Thursday, May 16, 2019

A World-Class Trackway in the Coconino Sandstone Announced in Grand Canyon

In December, 2016 I posted a piece about a trackway found along the Bright Angel Trail (see here). That site has received a lot of national attention in the last year and is being studied in detail by Dr. Steve Rowland at UNLV, Nevada.

Now the National Park Service has announced work completed on another trackway found along one of Grand Canyons backcountry trails. The News Release, revealed yesterday is copied below with figures.

I was fortunate to have visited this site in 2015 and can attest to its spectacular nature. The tracks are some of the largest I have seen in the canyon. At the time I was unaware of the species that left them. Most trackways in the Coconino Sandstone can be found at the base of the deposit where it overlies the Hermit Formation. The Hermit acted as an aquaclude to groundwater, meaning that the earliest Coconino environment likely contained many oases or springs, supporting life.

The Grand Canyon never disappoints!

-------------------------------------------------

 
U.S Department of Interior
National Park Service

Grand Canyon National Park
P.O Box 129
Grand Canyon, AZ 86023
For Immediate Release May 15, 2019


Grand Canyon News Release
Newly Discovered Fossil Footprints from Grand Canyon National Park Force Paleontologists to Rethink Early Inhabitants of Ancient Deserts 
Grand Canyon, AZ - An international team of paleontologists has united to study important fossil footprints recently discovered in a remote location within Grand Canyon National Park, Arizona. A large sandstone boulder contains several exceptionally well-preserved trackways of primitive tetrapods (four-footed animals) which inhabited an ancient desert environment. The 280-million-year-old fossil tracks date to almost the beginning of the Permian Period, prior to the appearance of the earliest dinosaurs.

The first scientific article reporting fossil tracks from the Grand Canyon was published in 1918, just a year before the park was established as a unit of the National Park Service. One hundred years later, during the Centennial Celebration for Grand Canyon National Park, new research on ancient footprints from the park is being presented in a scientific publication released this week. Brazilian paleontologist Dr. Heitor Francischini, from the Laboratory of Vertebrate Paleontology, Federal University of Rio Grande do Sul, is the lead author of the new publication, working with scientists from Germany and the United States.

Francischini and Dr. Spencer Lucas, Curator of Paleontology at the New Mexico Museum of Natural History and Science in Albuquerque, New Mexico, first visited the Grand Canyon fossil track locality in 2017. The paleontologists immediately recognized the fossil tracks were produced by a long-extinct relative of very early reptiles and were similar to tracks known from Europe referred to as Ichniotherium (ICK-nee-oh-thay-ree-um). This new discovery at Grand Canyon is the first occurrence of Ichniotherium from the Coconino Sandstone and from a desert environment.  The Coconino Sandstone is an eolian (wind-deposited) rock formation that exhibits cross-bedding and other sedimentary features indicating a desert / dune environment of deposition. In addition, these tracks represent the geologically youngest record of this fossil track type from anywhere in the world.

The Ichniotherium footprint is believed to have been made by an enigmatic group of extinct tetrapods known as diadectomorphs, a primitive group that possessed characteristics of both amphibians and reptiles. The evolutionary relationships and paleobiology of diadectomorphs have long been important and unresolved questions in the science of vertebrate paleontology.

Although the actual track maker for the Grand Canyon footprints may never be known, the Grand Canyon trackways preserve the travel of a very early terrestrial vertebrate. The measurable characteristics of the tracks and trackways indicate a primitive animal with short legs and a massive body. The creature walked on all four legs and each foot possessed five clawless digits.

According to Francischini, "These new fossil tracks discovered in Grand Canyon National Park provide important information about the paleobiology of the diadectomorphs. The diadectomorphs were not expected to live in an arid desert environment, because they supposedly did not have the classic adaptations for being completely independent of water. The group of animals that have such adaptations is named Amniota (extant reptiles, birds and mammals) and diadectomorphs are not one of them."

Lucas also notes that "paleontologists have long thought that only amniotes could live in the dry and harsh Permian deserts. This discovery shows that tetrapods other than reptiles were living in those deserts, and, surprisingly, were already adapted to life in an environment of limited water."

During 2019, in recognition of the Grand Canyon National Park Centennial, the National Park Service is undertaking a comprehensive paleontological resource inventory for the park. A large team of specialists in geology and paleontology will participate in fieldwork and research to help expand our understanding of the rich fossil record for Grand Canyon National Park.

