|Field Trip Chairs|
|Trips During the Meeting|
Before the Meeting
- 401. A Geologic and Anthropogenic Journey from the Precambrian to the New Energy Economy through the San Juan Volcanic Field
Wed.–Sat., 27–30 Oct. US$460 (B, L, D, R, 3ON).
Cosponsors: USGS; NTS Group; Fort Lewis College; CDPHE.
Leaders: Douglas B. Yager, USGS Mineral Resources Program; Alison Burchell; Raymond H. Johnson; Austin Buckingham.
- The San Juan volcanic field comprises 25,000 km2 of intermediate composition, mid-Tertiary volcanics and dacitic to rhyolitic calderas, including the La Garita caldera (75 km diameter) super-volcano. The region is famous for geological, ecological, hydrological, archeological, and climatological diversity, characteristics that supported ancestral Puebloan populations. The area is also important for mineral wealth, which once fueled economic vitality. Today, mitigating impacts of mining and establishing the region as a climate base-station are the research focus. Studies include advanced water treatment, the acid-neutralizing capacity (ANC) of propylitic bedrock for use in mine cleanup, the use of soil amendments, including biochar from beetle-kill pines to aid re-vegetation by incorporation into soils to reduce erosion and improve productivity and moisture retention and the natural terrestrial carbon sequestration (NTS) potential of volcanic soils to help offset atmospheric CO2 emissions. This field trip will examine the volcanic and cultural history of the area, including its structures, economic deposits and impacts, recent mitigation measures, and associated climate research. Field-trip stops include the Summitville superfund site to explore quartz alunite-Au mineralization, associated alteration, and new water-quality mitigation strategies; the historical Creed epithermal-polymetallic-vein district, with its remarkably preserved resurgent calderas, keystone-graben and moat-sediments; sunset at Mesa Verde; the historical mining town of Silverton, located in the nested San Juan–Silverton caldera complex, which exhibits base-metal-Au-Ag mineralization and is the site of ANC and NTS studies. The return to Denver will traverse Grand Mesa, a high-NTS area with Neogene basalt-derived soils, with a stop to soak in the geothermal waters of the Aspen Anomaly at Glenwood Springs.
- 402. Lewis and Clark Line, Montana: Tectonic Evolution of a Crustal-Scale Structure of the Rocky Mountains
Wed.–Fri., 27–29 Oct. US$347 (L, R, 4ON).
Leaders: James Sears, University of Montana; Jeff Lonn; Katie M. McDonald.
- The trip will focus on the tectonic evolution of the Lewis and Clark line from its initiation as a crustal-scale fracture in the Mesoproterozoic Belt basin through its function as a sinistral transpressive shear zone during the Laramide orogeny to its re-activation as a dextral transtensional shear zone in the Eocene and Miocene. The trip will examine structures in Precambrian through Cretaceous sedimentary rocks as well as Cretaceous granitic intrusions and associated contact metamorphism, and Eocene volcanic rocks. The trip will begin and end in Missoula; we will be based out of a single hotel and return to Missoula each night.
- 403. Late Cenozoic Evolution of the Colorado Rockies: Interplay between Uplift, Climate, and Drainage Integration
Thurs.–Sat., 28–30 Oct. US$306 (L, R, 2ON).
Cosponsor: GSA Quaternary Geology & Geomorphology Division.
Leaders: Andres Aslan., Mesa State College; Karl Karlstrom; Laura Crossey.
- The Colorado River system, as the single river system that drains the western slope of the Colorado Rocky Mountains, is a sensitive gauge of the uplift history and landscape evolution of the western U.S. This trip focuses on the Upper Colorado River basin and evaluates the hypothesis that the river system and modern Colorado Rockies are being shaped by neotectonic epeirogenic uplift of the Colorado Rockies, interacting with climatic and geomorphic forcings. In the context of key outcrops and new data, we will discuss (1) geomorphic analysis of river profiles; (2) new incision rates showing differential incision and important transient knickzones along the river system; (3) effects of isostatic response to denudation; (4) thermochronologic evidence for broad epeirogenic uplift starting 20–6 Ma; (5) new mantle tomographic images of the Aspen Anomaly that may be driving surface uplift; (6) evidence for mantle- derived 3He in Colorado hot springs as evidence for mantle- to-surface interconnections; and (7) terrace chronologies that reveal climatic influences on river aggradation and incision superimposed on longer-term tectonic signals. Trip stops in the upper Colorado and Yampa River valleys include the Gore Range, Glenwood Canyon, Lava Creek B ash at Dotsero, salt-collapse near Carbondale, Miocene lava flows at Grand Mesa, Colorado River terraces, and Browns Park Formation near Yampa. Includes two nights at Glenwood Springs with complimentary access to the hot springs.
