1. Wake up before dawn
2. Make sure Venus still exists
3. Do my daily ablutions outside
4. Drive on the left side of the road
5. Navigate using GPS, topographic maps, and geologic maps
6. Use a phone card
7. Walk on desert pavement
8. Wade through spinifex and get punctured
9. Look at rocks and sedimentary strata
10. Use a rock hammer
11. Identify grasses, wildflowers, shrubs, and trees
12. Peer through a handlens at tiny round things
13. Watch wedge-tailed eagles, kestrels, galahs, willy wagtails, magpie-larks, spinifex pigeons, and kestrels
14. Climb steep rubbly hillsides
15. Wear a watch and keep track of multiple time zones
16. Sit on the edge of a cliff and eat lunch
17. Calculate the number of tyres on passing road trains
18. Say “no dramas, mate”
19. Enjoy all the scenery
20. Dig a fire pit, collect and burn wood
21. Cook by headlamp
22. Hear bats echo locate and fly overhead
23. Eat Tim Tams
24. Sleep outdoors in a different place every night
25. Sleep in a tube of cotton, plastic, and Goretex
26. Watch shooting stars at night
27. Count the number of stars in Scorpio (19) and study the shape of the Milky Way
28. Fall asleep at 9 pm
29. Be in the present for hours at a time
Showing posts with label West MacDonnell Range National Park. Show all posts
Showing posts with label West MacDonnell Range National Park. Show all posts
Tuesday, June 23, 2009
Undisclosed Location
June 20, second day of field work. After a warm swag out at Weeli Wolli Springs, we headed west and somewhat north to my next target site. After 35 kilometers of corrugated dirt track and a several times that on the Great Northern Highway (all of two lanes), the site came into view. It's a nice steep hill of strata .
I’d been to this location before. The plan was similar to much of the research emphasis of this trip: make repeated vertical measurements of stratigraphy (sedimentary layering and its characteristics) at regular intervals along the outcrop zone and to study the spherule-rich zones in particular. I’m trying to do this all over the Hamersley Range, as I described in an earlier post.
I knew from satellite imagery that there was turn off from the main road onto a dirt track that would pass close in front of the hill. The road looked familiar from space; it seemed to be the same track I’d traveled on in 1989 and 1996. The turn appeared as expected. I hauled the steering wheel left and the Landcruiser headed onto dirt. The track was new. Same exit point off the main highway, but it cut at a different angle across the bush. A sign appeared: “Warning Buried Fibreoptic Cable”. Hmm, must be a communications line for the West Angelas iron mine. No worries, the track was in good shape and headed where I wanted to go.
Eventually we reached the point of closest passage to the hill. Another left turn, over the berm at the edge of the track. A short cross country bounce, till I felt we were close enough to walk, climb the hill, find the layer, and still get enough exercise to feel virtuous.
I was pleased to see an extensive outcrop of limestone at the base of the hill. The geologic unit which I am studying at present is the Wittenoom Formation. It’s named after the Wittenoom family, who were early Dutch homesteaders or the equivalent in the Pilbara. The Wittenoom has two parts. The lower part is the Paraburdoo Member. It’s basically all dolomite – a type of limestone containing magnesium in addition to calcium. This dolomite also has lots of iron in it. It is thus a pleasant yellow to brown colors in weathered outcrops. It’s named after the mining town of Paraburdoo; I’ve read that Paraburdoo means “meat feathers” in the local Aboriginal language. The Paraburdoo is what I was seeing at the base of the hill.
The upper part of the Wittenoom Formation is called the Bee Gorge Member. It’s named after Bee Gorge, and I haven’t a clue who or what “Bee” was. There are certainly plenty of bees around here when wildflowers are blooming. I know the Bee Gorge Member very well. Not only does the impact layer occur in these strata, but the rocks on which I did my PhD research occur here.
The Bee Gorge sequence is like an old friend I visit regularly, who always shows me new and exciting things. It’s a diverse suite of rocks. The basic framework is shale, limestone, chert (very fine grained quartz), and ferruginous chert that represent the slow accumulation of fine grained sediment in the ocean through time. Intermixed with these are volcanic sandstones, the impact layer, sandstones, and other limestones that were deposited suddenly and episodically, interrupting the normal quiet conditions. This is the part that attracts me; the abrupt events when something exciting happens. Puzzling out what happened in these events is fun and creative work. It’s also rewarding to look at the Bee Gorge because it’s never the same in two places. The general sequence of rock types and units is constant, but the details - the charming part - keep changing.
