Transcript Chapter 8: Major Elements

Geology of the Walla Walla Area
The French use the term “Terroir” to describe the
complex interplay of temperature, sunshine, rainfall,
soil, bedrock, viticultural practice, and other physical
factors that influence the character and quality of wine
Dr. John D Winter
Department of Geology
Defined by elevation contour on S and E, and by lines
approximating drainage divide on the N
Revised effective April 27, 2001
VAs defined by US Bureau of Alcohol, Tobacco, and
Firearms- define by geography
Appelations of France defined in terms of wine
characteristics
The Modern Plates
Three types of plate boundaries
Three types of plate boundaries
Age of the ocean crust
Hot Spots
Hot Spots
Convergent
boundary
Three sub-types
 Ocean-Continent
 Ocean-Ocean
 Continent-Continent
Can you name an
example of each?
Plate Tectonics in the Pacific Northwest
Igneous Processes
The Edge of the
North American
Craton
Mantle has low Rb which 
87Sr over time, so low 87/
86
Old continental crust has high
Rb so high 87/86
Terranes of NE Oregon
Terranes of NE Oregon
Terranes of NE Oregon
Terranes of
NE Oregon
Filling of the
Columbia
Embayment
Westward roll-back of
subduction
Fills Columbia Embayment
Stabilized near present
location for ~ 40 Ma
Cascade range:
Uplift affects climate on east
side
Volcanoes supply ash to
winds and area
The Columbia River Basalts
Table 15-1. Major Flood Basalt Provinces
Name
Volume
5
3
Age
Locality
CRB
(1.7x10 km )
Miocene
NW US
Keeweenawan
(4x105 km3)
Precambrian
Superior area
Deccan
(106 km3)
Cret.-Eocene
India
Parana
(area > 106 km2 ) early Cret.
Karroo
(2x106 km3?)
Brazil
early Jurassic S. Africa
The Columbia River Basalts
The Columbia River Basalts
Aerial extent of the N2 Grande Ronde flow unit (approximately 21 flows).
The Columbia River Basalts
Location of the exposed feeder dikes
red) and vents (blue V's) of the
southeastern portion of the
Columbia River Basalts.
CRBs probably result from SRPYellowstone hot-spot- difficult to
explain northward deflection
WW
The Columbia River Basalts
Basalts yield
excellent soils in
Hawaii and other
tropical areas where
rainfall is high and
the climate is warm
Our soils in WW are
not derived from the
underlying basaltsan unusual feature
Continental Glaciation
~ 125,000 until 13,000 years ago
Continental Glaciation
Wind-blown Loess deposits
Continental Glaciation
Wind-blown Loess deposits
Palouse Hills to north of WW: > 10,000 km2 and up to 75m thick (depends
on sub-loess topography)
The Great Floods
~ 12,000 years ago
Ice dam founders and releases up to 2500 km3 of water out across the plateau
The Great Floods
~ 12,000 years ago
J Harlan Bretz in 1930’s- a
controversial proposal
The Great Floods
~ 12,000 years ago
The Great Floods
~ 12,000 years ago
The Great Floods
~ 12,000 years ago- Burlingame Canyon
Suggests up to 90 individual floods
WW received silts as “slackwater” deposits
Sediments range from gravels near Wallula to
massive silts and sands toward Blue Mts
Winds continue to redistribute loess, silts, ash, etc.
Uplift of Blue Mts.
Erosion by river system
Mill Creek, Cottonwood, Birch Creek...Walla Walla River
Valley erosion in Blues  floodplain sediments in WW valley
Walla Walla River Floodplain
Note Horse Heaven Hills- anticline of folded CRBs
Surface geological units
Note old WWVA boundaries- pre-2000 vineyards are in black
Strong correlation between units and elevation (also
climate)
Basalts at highest elevations and where erosion exposes them
Loess at higher elevations than slackwater deposits (north and
on Blues-Horse Heaven Hills)- mostly silt
Slackwater deposits: mostly sand and silt in WWVA
Loess and slackwater silts are glacial- derived from Canadaqtz-feldspar..not basaltic
Floodplain at lowest elevation-locally cobbles, gravel, sand,
silt, clay- highly variable
From Meinert and Busacca, 2000.