- 404. Behind Colorado’s Front Range—A New Look at Laramide Basin Subsidence, Sedimentation, and Deformation in Central Colorado
Fri.–Sat., 29–30 Oct. US$179 (L, R, 1ON).
Cosponsor: GSA Sedimentary Geology Division.
Leaders: James C. Cole, USGS; James H. Trexler Jr.; Patricia Cashman.
- The early Tertiary uplift history of the Colorado Front Range has been well documented by detailed studies of stratigraphy, sedimentology, and paleobotany from the Laramide-age Denver Basin along the eastern range flank. This field trip will examine contrasting and comparative evidence from the “back-side” of the Front Range in the elongate structural basin underlying the Middle Park and North Park physiographic areas. We will visit sections in the Paleogene Middle Park Formation and (largely coeval) Coalmont Formation to examine evidence of sedimentation, depositional environments, source areas, paleogeography, isotopic ages, paleobotany, and related topics. This excursion will present results from an entirely new, interdisciplinary investigation of the area that challenges major elements of conventional thinking about the timing and structural controls of basement-block uplift during the Laramide orogeny. For example, internal unconformities within the Middle Park Formation suggest that local basement blocks adjoining the broad structural swale were moving independent of each other, chiefly in vertical directions. Additional stops will explore sedimentology of the Coalmont Formation within the North Park basin, including lacustrine delta complexes and coal mires. The geometry of post-Coalmont folding and faulting will be described in the context of uplift of surrounding basement blocks. Oil and gas exploration from 1925–1980 was marginally successful in targeting structural traps in Cretaceous rocks. New exploration in the last two years has produced oil from stratigraphic targets that hints at wider potential in the basin. Friday night poster presentations and discussions at accommodations in Walden, Colorado, will cover wide-ranging topics including Neogene volcanism, drainage integration, and Quaternary history of the region. All field-trip stops are roadside; limited walking/hiking is involved. Great scenery is included.
- 405. Quaternary Geology and Geochronology of the Uppermost Arkansas Valley—Glaciers, Ice Dams, Landslides, Floods
Fri.–Sat., 29–30 Oct. US$228 (L, D, R, 1ON).
Cosponsors: GSA Quaternary Geology & Geomorphology Division; Crestone Science Center.
Leaders: James P. McCalpin, GEO-HAZ Consulting, Inc.; Jason Briner; Nicolás E. Young; Eric Leonard; C.A. Ruleman.
- Day one of this two-day trip will highlight recent findings from STATEMAP 1:24,000-scale mapping in the Climax and Leadville South 7.5' quadrangles, at the head of the Rio Grande rift. Previous smaller-scale mapping underestimated the extent of landsliding, which is widespread but often subtle. Following an overnight in Leadville, Colorado, day two will focus on the cosmogenic exposure dating chronology of Pinedale glaciation and associated outburst flood deposits. Beryllium-10 ages from massive moraines deposited by glaciers believed to have dammed the upper Arkansas River date to the Pinedale Glaciation and contain age modes that are remarkably similar to 10Be ages from downstream flood terrace boulders. The broader Pinedale history is constrained by 10Be ages from glacier-sculpted bedrock behind the moraines to constrain the timing of glacier retreat upvalley. We will visit giant boulders on the flood terraces, moraines, and glacier sculpted bedrock sites. The field trip is staged beneath Colorado’s highest peaks in an area renowned for excellent hiking, fishing, and of course, moraine sequences.
