2023 Rocky Mountain Section Meeting

23–25 May 2023

Fort Collins, Colorado, USA
Lory Center, Colorado State University

Welcoming Reception:
Mon., 22 May, 5:30–7 p.m.

Meeting Program
Program PDF
Events Code of Conduct

Field Trips

Field trip co-chairs: John Singleton, john.singleton@colostate.edu; Yvette Kuiper, ykuiper@mines.edu; and Jonathan Caine, jscaine@usgs.gov.

Pre-Meeting

FT1. Why is Kilometer-Scale Exhumation Diachronous across the Colorado Rockies and Great Plains?

Canceled

Endorsed by GSA Structural Geology and Tectonics Division; GSA Geochronology Division.

Lon Abbott, University of Colorado, lon.abbott@colorado.edu; Rebecca Flowers, University of Colorado, rebecca.flowers@colorado.edu; James Metcalf, University of Colorado, james.metcalf@colorado.edu; Sabrina Kainz, University of Colorado, sabrina.kainz@colorado.edu.

Description: A three-day trip. Low-temperature thermochronologic data reveal that different segments of the Colorado Rockies and Great Plains experienced exhumation at different times. Less than 1–2 kilometers of exhumation has occurred since the Carboniferous in some areas, whereas 4–6 km of material has been stripped from others since the Late Miocene. We explore evidence for and possible causes of this phenomenon.

FT2. After the Asteroid: Stratigraphy and Paleontology of the K-Pg Succession at Corral Bluffs, Colorado.

Canceled

James Hagadorn, Denver Museum of Nature & Science, jwhagadorn@dmns.org; Gussie MacCracken, Denver Museum of Nature & Science, gussie.maccracken@dmns.org.

Description: This trip will focus on the D1 Sequence at Corral Bluffs. The succession at this protected site preserves one of the most exceptional fossil records from the first million years after the Cretaceous Paleogene extinction event. The emerging geochronological, biostratigraphic, and paleoenvironmental framework for these strata are impactful for understanding biotic recoveries and earth-system succession.

FT3. An Examination of Late Paleozoic Stratigraphy, Laramide Folds, and the Rocky Mountain Erosion Surface.

Mon., 22 May. Free.

Michael Kendrick, Retired Petroleum Geoscientist, mkendrick9@icloud.com; John Singleton, Colorado State University, john.singleton@colostate.edu.

Description: Tucked up against the Wyoming border in northern Larimer County, Colorado, Red Mountain Open Space offers 25 square miles of geologic theater, presenting late Paleozoic stratigraphy, Laramide tectonics, Eocene erosion, burial by Oligo-Miocene strata, and ongoing erosion. A scenic hiking tour will examine all these features.

FT4. Overview and Geologic History of Quaternary Fluvial and Eolian Deposits in the Northern Colorado Piedmont.

Canceled

Endorsed by GSA Quaternary Geology and Geomorphology Division.

Stephen M. Keller, Colorado Geological Survey, skeller@mines.edu; Kassandra O. Lindsey, Colorado Geological Survey, kolindsey@mines.edu; Alexander E. Marr, Colorado Geological Survey, alexmarr131@gmail.com; Matthew L. Morgan, Colorado Geological Survey, mmorgan@mines.edu; Michael K. O’Keeffe, Colorado Geological Survey, okeeffe@mines.edu.

Description: This field trip will examine Pleistocene-Holocene exposures of alluvium, eolian sand, and loess and will be based on 17 geologic quadrangle maps done by the Colorado Geological Survey since 2015. The lithology, geochronology, hydrogeology, geologic hazards, and mineral resources of the deposits will be presented.

Mid-Meeting

FT5. A VIP Behind-The-Scenes Tour at the Denver Museum of Nature & Science.

Tues., 23 May. Cost: US$10.

James Hagadorn and others, Denver Museum of Nature & Science, jwhagadorn@dmns.org.

Description: Evening tour of the extensive fossil, mineral, rock, and meteorite collections, plus some creepy-crawly spaces in the bowels of the Denver Museum of Nature & Science.

Post-Meeting

FT6. Proterozoic Tectonics of the Northern Colorado Front Range.

