Australia - Tropics, Deserts and City

For the month of March I am lecturing on a Smithsonian Journeys trip to Australia and New Zealand. The flight over on the Airbus 380 was relatively easy - I can highly recommend the comfort on this exquisite and roomy jet (and I flew on cattle class!). I was able to take in four movies - The Shape of Water, Three Billboards Outside Ebbing Missouri, The Man From Snowy River, and Crocodile Dundee. Good fun. Once on the ground here, the distances are vast and we can only see but a small slice of this immense landscape. However, the rewards are grand and varied, from tropical forests, to deserts to a very expensive city.

We arrived in Cairns after torrential rains. This is the Barron River in flood.

The spray coming up out of the gorge behind the gondola is from the Barron Falls, normally a small trickle (due to dewatering in a hydro-electric scheme) that falls 900 feet.

This is Barron Falls in late October, 2015 - the last time I visited here.

View from the same platform in March, 2018. You can watch a one minute video of the flood here.

The newspapers were full of stories about the rain and the floods.

Some areas received 24 inches in three days and a few towns were cut off when bridges went out.

The rain had stopped by the time we arrived and our walk through the rainforest was on the cool side.

I wish I could remember the name of this emergent giant in the rainforest. Almost as tall as a California redwood, the species was harvested for wood and is nearly gone from this forest.

The Daintreee is considered the oldest continuously existing rainforest in the world, perhaps as old as the Cretaceous time period. The Daintree may be 125 million years old.

On to the Great Barrier Reef at Michaelmas Caye. The following are shots I took with my underwater camera. With over 600 species of coral found here, I have no idea what the names are.

But they are beautiful.

Corals are very tiny organisms that build calcium "homes" for themselves. The colonies are the great limestone factories on planet Earth.

A large colorful parrotfish.

Brain coral and giant clams.

Close-up of a giant clam, which can weigh over one ton! Here the animal has its shells wide open. Another brilliant snorkel on the Great Barrier Reef. This time I had no issues with water leaking into my mask as I lathered the Vaseline real thick on the mustache.

So, it is time to leave green and rainy Queensland behind and head west to the Outback! Note the difference in color between this near-coastal scene and the one that follows from the interior of the continent.

Landing at Alice Springs in the Red Center of Australia. Note the water gap running through the upturned ridge of rock - that is Hevitree Gap cut by the Todd River.

Australia is no different from any other country in having its war memorial to remind the citizens that they are warriors. The many signs leading up to the hilltop view list every single war Australia has participated in. The one for Afghanistan still has no end date.

Although most people conflate the Outback with desert, this area is more akin to semi-arid with many trees and the invader grass called bufflegrass. The Outback as well had received a lot of rain in the previous 10 days.

We experienced an Aboriginal encounter with the local tribe. Here they are selling their art painted on canvas.

Mark is showing how to throw the boomerang.

We got to try a bit of kangaroo tail. It tasted like pork.

And we enjoyed some hot tea from the billie.

Next, on the open road west from Alice Springs along the MacDonnell Ranges. These Precambrian quartzite and shale rocks were folded during the Alice Springs Orogeny between 350 and 300 million years ago. Many water gaps are cut through these linear uplifts.

These are cycads, an ancient plant that evolved as early as the Jurassic period, some 200 to 145 million years ago. These MacDonnell cycads (Macrozamia macdonnellii) were seen in the Standley Gorge as refugia specimens held over from wetter times.

The sheer walls of the Standley Gorge, cut into the Hevitree Quartzite.

We visited another water gap called Simpson's Gap. This is my favorite as its form is gentler and more welcoming.

This is the reflecting pool in the narrows of Simpson's Gap.

An example of the Hevitree Quartzite, deposited as sandstone around 900 to 800 million years ago.

Now we are making our way over 450 kilometers from Alice Springs to the southwest and Uluru or Ayers Rock. The road was quite good and fairly lush given the recent rains.

That's Mt. Connor in the distance rising about 1200 feet above the plain. It is composed of a hard sandstone/quartzite caprock underlain by softer shales and mudstones.

Close-up of Ayers Rock with a nice cirrus cap.

The bare sandstone monolith funnels water off of the top into numerous pools at the base. These were much sought-after locations for water and animal resources, which were also attracted to the water.

View to the northeast on the south side of Ayers Rock. The rock is technically composed of a sandstone called arkose. These are sandstones that contain much pink feldspar, which suggests that the source area was not far away when this was deposited 550 Ma. Feldspar tends to weather chemically more rapidly than other minerals and its presence here means there was not much transport distance. See below for an explanation.

