Morphology and Spatial Distribution of Cinder Cones at Newberry Volcano, Oregon: Implications for Relative
Ages and Structural Control on Eruptive Process
Steve TaylorEarth and Physical Science Department
Western Oregon UniversityMonmouth, Oregon 97361
• Introduction
• Geologic Setting
• Morphometric Analysis
• Cone Alignment Analysis
• Summary and Conclusion
INTRODUCTION
History of Newberry Work at Western Oregon University2000 Friends of the Pleistocene Field Trip to Newberry Volcano
2002-2003 Giles and others, GIS Compilation and Digitization of Newberry Geologic Map (after MacLeod and others, 1995)
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 PleistoceneAsh-Flow Tuffs (GSA Cordilleran Meeting 2004; Oregon Academy of Science, 2007; GSA Annual Meeting 2009; AGU Annual Meeting 2010)
2011-Present Taylor and WOU Students, ES407 Senior Seminar Project,Pilot Testing of Lidar Methodologies on Cinder Cone Morphometry
NOTE: Work presented today was conducted in pre-Lidar days mid-2000’s
Relevance of Research - Newberry Geothermal Exploration
Alta Rock Energy - U.S. Department of Energy
Geologic Setting
Coa
st
R
ange
Wes
tern
C
asca
des
Klam athMountains
Cas
cadi
a
Sub
d uct
ion
Z
one
Hig
hC
asca
des
Basin and Range
1 0987
6
5
1
4 . 5 c m / y r
OwyheeUpland
Blue Mountains
Deschutes-Um atillaPlateau
Will
amet
te V
alle
y
High LavaPlainsWRFZ
BFZ
TFZ
E xtent o f N ewberry Lava F low s New berry C aldera
R hyo lite Isochrons (M a)9
Faults: TFZ = Tum alo Fault Zone W RFZ = W alker R im F ault Zone B FZ = B rother Fault Zone
M H
M J
T S
M W
C L
0 1 0 0 k m
4 2 N
4 4 N
4 6 N
1 2 4 W 1 2 2 W 1 2 0 W 1 1 8 W
Geology after Walker and MacLeod (1991); Isochrons in 1 m.y. increments (after MacLeod and others, 1976)
km0 100
44N
122W120W
BR
HLPCR
TFZ
BFZ
WRFZ
1
8
5
7
6
1
6109
Extent of Newberry lava flowsRhyolite isochrons (Ma)Newberry CalderaFault Zones: BFZ=Brothers TFZ = Tumalo WRFZ=Walker Rim
O regon
StudyArea
Basalt and basaltic andesite flows:early P le istocene to H olocene
Rhyo lite to dacite dom es, flow s, pum ice rings,and vent com plexes: early P le istocene toHolocene
Pum ice fa lls, ash flows, and a lluvial deposits:P leistocene to H olocene
Andesite Tuff (west flank): P leistocene
B lack Lapilli Tuff (west flank): P le is tocene
A lluvia l deposits w ith interbedded lapilli tu ff, ashflow tuff, and pum ice fa ll deposits: P leistocene
Tepee D raw Tuff (east flank): P leistocene
Basalt and basaltic andesite of sm all shie lds:P leistocene
Fluvia l and lacustrine sedim ents: P le istoceneand P liocene(?)