Fri., 26 May. Cost: US$50.

Endorsed by GSA Structural Geology and Tectonics Division; GSA Mineralogy, Geochemistry, Petrology, and Volcanology Division.

Graham Baird, University of Northern Colorado, graham.baird@unco.edu; Tim Grover, University of Northern Colorado, timothy.grover@unco.edu; Kevin Mahan, University of Colorado Boulder, kevin.mahan@colorado.edu.

Description: The Big Thompson Canyon and surrounding areas offer excellent exposure of rocks generated during Paleoproterozoic accretionary tectonism and modified by Mesoproterozoic magmatism. This field trip will explore the tectonic setting of accretion and subsequent modification of the variably metamorphosed and deformed clastic sedimentary rock sequences and plutonic suites.

FT7. Stratigraphy and Structural Geology of the Front Range near Fort Collins, Colorado.

Fri., 26 May. Free.

John Singleton, Colorado State University, john.singleton@colostate.edu; Jeremy Rugenstein, Colorado State University, jeremy.rugenstein@colostate.edu.

Description: This trip will visit outcrops of Paleozoic and Mesozoic sedimentary rocks in the Front Range surrounding Fort Collins. Topics covered include the formation of clastic dikes and paleosols in the Fountain Formation, depositional environments of Pennsylvanian-Permian strata, and the geometry and kinematics of Laramide deformation.

FT8. Geomorphology and Structures in the Epicentral Area of the 1882 M6.6 Earthquake.

Canceled

James P. McCalpin, GEO-HAZ Consulting, Inc., mccalpin@geohaz.com.

Description: On 7 Nov. 1882, the largest earthquake in Colorado history shook the Front Range. Spence et al (1996) place the epicenter just north of Estes Park, with a magnitude of Mw6.6 (i.e., large enough for surface rupture). We will examine bedrock structures and anomalous landforms within a few hundred meters of roads.

FT9. FULL Cenozoic Geology and Geomorphology of the Laramie Mountains, Wyoming.

Fri.–Sat., 26–27 May. Cost: US$119.

Endorsed by GSA Quaternary Geology and Geomorphology Division; Wyoming Geological Survey.

Emmett Evanoff, University of Northern Colorado, emmett.evanoff@unco.edu.

Description: The Laramie Mountains in southeast Wyoming is a northern extension of the Front Range. The range was not glaciated and retains the Cenozoic deposits along its flanks and in the mountains. This trip will use Cenozoic stratigraphy and geomorphology to illustrate the late Cenozoic tectonic history and development of landforms along the Rocky Mountain front.

FT10. From Mantle to Mountain Top—Palinspastic Restoration of the I-70 Transect across the Basement Uplifts of Central Colorado.

Canceled

Endorsed by GSA Structural Geology and Tectonics Division.

Ned Sterne, independent geologist, nedsterne@aol.com; Bob Raynolds, Denver Museum of Nature & Science, bobraynolds1@gmail.com; Jim Granath, consulting structural geologist, jwgranath@q.com.

Description: A two-day trip exploring data and techniques used to inform the Interstate 70 transect. Magnetotellurics, low-temperature thermochronology, seismic, wells, outcrop and strike analogs constrain the interpretation of Ancestral Rockies, Laramide, and post-Laramide deformation. Palinspastic restoration reveals ~50 miles of horizontal translation across the basement uplifts of central Colorado.

FT11. Introduction to the Stratigraphy and Depositional Settings of the Classic Outcrops of the Book Cliffs.

Canceled

Howard Feldman, Colorado State University, howard.feldman@colostate.edu; Vitor Abreu, Act Geosciences, vitor@act-geo.com.

Description: A two-day trip. The Book Cliffs exposes a depositional dip cross section through a succession of shoreface and fluvial deposits in the Cretaceous upper Blackhawk and Castlegate formations. We will visit the classic outcrops starting in proximal settings near Green River, Utah, and ending near Grand Junction, Colo., over the course of two days. The outcrops will be supplemented with recently released high-resolution core photographs. The trip begins and ends in Grand Junction, Colo.