Geoscience Canada, 27, 149-170.
Soil textural classes
WW very low in clay except in some
areas of the WW River floodplain
Soil Types
~75 soil types in WW Soil Survey, can lump into ~8 groups (remember strong
elevation-rainfall gradient too)
1- Cobble-loam-silt of floodplains and terraces of WW River and tributaries: long
used for orchards- most vineyards now on the terraces with thin loess
Well-drained, and low organics- permits good control of grape vigor by
management of water and nutrients
2- Loamy to silty in same floodplain-terrace areas
Poorly-drained, saline and alkaline- good for onions- Three Rivers on a welldrained terrace close to these
3- Loess over slackwater deposits on dissected terraces and uplands
Well-drained and silty Woodward Canyon Vineyard
Where loess thin (<60 cm) and low elevation cost of water may be a problem
4- Similar to 3- Loess over slackwater on dissected terraces
Silty, uniform, low to mod organic matter- extensive vineyards
5- Excessively drained sandy soils of dunes with < 30 cm/yr rain some juice grapes
6- Silty soils of deep loess on uplands 20-38 cm/yr rainfall
7- Silty soils of deep loess on uplands 38-58 cm/yr rainfall- more organics
8- Loamy to cobbly well-drained soils on steep mountain slopes- Figgins Mill Creek
Upland Vineyard is only one yet
From Meinert and Busacca, 2000.
Geoscience Canada, 27, 149-170.
Wind and rainfall patterns
From Meinert and Busacca, 2000.
Geoscience Canada, 27, 149-170.
SW-NE Cross Section
WW vineyards on four fundamentally different substrates:From
slackwater
terrace,
loess,
Meinert and
Busacca,
2000.
river gravel, and floodplain silt
Geoscience Canada, 27, 149-170.
Majority are in loess, either thick over basalt or thin over slackwater silts (which in
turn are on basalt)
Again, well-drained silts with low organics allow the vintner to manage moisture and
nutrients
Overly fertile floodplain soils develop strong vegetal flavors
Good slopes allow good airflow too- colder air sinks away so fewer frost problems
Cristophe Baron’s Caillouxe – searched with Kevin Pogue for very cobbly floodplain
area- Forces roots deep, heated cobbles radiate, calcic soils stress vines combine to > very concentrated fruit
Some Examples
From Meinert and Busacca, 2000.
Geoscience Canada, 27, 149-170.
Examples
Pepper Bridge cabernet on thin loess
Vineyard-covered “island” of slackwater
deposits on WW River floodplain
Cottonwood Creek vineyard chardonnay
grapes on floodplain silts over gravel
From Meinert and Busacca, 2000.
Geoscience Canada, 27, 149-170.
Examples
Caillouxe vineyard syrah on floodplain
gravels. E shows trench and deep roots.
From Meinert and Busacca, 2000.
Geoscience Canada, 27, 149-170.
Examples
Generalizations:
Low-precipitation during growing season, low organics, well-drained silts
allows the vintner to control moisture and nutrients to develop vigor and
complexity (and yield)
Highest quality vineyards lower their yield to 2-3 tons/acre (compared to 4-5
Seventon
Hills
on 2 meters
of loess (over
statewide
average)
Canyon-bottom floodplain soils are
slackwater deposits)
for fruity
wines,
such as
W  E variation in elevation & rainfall, plusbetter
variations
in soils,
drainage,
Biscuit Ridge
Gewurtztraminer)
organic content, water table level of loess, slackwater
deposits,
floodplain 
Rich diversity of Terroirs
Latitude affects summer sunlight and temperatures (day and night)
Mill Creek Upland vineyard tries
out the higher-elevation loess
Unique geological and soil features in WW suggest that our wines “may develop
flavor and quality characteristics that set them apart from other wine-producing
From Meinert and Busacca, 2000.
areas”
Geoscience Canada, 27, 149-170.