Basalt, basaltic andesite , and andesite flows, ashflow tuffs, and pum ice deposits o f the CascadeRange: P le istocene
Basalt flows and in te rbedded cinders and scoriadeposits: late M iocene
Rhyo lite and andesite flow s, dom es, andpyroclastic rocks of P ine M ounta in : earlyM iocene
New berry Caldera com plex
Cinder cones and fissure vents
Fau lts
0 5 km
Basaltic Flows (Pl.- H)
Caldera
Tepee Draw Tuff
Cinder Cones “Qc”
Southeast Cinder Cone Field
Lava Butte: Poster child of cone youth…
GEOMORPHIC ANALYSIS OFCINDER CONES
Time
Cinder Cone Morphology and Degradation Over Time
• Cone Relief Decreases• Cone Slope Decreases• Hco/Wco Ratio Decreases• Loss of Cater Definition• Increased Drainage Density
(Valentine et al., 2006)
S
Wcr
Hco
Wco
Wcr = crater diameterWco = cone basal diameterHco = cone heightS = average cone slope
MASS WASTING AND SLOPE WASH PROCESSES:Transfer primary cone mass to debris apron
(Dohrenwend et al., 1986)
Cone Alignment Via Fracture-Related Plumbing
km0 100
44N
122W120W
BR
HLPCR
TFZ
BFZ
WRFZ
1
8
5
7
6
Newberry: Junction of Tumalo-Brothers-Walker Rim Fault Zones
Rooney et al., 2011
Cinder Cone Research Questions
Are there morphologic groupings of ~400 cinder cones at Newberry? Can they be quantitatively documented?
Are morphologic groupings associated with age and state of erosional degradation?
Are there spatial patterns associated with the frequency, occurrence, and volume of cinder cones?
Are there spatial alignment patterns? Can they be statistically documented?
Do regional stress fields and fracture mechanics control the emplacement of cinder cones at Newberry volcano?O regon
S tudyArea
Basa lt and basa ltic andesite flows:ea rly P le istocene to H olocene
Rhyolite to dacite dom es, f low s, pum ice rings,and vent com p lexes: early P le is tocene toHo locene
Pum ice falls , ash flow s, and a lluv ial deposits:P leistocene to H olocene
Andesite T uff (w est f lank): P leis tocene
Black Lap illi Tuff (west flank): P leis tocene
Alluvial deposits w ith in terbedded lapilli tuff, ashflow tuff, and pum ice fall deposits: P leistocene
Tepee D raw T uff (east f lank): P le istocene
Basa lt and basa ltic andesite of sm a ll shields:P leistocene
F luvia l and lacustrine sedim ents: P le istoceneand P liocene(? )
Basa lt, basa ltic andesite , and andesite flow s, ashflow tuffs , and pum ice deposits o f the CascadeRange: P leis tocene
Basa lt f lows and inte rbedded cinders and scoriadeposits: late M iocene
Rhyolite and andesite flow s, dom es, andpyroclastic rocks of P ine M ounta in: earlyM iocene
Newberry C aldera com plex
Cinder cones and fissure ven ts
Faults
0 5 km
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)
USGS 10-m DEM vs. LIDAR 1-m DEM
Note: This study utilizes 10-m DEMs;LIDAR Updates In Progress
Single Cone DEM Example
Composite ConeDEM Example
(n = 182)(n = 165)