-NPS-
FIGURE 1: Map of Arizona (southwestern USA), indicating the main localities mentioned in the text. The Grand Canyon National Park area is shaded dark brown (left). Stratigraphic section of the Pennsylvanian and Permian rocks exposed in the Grand Canyon area (right). Modified from Blakey and Knepp 1989.
FIGURE 2: The track-bearing boulder (Coconino Sandstone), Grand Canyon National Park, Arizona. General view of the boulder and the tracks (left). False color depth map (depth in mm) (right). Scale: 50 cm (NPS Photos)
FIGURE 3: Close-up view of the Ichniotherium trackway from Grand Canyon National Park. Photo courtesy of Heitor Francischini.
FIGURE 4: Artwork depicting the Coconino desert environment and two primitive tetrapods, based on the occurrence of Ichniotherium from Grand Canyon National Park.  Illustration courtesy of Voltaire Paes Neto.

Friday, May 03, 2019

The 1st Grand Canyon Geology and Geoscience Education Symposium - April 19-20, 2019

As part of the year-long commemoration events for the 100th anniversary of Grand Canyon National Park, the first ever Geology and Geoscience Education Symposium was held a the Shrine of the Ages auditorium on April 19 and 20. Nearly 90 people were in attendance. Organizers Karl Karlstrom and Laura Crossey, professors of geology at the University of New Mexico and originators of Grand Canyon's Trail of Time say that this may be an every second-year or every third-year event.

Signs welcoming the public to attend the talks and events were on display through out the village.

Dr. Karl Karlstrom delivers the opening talk on "Grand Canyon Geology Debates and Their Global Reverberations"

I was particularly gratified to be part of this event. For decades I have been lamenting the fact that other disciplines routinely held symposiums in which non-specialists could attend and understand something far outside their expertise. Not so with geology it always seemed. There was always too much jargon to wade through, too many sub-specialties, not enough interest on the part of geoscientists to relate to non-specialists. No more! This event was publicized as open to non-specialists and about half of the talks were given such that a general audience could follow along. 

The first day of the symposium was devoted to specialists speaking to some aspect of the canyon's geology. The talks were chronological beginning with the basement rocks and finishing with talks about springs and spring water. Here is a list of the Day 1 speakers and their topics:

Day 1: Friday, April 19 
8:15: Welcome by Grand Canyon National Park Division of Science and Resource Management- Jeanne Calhoun 
8:30: Grand Canyon Geology Debates and Their Global Reverberations – Dr. Karl Karlstrom, University of New Mexico 
9:00: The Vishnu basement rocks: Formation of continental crust and its relationship to the supercontinent cycle - Dr. Mark Holland, University of New Mexico 
9:30: Snapshots from the Great Unconformity found in the Grand Canyon Supergroup: The Unkar Group - Dr. Michael Timmons, New Mexico Bureau of Geology 
10:00: Break
10:30: The Neoproterozoic Chuar Group of Grand Canyon: A gem of unique scientific discoveries - Dr. Carol Dehler, Utah State University
11:00: Tonto Group: What can really old layers of sand, mud, and lime tell us? - Dr. James Hagadorn, Denver Museum of Nature and Science
11:30: The oldest vertebrate trackway in Grand Canyon and the dawn of reptiles - Dr. Steven Rowland, University of Nevada Las Vegas 12:00-1:30: lunch on your own 
1:30: Source regions for Paleozoic sedimentary rocks: Dr. George Gehrels, University of Arizona. 
2:00: Uplift and age of Grand Canyon and Grand Staircase - Carmen Winn, University of New Mexico 
2:30: Where was the downstream end of the pre-Pliocene Colorado River - Dr. James W. Sears, University of Montana 
3:00: Break
3:15: What a conflict of fire and water! – Lava Dams in Grand Canyon - Dr. Ryan Crow, United States Geological Survey
3:45: The Bouse connection and controversies - Dr. Phil Pearthree, Arizona Geological Survey
4:15: The shape of water - Dr. Laurie Crossey, University of New Mexico
4:45: The Coconino and Redwall-Muav aquifers of the Grand Canyon region and their importance for people and ecosystems - Dr. Abe Springer, Northern Arizona University 
The second day of the Symposium was devoted to geoscience education. Talks were given to elucidate how geologists can better connect with the public. Dr. Steve Semken of Arizona State University is one of the leaders in this field and led off the session with his talk on place-based learning and ethnogeology. Dr. Semken taught geology on the Navajo Indian Reservation for many years. I gave a talk on how the history of ideas for Grand Canyon's origin can draw people into geologic thinking. The idea is that geology can be more easily approached by non-specialists if some human references are included. Here is a full list of the Day 2 speakers and events:
Day 2: Saturday, April 20 
8:15: Welcome by the Park Division of Interpretation - Todd Stoeberl
8:30: Place-based geoscience education, interpretation, and ethnogeology at Grand Canyon - Dr. Steven Semken, Arizona State University
9:00: Engaging the Public in Geology and Geoscience: Techniques Learned Using the History of Ideas on the Origin of Grand Canyon, Wayne Ranney
9:30: Implications of Learning Outcomes of In-Person and Virtual Field-Based Geoscience Instruction at Grand Canyon National Park Tom Ruberto, Arizona State University
10:00: The Old Red of John Wesley Powell: Using Geology to Solve the Historical Question of Powell’s 1869 Grand Canyon Camps - Richard Quartaroli
10:30: The Trail of Time Exhibit: - Karl Karlstrom and Laura Crossey
11:00: Brainstorming a next century of informal science education - panel
11:30: Recap and organize the Trail of Time walk- Karl Karlstrom and Laura Crossey
12:00 -1:30: lunch on your own
2:00-5:00: Walk the Trail of Time with geologists
And here are a few pictures from the Trail of Time walk many of the visiting public in attendance.
Dr. Karl Karlstrom giving the opening talk at the west portal to there Trail of Time. Note the two little boys, Connor and Sawyer, who were visiting from Louisiana.

