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PRELIMINARY INVESTIGATION OF THE THOUSAND LAKES FAULT FROM THE MID MIOCENE TO LATE PLEISTOCENE: AN APPROACH FOR CHARACTERIZING LOW SLIP RATE NORMAL FAULTS USING GEOMORPHOLOGY AND PALEOSEISMOLOGY

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Nathan A Toké at Utah Valley University
Nathan A Toké
Joseph Phillips at Utah Valley University
Joseph Phillips
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Preliminary Investigation of the Thousand Lake Fault from
the Mid Miocene to Late Pleistocene:
An Approach for Characterizing Low Slip Rate Normal Faults Using Geomorphology and Paleoseismology
Dr. Nathan A. Toké, Associate Professor of Earth Science, Utah Valley University 2017 GSA Annual Meeting
114-4 in T209 Challenges in Tectonics: Fault Zone Behavior Through Time from Earth’s Surface to upper Mantle Slide 1 of 13
Dr. Nathan A. Toké, Associate Professor of Earth Science, Utah Valley University 2017 GSA Annual Meeting
114-4 in T209 Challenges in Tectonics: Fault Zone Behavior Through Time from Earth’s Surface to upper Mantle Slide 2 of 13
Freemont River Basin
Thousand Lake Fault: TLF
Freemont River:
Thousand Lake Mtn.
Boulder Mtn.
Tectonic and Geomorphic Setting
Dr. Nathan A. Toké, Associate Professor of Earth Science, Utah Valley University 2017 GSA Annual Meeting
114-4 in T209 Challenges in Tectonics: Fault Zone Behavior Through Time from Earth’s Surface to upper Mantle Slide 3 of 13
Quaternary Activity?
•Last Activity since 750 ka (Utah Q Fault Database)
- faulted terraces that formed since start of Mid Quaternary
•Last Active before 125 ka (Marchetti et al., 2007)
- undisturbed landslide deposits covering TLF on Boulder Mtn.
Earthquake Size?
•Fault Length ~ 49 km
Slip Rate?
•< 0.2 mm/yr (Utah Q Fault Database)
From Utah Geological Survey: http://files.geology.utah.gov/emp/geothermal/quaternary_faults.htm
What more can we say today?
Prior Information about the Thousand Lake Fault
Methods: Mapping, Paleoseismic Recon, and Spatial Analysis
Dr. Nathan A. Toké, Associate Professor of Earth Science, Utah Valley University 2017 GSA Annual Meeting
114-4 in T209 Challenges in Tectonics: Fault Zone Behavior Through Time from Earth’s Surface to upper Mantle Slide 4 of 13
(Biek, 2016)
UVU Field
Camp
What’s the character of faulting
•Fault zone width?
•Seek out Paleoseismic outcrops.
•Displacement per event?
•Most recent activity?
•Slip rate?
