18 minute read
Special Feature
from AEG News Vol. 65 No. 5 - Winter 2022
by Association of Environmental & Engineering Geologists (AEG)
HEADER HERE Special Section Special Section RECAP
AEG 65th Annual Meeting “Geology in the Wild”
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Jerry King and Nick Saines, 2022 Annual Meeting Co-chairs
Stop two of Field Course #3 overview of the Las Vegas Valley Shear Zone
EG’s 65th Annual Meeting was held at the Planet Hollywood Las Vegas Resort & Casino on the Las Vegas Strip from September 12 –17, 2022. A
The centrally located hotel venue was great, and the technical sessions and field courses were outstanding. Residual concerns about COVID and high airfares limited meeting attendance to about 385 people, but those who attended had an exceptional professional experience. Although twentyeight guests registered, which is a good number, not enough signed up for the scheduled guest activities, so those were canceled. Evidently, Las Vegas itself is a guest activity.
Field Courses
The meeting kicked off on Monday, September 12, with two field courses. Seventeen people attended Field Course No. 1, Field Analysis of the Blue Diamond Landslide, led by John Peck
and Nick Saines. Forty people participated in Field Course No. 2, Hard Hat Tour of the Hoover Dam and the Hoover Dam Bypass Bridge, organized by the AEG Dams & Levees Technical Working Group.
Two more field courses were run on Tuesday, September 13. Twenty-seven people went on Field Course No. 3, The Great Unconformity, Las Vegas Valley Shear Zone, and Discovery of Extensional Tectonics, led by Professor Steve Rowland of UNLV. Twenty people attended Field Course No. 4, Las Vegas Valley Groundwater Recharge Well Field, led by Jim Prieur of the Las Vegas Valley Water District.
Pre-Meeting Receptions
A student/professional networking reception, the general meeting icebreaker, and a young at heart student/professional special event were held Tuesday evening.
Led by John Peck and Nick Saines (pictured at right)
AT LEFT: Fault (see the dark band) at the Hoover Dam on left abutment BELOW LEFT: The Bypass Bridge BELOW RIGHT: Visty Dalal points out the historic low water level (since 1930s) at Lake Mead.
Field Course #3 for the Win
The Great Unconformity, Las Vegas Valley Shear Zone, and the Discovery of Extensional Tectonics: A Trifecta of Geologic Intrigue
Martha Whitney, Whitney Geologic
here is no better way to kick off an AEG Annual Meeting than to join one or more of the pre-meeting Field Courses. The thoughtfully curated selection always offers trips to the best of the region’s sites of geologic intrigue as well as opportunities to get behind-the-scenes access to civil engineering works where applied geology was fundamental to design and construction. No matter what the destination or topic, AEG field courses provide the perfect mix of learning, adventure, and meeting new people. Participating in a Field Course before the meeting is also a great way to expand your social circles during the actual meeting as you encounter your fellow field trippers in the meeting halls and at the various social events.
The many great Field Course options of AEG’s Annual Meeting in Las Vegas made it hard to choose one! But time was limited, and I decided on Field Course #3: The Great Unconformity, the Las Vegas Valley Shear Zone, and the Discovery of Extensional Tectonics led by Stephen M. Rowland (Professor Emeritus of Geology, University of Nevada Las Vegas) and James E. Faulds (Nevada State Geologist, Director, Nevada Bureau of Mines and Geology Professor, Mackay School of Earth Sciences and Engineering, University of Nevada, Reno).
