akin to freeze-dried ice cream. Continuing, we crossed the Fitzroy River (but did not spot any freshwater crocodiles) and stopped briefly to re-gas in Derby before turning onto the Gibb River Road. Rather than drive at night (and risk hitting a wayward roo or emu), we camped on the side of the road next to a boab tree with a 3-4 meter wide trunk. After dinner, people played music on a guitar, a harmonica, and a bucket, and sang.

The stars here are incredible. The thick, bright band of the Milky Way, scarred with dark patches caused by dust clouds, runs across the heavens, while the faint patches of the Magellanic Clouds, our satellite galaxies, hang at the southern end of the sky. In the middle of the night, Orion could be seen, hanging upside down by his ankles in the north.

Monday, August 16, 2004: Windjana Gorge and Tunnel Creek

Cody was the first to climb the local boab tree and was divebombed by a large hawk when he discovered a nest containing three eggs. Avoiding the nest, we proceeded to take a group photo in the tree; after which some members of the group began expressing deeply-rooted primate traits, scratching their arm pits and screeching like monkeys. Despite the distraction, we hit the road early and arrived at the Devonian reefs midmorning. The reefs are stunning: you're driving through flat desert, then flat light jungle, then flat plains, and suddenly you hit a massive 100-meter tall vertical wall of limestone. Jessie gave a short talk on the science and history of the reefs -- the "Great Barrier Reefs of the Devonian" -- before we were let loose. Walking down the gorge, we saw flocks of white cockatoos with raucous calls and a few dozens of freshwater crocodiles sunning themselves. The crocodiles are about one or two meters long, and they apparently do not eat humans. Logan tested this theory by approaching a crcodile, but backed off when it opened its mouth to reveal a mouthful of sharp white teeth.

After lunch, we drove further down the road to Tunnel Creek, a large cave system with pools of water and waterfalls. High up on the walls of the caves, a few aboriginal pictographs are visible. Beaches of sand surround wide shallow pools, and large fruitbats live in parts of the caves. Deeper into the �Tunnel�, it was DARK, necessitating the use of flashlights and headlamps, and wading in and out of shallow pools and sand-covered river beds. Giant stalagmites hung from the ceiling, only visible in the ghostly lights from the occasional lamp or camera flash. Weird shapes of elongate amphibians slithered under the ripples in the dark waters, only disturbed by the barefoot students trying to avoid the sharp rocks on the stream floor.

We drove onward to Fitzroy River Crossing, where we setup camp at Fitzroy River Lodge at around 4 pm. To our delight, two different people brought Frisbees. We perfected throwing two at a time (with at least 90% confidence). There were a few near misses (a cooking pot almost overturned). And the caravan park had an Internet connections.

Tuesday, August 17, 2004: Egan Formation and Wolfe Creek Crater

Joe roused Koseki this morning with news of a walking stick nearly a foot-long, which was accompanied by much screaming and shouting on Logan's point. We started our drive to Wolfe Creek Crater and stopped along route at a road side exposure of the Egan Formation. The Egan Formation is a late Neoproterozoic glacial unit, which some people believe occurs after the second generally-accepted Snowball Earth event. It was here that most of us made our first acquaintance with Spinifex grass, the lawn grass of the apocolypse, which precipitated sharp rods of silica. We also saw our first kangaroo, which narrowly avoided running into a passing car.

Mid-afternoon, after a long drive on dirt roads, we arrived at Wolfe Creek Crater, where we are spending the night. Francis, following Gene Shoemaker's notes, has completed the basic geological map of the crater, and he led us around the rim and into the center of the crater itself. A currently dry playa lake bed, guarded on the south side by Spinifex, sits in the middle of the crater. We rummaged through ejecta on the southeast edge of the crater (the impact came from the northwest) for meteorite fragments; Francis and Dave managed to find a couple of weathered, highly magnetic bits.