COMPOSITE
RESULTS OF MORPHOMETRIC ANALYSES – SINGLE CONES
Table 1. Explanation of Qualitative Cone Morphology Rating
1 Good-Excellent Cone shape with vent morphology2 Good Cone shape with less defined vent morphology3 Moderate-Good Cone shape, lacks well-defined vent morphology4 Moderate Cone shape, no vent5 Moderate-Poor Cone shape, poor definition6 Poor Lacks cone shape7 Very Poor Lacks cone shape, very poorly defined morphology
Single Cones (n=182)
0 500 m
Pum ice Butte(Cone M orphology Rating = 4)
Hunter Butte(Cone Morphology Rating = 7)
Lava Butte(Cone M orphology Rating = 1)
0 500 m
Pu mice B u tte(Co ne Mo rph olo gy R at ing = 4)
Hu nter Butte(C on e M or pho log y Rat in g = 7)
Lava B u tte(C on e Mo rph olog y R atin g = 1)
0 500 m
Pum ice Butte(Cone Morphology Rating = 4)
Hunter Butte(C one M orphology Rating = 7)
Lava B utte(Cone Morphology R ating = 1) 0 500 m
Pum ice B utte(C one M o rp ho log y R atin g = 4)
Hu nter B utte(C on e M o rp h olog y R atin g = 7)
L ava B utte(Co ne M orp holo gy Rat ing = 1 )
0 500 m
Pum ice Butte(Cone M orphology Rating = 4)
Hunter Butte(Cone Morphology Rating = 7)
Lava Butte(Cone Morphology Rating = 1)
0 500 m
Pum ice Bu tte(C one M or pho log y Rat in g = 4)
Hu nter B utte(C on e M o rp ho logy R atin g = 7)
Lava B utte(Co ne M orp holo gy Rat ing = 1)
n=182
Cone Morphology Class
No. Avg Slope (deg) Cone Height (m) Hco/Wco
Mean Variance Mean Variance Mean VarianceClass 1 11 19.9 11.8 132.4 1344.9 0.18 0.0012Class 2 21 18.2 10.5 124.4 2282.4 0.20 0.0073Class 3 10 18.1 2.7 126.2 1991.0 0.19 0.0017Class 4 35 14.9 12.1 76.2 1918.4 0.15 0.0014Class 5 35 14.4 10.6 78.1 1682.9 0.15 0.0012Class 6 11 11.9 13.7 59.5 1721.3 0.13 0.0025Class 7 59 10.2 19.0 50.4 1401.3 0.14 0.0046
All Cones 182 13.6 24.2 76.4 2520.7 0.2 0.0038
Table 2. Summary of Relevant Cone Morphometry Data.Cone Morphology Class
No. Avg Slope (deg) Cone Height (m) Hco/Wco
Mean Variance Mean Variance Mean VarianceClass 1 11 19.9 11.8 132.4 1344.9 0.18 0.0012Class 2 21 18.2 10.5 124.4 2282.4 0.20 0.0073Class 3 10 18.1 2.7 126.2 1991.0 0.19 0.0017Class 4 35 14.9 12.1 76.2 1918.4 0.15 0.0014Class 5 35 14.4 10.6 78.1 1682.9 0.15 0.0012Class 6 11 11.9 13.7 59.5 1721.3 0.13 0.0025Class 7 59 10.2 19.0 50.4 1401.3 0.14 0.0046
All Cones 182 13.6 24.2 76.4 2520.7 0.2 0.0038
Cone Morphology Class
No. Avg Slope (deg) Cone Height (m) Hco/Wco
Mean Variance Mean Variance Mean VarianceClass 1 11 19.9 11.8 132.4 1344.9 0.18 0.0012Class 2 21 18.2 10.5 124.4 2282.4 0.20 0.0073Class 3 10 18.1 2.7 126.2 1991.0 0.19 0.0017Class 4 35 14.9 12.1 76.2 1918.4 0.15 0.0014Class 5 35 14.4 10.6 78.1 1682.9 0.15 0.0012Class 6 11 11.9 13.7 59.5 1721.3 0.13 0.0025Class 7 59 10.2 19.0 50.4 1401.3 0.14 0.0046
All Cones 182 13.6 24.2 76.4 2520.7 0.2 0.0038
Table 2. Summary of Relevant Cone Morphometry Data.Single Cones