About twenty-eight folks loaded up on the bus, and as we made our way out of the sprawling metropolis of Las Vegas, I observed a different side of this city. I had only ever been to The Strip, and as we traversed the sprawling residential neighborhoods, I saw a more honest and intimate side of the city. It was
Tsomehow refreshing. We approached the eastern margin of the Basin, which is well-defined by Frenchman Mountain (aka Sunrise Mountain). Despite the sunrise peaking over the mountain, and with the help of the beautiful sketch provided in the guidebook, we were able to make out the famous stratigraphic section of the Grand Canyon rocks as exposed in Frenchman Mountain. Our first stop was just along the boundary between crudely stratified, consolidated Quaternary gravel and well-stratified new housing construction. We walked up Owens Road a few hundred meters to a spectacular road cut exposure of the Frenchman Mountain Fault. Quaternary gravel forms the hanging wall, and the Vishnu basement complex defines the footwall. Stephen Rowland provided an overview of the development of extensional tectonics of the Basin and Range Province and the formation of the Las Vegas Shear Zone. Seth Dee (Geologic Mapping Program Manager, Nevada Bureau of Mines and Geology, Mackay School of Earth Sciences and Engineering, University of Nevada, Reno) presented preliminary results of tectonic geomorphologic mapping and paleoseismic trenching along range front faults in the basin. Stop two was a visit to Frenchman Mountain’s very own exposure of The Great Unconformity. A global phenomenon, this particular exposure represents an erosional contact between 1.7 Ga basement rocks and 0.5 Ga Tapeats Sandstone. We discussed the misnomer of ‘missing time,’ the evidence of a changing ocean chemistry, its impact on chemical weathering of continental crust, and the response of microorganisms. The
Field Course attendees in front of the Frenchman Mountain Fault
Stephen M. Rowland talks about the Great Unconformity
Group hiking up to examine one of the massive clasts of rapakivi granite—the east side of Frenchman Mountain looms in the background.
various events that resulted in the Great Unconformity and how they may have led to the Cambrian Explosion is an evolving story and this stop was a great introduction. The folks at UNLV have worked hard over the years to raise awareness and promote the geo-heritage of this important Geologic Interpretive Site. There used to be interpretive signs installed at the parking area and a well-maintained trail led to the outcrop. Further upslope, there is an excellent view of the range front and the Las Vegas Basin. Unfortunately, the proximity of the site to the city results in it being well visited but not always for the exceptional geology. It is a local party spot and has been subject to vandalism including graffiti on the sacred exposure(!). The Bureau of Land Management (BLM) graffitiremoval crew has managed to remove some of the graffiti, and this is evidenced by the lack of varnish on the Tapeats Sandstone nearest to the contact. After a short but steep jaunt up to the overlook, we enjoyed stunning views of the city nestled in the increasingly cozy graben that is the Las Vegas Basin. James Faulds discussed the regional tectonic setting, and we learned that Frenchman Mountain is part of the southern Walker Lane structure. Spoiler alert: the Walker Lane may become the new plate boundary between the Pacific and North American Plates. Stop three took us just a bit further from Close-up of The Great Unconformity. Tapeats Sandstone overlying weathered Vishnu schist. This unconformity represents 1.2 b.y. of geologic history! the city to Rainbow Gardens where we learned about Chester Longwell, the legendary geologist of southern Nevada, and the huge clasts of rapakivi granite that he mapped 64 km from their source at Gold Butte. How did they get there? It’s a great story and one that echoes that of other pioneering geologists around the world and across time, from James Hutton to J Harlan Bretz. The area from Frenchman Mountain to Rainbow Gardens is a special place, and I was grateful to have the opportunity to visit with other members of AEG. I met up with a few old friends, made some new ones, and learned heaps!
Up-close and personal with the rapakivi granite (a type of granite with distinctive plagioclase rims around large round orthoclase crystals) INSET: James Faulds discussed the regional tectonic setting.
Seth Dee – Geologic Mapping Program Manager, Nevada Bureau of Mines and Geology, Mackay School of Earth Sciences and Engineering, University of Nevada, Reno
The land we visited is currently managed by the BLM and has been designated as an Area of Critical Environmental Concern. This designation is due in part to the exposure of the Great Unconformity, but also to the presence of the endangered species Arctomecon californica, aka Las Vegas Bearpoppy. The land east of Las Vegas also provides an opportunity for people living nearby to experience nature and have safe recreational opportunities. Most importantly, these lands are sacred to the Nuwuvi (Southern Paiute) peoples and include sites used for ceremonies that are vital for maintaining their connections to the land and their life journey. For these reasons, an effort to have the area designated as a National Monument is well underway. If this interests you, please visit eastlasvegasmonument.org and sign the petition.