- 406. Boulder Creek: A Stream Ecosystem in an Urban Landscape
Sat., 30 Oct. US$87 (L, R).
Cosponsors: U.S. Geological Survey; GSA Quaternary Geology and Geomorphology Division.
Leaders: Sheila Murphy, USGS; Philip L. Verplanck; Pete Birkeland; John Pitlick; Sarah Spaulding; Larry Barber.
- The Boulder Creek Watershed, like many western watersheds, is comprised of a high-gradient upper reach mostly fed by snowmelt, a substantial change in gradient at the range front, and an urban corridor within the lower section. Water from Boulder Creek provides drinking water, crop irrigation, power plant cooling, wastewater disposal, recreation, and aquatic life habitat. A multi-use path follows Boulder Creek through the city of Boulder, serving as a link to parks, schools, a hospital, a library, public transportation, and businesses, and provides the opportunity to observe many of the important uses and features of the Boulder Creek corridor. This 16-mile field trip will follow this path, using rented bicycles, to explore the hydrology and geochemistry of Boulder and South Boulder Creeks. Topics will include flood frequency and hazards, aqueous geochemistry of the watershed, and potential impacts of invasive species, nonpoint source pollution, and emerging contaminants on stream ecology.
- 407. Mechanisms of Post-Laramide Fracturing in the Rockies: Insights from Outcrops and Industry Data from the Northern Denver Basin, Colorado
Sat., 30 Oct. US$88 (L, R).
Cosponsors: GSA Structural Geology and Tectonics Division; GSA Geophysics Division.
Leaders: Eric A. Erslev, University of Wyoming; Cody Lee Allen; Bryan W. Richter.
- The orientations and intensities of open fractures are critically important to water and petroleum production as well as CO2 sequestration in the U.S. Rocky Mountains. Post-Laramide fractures commonly form dominant fluid pathways, and a better understanding of their mechanisms is needed to predict reservoir heterogeneities and site horizontal wells. Unfortunately, a multitude of potential fracture-forming processes has been documented, including several periods of regional extension and more localized backsliding on Laramide thrusts, gravity detachments into basins, petroleum maturation, and erosional denudation. This field trip will examine extensional fractures in outcrops of the Niobrara Formation and adjacent units along the Front Range between Boulder and Fort Collins. The Niobrara Formation is an important resource play due to in situ trapping of oil generated in its source beds. Moderate walks to excellent exposures will show a complex fracture history, with minor faults, splitting fractures and styolites due to Laramide shortening overprinted by, and sometimes reactivated by, post-Laramide normal faults and extensional fractures. We will also present 3-D seismic and well data from the Denver Basin showing the fundamentally different orientations and styles of fracturing on the western and eastern sides. The results of other industry-academic collaborations from elsewhere in the Rockies will be used to demonstrate the multiple ages and mechanisms of Rocky Mountain fracturing. These hypotheses will be debated on the outcrop – a lively discussion in beautiful scenery is guaranteed!
- 408. A Hike through Geologic Time at Red Rocks and Dinosaur Ridge
Sat., 30 Oct. US$93 (L, R).
Cosponsor: Friends of Dinosaur Ridge, GSA Sedimentary Geology Division.
Leaders: Chris Carroll, Friends of Dinosaur Ridge; Tim Connors.
- The Front Range near Denver contains bedrock geologic exposures from the Precambrian through the Pliocene. Join the Friends of Dinosaur Ridge geologists on a hike through geologic time. We will hike from the Red Rocks Amphitheater to Green Mountain over Dinosaur Ridge. At Red Rocks, we will observe the unconformable contact between the Pennsylvanian-age Fountain Formation and underlying Precambrian rocks. We will hike downhill but upsection through the conglomeratic facies of the Fountain through the Penn-Permian-age Lyons Sandstone and Triassic Lykins Formation. The main hike emphasis will be on the Mesozoic stratigraphy and dinosaur tracks and bones in the Jurassic Morrison Formation (type-section) and Cretaceous Dakota Sandstone on Dinosaur Ridge. Our lunch stop will be at the Dinosaur Ridge Visitor's Center located in the Cretaceous Pierre Shale, followed by an afternoon hike to observe the latest Cretaceous Fox Hills Sandstone and Laramie Formation exposures and the Tertiary stratigraphy preserved on Green Mountain. Participants must be able to hike up to 2 miles on mostly downhill paved roadways, but van support will also be provided.