We climbed the hill. After some casting about, I found a bed that I thought should be the impact layer. Louis eventually found spherules at its base, confirming that we were in the right place. We did our work. The spherule-rich part of the bed – the five or so centimeters at its base – also contained lots of small platy particles about the size and shape of a fingernail. These chips were bits of the sea floor under the impact layer that were eroded when it was deposited. They’re badly rusted; they were probably pyrite in the seafloor at the time they were eroded. The layer was just crammed with them. It was really unusual, and a challenge to try and understand how the cramming happened. I am still working on it.
We were done by late afternoon: time to head back to the truck and camp. I pointed us down through the Paraburdoo Member. One narrow drainage looked to have close to 100% exposure. It was a good place for a quick scan in search of a mythical missing impact layer. It was hard to walk down hill through steep, rubbly outcrop and look for tiny spherical particles.
I carefully descended a steep smooth face of delicately brown and tan banded limestone. I thought, great photograph; the light was good. I stopped at the base to get out my camera. As I turned, a loose slab of rock caught my eye. It had petroglyphs on it! Almost the whole surface had Aboriginal imagery: whirls and what I think were representations of throwing sticks. Time indeed for a few pictures. This was exciting; I’ve found petroglyphs only once before in the Pilbara. It was a natural place for Aboriginal art; there was a spring in the middle of the drainage, and actually a couple tiny pools of standing water. Spring fed pools were new to me in this area. It made sense that they would be here. Being limestone, the Paraburdoo Member would be dissolved by rainwater and form caves, i.e., underground plumbing systems for groundwater. This spring was a spot where groundwater was leaking onto the surface. The other Aboriginal site I have “found” also showed signs of springs.
We searched around the drainage looking at all the flat rocks, but could not find any additional art. It’s a place I could well imagine Aboriginals using. In addition to surface water (a rare commodity), there was food, evidenced by plenty of wallaby scat and a couple of plants that could provide small berries and fruit.
Further down the drainage, I found a piece of nautilus shell. I can’t imagine how this piece of a sea animal got here. It was not a fossil. In any case, the rocks under it are a factor of ten times too old to have such fossils in them. It’s of course exciting to imagine an Aboriginal transporting the shell here hundreds or thousands of years ago. It’s also possible that some Westerner dropped it in the drainage recently. There were some test bore holes nearby. Still, another exciting discovery.
So, for the second time on this trip, I’ve had an experience which has brought me a step further in knowing Aboriginal senses of place. Tnorala was explained; this site, as far as I know, is unreported. I’ll investigate that back in Perth.
I’d been to this location before. The plan was similar to much of the research emphasis of this trip: make repeated vertical measurements of stratigraphy (sedimentary layering and its characteristics) at regular intervals along the outcrop zone and to study the spherule-rich zones in particular. I’m trying to do this all over the Hamersley Range, as I described in an earlier post.
I knew from satellite imagery that there was turn off from the main road onto a dirt track that would pass close in front of the hill. The road looked familiar from space; it seemed to be the same track I’d traveled on in 1989 and 1996. The turn appeared as expected. I hauled the steering wheel left and the Landcruiser headed onto dirt. The track was new. Same exit point off the main highway, but it cut at a different angle across the bush. A sign appeared: “Warning Buried Fibreoptic Cable”. Hmm, must be a communications line for the West Angelas iron mine. No worries, the track was in good shape and headed where I wanted to go.
Eventually we reached the point of closest passage to the hill. Another left turn, over the berm at the edge of the track. A short cross country bounce, till I felt we were close enough to walk, climb the hill, find the layer, and still get enough exercise to feel virtuous.