-Mapped/Recon. about 5 x 2.5 km
-Used GIS to determine LT Slip Rate
-Documented paleoseismic outcrops
-Measured displacement of surfaces
-Explored Freemont R. terraces in GIS
Total Displacement and Long Term Slip Rate
Dr. Nathan A. Toké, Associate Professor of Earth Science, Utah Valley University 2017 GSA Annual Meeting
114-4 in T209 Challenges in Tectonics: Fault Zone Behavior Through Time from Earth’s Surface to upper Mantle Slide 5 of 13
a
a’
1500-2500 m
•Age of Displaced Volcanics ~24.5 Mya (e.g., Mattox, 1991)
•Tectonic Initiation 10-16 Mya (e.g., McQuarrie and Warnicke, 2005)
Near Fault Center
Minimum Long Term Slip Rate ~ 0.1 mm/yr
Maximum Long Term Slip Rate ~ 0.25 mm/yr
aa’
Earthquake Evidence –Fault Scarps
Dr. Nathan A. Toké, Associate Professor of Earth Science, Utah Valley University 2017 GSA Annual Meeting
114-4 in T209 Challenges in Tectonics: Fault Zone Behavior Through Time from Earth’s Surface to upper Mantle Slide 6 of 13
Fault Scarp Displacement Analysis
Dr. Nathan A. Toké, Associate Professor of Earth Science, Utah Valley University 2017 GSA Annual Meeting
114-4 in T209 Challenges in Tectonics: Fault Zone Behavior Through Time from Earth’s Surface to upper Mantle Slide 7 of 13
2205
2210
2215
2220
2225
2230
25 50 75 100 125 150 175 200 225 250 275
Alluvial Fan Scarp
(2x Vertical Exaggeration)
~ 4 m fault displacement (since fan abandonment)
aa’
a
a’
Earthquake Evidence –Footwall Colluvial Wedge
Dr. Nathan A. Toké, Associate Professor of Earth Science, Utah Valley University 2017 GSA Annual Meeting
114-4 in T209 Challenges in Tectonics: Fault Zone Behavior Through Time from Earth’s Surface to upper Mantle Slide 8 of 13
Footwall Event
Dr. Nathan A. Toké, Associate Professor of Earth Science, Utah Valley University 2017 GSA Annual Meeting
114-4 in T209 Challenges in Tectonics: Fault Zone Behavior Through Time from Earth’s Surface to upper Mantle Slide 9 of 13
Earthquake Evidence –Fault-derived Colluvium
Dr. Nathan A. Toké, Associate Professor of Earth Science, Utah Valley University 2017 GSA Annual Meeting
114-4 in T209 Challenges in Tectonics: Fault Zone Behavior Through Time from Earth’s Surface to upper Mantle Slide 10 of 13
alluvium
Paleoseismic Reconnaissance Recap
~ 1 m
•Footwall faulting in Terrace 10-12 m above local
base level: Slip-per-event = ~ 1+ m/event
Expected recurrence rate
-1m/0.25 mm/yr = 4,000 yrs
-2m/0.1 mm/yr = 20,000 yrs
•Alluvial Fan surface with 4 m displacement
-Given slip rate, possibly a surface
associated with end of Last Glacial
Maximum (15-25 kya)
-2-4 events since surface abandonment.
•Anticipated Mw: 6.8 - 7.2
(30-50 km-long ruptures, 1-2 m displacement, 20 km depth)
1500
1600
1700
1800
1900
2000
2100
2200
2300
15000 35000 55000
Repka, Anderson, and Finkel, 1997:
CRN Terrace Ages downstream
~0.8 mm/yr Incision Rate
Estimated headwaters exhumation of 30m/Ma
Pleistocene Activity Evidence –Terrace Warping
Dr. Nathan A. Toké, Associate Professor of Earth Science, Utah Valley University 2017 GSA Annual Meeting
114-4 in T209 Challenges in Tectonics: Fault Zone Behavior Through Time from Earth’s Surface to upper Mantle Slide 11 of 13
Marchetti and Cerling, 2005:
CRN (He) - ~200 kya
C Terrace
~100 m
JM Terrace
~100 m
Preliminary Findings Thousand Lake Fault
Dr. Nathan A. Toké, Associate Professor of Earth Science, Utah Valley University 2017 GSA Annual Meeting
114-4 in T209 Challenges in Tectonics: Fault Zone Behavior Through Time from Earth’s Surface to upper Mantle Slide 12 of 13
•Geologic Slip Rate 0.1-0.25 mm/year
•Likely Active During the Late Pleistocene
•Recurrence Rate 4,000 –20,000 years per event
•Anticipated Moment Magnitude: 6.8-7.2
Work to come:
-C-14 Ages from Footwall Colluvial Wedge Material
-Possibly trench adjacent displaced terrace or fan.
