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.

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.