Imagine standing in front of towering sandstone formations in Colorado that preserve clues to one of the most dramatic climate events our planet has ever experienced. This October, an expert-led Geological Society of America field trip offers the chance to explore these extraordinary rocks and uncover the story they tell about Snowball Earth.
Around 700 million years ago, during the Cryogenian Period, Earth may have been locked in a near-global deep freeze, with massive ice sheets covering much of the planet. Evidence of this ancient world is remarkably scarce, but the Colorado Front Range is home to an exceptional geological archive: rare sandstone dikes that may have formed beneath those vast continental glaciers. These unusual features are helping scientists reconstruct the conditions that existed during one of Earth’s most extreme ice ages.
The GSA Connects 2026 field trip, Exploring Cryogenian Snowball Earth Deposits along the Colorado Front Range, takes participants directly to these remarkable outcrops alongside the researchers studying them. Along the way, you’ll examine key field sites, learn how new discoveries are reshaping our understanding of Cryogenian geology, and experience one of the world’s rarest terrestrial records of Snowball Earth firsthand.
Whether you’re a geoscientist, student, or simply fascinated by Earth’s deep past, this is a unique opportunity to see groundbreaking science where it happened.
Warren Hamilton: New Insights into the Ancestral Rocky Mountain and Laramide Orogenies, Oligocene Magmatism and Metamorphism, and Rio Grande Rift Extension Along the Western Flank of the Sangre de Cristo Range, Southern Colorado
Price: US$459 for non-members; US$380 for professional members; US$230 for student members; US$320 for early career professional members
Leader(s): John Singleton; Samantha Malavarca; Michelle Gevedon
Date: Thu.–Sat., 8–10 Oct. 2026
Departing Location: Colorado Convention Center, Denver, Colorado, USA
Description: This three-day, two-night field trip explores the complex geologic history of the Sangre de Cristo Range near Great Sand Dunes National Park and Crestone, Colorado, focusing on new research that provides significant insight into several aspects of the tectonic evolution of the region.
The Sangre de Cristo Range exposes some of the deepest Cenozoic structural levels in the Rocky Mountain region and is a key locality for understanding how different orogenic events and geologic structures relate to each other. Field trip stops will involve short (<0.5 mile) to moderate-length (~3 miles) hikes to visit outcrops related to the Pennsylvanian–Permian Ancestral Rocky Mountains, the Late Cretaceous–early Paleogene Laramide orogeny, Oligocene intrusive magmatism and contact metamorphism, and Rio Grande Rift extension.
Some field trip highlights include spectacular exposures of brittle-plastic deformation along the Mosca Creek thrust and evidence for an early Oligocene pulse of ENE-directed shortening; examples of the likely highest-grade metamorphism of Phanerozoic strata in the Rocky Mountain region; mylonitic fabrics recording thrust- and normal-sense shear along the Independence Mine shear zone; Quaternary fault scarps up to ~10 m high; and the tallest sand dunes in North America.
Discussion topics will include structural reactivation and the relation between contractional and extensional structures, the transition between Laramide shortening and Rio Grande Rift extension, the relation between Oligocene magmatism and deformation, and the impact of deglaciation on late Pleistocene to Holocene fault slip. Participants will stay in dormitory-style lodging at Colorado College’s Baca Campus near Crestone, where evening presentations and discussions will be held. Petrographic microscopes will also be available to view thin sections related to field trip stops.
Considerations: Participants will need to provide their own linens or sleeping bags. Please let us know if you need assistance with any gear. Be prepared for the possibility of cold weather and snow. Cost includes lodging, ground transportation, and all meals. The Warren Hamilton Field Trip funds support student registrations for the trip.
