morphology and spatial distribution of cinder cones at newberry volcano, oregon: implications for...

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)

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



All Cones 182 13.6 24.2 76.4 2520.7 0.2 0.0038




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


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


t Critical one-tail

P(T<=t) two-tail

t Critical two-tail








t Critical one-tail

P(T<=t) two-tail

t Critical two-tail






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 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 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)

##

#

#

#

###

##

#

# # ##

###

# #

# #### #

##

#

#

#

#

####

#

##

#

# ## # ### #

##

# # #

###

### #

##

##

##

##

##

##

#

#

#

####

#

#

###

##

###

##

#

##

#

#

# ##

##

#

#

#

##

##

##

# #

##

##

# ## # #

#

### #

#

#

#

##

#

#

#

#

###

# ##

###

# #

#

###

##### #

##

##

##

# ###

####

# ## #

#

##

# ##

## #

#

# # #

##

#######

### #

#

## # #

##

# ##

#

#

#

#

#

#

#

#

#

######

#

#

#

#

##

##

##

#####

#

####

##

##

##

#

##

##

##

#######

#####

# #

#####

#

###

###

# ##

## ##

###

###

# #

#

####

##

#

#

#

#

## ####

##

###

#

#####

## #

## # # #

##

# ##

# ##

###

###

# #

####

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 = 149 conesLine Segments = 11,026


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

morphology and spatial distribution of cinder cones at newberry volcano, oregon: implications for...

Documents

cinder cone volume

cone heights

cinder cone research

cinder cone morphometry

volume of cinder cones

emplacement of cinder

cone basal diameterhco

average cone slopemass