References:
Dr. Nathan A. Toké, Associate Professor of Earth Science, Utah Valley University 2017 GSA Annual Meeting
114-4 in T209 Challenges in Tectonics: Fault Zone Behavior Through Time from Earth’s Surface to upper Mantle Slide 13 of 13
•Anderson, R.E., and Barnhard, T.P., 1986, Genetic relationship between faults and folds and determination of Laramide and neotectonic paleostress,
western Colorado Plateau-transition zone, central Utah: Tectonics, v. 5, p. 335-357.
•Biek, R.F., 2016, Interim Geologic Map of the Bicknell Quadrangle, Wayne County, Utah, Utah Geological Survey Open-File Report 654.
•Doelling H. and P. Kuehne, 2007, Interim Geologic Map of the East Half of the Loa 30’ x 60’ Quadrangle, Wayne, Garfield, and Emery Counties, Utah,
Utah Geological Survey Open-File Report 489.
•Harty, K.M., 1987, Field reconnaissance of Thousand Lake fault zone: Utah Geological and Mineral Survey, memorandum, 2 p.
•Hecker, S., 1993, Quaternary tectonics of Utah with emphasis on earthquake-hazard characterization: Utah Geological Survey Bulletin 127,
157 p., 6 pls., scale 1:500,000.
•Marchetti, D. and T. Cerling, 2005, Cosmogenic 3He exposure ages of Pleistocene debris flows and desert pavements in Capitol Reef National Park,
Utah, Geomorphology, v. 67, 423-435.
•Marchetti, D., T. Cerling, and E. Lips, 2005, A glacial chronology for the Fish Creek drainage of Boulder Mountain, Utah, USA, Quaternary Research,
v. 64, 264-271.
•Marchetti, D., T. Cerling, J. Dohrenwent, and W. Gallin, 2007, Ages and significance of glacial and mass movement deposits on the west side of Boulder
Mountain, Utah, USA, PALAEO, v. 252, 503-513.
•Mattox, S.R., 1991. Petrology, age, geochemistry, and correlation of the tertiary volcanic rocks of the Awapa Plateau, Garfield, Piute, and Wayne Counties,
Utah. Utah Geol. Surv. Misc. Publ. 91-5,46 pp.
•National Agricultural Imagery Program, 2014, NAIP imagery acquired from Utah AGRC: https://gis.utah.gov/data/aerial-photography/
•Repka, J., R. Anderson, and R. Finkel, 1997, Cosmogenic dating of fluvial terraces, Freemont River, Utah, Earth and Planetary Science Letters, V. 152, 59-73.
•Smith, J., I. Huff, K. Hinrichs, and R. Luedke, 1957, Preliminary Geologic Map of the Loa 1 SE Quadrangle, Utah, Mineral Investigations
Field Studies Map MF 101.
•State of Utah, 2006, Auto-Correlated 5 meter DEM, Utah AGRC: https://gis.utah.gov/data/elevation-terrain-data/
•Utah Quaternary Fault and Fold Database: https://geology.utah.gov/resources/data-databases/qfaults/
•Utah Geological Survey Aerial Imagery Collection: 1950 DKT, 1958 EEZ, and 1966 EEZ https://geodata.geology.utah.gov/imagery/
ResearchGate has not been able to resolve any citations for this publication.
Ages and significance of glacial and mass movement deposits on the west side of Boulder Mountain, Utah, USA
Article
Full-text available
  • Sep 2007
  • PALAEOGEOGR PALAEOCL
Using air photos, satellite images, and field observations we mapped Quaternary glacial and mass movement deposits on the west side of Boulder Mountain in south-central Utah, USA. Prominent glacial moraines were deposited by outlet glaciers that emanated from an ice cap that existed atop Boulder Mountain. Cosmogenic 3He exposure ages of these deposits range from 20.2±1.5 to 22.5±2.5 ka and indicate maximum ice advance during the global last glacial maximum (LGM). Three 3He exposure ages of boulders from the Pine Creek slump deposit indicate that the slumping likely occurred at or before ∼125 ka. Eight 3He exposure ages of boulders from the Miller Creek Potholes debris flow deposit range from 20.2±2.0 to 50.4±3.0 ka; five of those boulders yielded ages in the range of 26–33 ka and suggest emplacement of the debris flow deposit during that time. Both of these mass movement features cover prominent fault traces related to the Thousand Lakes fault but do not appear to be offset, suggesting that major faulting has not occurred since ∼125 kyr ago in this area.