Wednesday, August 18, 2004: Termites, Halls Creek, and Geike Gorge

Last night we were again treated to a beutiful sky; after the sun set a sliver of the crescent moon shone, set in the zodiacal lights. The lights, reflected off dust in the solar system, extended high up above the horizon. We left Wolfe Creek Crater this morning to begin our ~1000km drive to 80 Mile Beach just north of Port Hedland. Along the way, we stopped next to the highway to learn about termites. Natalia made an excellent and comprehensive presentation next to a large termite mound. We made the appropriate jokes about The Sermon on the Mound, and Natalia covered aspects of termite ecology, behavior, and evolution. Her uncle spent his academic career studying termites, so Natalia was well-versed in all things termite.

We made a fuel stop at Halls Creek, where mechanized public toilets provided much amusement. Further along the road we stopped for a quick lunch. We made it to Fitzroy Crossing in the afternoon where the food groups all resupplied at the supermarket. Many of us bought commmemorative "stubby holders" to remind us of our time at the Crossing when we are back in the States.

We decided to have one more look at the Devonian reefs, so we made a brief stop at Geike Gorge, just outside of Fitzroy Crossing. Debris in the treetops along the riverbanks gave a sense of the power and discharge of the river during the Wet. Although Geike Gorge is known for freshwater crocodiles, no one in the group spotted any during our hike. Some of us spoke with a park ranger who was familiar with the work Jesse had presented earlier in the trip on Playford's studies of the reef systhem.

We are bush camping this evening among boab trees at the base of some low reef exposures - excellent karst examples. Some folks spotted their first (live) kangaroos on the way to the site. The setting sun is backlighting the crags of the reef ridge. The stars are incredible, with a fingernail moon and Saturn just below and to the left of it. The guitar/water tub/dinner pot band played into the night, watching the embers of the camp fire fade under the solid hemisphere of stars.

Thursday, August 19, 2004: Eighty Mile Beach

This is a wonderful crew - 3/4 of the gang were up and finished with breakfast before sunrise, and for the nth straight day we were on the road at around 7 AM. Students are rotating between vans every day, sharing music and experiences. Today was a driving day; we travelled around 600 km from last night's camp site, to a caravan park at Eighty Mile Beach. En route, we passed a number of brush fires burning alongside the road. The caravan park is almost a town in itself, with long-term residents and vendors operating out of campsites. We were able to do our laundry here and spend the late afternoon at the beach, recovering from the long drives and collecting shells. The sands here are carbonate sands, like those in the Bahamas; had we had a microscope and a magnet, it likely would have been a good place to prospect for magnetic bacteria. The beach was not a good swimming beach, for the water persisted at near-ankle depths for considerable distances off shores.

Friday, August 20, 2004: Drive to North Pole Dome

Our morning began with a talk by Zhonghua on wildfires and how they have shaped the ecology of Western Australia, then we set off on the second stage of the field trip: the Pilbara region. Our trip began with a drive to Port Hedland, the Pilbara's largest town, where we stopped for lunch, groceries, and a tour of the Rock Shed, a quite nice rock shop. We then headed down to the North Pole Dome area. Driving over Archean granites eroded flat and covered with desert vegetation, we stopped near a chert outcrop that Roger Buick believes is the site at which Stan Awramik collected what may be some of the world's oldest microfossils in the early 1980's. (Unfortunately, Awramik was not able to identify precisely from which hill in the local area his samples came.) The chert is generally believed to be ~3.3-3.5 billion years old, though Buick thinks this particular outcrop may in fact be part of the considerably younger Fortescue Group (2.7 billion years). Continuing on a bit farther on somewhat rough track, we drove out to the old Panorama Homestead, now abandoned. We camped at a largely Spinifex-free area near the Homestead.

Saturday, August 21, 2004: North Pole Dome and Marble Bar

Today began with talks by Judith and Tina on, respectively, aboriginal culuture and rock art. Francis added some insights into the relationship between the government and the aboriginals, and how that has changed over the last fifty years. Most aboriginals today live in autonomous communities in Western Australia, set up in the 1970's by the government, which are lacking in economic resources, survive off of subsidies, and host numerous social ills. The healthiest communities are those near Darwin, which are sufficiently well-endowed with natural resources to support a ranching-based economy. Most of the aboriginals in the more resource-rich, non-desert parts of the country, where artifacts attest to their past presence, were likely wiped out by disease early in colonial history.