I was pleased to see an extensive outcrop of limestone at the base of the hill. The geologic unit which I am studying at present is the Wittenoom Formation. It’s named after the Wittenoom family, who were early Dutch homesteaders or the equivalent in the Pilbara. The Wittenoom has two parts. The lower part is the Paraburdoo Member. It’s basically all dolomite – a type of limestone containing magnesium in addition to calcium. This dolomite also has lots of iron in it. It is thus a pleasant yellow to brown colors in weathered outcrops. It’s named after the mining town of Paraburdoo; I’ve read that Paraburdoo means “meat feathers” in the local Aboriginal language. The Paraburdoo is what I was seeing at the base of the hill.
The upper part of the Wittenoom Formation is called the Bee Gorge Member. It’s named after Bee Gorge, and I haven’t a clue who or what “Bee” was. There are certainly plenty of bees around here when wildflowers are blooming. I know the Bee Gorge Member very well. Not only does the impact layer occur in these strata, but the rocks on which I did my PhD research occur here.
The Bee Gorge sequence is like an old friend I visit regularly, who always shows me new and exciting things. It’s a diverse suite of rocks. The basic framework is shale, limestone, chert (very fine grained quartz), and ferruginous chert that represent the slow accumulation of fine grained sediment in the ocean through time. Intermixed with these are volcanic sandstones, the impact layer, sandstones, and other limestones that were deposited suddenly and episodically, interrupting the normal quiet conditions. This is the part that attracts me; the abrupt events when something exciting happens. Puzzling out what happened in these events is fun and creative work. It’s also rewarding to look at the Bee Gorge because it’s never the same in two places. The general sequence of rock types and units is constant, but the details - the charming part - keep changing.
We climbed the hill. After some casting about, I found a bed that I thought should be the impact layer. Louis eventually found spherules at its base, confirming that we were in the right place. We did our work. The spherule-rich part of the bed – the five or so centimeters at its base – also contained lots of small platy particles about the size and shape of a fingernail. These chips were bits of the sea floor under the impact layer that were eroded when it was deposited. They’re badly rusted; they were probably pyrite in the seafloor at the time they were eroded. The layer was just crammed with them. It was really unusual, and a challenge to try and understand how the cramming happened. I am still working on it.
We were done by late afternoon: time to head back to the truck and camp. I pointed us down through the Paraburdoo Member. One narrow drainage looked to have close to 100% exposure. It was a good place for a quick scan in search of a mythical missing impact layer. It was hard to walk down hill through steep, rubbly outcrop and look for tiny spherical particles.
I carefully descended a steep smooth face of delicately brown and tan banded limestone. I thought, great photograph; the light was good. I stopped at the base to get out my camera. As I turned, a loose slab of rock caught my eye. It had petroglyphs on it! Almost the whole surface had Aboriginal imagery: whirls and what I think were representations of throwing sticks. Time indeed for a few pictures. This was exciting; I’ve found petroglyphs only once before in the Pilbara. It was a natural place for Aboriginal art; there was a spring in the middle of the drainage, and actually a couple tiny pools of standing water. Spring fed pools were new to me in this area. It made sense that they would be here. Being limestone, the Paraburdoo Member would be dissolved by rainwater and form caves, i.e., underground plumbing systems for groundwater. This spring was a spot where groundwater was leaking onto the surface. The other Aboriginal site I have “found” also showed signs of springs.
We searched around the drainage looking at all the flat rocks, but could not find any additional art. It’s a place I could well imagine Aboriginals using. In addition to surface water (a rare commodity), there was food, evidenced by plenty of wallaby scat and a couple of plants that could provide small berries and fruit.
Further down the drainage, I found a piece of nautilus shell. I can’t imagine how this piece of a sea animal got here. It was not a fossil. In any case, the rocks under it are a factor of ten times too old to have such fossils in them. It’s of course exciting to imagine an Aboriginal transporting the shell here hundreds or thousands of years ago. It’s also possible that some Westerner dropped it in the drainage recently. There were some test bore holes nearby. Still, another exciting discovery.
So, for the second time on this trip, I’ve had an experience which has brought me a step further in knowing Aboriginal senses of place. Tnorala was explained; this site, as far as I know, is unreported. I’ll investigate that back in Perth.