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A glacial chronology for the Fish Creek drainage of Boulder Mountain, Utah, USA
Article
Full-text available
  • Sep 2005
Boulder Mountain, located in South Central Utah, is one of several mountain ranges on the Colorado Plateau that was glaciated during the late Pleistocene. Using 3He exposure-age dating (corrected for non-cosmogenic 3He with shielded samples), we determined 3He exposure-ages for boulders from the most well-preserved moraines in the Fish Creek drainage of Boulder Mountain. 3He exposure-ages indicate a last glacial maximum (LGM) advance ∼23,100 ± 1300 to 20,000 ± 1400 yr ago and a later and smaller advance ∼16,800 ± 500 to 15,200 ± 500 yr ago. This chronology is very similar to other cosmogenic glacial chronologies from the Western U.S. and suggests that the timing of glacial advance and retreat on the Colorado Plateau was generally in phase with the rest of the Western U.S. during the late Pleistocene.
View
Cosmogenic 3He exposure ages of Pleistocene debris flows and desert pavements in Capitol Reef National Park, Utah
Article
Full-text available
  • Apr 2005
  • GEOMORPHOLOGY
The Quaternary history of the Capitol Reef area, Utah, is closely linked to the basaltic-andesite boulder deposits that cover much of the landscape. Understanding the age and mode of emplacement of these deposits is crucial to deciphering the Quaternary evolution of this part of the Colorado Plateau. Using cosmogenic 3He exposure age dating, we obtained apparent exposure ages for several key deposits in the Capitol Reef area. Coarse boulder diamicts capping the Johnson Mesa and Carcass Creek Terraces are not associated with the Bull Lake glaciation as previously thought, but were deposited 180±15 to 205±17 ka (minimum age) and are the result of debris flow deposition. Desert pavements on the Johnson Mesa surface give exposure ranging from 97±8 to 159±14 ka and are 34–96 kyears younger than the boulder exposure ages. The offset between the boulder and pavement exposure ages appears to be related to a delay in pavement formation until the penultimate glacial/interglacial transition or periodic burial and exposure of pavement clasts since debris flow deposition. Incision rates for the Capitol Reef reach of the Fremont River calculated from the boulder exposure ages range from 0.40 to 0.43 m kyear−1 (maximum rates) and are some of the highest on the Colorado Plateau.