We drove about three kilometers over an overgrown trails to an old mining exploration camp and core shed. Ruins were everywhere at this site, from the electric grill with its electronic components sitting out next to it to the rusted old drilling equipment. The core shed itself was the victim of several typhoons, with core boxes scattered and core bits all over the place. From here, we walked to an outcrop of the ~3.46 billion year old Apex Formation. The Apex chert, which was originally carbonate, contains ripple structures indicative of the presence of water, as well as some of the world's oldest stromatolites, on which Bob gave a short talk. Stromatolites, laminated sedimentary structures with a point or surface of growth, are often but not always produced by microbial mats either precipitating or trapping and binding sediments. In most cases, it is not yet possible to conclude solely on the basis of morphology that microbes played a role in stromatolite formation; it remains unknown whether these stromatolites indicate the presence of life on Earth. Tomorrow, we will be visiting younger stromatolites of the Fortescue Group, which contain diverse microfossils and morphologies, and are generally accepted as being biogenic.

We then hiked to an outcrop of bedded barite (barium sulfate) in the stratigraphically higher Dresser Formation, where Katie F. gave a talk. It is still controversial whether the barite represents a primary precipitate (which Joe believes) or a replacement of gypsum (hydrous calcium sulfate), but its presence does indicate the presence of oxidized sulfur in the middle Archean oceans. Similar sulfate deposits are not present from ~2.8 to ~2.3 billion years ago, which has led some to suggest the evolution of sulfate reducing bacteria at ~2.8 Ga.

Next, we headed to the small town of Marble Bar. Early in the trip, one of the vans encountered an emu, which unfortunately ran into the van. None of our party was hurt, but the emu was killed. When we reached Marble Bar, we went to look at the beautiful bedded, iron-pigmented Marble Bar chert (~3.4-3.5 Ga), which one outlying member of the geobiology community, Hiroshi Ohmoto, is convinced represents evidence for oxygen in the atmosphere at this early date. (More common opinion places the evolution of oxygen-producing cyanobacteria between 2.7 and 2.2 Ga). Based on data from the Astrobiology Institute's drill core through the Marble Bar chert, most of the red, iron oxide coloring is likely of surficial origin.

A number of us (Francis, Dave, Bob, Cody, and Nir) hiked from the Marble Bar Pool up Chinaman Creek to the locality where Bill Schopf's student Julie Packard collected samples in the late 1980's that they found to contain filamentous microfossils they interpreted as cyanobacteria. Recent microscopic work by Martin Brasier's group at Oxford has led to questions about the interpretation of these "microfossils" as microfossils, and geological mapping of the sampling locality by Brasier's group indicates that the chert in which these microfossils are found are part of a massive hydrothermal chert dike intruding through an older stratigraphy of pillow basalts and stratified chert. Looking at the locality, it was clearly that the black chert Packard had sampled was quite different from the stratified chert of obvious sedimentary origin. If the black chert is, indeed, hydrothermal, then it is extremely unlikely that the filamentous microfossils, if they are real, represent photosynthetic bacteria of any sort.

Meanwhile, while these five were exploring the Schopf and Packard locality, the rest of the group was at a swimmable billabong, swinging by a rope into the water. We're now spending the night at the Marble Bar Caravan Park, which is an important laundry site.

Sunday, August 22, 2004: Meentheena and the Drive to Karijini

Today we woke up in Marble Bar Caravan Park, took some quick showers (five hundred liters for the whole camp), and headed off for Karinjini National Park. First, though, Bob had a Fortescue Group stromatolite locality in the Meentheena area, about eighty kilometers away, that he wanted us to check out. The road was a bit rough at the very end, and people became a little quizzical as to whether we'd actually GET to the stromatolites. Fortunately for us, Bob and Francis found it, and it was truly spectacular. The outcrop stretched for at least a kilometer, with stromatolites of many forms, from fenestrate forms a few cm in scale to digitate stromatolites a few tens of cm high to domal stromatolites a meter high, preserved throughout. As Francis said, these are probably the best stromatolites most of us will ever see in our lifetimes. Nevertheless, after this Bob got the rap as the "stromatolite guy" for the rest of the trip.