Cone Morphology Class
df t Stat P(T<=t) one-tail
t Critical one-tail
P(T<=t) two-tail
t Critical two-tail
Test Result Morphometric Group
Class 1-Class 2 30 0.05 1.38 0.089 1.70 0.177 2.04 Accept Ho Group IClass 2-Class 3 29 0.05 0.11 0.458 1.70 0.915 2.05 Accept Ho Group I
Savg Class 3-Class 4 43 0.05 2.85 0.003 1.68 0.007 2.02 Reject Ho Group IIClass 4-Class 5 44 0.05 0.36 0.360 1.68 0.719 2.02 Accept Ho Group IIClass 5-Class 6 44 0.05 2.05 0.023 1.68 0.046 2.02 Accept Ho Group IIClass 6-Class 7 92 0.05 1.88 0.032 1.66 0.064 1.99 Accept Ho Group IIClass 1-Class 2 30 0.05 0.49 0.315 1.70 0.631 2.04 Accept Ho Group IClass 2-Class 3 29 0.05 -0.10 0.459 1.70 0.918 2.05 Accept Ho Group I
Hco Class 3-Class 4 43 0.05 3.17 0.001 1.68 0.003 2.02 Reject Ho Group IIClass 4-Class 5 44 0.05 -0.13 0.450 1.68 0.899 2.02 Accept Ho Group IIClass 5-Class 6 44 0.05 1.30 0.100 1.68 0.200 2.02 Accept Ho Group IIClass 6-Class 7 92 0.05 1.09 0.140 1.66 0.280 1.99 Accept Ho Group IIClass 1-Class 2 30 0.05 -0.61 0.272 1.70 0.545 2.04 Accept Ho Group IClass 2-Class 3 29 0.05 0.40 0.346 1.70 0.692 2.05 Accept Ho Group I
Hco/Wco Class 3-Class 4 43 0.05 2.92 0.003 1.68 0.006 2.02 Reject Ho Group IIClass 4-Class 5 44 0.05 0.20 0.420 1.68 0.840 2.02 Accept Ho Group IIClass 5-Class 6 44 0.05 0.93 0.179 1.68 0.359 2.02 Accept Ho Group IIClass 6-Class 7 92 0.05 -0.39 0.349 1.66 0.697 1.99 Accept Ho Group II
Table 3. Results of Systematic T-Test Analyses.Cone Morphology Class
df t Stat P(T<=t) one-tail
t Critical one-tail
P(T<=t) two-tail
t Critical two-tail
Test Result Morphometric Group
Class 1-Class 2 30 0.05 1.38 0.089 1.70 0.177 2.04 Accept Ho Group IClass 2-Class 3 29 0.05 0.11 0.458 1.70 0.915 2.05 Accept Ho Group I
Savg Class 3-Class 4 43 0.05 2.85 0.003 1.68 0.007 2.02 Reject Ho Group IIClass 4-Class 5 44 0.05 0.36 0.360 1.68 0.719 2.02 Accept Ho Group IIClass 5-Class 6 44 0.05 2.05 0.023 1.68 0.046 2.02 Accept Ho Group IIClass 6-Class 7 92 0.05 1.88 0.032 1.66 0.064 1.99 Accept Ho Group IIClass 1-Class 2 30 0.05 0.49 0.315 1.70 0.631 2.04 Accept Ho Group IClass 2-Class 3 29 0.05 -0.10 0.459 1.70 0.918 2.05 Accept Ho Group I
Hco Class 3-Class 4 43 0.05 3.17 0.001 1.68 0.003 2.02 Reject Ho Group IIClass 4-Class 5 44 0.05 -0.13 0.450 1.68 0.899 2.02 Accept Ho Group IIClass 5-Class 6 44 0.05 1.30 0.100 1.68 0.200 2.02 Accept Ho Group IIClass 6-Class 7 92 0.05 1.09 0.140 1.66 0.280 1.99 Accept Ho Group IIClass 1-Class 2 30 0.05 -0.61 0.272 1.70 0.545 2.04 Accept Ho Group IClass 2-Class 3 29 0.05 0.40 0.346 1.70 0.692 2.05 Accept Ho Group I
Hco/Wco Class 3-Class 4 43 0.05 2.92 0.003 1.68 0.006 2.02 Reject Ho Group IIClass 4-Class 5 44 0.05 0.20 0.420 1.68 0.840 2.02 Accept Ho Group IIClass 5-Class 6 44 0.05 0.93 0.179 1.68 0.359 2.02 Accept Ho Group IIClass 6-Class 7 92 0.05 -0.39 0.349 1.66 0.697 1.99 Accept Ho Group II
Cone Morphology Class