View
Genetic Relationship Between Faults and Folds and Determination of Laramide and Neotectonic Paleostress, Western Colorado Plateau-Transition Zone, Central Utah
Article
  • Apr 1986
Faults in the western part of the Colorado Plateaus and the adjacent eastern part of the structural transition zone to the Basin and Range in central Utah represent two stages of deformation: Laramide compressional faults on the plateau (eastern) side and late Cenozoic extensional faults on the transition-zone (western) side. The faults range in displacement from a few centimeters to several hundred meters. This study of minor structures provides strong evidence for regional NE-SW horizontal maximum compressive stress as a dynamic component of monoclinal flexure; the results further suggest that it is inaccurate to interpret the monoclines simply as passive drape folds formed during vertical block up-lift. The Laramide faults on the plateau side cut two types of large-scale folds: (1) a broad warp called the Teasdale anticline, and (2) two monoclines that flank the Teasdale anticline, called the Waterpocket and Cocks Comb monoclines. The faults that cut the monoclines dip steeply and have mostly strike-slip displacements. Strike azimuths of dextral and sinistral faults tend to occupy separate sectors, suggesting that they are conjugate shears activated in a stress field with a subhorizontal maximum compressive stress (σ1) oriented northeast-southwest. This orientation is confirmed by computations of mean paleostress characteristics by inversion of fault-slip data. The monoclines differ from one another in trend by 30°, so it is possible to compare these trends with the results of separate paleostress computations for faults from each monocline. Four separate computed σ1 axes (three from the Cocks Comb monocline) are approximately horizontal and cluster within 10° of the N. 65° E. normal to the axial trace of the Waterpocket monocline, suggesting that the Waterpocket at the latitude of our study formed approximately perpendicular to the local Laramide compressive-stress direction. The maximum compressive stress (σ1) is located clockwise about 30° from the normal to the Cocks Comb monocline. We interpret this discordance as evidence that the Cocks Comb trend was influenced by, and in large part inherited from, the trend of an ancient buried fault rooted in the basement, whereas the exposed faults from which σ1 was computed are structures that formed in, and are probably restricted to, the sedimentary cover rocks. The exposed faults probably formed fresh in the cover rocks during Laramide compression and are generally more reliable indicators of compressional kinematics than fold orientations. Part of the Cocks Comb monocline shows a 13° distortion of its axial trace by cumulative dextral slip on hundreds of small-displacement transverse faults. We interpret this distortion as a late-stage, brittle compressional strain (20%) related to the buttressing by mechanically resistant rocks in the most structurally elevated part of the adjacent Teasdale anticline. Fault-slip data were gathered from the Thousand Lake fault, the easternmost main fault zone of the transition zone. Faults that parallel the main fault show mainly dip slip, but many faults in the zone strike oblique to it and show strike slip or dip slip. Analysis of the predominantly dip-slip faults indicates a west-northwest/east-southeast (285°) least principal stress/strain axis that we interpret as the neotectonic extension direction for the area.
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Associate Professor of Earth Science, Utah Valley University 2017 GSA Annual Meeting 114-4 in T209 Challenges in Tectonics: Fault Zone Behavior Through Time from Earth's Surface to upper Mantle Slide 13 of 13
  • Dr
  • A Nathan
  • Toké
Dr. Nathan A. Toké, Associate Professor of Earth Science, Utah Valley University 2017 GSA Annual Meeting 114-4 in T209 Challenges in Tectonics: Fault Zone Behavior Through Time from Earth's Surface to upper Mantle Slide 13 of 13
Interim Geologic Map of the Bicknell Quadrangle
  • Jan 2016
  • R F Biek
• Biek, R.F., 2016, Interim Geologic Map of the Bicknell Quadrangle, Wayne County, Utah, Utah Geological Survey Open-File Report 654.
Field reconnaissance of Thousand Lake fault zone: Utah Geological and Mineral Survey, memorandum
  • Jan 1987
  • K M Harty
• Harty, K.M., 1987, Field reconnaissance of Thousand Lake fault zone: Utah Geological and Mineral Survey, memorandum, 2 p.
Petrology, age, geochemistry, and correlation of the tertiary volcanic rocks of the Awapa Plateau
  • Jan 1991
  • pp
  • S R Mattox
• Mattox, S.R., 1991. Petrology, age, geochemistry, and correlation of the tertiary volcanic rocks of the Awapa Plateau, Garfield, Piute, and Wayne Counties, Utah. Utah Geol. Surv. Misc. Publ. 91-5,46 pp.
  • Jan 1997
  • 59-73
  • J Repka
  • R Anderson
  • R Finkel
• National Agricultural Imagery Program, 2014, NAIP imagery acquired from Utah AGRC: https://gis.utah.gov/data/aerial-photography/ • Repka, J., R. Anderson, and R. Finkel, 1997, Cosmogenic dating of fluvial terraces, Freemont River, Utah, Earth and Planetary Science Letters, V. 152, 59-73.