This is the northwest side of the rock and where the trail goes to the top. It was announced while we were here that climbing of the rock will be outlawed officially on October 26, 2019. It is now heavily discouraged but still attainable, although it is forbidden on days when the temperature reaches 36ºC.

This is the beginning of our champagne sunset from the viewing area.

We saw this one with about 700 other people. About 500,000 people visit Uluru every year.

Last shot of the evening.

The next day we headed further west to Kata Tjuta, formerly known as the Olgas. Kata Tjuta is the local Aboriginal name meaning "Many Heads" for the 36 domes of rock.

Telephoto shot of the Olgas across the plain.

While only 16 miles away from Uluru, the rocks here are much coarser being composed of boulder and cobble conglomerate. Some of the large clasts are well-rounded, while others are sub-rounded or even sub-angular.

The clast compositions suggest that the material was derived from the nearby Petermann Mountains, observed to the southwest of Kata Tjuta. I find it amazing that after 550 million years, the source area is still standing and still presumably shedding debris outwards!

Basalt clast from the Pertermann Mountains. This was the end of our Outback experience.

Flying into the city of Sydney, Australia's largest.

It is really quite scenic and easy to get around (at least in the city center where we stayed - the suburbs have terrible traffic).

The iconic Harbor Bridge and Sydney Opera House as seen from Lady MacQuarie's Chair.

This is the entrance to Port Jackson (Sydney Harbor) looking north. The open Pacific Ocean is to the right and the peninsula across the way is called North Head with the photo taken from atop South Head. Within this harbor are numerous inlets. Sydney-ites are obsessed with home prices and we were told that the median home price today is $1.2 million AUD.

Inside the Sydney Opera House.

It took 13 years to build and there really is no other structure quite like it. Inside of it are five venues offering everything from operas to ballets, to theater, to rock concerts!

The shells are covered in ceramic tiles made in Sweden.

The Harbor Bridge as seen from the upper terrace of the Opera House.

Sydney is known for its beautiful sandstone buildings and convict labor was used to quarry the stone. Near the Opera House you can see where carving of the sandstone has occurred. The deposit is called the Hawkesbury Sandstone and it is a Triassic fluvial deposit showing minimal mudrock lenses within Sydney. The source area was located to the south (modern coordinates), likely from a place now covered in ice in Antarctica!

It really has some beautiful textures and colors as seen on this wall on MacQuarie Street. This completes my 2018 trip to Australia. Now on to New Zealand!

Spectacular Red Rock Cliffs near Flagstaff - Not Sedona!

Just outside of Flagstaff lies an unknown landscape - forgotten, wild, and surreal. The colors and textures are electric. My friend Scott Thybony took myself and three others out here on a blue-bird winters day in February. We live for this kind of exploration and were not disappointed.

The approach and the openness of a wild land.

Resembling a Navajo hogan, this rocky outcrop serves as a guidepost to the natural wonders of the Adeei Ecchi Cliffs. These strata belong to the eolian (wind-blown) Jurassic Wingate Sandstone (about 205 Ma). Just about 10 miles from here, the unit grades into the Moenave Formation, a fluvial (river) deposit. A reconstruction of the Early Jurassic landscape as documented by these changing lithologies, reveals a desert dune environments encroaching on an arid floodplain. The modern Persian Gulf is a great analogy.

First stop, a trackway site with over 400 dinosaur footprints.

Some are very well preserved with clearly delineated claw marks.

Moving toward the cliffs.

A preview of the strange erosional forms here.

Normally, wind has very little power in eroding and shaping landforms in the southwest. It does often transport grains away that are already dislodged. But the wind probably has little eroding power. The relatively weak cementation here allows for the likely sculpting by the wind.

Especially along weaker cemented horizons like the thin pedestal seem here.

Remarkable, isn't it.

Note the obvious cross-bedding highlighted by alternating layers of oxidized (red) and reduced (green to white) horizons along specific beds.

Looking out toward Gray Mountain to the west and the Grand Canyon area. Wide-eyed boys enjoying wide-ranging views,

An old Navajo hogan in ruins. The hogan is constructed of gray limestone beds from within the Wingate Sandstone. I had never before seen limestone beds from the Wingate. They are quite common in the overlying Navajo Sandstone and represent oasis' deposits during the Jurassic when the water table was high. If algae is present in the oasis ponds, calcium will be secreted and deposited. as limestone

A wonderland of seemingly jumbled rocks. But most of these have not moved and have merely weathered in place

During uplift, a consistent joint pattern is imprinted in the rock mass and erosion can attack these vertical lines of weakness to ultimately create ghost-like forms. Full moon night hike anyone?