After this, we began the over three hundred kilometer trip down south to Karijini National Park. We passed an abandoned gold mine, which we did not go into for the sake of time. But about half way to the park, Isaac gave a talk on some ~3.5 billion year old granites about the Shaw Batholith. We stopped at Asuki Roadhouse for gas and refreshments and were back on the road. Upon entering the Hamersley Basin, where we'd be spending the next couple of days, Nora gave a presentation on the overall history of the basin. This was done on a beautiful overlook of some banded iron formations. After that, we had to race against the sun to make it to the park. Francis had a few flat tires, so he stayed behind to fix up his car with Ryan's vehicle. A little past dark, we finally got to our destination: Dales Gorge Campground. Since it was dark, though, we couldn't find the one reserved for our group. So, for the sake of time, we found a free, large campground to stay at. We quickly ate, and went to sleep to prepare for the next 2 days in Karinjini National Park.

Monday, August 23, 2004: Dales Gorge

We woke up today in Dales Gorge Campground, not sure if we'd be able to keep the grounds we staked out the night before. However, we were ready, after a day of driving, to hit the trails. So bright and early, we walked to the edge of Dales Gorge, and headed down. The trail nearest our sight was Fortescue Falls trail; after descending the steep staircase, we arrived atop the beautiful waterfalls. The ironstones were a makeshift staircase, and we could walk all the way down to the pool of water the falls fell into. There, Charlie gave a talk about the stratigraphy of Dales Gorge, and Nir gave his presentation on the deposition of banded iron formations. After that, we were let loose for the entireity of the day. Most of us walked the length of the gorge, about three kilometers, to the very end. As we scrambled over the stones, we could see the banding of the stones, as well as the layers of asbestos in between. This deserves mention, for it is the asbestos we saw, crocidolite, which can cause cancer (but only in high doses!). At the end of the gorge, we were "rewarded" with the Circular Pool, a small, deep pool full of frigid water. Cody got in first, around 10 am, before the sun started shining into the gorge. People straggled in and out for the remainder of the morning, more when the sun was out to warm people up a bit. The small waterfalls surrounding the pool made for a good shower, since our campground had none.

In the afternoon, some people headed back to camp to eat and relax. Some, however, walked back to Fortescue Falls, the other end of the gorge. By mid-afternoon, the swimming was perfect there, and many people went in. Some people jumped off the iron cliffs surrounding the waterfalls. By the end of the day, we were all around the waterfalls, sunning, laughing, reading, or admiring the gorge. We then headed back out, and had dinner at Karinjini. It should be noted that we're staying in Karinjini for three days, which will be the first time we've kept camp for more than a night.

Tuesday, August 24, 2004: Slot Canyons

Today was a slow morning, probably due to the fun and hiking of yesterday. The plan today was more gorges, this time about thirty kilometers west. On the western side of Karinjini National Park, four ironstone gorges meet: Weano Gorge, Wittenoom Gorge, Hancock Gorge, and Knox Gorge. We started by walking to an outlook where we could see the meeting point of all four. There, Judith gave a talk about asbestos, reassuring us that we were, in fact, safe, though the same could not have been said of the residents of the former mining town of Wittenoom. Then, we all headed down Weano Gorge. This, for some, was one of the highlights of the trip. After descending down to the bottom, we had to swim, wade, rock-climb, and crawl to the end of the gorge. It was about an hour down, but well worth the effort. Not everyone made it all the way through, since the climbing was dicey by the end. For those that were willing to scale an ironstone wall that bordered a deep, cold pool of water below, the end was worth it. Another waterfall and swimming pool awaited. By the time we ascended the gorge again, it was time for a packed lunch in the parking lot.

While Ryan and Francis went to restock on food (every group was out of bread), others explored the various other areas of Karinjini. Some descended Hancock Gorge, some went back into Weano Gorge, and some chatted with other Aussies on holiday. After the short hike, the group split up again. Some went back to camp to swim in Fortescue Falls again or relax, while about fourteen of us went to a different gorge that, according to the ranger, had rock art. That group went into the third gorge of the day and made the three kilometer hike to the rock arch at the end of the trail. Just beyond this was, theoretically, aboriginal rock art. However, all we found were rocks arranged on the ground, and some weathering on the walls of the ironstone cliff. Joe hypothesized that the weathering could be rock art, but some, including Logan, think that we may have been duped. In any case, the trail was fairly easy and beautiful. Like Weano, it included some swimming, and some cliff-scaling too. By that time, it was five o'clock, and everyone was tired. So we headed back to camp and got ready to leave the next day.