- 409. Garden of the Gods at Colorado Springs: Paleozoic and Mesozoic Sedimentation and Tectonics
Sat., 30 Oct. US$69 (L, R).
Cosponsor: GSA Sedimentary Geology Division
Leaders: Timothy L. Clarey, Delta College; John H. Whitmore; Marcus R. Ross; William A. Hoesch; Steven A. Austin.
- Participants in this eight-hour field trip will visit five sites along the Rampart Range and Ute Pass fault zones west of Colorado Springs, Colorado. The purpose is to observe and discuss the processes of sedimentation and tectonics at superb exposures near the Garden of the Gods. Only short hikes will be made from the vehicles. Five sites are to be visited: (1) a nonconformity below Cambrian strata at the base of the Sauk Sequence; (3) coarse clastic sedimentation in the late Paleozoic Fountain Formation; (3) marine sandstones and shales as evidence of the Cretaceous Western Interior Seaway; (4) clastic dikes (sand “injectites”) within the fault hanging wall; and (5) upturned strata at Garden of the Gods in association with Laramide tectonics on the Rampart Range fault.
- 410. Geology and Natural Hazards of Golden
Sat., 30 Oct. US$50, For Students Only. (L, R).
Cosponsor: GSA Engineering Geology Division.
Leaders: Paul Santi, Colorado School of Mines; Jerry Higgins.
- GSA's Engineering Geology Division is pleased to sponsor this field trip, which is designed especially for students with interests in environmental, applied, and engineering geology. The trip will visit sites around the city of Golden, west of Denver, to learn the local geology and observe landslides, rockfall areas, debris flow hazards, heaving bedrock damage, and mine settlement and collapse. We will make a short lunch stop in downtown Golden (not included in the trip fee). The day will finish with another student classic: a short tour of the Coors brewery — straight to the sampling room! The first 33 student registrants for the "Geology and Natural Hazards of Golden" field trip will be reimbursed US$20 after the meeting by the Engineering Geology Division. You must pay the full field-trip fee when registering.
- 411. Subaru Outback Mountain Biking & Discovery Adventure — with Trek & Globe Trekker
Sat., 30 Oct. US$85 (L, R).
Leaders: Laurie Brandt, BuckhornGeotech; Abana Jacobs, Subaru; Matt Morgan, Colorado Geological Survey; Martin Lockley, University of Colorado–Denver Dinosaur Tracks Museum
- Ride in a Subaru Outback to the Matthews/Winters Park Open Space in Denver's foothills, where the Rocky Mountains dramatically uplift Paleozoic deposits of the Ancestral Rockies and younger Mesozoic strata into steeply dipping hogbacks. Learn the geology of the Front Range while riding a Trek mountain bike and hiking on trails on Dinosaur Ridge. The trails are easy to moderately strenuous, and we will be stopping often to observe and discuss landforms, features in the formations, and the area's geologic history. The hike will also include a newly discovered tracksite. A brief review of mountain bike skills will be offered, and the ride will be on guided trails for further geological exploration. While half of the group is riding on the Red Rock Trails viewing the Fountain, Lyons, and Lykins Formations, laid down during the uplift and erosion of the late Paleozoic Ancestral Rockies and later tilted into steeply dipping hogbacks during the Laramide Orogeny, the other half of the group will be hiking on Dinosaur Ridge, observing the resource-rich of Mesozoic-aged Morrison Formation and Dakota Group. Uranium, oil and gas, gravel, clay, gypsum, landslides, groundwater, and dinosaur tracks and fossils are found in these formations. Participants must be willing to appear on film. Bring sturdy hiking and/or riding shoes, helmet, pack, comfortable layered clothes, and outer gear for inclement weather. You must be willing to appear on film.
- 412. To Reactivate or Not to Reactivate: Nature and Varied Behavior of Structural Inheritance in the Proterozoic Basement of the Eastern Colorado Mineral Belt over ~1.7 Billion Years of Geologic Time
Sat., 30 Oct. US$85 (L, R).