df t Stat P(T<=t) one-tail
t Critical one-tail
P(T<=t) two-tail
t Critical two-tail
Test Result Morphometric Group
Class 1-Class 2 30 0.05 1.38 0.089 1.70 0.177 2.04 Accept Ho Group IClass 2-Class 3 29 0.05 0.11 0.458 1.70 0.915 2.05 Accept Ho Group I
Savg Class 3-Class 4 43 0.05 2.85 0.003 1.68 0.007 2.02 Reject Ho Group IIClass 4-Class 5 44 0.05 0.36 0.360 1.68 0.719 2.02 Accept Ho Group IIClass 5-Class 6 44 0.05 2.05 0.023 1.68 0.046 2.02 Accept Ho Group IIClass 6-Class 7 92 0.05 1.88 0.032 1.66 0.064 1.99 Accept Ho Group IIClass 1-Class 2 30 0.05 0.49 0.315 1.70 0.631 2.04 Accept Ho Group IClass 2-Class 3 29 0.05 -0.10 0.459 1.70 0.918 2.05 Accept Ho Group I
Hco Class 3-Class 4 43 0.05 3.17 0.001 1.68 0.003 2.02 Reject Ho Group IIClass 4-Class 5 44 0.05 -0.13 0.450 1.68 0.899 2.02 Accept Ho Group IIClass 5-Class 6 44 0.05 1.30 0.100 1.68 0.200 2.02 Accept Ho Group IIClass 6-Class 7 92 0.05 1.09 0.140 1.66 0.280 1.99 Accept Ho Group IIClass 1-Class 2 30 0.05 -0.61 0.272 1.70 0.545 2.04 Accept Ho Group IClass 2-Class 3 29 0.05 0.40 0.346 1.70 0.692 2.05 Accept Ho Group I
Hco/Wco Class 3-Class 4 43 0.05 2.92 0.003 1.68 0.006 2.02 Reject Ho Group IIClass 4-Class 5 44 0.05 0.20 0.420 1.68 0.840 2.02 Accept Ho Group IIClass 5-Class 6 44 0.05 0.93 0.179 1.68 0.359 2.02 Accept Ho Group IIClass 6-Class 7 92 0.05 -0.39 0.349 1.66 0.697 1.99 Accept Ho Group II
Table 3. Results of Systematic T-Test Analyses.Single Cones
Reject Ho
Reject Ho
Reject Ho
1 2 3 4 5 6 7
Con e M orpho logy Rating
0
5
10
15
20
25
30
Ave
rage
Con
e Sl
ope
(Deg
rees
)n = 11 n = 21
n = 10n = 59
n = 35n = 11
n = 35
Morphom etric Group I
Morphometric Group II
Standard DeviationRangeM ean
Single Cones
1 2 3 4 5 6 7
Cone M orphology Rating
0
50
100
150
200
250
Con
e H
eigh
t (m
eter
s)
Morphom etric Group I
Morphom etric Group II
n = 11 n = 21
n = 10n = 35
n = 11
n = 35 n = 59
Single Cones
1 2 3 4 5 6 7
Cone M orphology Rating
0
0.1
0.2
0.3
0.4
0.5
0.6
Con
e H
eigh
t / C
one
Wid
th
Morphom etric Group I
Morphom etric Group II
n = 11
n = 21
n = 10
n = 35
n = 11
n = 35
n = 59
Single Cones
NewberryCaldera
0 5 km
Moprhom etric Group I(M orphology RatingClasses 1, 2, and 3)
Morphom etric Group II(M orphology RatingClasses 4, 5, 6, and 7)
“Youthful”
“Mature”
Southern Domain
Group I: n = 16 (9%)Group II: n = 64 (35%)
Northern Domain
Group I: n = 26 (14%) Group II: n = 76 (42%)
Single Cones
Extent of Hypothesized Newberry Ice Cap (Donnelly-Nolan and Jensen, 2009)
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4 0 4 8 Kilometers
N
Caldera_lakes.shp# Composite_cones_no_ice.shp# Single_cones_no_ice.shp# Composite_cone_ice_cap.shp# Single_cones_ice_cap.shp
Ice_cap_limits.shpIce cap limitSingle cones within ice limitComposite cones within ice limitSingle cones outside ice limitComposite cones inside ice limit Caldera lakes