The Opening Session
Keynote speaker Colby Pellegrino, Deputy General Manager of the Southern Nevada Water District
2021–22 Jahns Lecturer Richard Wooten
AEG 2021–22 President Maddie German with 2022–23 Jahns Lecturer Vincent Cronin
The team from the Southern Nevada Water Authority winners of the OEEG Award with AEG 2021–22 President Maddie German (L)
The General Session opened Wednesday morning and featured an outstanding keynote address by Colby Pellegrino, Deputy General Manager of the Southern Nevada Water District, on the status of the Colorado River, drought in the Southwest, and water conservation efforts in the Las Vegas Valley. Following Pellegrino’s address, AEG’s Outstanding Environmental and Engineering Project Award was presented to the Southern Nevada Water Authority for its Lake Mead Intake No.3 and Low Lake Level Pump Station. The award was accepted by Peter Jauch, Director of Engineering of the Southern Nevada Water Authority. AEG members can read about the project and see a number of photos on page 37 of the meeting’s Program with Abstracts available online here: https://www.aegweb.org/aegnews-2. The opening session ended with presentations from the 2021–2022 AEG/GSA Richard H. Jahns Distinguished Lecturer in Applied Geology, Richard Wooten, and from the 2022–2023 Jahns Lecturer, Vincent Cronin.
The Technical Program
The technical program included talks that ran from Wednesday afternoon through Friday, and also included ten poster presentations. The technical sessions included symposia on Diversity, Equity, and Inclusion—Words Matter; Tunneling; Tectonics and Seismicity of the Walker Lane: A Potential Incipient Plate Boundary; Water Management in the Era of Climate-ChangeCaused Megadroughts and Mega-Floods; Naturally Occurring Asbestos; Wild Problems with Geophysics Solutions; Dams and Levees; Infrastructure and the Environment: Impacts on the Built World; and Land Subsidence. There also were technical sessions on Landslides, Hydrogeology and Groundwater Recharge, and Geologic and Seismic Hazards. So many interesting talks happening simultaneously made it difficult to decide which session to sit in on.
A meeting highlight was Wednesday night’s special event, A Night on the Town, when people took advantage of Las Vegas’ many attractions. The night included group reservations on the 550-foottall High Roller (pictured above), which is the biggest Ferris wheel in the United States. Other highlights included meetings of the AEG Executive Council and AEG Foundation, the Strength Through Equity—AEG Inclusion Luncheon, the AEG Finance Committee meeting, the Board of Directors meeting, and the Annual Banquet, at which AEG’s prestigious award recipients were honored.
Meeting attendees had plenty of opportunities to socialize while being informed. Pictured top to bottom: Poster displays, Exhibitor booth, Exhibitor luncheon, and Session break.
The AEG Board of Directors gathered for dinner at the Rain Forest Cafe.
Fourteen AEG Past Presidents joined 2023–24 President Nate Saraceno (plaid shirt) to celebrate a successful Annual Meeting.
Celebrating achievements and being together in person again!
Coming together to bestow welldeserved awards over a meal and conversation with colleagues and friends.
More from the Awards Banquet
Top Two: Members having fun at A Night on the Town
Bottow Two: Past Presidents champagne toast Middle Four: Wine-Tasting Fundraiser
The closing Beer & Wine Reception sponsored by Lettis International was a final chance for attendees to gather and say goodbye to colleagues old and new.
INSET: The AEG 2022–23 Executive Council
BELOW: The 2022 Corporate Business Meeting
The AEG Executive Council with the AEG Foundation Board
Grand Canyon Skywalk
n Saturday, September 17, 2022, a busload of lucky AEG Members visiting Las Vegas after the Annual
Meeting got to accompany John Peck (Honorary Member, Southern Nevada Chapter) on a Field Trip to Arizona for a firstperson tour of “One of the Seven Natural Wonders of the World—the Grand Canyon.”