Cosponsors: GSA Structural Geology and Tectonics Division; U.S. Geological Survey; Society of Economic Geologists.
Leaders: Jonathan Saul Caine, USGS; John Ridley; Zachary R. Wessel.
- The eastern Rocky Mountain Front Range of Colorado has long been a region of geologic interest because of Laramide-age hydrothermal polymetallic vein-hosted ores and associated hypotheses regarding structural inheritance. The mineralized areas are collectively termed the Colorado Mineral Belt (CMB) and are interpreted to have been localized along a persistent and deep-seated zone of weakness in the North American Proterozoic crust. The region hosts a well-exposed array of geologic structures associated with ductile and brittle deformation, which record crustal strain over a period of ~1.7 billion years. The Front Range Proterozoic, basement-cored surface uplift has been mapped at numerous scales, resulting in an exceptional structural geologic dataset. However, detailed controls on location, orientation, kinematics, density, permeability, and relative strength of various geological structures in relation to mineral deposit formation are poorly understood. As part of ongoing research, structures resulting from protracted deformation in the Front Range are being reexamined to better understand this complex system. The field trip objectives are to show key localities that exemplify the types of structures present, show recently compiled existing data as well as new data generated from new approaches, offer a new conceptual model, and to foster dialogue. Topics to be discussed include (1) structural history of the eastern Front Range; (2) characteristics, kinematics, orientations, and age of ductile and brittle structures and how they may or may not relate to one another; and (3) characteristics, localization, and evolution of the metal- and non-metal bearing hydrothermal systems in the eastern CMB.
- 413. Historic Dinosaur Quarries within a Newly Interpreted Paleoenvironmental Context
Sat., 30 Oct. US$118 (L, R).
Cosponsors: Colorado Scientific Society, Morrison Natural History Museum, Colorado Geological Survey, GSA History of Geology Division, GSA Sedimentary Geology Division, Escalante Mines, Inc.
Leaders: Thomas R. Fisher & Lisa R. Fisher, Escalante Mines, Inc., ; Matt Mossbrucker; Libby Prueher; Erin Fair.
This trip also runs before the meeting (see trip 418), and is presented in conjunction with Topical Session T94.
- Participants will examine the geology and paleontology of the area around Morrison, Colorado, where we will focus on past and present paleontological discoveries in the Jurassic Morrison, and explore historic 1870s dinosaur quarries of Arthur Lakes. New interpretations of the paleoecology and environments of the Morrison will be applied to understanding the evolution of the landscape through time. The trip will be lead by researchers from the Morrison Natural History Museum (MNHM), an active research and education facility staffed by experts in paleontology, geology, ecology, and education, and will include a museum tour. We will also explore some of the colorful history of Lakes’ quarries, and how they helped fuel the famous “Bone Wars” between Edward Cope and O.C. Marsh. The Paleozoic-Mesozoic section of the area will be examined, and we will visit and explore some of Lake’s quarries and dig sites, including Yale Quarries 5, 10, and “XYZ” where holotypes of Stegosaurus armatus and Apatosaurus ajax were excavated in 1877. The MNHM relocated and reopened Lakes’ 1877 Yale Quarry 10 beginning in 2002. This quarry yielded the world’s first specimen of Stegosaurus, Yale No. 1850, which is now in residence at MNHM. MNHM researchers are conducting a reexamination of previously excavated fossils and examining the significance of exciting new finds, such as recently discovered lungfish fragments associated with Stegosaurus No. 1850. These discoveries are providing new insights into the paleoecology of the type section of the Morrison, and forcing re-evaluation of certain well-known dinosaur species.
- 414. Old and New Geologic Studies along the Front Range between Golden and Morrison Including Structural, Volcanic, and Economic Geology and Paleontology
Sat., 30 Oct.
- Sorry, this trip has been canceled.
However, this field trip also runs after the meeting (see trip 419) and as a family trip during the meeting (see trip 415).
click to enlarge
click to view more photos
click to view more photos
click to view more photos
click to view more photos