Wednesday, August 25, 2004: Wittenoom Gorge

Though we rose early, our departure for Tom Price was delayed by the local Park Ranger, who insisted that the main office had miscalculated our camping fees, and we had to swing by the office (which only opened at 9am) to pay an additional $50. Anything with the Park Service takes forever, and this was no exception - we finally rolled out about 10 am, and made our way back to the Auskie Road House to feed our thirsty vans the Diesel they needed.

Our first geology stop of the day was at Wittenoom Gorge, where Belle told us about the various impact spherule layers that have been found within the Hammersley Ranges. Francis was able to locate the 2.54 Ga bed containing the Wittenoom impact spherules. Numerous spheres, some with dumbbell morphologies, were easily visible in hand sample or with the aid of a hand lens.

Although the site at Wittenoom Gorge was by a lush billabong, with beautiful shade trees, the idea of having lunch there was squelched when someone noticed that the gravel in the parking area contained a few percent crocidolite, which agitated some students and prompted our prompt but reasonably dustless departure. (While crocodolite, also known as blue asbestos, is the dangerous form of asbestos -- the ferric iron in the minerals can lead to the formation of carcinogenic superoxide radicals when the asbestos needles penetrated into cells -- the heightened risk of cancer comes from long-term exposure, not half an hour of exposure). The Harvard contingent, Francis and Dave, then left the group for their long drive back to Melbourne, which prompted concern about *who* in Joe's food group could possibly match Francis' skill at the skillet and how the group would cope without Francis' leadership! About an hour down the road, we found a few nice shade trees along a dry, asbestos-free wash that provided a pleasant lunch stop.

We rolled into the little mining town of Tom Price at around 3:30, checked into the caravan park, did a massive grocery run at the local Cole's, picked up another propane stove, and allowed a few students to relieve their Internet Addiction at the local computer/Internet store. On the way back to the caravan park, we took a detour up a steep, windy dirt road to the top of "Mt. Nameless", the highest road-accessible peak in Western Australia, a whomping 1,016 meters above sea level. This gave us a spectacular view of the Tom Price Iron Mine, and a beautiful sunset view of the western margin of the Hammersley Basin.

Dinner was prepared in the "Camper's Kitchen" at the caravan park, and the laundry machines were running until the wee hours of the morning. To allow people to sleep properly, we had to turn off a large floodlight that was keeping us awake. Joe finally found the circuit breaker, and peace descended on the camp.

Thursday, August 26, 2004: Tom Price

Our main item for this morning was a visit to the Tom Price Iron Mine (run by Hammersley Iron, Pty. Ltd.), for which we had to be at the mine gate by 8 am. Most of the students were unusually prompt at making breakfast, although one sleepy body had to be extracted from its sleeping bag by force. All were reminded not to wear open-toed sandals or thongs, as the mine required toe protection.

A few minutes before our departure for the mine, Laura B. woke us all up with a stimulating presentation on the ore-forming process that turned the ordinary banded iron formations (that we had been living in for the past 3 days) into the nearly pure hematite used for iron and steel smelting.

Somehow we managed to roll up to the main mine entrance gate promptly at 8 am, and were met by two of the mining enginers, Jim and Matt, and two large air-conditioned buses. After a brief orientation about the mine, we were given helmets, safety glasses, and a 41-page color, spiral-bound site visit handout all about the history, geology, and economics of the mine. They then took us on a guided tour, and allowed us to collect all the samples of hematite ore and pyrite concretions from the underlying shales that we could carry. Jim and Matt were clearly pleased to have a crew of actual geologists to show around, as their last group was a bunch of lawyers, who didn't ask a single question! Mid-way through the tour, we were joined by their Boss, Pat Mackenzie, who had helped arrange the visit. The highlights were the group photo in front of one of the mining ore trucks - 'huge' is just not an adequate description - and the search for golfball-sized pyrite lumps in the Mt. McRae Shale at the base of the deposit. Libin Z. gave us his presentation on the cyanobacterial biomarkers in this shale, in front of smoke eminating from spontaneous combustion of the shale unit! Archean petroleum burning away! We're still puzzled about the juxtaposition of highly reducing shales next to one of the world's most oxidizing iron ore deposits! Go figure ... ain't geology wonderful!