Differential weathering - the well-cemented horizons protrude outwards, the weaker cemented horizons are indented. These conditions were imprinted while the rocks were still buried but upon being exposed, the forms take shape.

Cross-section of a dune. Note the darker wedges of sand coming in from the upper right. These are sand flow toes - formed when the crest of dune becomes oversteepened in a windstorm and then cascades down the leeward side. The direction of dip documents the direction of dune migration and wind direction. Sorry YEC's. These features are ubiquitous in arid dune environments today and the rocks were not formed in a world-wide flood from the Superstition Period. No offense meant - just sayin'.

One has to imagine that these forms are constantly changing - well, at least with respect to deep time. Something like this might change drastically in only 1,000 years. Or not.

Underlying the Wingate Sandstone is the Chinle Formation, soft gray mudstone that gives rise to the famous Painted Desert landscape. Here, Wingate Sandstone boulders have come to rest in equi-distant positions along the base of the small cliff. It reminded me of spokes in a wheel. Thanks Scott for a great day of exploration on our own two feet!

A Winter Grand Canyon Hike

Sorry everyone - I took a month off. I am now back to blogging. This first post after my break highlights a winter hike down to Phantom Ranch in the bottom of the Grand Canyon. This is an excellent time to be here.

Photo by Gina Longo

The temperatures this time of year are usually the cold side in the morning but the sun is often out and by 10 AM is is nice and warm. Here I am answering a question by one our guests on the South Kaibab Trail.

Photo by Gina Longo

In spite of the cool temperatures, it's always a good idea to get an early start on the trail. That gets us to the destination sooner where more fun can be had!

About three miles down the South Kaibab Trail is this eroded breccia pipe. Breccia is an Italian word for very angular deposits. However, the word pipe signifies a cylindrical shape that extends through the strata for thousands of feet. These are important features in the Grand Canyon region because many of them are rich in Uranium. We can say that the breccia pipes are uraniferous. Of course, this one will never be mined because it is inside the national park. But those located outside the park are sometimes mined. These features form on top of a cave whose roof progressively collapses with the material coming to rest on the cave floor. Through time, the process leaves a vertical shaft filled with breccia - a perfect environment for soluble uranium to precipitate out into the matrix of the breccia.

At the Tip-Off, about five miles in, we saw the mules hauling out trash from Phantom Ranch. What an essential Grand Canyon scene!

Look at this lovely woman fixing of lovely trail lunch - yum! Helen, my wife, is seen in her element along a Grand Canyon trail. She added so much to the success of this trip.

A young Bighorn sheep watching the hikers go by the trail. That's Buddha Temple in the background capped by a thin layer of the Toroweap Formation which rests on top of a thicker white band of the Coconino Sandstone (note the thin planar band at the contact of the two).

The same sheep now seen in front of Zoroaster Temple.

This is the River Trail paralleling the Colorado River. It is one of my favorite day hikes while staying in the Phantom Ranch area. It was built by the Civilian Conservation Corps in 1935 using a lot of dynamite.

As luck would have it, we saw the Park Service mules bringing down the groceries for the rangers.

Helen raced ahead and got everyone's keys to their cabins. This is Norma Longo, a friend with whom I have traveled with before. She is also a geologist and was doing this hike for the second time.

There were still golden cottonwood leaves in the early winter.

Photo by Gina Longo

Wayne and Norma on the River Trail.

A beautiful scene on trhe Bright Angel Trail in the Tapeats Narrows.

This passerby was standing along the Bright Angel Fault as it cuts through the Redwall Limestone, so I asked him to admire the fault for scale. The two buttresses on either side of the wall are on the upthrown side of the fault (about 150 feet of offset here). The wall has been sheared smooth by movement along the fault.

The cavities formed when groundwater percolated through the downthrown block and intercepted the fault. All of this. - fault movement and cavity formation occurred while the area was still buried and before the Grand Canyon formed. Later erosion (helped with a bit of dynamite) then exposed the rocks.

The Jacob's Ladder section along the Bright Angel Trail.

If you would like to come with me and Helen on an informative Grand Canyon trek while staying in cabins two nights at Phantom Ranch (meals included!), write to me to reserve space on two trips I am offering next December! I hope to see you there!