Carl Bowman, longtime National Park Service ranger at Grand Canyon contributed ideas related to paleontology on our walk.

What beautiful day for walk on the rim discussing geology and geologic time!

Kids love to touch the rocks. In fact, the pedestals on which the rocks rest say, "Touch me!"

Carl Bowman using a styrofoam ball to illustrate a period in Earth history known as Snowball Earth, which occurred in two pulses around 710 and 640 Ma, each lasting about 10 million years.

Here I am pointing out features within the canyon. The three of us who led this trip worked very well together and each of us was able to add some other aspect to the canyon's geology to visitors. Photo credit to Justin Wilgus.

One group started at Yavapai Geology Museum and the other at Verkamp's Store Visitor Center. Near the 740 million year mark, the two groups passed one another.

Group shot of the two groups who walked the Trail of Time with professional geologists on April 20, 2019. Photo courtesy of Michael Quinn, National Park Service.

I will be sure to get the word out when the next Geology and Geoscience Symposium will be held at Grand Canyon National Park.

Sunday, April 07, 2019

New Zealand's South Island

We transitioned to the South Island and an arrival in Christchurch just two weeks after the shootings. The South Island is much different than the north with fewer people, higher mountains and one very large transform fault, the Alpine Fault.

Map showing our route across the South Island. The right lateral Alpine transform fault runs along the western side of the Southern Alps and goes offshore just north of Doubtful Sound. Originally, Maoreki and Dunedin were not on the itinerary but the bridge to the Franz Josef Glacier was washed out days before we were to arrive. Up to one meter of rain (40 inches) fell there in a 48-hour period, washing out the bridge and our plans had to change.

To say that the city was shocked at what happened would not convey the depth of it all. Things like this do not normally happen in quiet, little New Zealand. Yet, it did. I was amazed at the way the Kiwi's came together as a nation after this. The path forward seems clear to just about everyone here.

Our Tour Director had a friend in Christchurch who made a bundle of red roses for each member of our group...

...and we placed them on the heap of flowers that has been growing for two weeks. The memorial garden is nearly 1/2 a kilometer long! There was a great sense of respect while we were here. Tears were shed.

This is the statue to Robert Falcon Scott (the leader of the second group to stand at the South Pole in 1911) along the Avon River in Christchurch. The statue was toppled in the February, 2011 earthquake and has only been replaced within the last year.

Here is a photo of the same statue I took in October, 1986 on my first trip to New Zealand. All of the buildings in the background were destroyed in the earthquake and are no longer there.

Christchurch is looking to the future. It was once the "Most British City" outside of England. But no longer. The earthquake leveled many buildings downtown and there are being replaced with more modern-looking, earthquake resistant designs.

Map showing the epicenters and location of aftershocks from a series of earthquake events near Christchurch between September, 2010 and December, 2011. The red dotted line below the Sept. 2010 date shows the blind fault (previously unrecognized) that ruptured transverse to the Alpine Fault. This first quake had the largest magnitude of the four major shocks, making all others (by definition) aftershocks. The February, 2011 quake was the most damaging to the Central Business District and 185 people lost their lives due to structure collapse. Note the rounded Banks Peninsula sticking out into the Pacific Ocean, a heavily eroded, late Miocene volcano between 9 and 11 million years old.

We were supposed to ride the train over the Southern Alps to Franz Josef Glacier but heavy rain closed the roads and the railroads. So we went south and passed through an interesting looking town called Oamaru, known for its limestone buildings. The limestone is quarried nearby.