Cinder Cone Distribution Relative to Hypothesized Extent of Newberry Ice Cap
Cone Morphology Comparison Relative to Hypothesized Extent of Newberry Ice Cap
Avg. Cone Long Axis/Short Axis Ratio 1.30 1.35 No Significant Difference
VOLUMETRIC ANALYSES:SINGLE + COMPOSITE CONES
VOLUME METHODOLOGY
Clip cone footprint from 10-m USGS DEM (Rectangle 2x Cone Dimension)
Zero-mask cone elevations, based on mapped extent from MacLeod and others (1995)
Re-interpolate “beheaded” cone elevations using kriging algorithm
Cone Volume = (Cone Surface – Mask Surface)
0 500 m
B. Masked 10-m DEM of Lava Butte Cone
A. Original 10-m DEM of Lava Butte Cone
Original DEM ofLava Butte
Masked DEM ofLava Butte
CONE VOLUME SUMMARY(SINGLE AND COMPOSITE)
Cubic Meters
CONE ALIGNMENT ANALYSESSINGLE + COMPOSITE
km0 100
44N
122W120W
BR
HLPCR
TFZ
BFZ
WRFZ
1
8
5
7
6
- 9 0 - 6 0 - 3 0 0 3 0 6 0 9 00
1 0
2 0
3 0
- 9 0 - 6 0 - 3 0 0 3 0 6 0 9 0Azimuth
0
10
20
30
-90 -60 -30 0 30 60 900
10
20
30
Freq
uenc
y
Brothers Fault Zone
Tumalo Fault Zone
Walker Rim Fault Zone
n = 142
n = 92
n = 165
- 9 0 - 6 0 - 3 0 0 3 0 6 0 9 00
1 0
2 0
3 0
- 9 0 - 6 0 - 3 0 0 3 0 6 0 9 0Azimuth
0
10
20
30
-90 -60 -30 0 30 60 900
10
20
30
Freq
uenc
y
Brothers Fault Zone
Tumalo Fault Zone
Walker Rim Fault Zone
n = 142
n = 92
n = 165
n = 142
n = 92
n = 165
REGIONAL FAULT-TREND ANALYSIS
Cone lineaments anyone? Question: How many lines can be created by connecting the dots between 296 select cone center points?
Answer:
Total Lines = [n(n-1)]/2 = [296*295]/2 = 43,660 possible line combinations
Follow-up Question: Which cone lineaments are due to random chance and which are statistically and geologically significant?
Freq
uenc
y
Azimuth
Azimuth
Freq
uenc
y
METHODS OF CONE LINEAMENT ANALYSIS
“TWO-POINTMETHOD”
(Lutz, 1986)
GIS
“POINT-DENSITYMETHOD”(Zhang andLutz, 1989)
- 9 0 - 6 0 - 3 0 0 3 0 6 0 9 0Azimuth
0
1000
2000
3000
-90 -60 -30 0 30 60 900
1000
2000
-90 -60 -30 0 30 60 900
1000
2000
3000
Freq
uenc
yTwo-Point Azimuths: Newberry Cones(Combined North and South Dom ains)
Two-Point Azimuths: Random Simulation(Combined North and South Domains)
n = 2 9 6 c on esT ota l L ine S eg me nts = 4 3,6 60
n = 29 6 con es / Re plica teRe plic a te no . = 3 00Lin e Se gme n ts / R e plica te = 4 3,6 60
Normalized Newberry Two-Point Azimuths(Combined North and South Domains)
A.
B.
C.
95% Critical Value
- 9 0 - 6 0 - 3 0 0 3 0 6 0 9 0Azimuth
0
1000
2000
3000
-90 -60 -30 0 30 60 900
1000
2000
-90 -60 -30 0 30 60 900
1000
2000
3000
Freq
uenc
yTwo-Point Azimuths: Newberry Cones(Combined North and South Dom ains)
Two-Point Azimuths: Random Simulation(Combined North and South Domains)
n = 2 9 6 c on esT ota l L ine S eg me nts = 4 3,6 60
n = 29 6 con es / Re plica teRe plic a te no . = 3 00Lin e Se gme n ts / R e plica te = 4 3,6 60
Normalized Newberry Two-Point Azimuths(Combined North and South Domains)
A.