And then we did the long drive towards the beach at Exmouth - nearly 600 km from Tom Price. Question: what is the probability that two separate vans would both get flat tyres within a minute of each other? Close enough in time that the radio messages between vans telling about the mishaps are misinterpreted? Well, it happened.

Friday, August 27, 2004: Exmouth and Ningaloo Reef

Ningaloo Reef! Exmouth! We spent the night in a youth-hostel style room, which was luxurious by our standards, though it was 8-10 people in a room. At 8am we trooped over to the Exmouth Dive Center to rent our snorkeling equipment and meet our guides for the day: Dave, Marin, and skipper Darren. After being equipped with full-body wetsuits, fins, masks, and snorkels, we piled onto a classic old bus for our short trip to the marina. We loaded up onto the beautiful 60-ft boat, and set off into Exmouth Bay. Many of us worked on attaining "sea legs," trying not to fall over on the pitching and rolling boat. Thankfully there wasn't too much swell. Our first quarry was the humpback whale. We saw 10-15 of these medium-sized whales, a few of them breaching or rolling over to wave their flippers at us. A few even swam within a few feet of the boat, so we could see their blowholes and barnacled backs.

Next we headed north toward the tip of the peninsula to hobnob with manta rays. These fish can attain a 9m "wingspan," but the ones we saw were only a couple of meters across. They were still impressive, especially when they suddenly appeared out of the murky water and swam right toward the group of snorkelers. When everyone had seen the mantas, we all clambered back on the boat for lunch. While our gallant crew prepared a gourmet meal, Selene gave us her report on the history of the Ningaloo Reef, one of only two west-facing coral reefs in the world. Up on the shore, we could see the brown cliff that was the previous iteration of the reef at the last interglacial. Once we'd eaten, those of us who were not seasick or cold (most of us, thankfully) plunged in for an afternoon snorkel over the reef. Most of the coral here was of the staghorn variety, giving us the feeling of flying over a bare forest of pointy blue and brown trees. The real highlight was the rainbow of fish that darted in and out of the coral network. Most common were the parrotfish chomping away on the coral with their beaks, but we also saw angelfish, yellowtail, pipefish, and moorish idols. A few members of the group also saw boxfish, a four-foot shark, and even a sea turtle! We returned sun-baked, salt-encrusted, and tired, but had a great experience. It was nice to have a shower, a relaxing evening, and a bed.

Saturday, August 28, 2004: Shark Bay

Today was mainly a driving day. We drove straight from Exmouth to Coral Bay, where we had a brief stop on the white beach to hear talks on the ecology by Katie D. and the Meteorite Bore Member by Isaac (an unusual diamictite which we did not get to see due to time constraints). We could see the waves breaking on the reef a few km out to sea; it looked like a nice place for a vacation. Off we went again, stopping only to take a goofy picture at the sign announcing the Tropic of Capricorn, to have a very brief lunch along the roadside, and to look at the carpet of wildflowers that spread below the now-greener bush. We almost stepped on some baby quail-like birds at the wildflower stop; they were making themselves as inconspicuous as possible while their parents tried to lead us away. Almost immediately after exiting the tropics we happened upon an area of scattered showers, and it was much cooler when we reached Shark Bay. It was clear that we were driving into true winter.

