Transcript Physiographic Setting - Western Oregon University

Spring 2011 ES407 Senior Seminar
New Approaches to Geomorphic Analysis of
Cinder Cones at Newberry Volcano
Jody “Coyote” Becker, Kelsii “Crusher” Dana,
Dan “Ger” Dziekan, Ricky “Flicky” Fletcher,
Bill “W.” Vreeland, Steve “Dr.” Taylor
• Introduction (Taylor)
• Physiographic Setting (Fletcher)
• Tectonic Setting (Vreeland & Dziekan)
• Geologic History (Becker & Dana)
• The “Cinder Cone Problem” / Previous Work (Taylor)
• Cinder Cone Methodology
 Cone Age-Morphology Concept (Fletcher & Dziekan)
 Structural Cone Emplacement (Becker)
 Cinder Cone Alignment (Vreeland)
 Lidar-Based Elevation Models (Dana)
• New Research / Pilot Testing with LIDAR Data
 Cinder Cone Drainage Density vs. Age (Becker)
 Modified Two-Point Analysis (Vreeland)
 Newberry Glacial Hypothesis (Fletcher)
 Lava Flow Margin Mapping with Lidar (Dana)
• Summary and Future Research (Taylor)
INTRODUCTION
Steve Taylor
Cascade Volcanic Arc
Linear chain of volcanoes
extending from southern British
Columbia through Washington
and Oregon into northern
California
WOU
Bend
Newberry Volcano
• 56 km east of Cascade Crest
• 40 km south of Bend, Oregon
History of Newberry Work at Western Oregon University
2000-Present
WOU Class Field Trips and Contextual Learning Modules
2000
Friends of the Pleistocene Field Trip to Newberry Volcano
2002-2003
GIS Compilation and Digitization of Newberry Geologic
Map (after MacLeod and others, 1995)
2003
Giles and others, Digital Geologic Map (GSA Fall Meeting)
2003
Taylor and others, Cinder Cone Volume and Morphometric
Analysis I (GSA Fall Meeting)
2005
Taylor and others, Spatial Analysis of Cinder Cone
Distribution II (GSA Fall Meeting)
2007
Taylor and others, Synthesis of Cinder Cone Morphometric
and Spatial Analyses (GSA Cordilleran Section Meeting)
2001-Present
Templeton, Petrology and Volcanology of Pleistocene Ashflow Tuffs (GSA Cordilleran Section Meeting 2004; Oregon
Academy of Science, 2007; Am. Geophys. Union, 2010)
2010-2011
Newberry LIDAR Elevation Data Available; ES407 Senior
Seminar Pilot Tests Next Generation Research Strategies on
Cinder Cones; Updated Literature Review
PHYSIOGRAPHIC SETTING
Rick Fletcher
124 W
120 W
122 W
118 W
MJ
Cascades
Cascades
MH
Deschutes-Umatilla
Plateau
Blue Mountains
TFZ
Coast
Western
MW
TS
1
High
Cascadia
44 N
Subduction
Zone
Range
4.5 cm /yr
Willa
mett
e Va
lley
46 N
WRFZ
BFZ
High Lava
Plains
5
6
CL
7
Klamath
Mountains
8
Owyhee
Upland
9
10
Basin and Range
42 N
0
Extent of Newberry Lava Flows
Newberry Caldera
Rhyolite Isochrons (Ma)
Faults:
TFZ = Tumalo Fault Zone
WRFZ = Walker Rim Fault Zone
BFZ = Brother Fault Zone
100 km
9
Newberry Volcano, South View from Lava Butte Lookout
Caldera Summit
Basaltic Aa Lava Flow from
Lava Butte; ~7000 yrs BP
Newberry Volcano, View to S-SE from Paulina Peak Lookout
High Lava
Plains
Fort Rock
(Tuff Ring)
Newberry Cinder Cones
Basin and Range
Newberry Volcano, View to West towards High Cascades
from Paulina Peak Lookout
South
Sister
Broken
Top
Middle
Sister
Newberry Volcano, View into Summit Caldera from Paulina Peak
Paulina Lake
East Lake
TECTONIC SETTING
Dan Dziekan and Bill Vreeland
Arc Volcanoes related
to Cascadia Subduction Zone
Juan de Fuca plate thrust
beneath North American plate
Magma Source in Subduction Zone
Back Arc
Fore Arc
35 – 7 Ma
7 – 0 Ma
Newberry
Position
Eastward Arc
Migration
Decreasing
Slab Dip
Current Crustal Deformation Rates and Directions
Newberry
Meigs et al., 2009
Basin and Range
Stretching
GEOLOGIC HISTORY
Jody Becker and Kelsii Dana
Overview of Newberry Volcano
•Shield-shaped composite volcano
•N-S orientation, 64 km x 40 km
•Total Area > 1300 km2
•Summit Caldera Area = 44 km2
•Elevation: 1300 m – 2400 m; Relief ~1100 m
•Composition: Basalt to Rhyolite
•Estimated Volume = 460 km3
•>400 cinder cones and fissure vents
•Quaternary in Age
Less than ~500,000 yrs old
Holocene activity: 10,000 – 1200 yrs BP
•One of largest U.S. Quaternary volcanoes
•Historic Annual Precipitation: 30 in/yr
East flank rain shadow of Cascades
Regional Geology
• Oregon-Idaho:
 Paleozoic-Mesozoic
oceanic volcanic arcs
 Accretionary complexes
 Basinal successions
• Cenozoic volcanism:





Ignimbrite sweep
Flood basalts
Bimodal (modern)
High Lava Plains
Snake River Plain
Regional Volcanism
• Two migrating tracks:
 NE along Snake River
Plain toward Yellowstone
 WNW along High Lava
Plains (Newberry)
• Indicated link between
High Lava Plains and
Cascades volcanism:
 Increased output
 Isotopic similarities
 Merging structures
122W
120W
Extent of Newberry
lava flows
Rhyolite isochrons ( Ma)
0
100
TFZ
km
Newberry Caldera
Fault Zones:
HLP
44N
BFZ=Brothers
TFZ = Tumalo
WRFZ=Walker Rim
BFZ
CR
1
WRFZ 5
BR
6
7
1
6
9 10
8
Geology after Walker and MacLeod
(1991); Isochrons in 1 m.y.
increments (after MacLeod and
others, 1976)
Central
Pumice
Cone
7200 yrs BP
East Lake
Big Obsidian Flow
1250 yrs BP
STATEMENT OF THE PROBLEM
GEOMORPHIC ANALYSIS OF
CINDER CONES
Steve Taylor
Basalt and basaltic andesite flows:
early Pleistocene to Holocene
Cinder Cone Research Questions
Rhyolite to dacite domes, flows, pumice rings,
and vent complexes: early Pleistocene to
Holocene
Pumice falls, ash flows, and alluvial deposits:
Pleistocene to Holocene
Are there morphologic groupings of
~400 cinder cones at Newberry? Can
they be quantitatively documented?
Andesite Tuff (west flank): Pleistocene
Black Lapilli Tuff (west flank): Pleistocene
Alluvial deposits with interbedded lapilli tuff, ash
flow tuff, and pumice fall deposits: Pleistocene
Are morphologic groupings
associated with age and state of
erosional degradation?
Tepee Draw Tuff (east flank): Pleistocene
Basalt and basaltic andesite of small shields:
Pleistocene
Fluvial and lacustrine sediments: Pleistocene
and Pliocene(?)
Are there spatial patterns associated
with the frequency, occurrence, and
volume of cinder cones?
Basalt, basaltic andesite, and andesite flows, ash
flow tuffs, and pumice deposits of the Cascade
Range: Pleistocene
Basalt flows and interbedded cinders and scoria
deposits: late Miocene
Rhyolite and andesite flows, domes, and
pyroclastic rocks of Pine Mountain: early
Miocene
Are there spatial alignment patterns?
Can they be statistically documented?
Newberry Caldera complex
Cinder cones and fissure vents
Faults
Do regional stress fields and fault
mechanics control the emplacement
Study
AreaNewberry volcano?
of 0cinder
cones
at
5 km
Oregon
Lava Butte Cone and Aa Flow
~7000 yrs BP (post-Mazama)
Ash &
Pumice
Southeast Cinder Cone Field
Existing Methodology


Digital Geologic Map Compilation / GIS of
Newberry Volcano (after McLeod and others, 1995)
GIS analysis of USGS 10-m DEMs

Phase 1 Single Cones/Vents (n = 182)
 Phase 2 Composite Cones/Vents (n = 165)

Morphometric analyses

Cone Relief, Slope, Height/Width Ratio
 Morphometric Classification

Volumetric Analyses

Cone Volume Modeling
 Volume Distribution Analysis

Cone Alignment Analysis

Two-point Line Azimuth Distribution
 Comparative Monte Carlo Modeling (Random vs. Actual)