Monday, June 15, 2009
Alice and West
Alice Springs was the obvious place to start. It’s the only town of any size in the Red Centre of Australia. At 30,000 or so people, it has all the necessary services: airport, truck rental, and stores (food, field guides, souvenirs). It’s a real town that largely caters to tourism. I thought that it would be a good place to get over jet lag.
Given the distortions of my body clock, my impressions of Alice are hazy. It’s tucked just north of the west-east trending strike ridges of the MacDonnell Ranges. The airport is south of the hills; we arrived in Alice per se through the dramatic piercement of Heavitree Gap, which is just wide enough for the two lane road, the Adelaide-Darwin railway, and the Todd River. The MacDonnells rise a thousand feet or so above the town. The sedimentary cliffs should have been pretty, but jet lag tunnel vision and lack of local orientation kept me focused where I was going and what’s immediately around me.
Reorientation to Australia. Look right, then left when crossing roads. Walk on the left side of the footpaths and sidewalks. Drive on the left; be very aware when entering roundabouts. It was comforting to shop for food and supplies at Woolworths; I’ve been in equivalent stores all over Australia. I know what brands I like. Finally, someplace where I knew where I was.
The influence of tourism on Alice is obvious. The downtown core has a high density of aboriginal art galleries, many of which sell very powerful original works. Paul did his part to support the Australian economy here. The pedestrian mall features a number of tour agencies and internet cafes. There are also the standard curio shops selling the same Australiana souvenirs that I’ve seen in Perth, the Pilbara, Sydney, Hobart, etc. The gradient of young backpackers increases to the west towards the youth hostel. I’ve heard French, German, Japanese, and possibly Russian being spoken.
We picked up a Nissan Patrol 4WD on Monday. It’s a decent vehicle, a little mushy in the suspension and steering, and the shift gates are a tad fussy. A wider wheel base than the Toyota FJ 100s I am used to. The hire company also provided gear; cook kit, table and chair, and swags. We filled the remaining space with food, gear, and water bottles.
Before setting out, we spent a half day at the Alice Springs Desert Park. It’s a sort of combination botanical garden and zoo. It does a superb job of presenting the major ecological zones of Central Australia within a walkable setting. I wish I had been less jet laggy, I would have absorbed more. The biological context is just different enough from the Pilbara that there was much to see and learn. I pretty much failed. Nonetheless, it was rewarding to wander through a series of small aviaries and see a wide variety of birds, to get a feel for the local species of spinifex (softer) and wildflowers (similar). The nocturnal house featured a colony of bilbys; these are sort of a rabbit-like marsupial that’s almost extinct (due to feral cats). The only odd part was a recurrent sense that this was a created landscape. I don’t know when the Park was opened, but the majority of the vegetation zones had to be installed; all the plants thus were about the same size. It lacked the range of young to old plants that occur in a native landscape, and it was not established enough to look “real”.
On Tuesday we headed west from Alice into West MacDonnell Range National Park. Our route followed a major valley between a couple major ridges of resistant sandstone. For some reason the road is called Larapinta Drive. This amused me, I think of a “drive” as having houses on it. Here it really was a drive, a route to new and interesting places. The main NP attractions are the stream valleys which have cut north through the Ranges, cutting narrow and scenic gorges. We stopped at several of these: Simpson Gap, Standley Chasm, Ormiston Gorge. They were each dramatic in different ways, ranging from the narrow notches at Standley to an outright canyon at Ormiston. Each stop was at most a few hours hike. Time to take pictures and learn a field protocol for fussing with all my camera gear. Also reflexive geology; observing the rocks to understand their sedimentological and deformational history. More orientation.
A first night’s bush camp; a chance for Louis to get oriented to how we do things. First, find the right off road spot. Make sure the truck is parked safely. Collect wood for fire, dig fire pit. Choose swag out spots and lay out gear. Assemble table, cook gear, and chairs. Enjoy happy hour while some one cooks.
A clear night, lovely to be back under the stars. Very cold, to be expected in the desert. I woke up to make use of a nearby bush, and discovered that my swag and gear were covered with frost. In the morning we all discovered that swags aren’t the best cold weather gear. While they kept the frost on the outside, their canvas sides also trapped much moisture inside. My sleeping bag verged on wet. The pad under me was damp. We had a leisurely breakfast while the sun dried everything out.
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