We stayed at the small caravan park at the Hamlin Pool Telegraph Station, which had nice grass, few lights, and very few people. Probably the most peaceful caravan park of our trip. Unfortunately the wash and shower water tasted as salty as blood. After claiming our camping area and taking a gander at the small museum containing lots of old telegraph equipment, we strolled out to look at the famed stromatolites, perhaps the closest living relatives of those we had seen preserved in rock billions of years old. The beach is composed almost entirely of small bivalve shells which crunch pleasantly in one's hand. It was remarked that they would make an incredibly crisp and calcium-rich breakfast cereal. A boardwalk brought us out to the hypersaline shallows, where we could see the blackened, dead stromatolite knobs protruding from above the water, as well as the pale green living heads below the water. Cody gave us an overview of the geology of Shark Bay, and Logan concluded with a talk on the different types of stromatolites that may be formed by cyanobacteria. We could see at least two types; the heads as hard as concrete and also the muddy algal mats.

It looked to be a nippy night, so we were grateful when the station owner built us an excellent bonfire. The wind picked up as the night wore on, but fortunately the fire was surrounded by sand. The moon rose nearly full, casting a cold white light which was nearly bright enough to read by. Tomorrow is our last long day of driving!

Sunday, August 29, 2004: Cervantes

After the coldest morning so far on the trip, we had one of the slowest departures so far, only pulling out after 8 am. We were all amused by a tiny bird attacking a much larger Australian crow, and another bird repeatedly attacking its image in one of the side mirrors of a van.

Mid-morning found us several hundred kilometers further South, at the Kalbarri National Park. Huddling in the cold wind, we saw the Ordovician Tumblagooda Sandstone that has some of the oldest traces of terrestrial animal life. Cody again gave a galvanizing lecture on the topic, expanding it to include the "failed rifting" event that led to the formation of the Paleozoic and Mesozoic sedimentary basins on the West Australian margin.

Further South, we found the climatic change presaged by yesterday's rain shower to be in full force - the dry desert scrub with the wildflowers, kangaroo and emu gave way to rolling hills of verdant green pasture lands, inhabited by occasional sheep and horses. The human population also increased dramatically, and we had lunch at a nice public park in the small town of Northampton. From there, we drove along the coastal route to the small town of Cervantes, camping at the Pinnacles Caravan Park about two hours North of Perth. Having such a large crew, they gave us a private grassy area to camp in, with our own private ablution block and camper's kitchen facility. Having spied an intriguing road sign labeled "Stromatolites", Cody, Bob, Nick, Jessie, and Isaac took a late jog over to investigate the site, while the rest of the crew watched a beautiful sunset over an eerily smooth but *cold* Indian Ocean.

Monday, August 30, 2004: The End

Our last day in Australia! The Gods of the Weather were indeed kind to us, as we were spared rain on all nights of the trip. (Most of us were sleeping out, under the stars, for the entire time!) Already mumbles are heard about hijacking one of the vans and continuing the trip another week, driving around the Southern part of the continent to Sydney. No! The Ge 120 class (summer field camp) departs in a few days for about half of the crew, so we must get the group back to Pasadena on schedule! As the flight to Perth will depart around Midnight, we had to organize our personal and group baggage for the journey. This meant scrubbing all of the Division ice chests till they were sparkling clean, sorting through all of the camping equipment (to be stored with a friend at the Perth Paleomag lab at the University of Western Australia) so Ben and Isaac can use it next year), and so forth. Just as we were about to leave, one of the vehicles eats another battery and we're delayed while a spare from another van is swapped in again. (Remember that this happened to us less than one hour after picking the van up in Broome on the first day!)

A short drive from the caravan park brought us to the "Pinnacles National Park", where numerous limestone pillars stick up through the wind-blown sand. Cody again summarized the local geology and history of the area, including the lithification of the Pleistocene carbonate sand dunes into limestone, their erosion into a 'Karst' unit, and periodic burial and exposure under the shifting sand dunes.

Arriving in Perth around 3:30pm, most of the group got dropped off at the airport while drivers took the vans to 4wdHire.com, barely arriving before their 5pm closing time. A couple of noble students remained at the airport watching the luggage, as Qantas wouldn't let us check in for our red-eye flight to Sydney till 9 pm. The remainder of the group took taxis to downtown Perth and explored the largest population center they had seen in several weeks.

Many thank to the GPS Division and Dr. Jenkins for making this trip possible

Last updated: Mon Jun 15 10:34:20 -0700 2009

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