John was one of many experts consulted on the design and placement of the spectacular new glass Skywalk. It is an engineering marvel that allows visitors to actually walk out on a cantilevered glass bridge that is suspended 4,000 feet above the Grand Canyon. It is a horseshoe-shaped glass walkway made of layered glass, 2.5 inches thick, overdesigned to support a load of 100 pounds per square foot. The Skywalk offers gut-dropping views of the colorful rock walls of the Grand Canyon all the way down to the Colorado River.
The Skywalk is located on land sacred to the Hualapai Nation at the west rim of the canyon in Peach Springs, Arizona. The roundtrip from Vegas passed quickly as John narrated enroute, with commentary on Lake Mead, the impact of the new solar panels on the desert tortoises, and of course, the geology. It was an excellent field trip.
John Peck not only conducted this excursion, but he actually planned all the field trips offered at this year’s Annual Meeting in Las Vegas. John shook everyone’s hand as we got off the bus and declared that this would be the last field trip that he would take responsibility for leading. So, it’s fitting for us to thank him for the great job he did planning this one and all the other Las Vegas field trips, but also for his excellent service to his Chapter, his Region, and our association over many years.
OLoren Lasky, 45-year AEG Member
The Colorado River is exposed at the base of the West Rim of the Grand Canyon in Arizona, on tribal land sacred to the people of the Hualapai Nation. With the Grand Canyon Skybridge in the background, Field Trip leader John Peck, explains the siting studies performed to determine where to build the structure.
The glass Skybridge lets visitors walk on a see-through platform suspended 4000 feet above the Canyon.
AEG field trip members assemble atop the West Rim of the Grand Canyon.
for these future AEG Annual MeetingsSave the Dates…
SEPTEMBER 10–14, 2024
Hilton Philadelphia at Penn’s Landing
AEG 68th Annual Meeting Chicago, Illinois
SEPTEMBER 23–27, 2025
Westin Chicago River North
Philadelphia, the nation's birthplace and capital from 1790 to 1800, is renowned for its rich history on display at the Liberty Bell, Independence Hall (where the Declaration of Independence and Constitution were signed), and many other historical sites. Also iconic are its cheesesteaks and the steps of the Philadelphia Museum of Art immortalized by Sylvester Stallone’s triumphant run in the film “Rocky.”
The Meeting Hotel
Overlooking the Delaware River with views across to New Jersey, the hotel is less than a mile from the Liberty Bell, the Museum of the American Revolution, and the Benjamin Franklin Museum. They are adjacent to Spruce Street Harbor Park, and Society Hill is less than a mile away. The hotel is located on the waterfront in Center City’s Historic District and steps from numerous attractions and an eclectic array of restaurants. Chicago is one of the top tourist destinations in the United States for a reason. It’s a welcoming city with plenty of world-class attractions. Located on Lake Michigan in Illinois, Chicago is famed for its bold architecture. In additional to engineering geology, the AEG 2025 Annual Meeting will focus on sustainability, health, climate change, and environmental geology.
The Meeting Hotel
Located in the heart of downtown Chicago in the prestigious River North neighborhood of the city, the Westin Chicago River North’s location makes it a perfect base to explore the historic and energetic Windy City with nearby attractions including the Millennium Park, The Chicago Theatre District, and the vibrant Chicago Riverwalk. Refreshed in early 2020, the flexible event space offers the perfect setting for meetings. Recharge in your choice of accommodations, from traditional rooms to luxury suites, all with a view of the Chicago River or the downtown skyline. Maintain your health goals with the delicious and healthy on-site dining at 320 RiverBar and the state-of-theart WestinWorkout fitness studio. Enjoy complimentary fitness classes as well as Rise + Ride with Westin and Peloton.