B.
C.
A.
B.
C.
95% Critical Value
Actual Two-Point Cone Azimuths
Random Two-Point Cone Azimuths
Normalized Two-Point Cone Azimuths
n = 296Line Segments = 43,660
n = 296 / replicateReplicates = 300
95% Critical Value
NORMALIZED ALIGNMENT FREQUENCY:FNORM = (FEXP / FAVG) * FOBS FNORM = normalized bin frequency FEXP = expected bin frequency FAVG = average random bin frequency FOBS = observed bin frequency
EXPECTED ALIGNMENT FREQUENCY:FEXP = (n*(n-1) / (2*k)) n = No. of Cinder Cones k = No. of Azimuthal Bins
CONE TWO-POINT ALIGNMENT ANALYSIS (after Lutz, 1986)
NULL HYPOTHESISDistribution of Actual Cone Alignments = Random Cone Alignments
CRITICAL VALUE:LI = [(FEXP / FAVG) * FAVG] + (tCRIT * RSTD) FEXP = expected bin frequency FAVG = average random bin frequency RSTD = stdev of random bin frequency tCRIT = t distribution ( = 0.05)
Two-Point Azimuths: Newberry Cones(North Dom ain)
Two-Point Azimuths: Random Simulation(North Dom ain)
n = 1 49 co ne sTo tal L ine S eg m e nts = 1 1,02 6
n = 14 9 co ne s / R ep lica teR ep lica te n o. = 3 0 0Lin e Se gm en ts / Re pli ca te = 11 ,02 6
Normalized Newberry Two-Point Azimuths(North Domain)
- 9 0 - 6 0 - 3 0 0 3 0 6 0 9 0Azim uth
0
500
-90 -60 -30 0 30 60 900
500
Freq
uenc
y
- 9 0 - 6 0 - 3 0 0 3 0 6 0 9 00
5 0 0
A.
B.
C.
95% Critical Value
Two-Point Azimuths: Newberry Cones(North Dom ain)
Two-Point Azimuths: Random Simulation(North Dom ain)
n = 1 49 co ne sTo tal L ine S eg m e nts = 1 1,02 6
n = 14 9 co ne s / R ep lica teR ep lica te n o. = 3 0 0Lin e Se gm en ts / Re pli ca te = 11 ,02 6
Normalized Newberry Two-Point Azimuths(North Domain)
- 9 0 - 6 0 - 3 0 0 3 0 6 0 9 0Azim uth
0
500
-90 -60 -30 0 30 60 900
500
Freq
uenc
y
- 9 0 - 6 0 - 3 0 0 3 0 6 0 9 00
5 0 0
A.
B.
C.
95% Critical Value
- 9 0 - 6 0 - 3 0 0 3 0 6 0 9 00
2 0 0
4 0 0
6 0 0
- 9 0 - 6 0 - 3 0 0 3 0 6 0 9 0Azim uth
0
200
400
600
-90 -60 -30 0 30 60 900
200
400
600
Freq
uenc
yTwo-Point Azimuths: Newberry Cones(South Domain)
Two-Point Azimuths: Random Simulation(South Domain)
n = 14 7 co ne sTo ta l Lin e Se gm en ts = 10 ,7 3 1
n = 1 47 co ne s / R ep licateR e plicate no . = 30 0L ine Seg me nts / R ep licate = 10 ,73 1
Normalized Newberry Two-Point Azimuths(South Domain)
A.
B.
C.
95% Critical Value
- 9 0 - 6 0 - 3 0 0 3 0 6 0 9 00
2 0 0
4 0 0
6 0 0
- 9 0 - 6 0 - 3 0 0 3 0 6 0 9 0Azim uth
0
200
400
600
-90 -60 -30 0 30 60 900
200
400
600
Freq
uenc
yTwo-Point Azimuths: Newberry Cones(South Domain)
Two-Point Azimuths: Random Simulation(South Domain)
n = 14 7 co ne sTo ta l Lin e Se gm en ts = 10 ,7 3 1
n = 1 47 co ne s / R ep licateR e plicate no . = 30 0L ine Seg me nts / R ep licate = 10 ,73 1
Normalized Newberry Two-Point Azimuths(South Domain)
A.
