columbia river basalt flows icing the cake. volcanic episodes 65 55 45 35 25 15 0 5 age (myrs)...
Post on 15-Jan-2016
215 views
TRANSCRIPT
Columbia River Basalt Flows
Icing the Cake
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Volcanic Episodes
65
55
45
35
25
15
0
5
Age (Myrs)
WesternCascade Arc(37-15 Myrs)
Challis Arc(55-42 Myrs)
High Cascade Arc(5-0 Myrs)
Columbia River Basalts(17-6 Myrs,Most 17-14 Myrs)
Yellowstone Hot Spot(14-0 Myrs)
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Large Igneous Provinces (LIPs)
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Flood basalt Age Volume (mi3 (km3))
Siberian Traps 250 Myrs 950,000 (4,000,000)
Deccan Traps 66 Myrs 475,000 (2,000,000)
CRBs/Steens Mt. 17-6 Myrs 60,000 (250,000)
Columbia River Basalts (CRBs)
F-1
Just the Facts:• 17.5-6 Myrs old
(mostly 16.5-14.5 Myrs)• Over 300 lava flows• Covers 63,200 mi2
(164,000 km2)• Volume = 41,600 mi3
(171,000 km3)
CRB Landmarks
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Haystack Rock, Cannon Beach
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Beacon Rock, Columbia Gorge
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Multnomah Falls
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Dry Falls
Palouse Falls
Relative Volume of the CRBs
Columbia RiverBasalts
(41,600 mi2) YellowstoneEruptions
Tambora, 1815
Krakatoa, 1883
Mt. St. Helens, 1980Crater Lake, 7,000 yrs ago
Mt. Pinatubo, 1991
Basalt Thickness QuickTime™ and a
TIFF (Uncompressed) decompressorare needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture. Thickness ofWanapum Formation
Divided into Four Main Formations(Based on chemistry, age, paleomagnetics)
All Basalts
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
F-6Age (Myr)
Formation Member # of FLows
Area (mi2)
Volume (mi3)
6
Saddle
Mountain
Lower Monumental 1 170 4
8.5 Ice Harbor 4 830 18
Buford 1 220 5
10.5 Elephant Mtn 2 5,190 105
12 Pamona 1 8,710 180
Esquatzel 1 1,050 17
Weissenfels Ridge 4 470 5
13 Asotin 1 2,490 53
Wilber Creek 2 1,190 17
13.5 Umatilla 2 5,830 170
TOTAL 19 11,800 574
14.5
Wanapum
Priest Rapids 3 22,120 670
Roza 4 15,580 310
15.3 Frenchman Springs 21 26,930 1,540
Eckler Mtn 8 2,350 41
TOTAL 36 37,050 2,561
15.7-15.6
Grande Ronde
7 members (N) 33 44,190 6,690
15.9-15.7 4 members (R) 45 45,450 12,740
16-15.9 2 members (N) 15 39,510 7,530
16.5-16 4 members (R) 27 37,320 8,680
TOTAL 120 57,530 35,640
17.5-17 Imnaha ? Members 26 19,380 2,280
GRAND TOTAL 311 63,200 41,588
6%
86%
7%
1%
Eruptions mostly
finished by14.5 Myrs
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Imnaha Basalts(17.5-17 Mys)
F-7
Grande Ronde Basalts(16.5-15.6 Mys)
F-7
Wanapum Basalts(15.3-14.5 Mys)
F-8
Roza Member Volume
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Roza Member(Wanapum Basalts)1300 km3 / 5-15 yrs
Mauna Loa1859 Eruption0.27 km3 / 10 months
Laki (Iceland)1783 Eruption14.7 km3 / 8 months
Hawaii1986-92 Eruption0.5 km3 / 6 yrs
One Flow in the Roza Member
Volume: 700 km3
Time: 7 daysVelocity: 5-15 km/hrFissure Length: >100 kmRate: 100 km3 per day(1 km3 per day per km of fissure)
For Comparison - 1 Hawaiin Flow(0.001 km3 per day per km of fissure)
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Saddle Mountain Basalts(13-6 Mys)
F-8
Other Flows - Part of CRB’s?Picture Gorge & Steens Mtn Basalts
F-8
Steens Mtn (16.5-15 Myrs)
CRB “Feeder Dikes”F-7
Grande Ronde Feeder Dike
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Photo by Vic Camp
Over 300 Basalt Flows
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Flow AnatomyQuickTime™ and a
TIFF (Uncompressed) decompressorare needed to see this picture.
Vesicular Top
Upper Colonnade(not shown)
Entablature
Pillows(if it flowed into water)
Main Colonnade
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Flow AnatomyVesicular Top
Upper Colonnade(not shown)
Entablature
Pillows(if it flowed into water)
Main Colonnade
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Flow Anatomy
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Vesicular Top
Upper Colonnade
Entablature
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Main Colonnade (below pictue)