Much of the town's architecture has been preserved.

And gentrified.

Savory pies are a staple in New Zealand and in this out-of-the-way shop I enjoyed a Thai Green Rice pie, absolutely the best that I had on this trip. There is a dominant sentiment that I detected in New Zealand that diversity in the population is welcomed and beneficial to the country.

Next stop down the east coast was the Maoreki Boulders. I had first heard of these strange beach rocks as a young geology student in the 1970s but this was my first visit to them.

They are technically septaria nodules (also called concretions) and formed in a 60 million year old mudstone, the Moreki Formation.

Here is a view of me next to one nodule still in place within the mudstone in the sea cliff.

The waves from big storms have cracked some of the boulders, allowing us to see the inside structure.

The septaria (cracks) are composed of calcite that has grown in the voids.

A last look at the boulder-strewn beach and cliff behind it.

Next stop Dunedin, a town of Scottish heritage and a large university, the University of Otago.

Map showing the location of Dunedin at the head of the Otago Harbor. Note the circular nature of the peninsula - like the Banks Peninsula near Christchurch, this is a 16 to 10 million year old volcano that has been heavily eroded in the last 10 million years. See more about the Dunedin volcano here.

The old railway station is a fine example of the architecture in this city. It is made of dark basalt blocks that are framed with Oamaru Limestone.

The New Zealand Pigeon (Hemiphaga novaeseelandiae) was seen on the top of a tree as we toured the Otago Peninsula.


As we made our way toward Queenstown, we stopped at the Kawarau Bridge where the sport of bungee jumping was invented. We arrived in time to see this person take the plunge.

He really had beautiful form with a nice, swan dive off the deck and a gentle curve down to the river. I would really like to be able to do this but I know that I would chicken out on the deck. It's too close to the earth. I would jump out of an airplane (again) in a heartbeat - it's high enough up for me.

You can request to barely touch the water - they have the length of the bungee down to a science - and this guy chose to do it.

The rebound back up toward the bridge looked to be the most fun and this guy made it more than half way back up!

The big excursion out of Queenstown was a day-long trip to Doubtful Sound. This is a map showing the Fiordland National Park, encompassing 3 million acres of pristine, virgin forests and deep fjords. The Park covers all of the mountainous terrain in the center of the map. There are 14 fjords that indent the coast.

The trip includes a boat ride across the freshwater Lake Manapouri, then a bus ride over Wilmot Pass, then on another ship on Doubtful Sound. The rocks in much of the Park are Cretaceous granite and gneiss, intruded when New Zealand was still attached to the Gondwana supercontinent.

Slide from one of my lectures showing the position of the southern continents during the Jurassic. Subduction occurred where the word New Zealand is located and the subducted slab melted at depth with the granite in Fiordland forming on the continental side of New Zealand.

The clouds lifted as we passed the Southern Arm of Lake Manapouri. This was incredible as this area gets an average of one inch of rain very day - an average of 360 inches per year.

The Captain took us on a side trip up the Northern Arm to show us these dikes running through the granite. The dikes are differentially eroded with the granite softer than the dikes.

Whoa - what a day! I love these clouds. High cirrus in Fiordland!

These are better exposures of the granite.

From Wilmot Pass we obtained our first view of Doubtful Sound, named when Captain James Cook doubted that he could turn the H.M.S Endeavour around in the narrow fjord. The road we were traveling on was constructed in the 1960s when a hydroelectric scheme was installed on Lake Manapouri. Read about this interesting and controversial project here. New Zealand's first nationwide environmental controversy ensued because of the project, ending in a compromise with the scheme being completed but without raising the natural level of Lake Manapouri.

Zoom lens view of Doubtful Sound.

Not a cloud in the sky. How does one do field geology in a place covered in vegetation?

A perfectly eroded U-shaped valley in the upper end of Doubtful Sound. The amount of ice that was here just 14,000 years ago is impressive.

We made it all the way out to the mouth of Doubtful Sound and the Tasman Sea. Only 2,000 miles to Tasmania! Doubtful Sound is not technically a sound, although that is the name Captain Cook gave it. A sound is a shallow river valley that has been submerged beneath rising seas (or sinking land). When Cook sailed here, geology as a modern science was not yet invented. Neither was the definition of a fjord known to the British. A fjord is a glacially carved, sea-flooded entrant on a coastline.

These tree ferns on the shore were so damn photogenic. The vegetation in New Zealand has suffered much from the arrival humans but in Fiordland National Park Park, it is preserved. This reminded me of what the forests in Gondwana might have looked like.

Another side arm in the fjord.

This concludes my trip to New Zealand. I'll be back next year with Smithsonian Journeys.