B.
C.
95% Critical Value95% Critical Value95% Critical Value
n = 147 conesLine Segments = 10,731
n = 147 / replicateReplicates = 300
n = 149 conesLine Segments = 11,026
n = 149 / replicateReplicates = 300
TWO-POINT ANALYSIS RESULTSNORTH DOMAIN SOUTH DOMAIN
1-km wide filter strips with 50% overlap
Filter strip-sets rotated at 5-degree azimuth increments
Tally total number of cones / strip / azimuth bin
Calculate cone density per unit area
Compare actual densities to random (replicates = 50)
Normalize Cone Densities: D = (d – M) / S D = normalized cone density d = actual cone density (no. / sq. km) M = average density of random points (n = 50 reps) S = random standard deviation
Significant cone lineaments = >2-3 STDEV above random
POINT-DENSITY METHOD(Zhang and Lutz, 1989)
0 1 0 km
TumaloFaultZone
BrothersFaultZone
10 20
n = 142
Comparison of Fault Trends andCinder Cone Lineaments at
Newberry Volcano
10 20
n = 9 2
10 20
n = 1 65
Walker RimFaultZone
C in d er c on e lo ca tio n
C o n e l in e am e nt d eter m in ed b yM on te C a rlo po in t -d en sity m eth o do f Z h an g an d L u tz (19 89 )
TFZ
BFZ
M is singW R FZ ?
Cinder C one Linea ments(Critica l L-value >2 SD )
n = 87
5
SUMMARY AND CONCLUSION
I. CONE MORPHOLOGY
• Degradation Models Through Time (Dohrenwend and others, 1986)
Diffusive mass wasting processes Mass transfer: primary cone slope to debris apron Reduction of cone height and slope Loss of crater definition
• Newberry Results (Taylor and others, 2003)
Group I Cones: Avg. Slope = 19-20o; Avg. Relief = 125 m; Avg. Hc/Wc = 0.19
Group II Cones: Avg. Slope = 11-15o; Avg. Relief = 65 m; Avg. Hc/Wc = 0.14
Group I = “Youthful”; more abundant in northern domain Group II = “Mature”; common in northern and southern domains
Possible controlling factors include: degradation processes, age differences, climate, post-eruption cone burial, lava composition, and episodic (polygenetic) eruption cycles
II. CONE VOLUME RESULTS
• Newberry cone-volume maxima align NW-SE with the Tumalo fault zone; implies structure has an important control on eruptive process
III. CONE ALIGNMENT PATTERNS
• Newberry cones align with Brothers and Tumalo fault zones• Poor alignment correlation with Walker Rim fault zone• Other significant cone alignment azimuths: 10-35o, 80o, and 280-
295o • Results suggest additional control by unmapped structural
conditions
• Cone-alignment and volume-distribution studies suggest that the Tumalo Fault Zone is a dominant structural control on magma emplacement at Newberry Volcano
IV. CONCLUDING STATEMENTS
• This study provides a preliminary framework to guide future geomorphic and geochemical analyses of Newberry cinder
cones
• This study provides a preliminary framework from which to pose additional questions regarding the complex interaction between stress regime, volcanism, and faulting in central Oregon
ACKNOWLEDGMENTSFunding Sources:
Western Oregon University Faculty Development FundCascades Volcano Association
WOU Research Assistants and ES407 Senior Seminar Students:Jeff Budnick, Chandra Drury, Jamie Fisher, Tony FalettiDenise Giles, Diane Hale, Diane Horvath, Katie Noll, RachelPirot, Summer Runyan, Ryan Adams, Sandy Biester, Jody
Becker, Kelsii Dana, Bill Vreeland, Dan Dzieken, Rick Fletcher