ES 290C
Origin and effects of the Yellowstone hotspot:
A case study involving many disciplines
1st Seminar, 4/10/06:
Hotspots, Large Igneous Provinces, and the Plume Hypothesis
J. Tuzo Wilson
1908-1003
Throughout his career Wilson
enjoyed travelling to unusual and
remote places. In the mid-1930s,
for example, when he was a
doctoral student at Princeton
University, he took time to become
the first person known to have
scaled Mount Hague (12,328 ft.) in
Montana. When he was in Moscow
in the summer of 1958 for the final
meeting of the special committee
which had organized the
International Geophysical Year, he
decided to travel to Beijing by the
Trans-Siberian Railway. This led to
his publication of One Chinese
Moon (1959), IGY, The Year of the
New Moons (1961), and Unglazed
China (1973)
Wilson: Hotspots and Bilateral Volcanic Chains
Hotspots - Flood Basalts - Continental Rifting
Hotspots and Hawaiian Island Type Chains
Wilson, Nature 1963
Wilson, Nature 1963
Wilson, Nature 1963
Hawaiian - Emperor Seamount Chain
Bend indicates change in Pacific plate movement over a hotspot(?)
W. Jason Morgan
Georgia Tech, B.S. 1957
Princeton, PhD 1964 Physics
*Put Wilson’s tectonics on a sphere
*Ascribed hotspot tracks to plumes
*Proposed plumes drive the plates
*Advocated relative fixity of hotspots
Aulacogens
Burke, 1977,
Ann. Rev. Earth Planet. Sci.
5, 371-396
Figure 1 The sequence of swell, rift, continental
rupture, and collision in aulacogen formation. A
swell within a continent (top lefti is crested with
volcanoes from which lavas flow and evolves
into a three-rift system (upper right) with
volcanoes, sediment fill (stippled), and axial
dikes. Two of the rifts develop to a continental
margin (lower left) and ocean (striped) forms on
their sites. A miogeoclinal wedge (stippled) is
deposited along the continental margin and a
delta progrades down the failed rift to lie on
ocean floor. Later (bottom right) another
continent crosses the closing ocean and two
continents collide. Rocks of the miogeoclinal
wedge are thrust onto the continents and eroded
by a river flowing down the aulacogen in the
reversed direction. A suture zone (vertical black
lines) marks th~ former site of the ocean and
igneous rocks develop in the thickened continent
on one side.
Aulacogens
Burke, 1977,
Ann. Rev. Earth Planet. Sci.
5, 371-396
To test if hotspots fixed relative to each other
1. Dated hotspot tracks on one plate, that have been used to derive a set of
rotations describing the relative motion of the hotspot reference frame with
respect to this plate. For example, for Africa we could use the dated tracks of the
Walvis Ridge (from the Tristan da Cunha hotspot) and other hotspots in the South
Atlantic Ocean to obtain a set of rotations describing the motion of the Africa
plate with respect to the hotspots through time.
2. A set of rotations describing the relative motion of the hotspots with respect to
another plate. For example, for the Pacific we could use the dated tracks of the
Hawaiian-Emperor chain and the Louisville Ridge.
3. A knowledge of the past relative motions of the same two plates, derived from
marine magnetic anomalies and fracture zone trends, and expressed as a set of
rotations of one plate relative to another plate.
On the uncertainties in hot spot reconstructions and the significance of moving hot spot
reference frames
O’Neill, Muller, Steinberger, 2005, Geochem. Geophys. Geosyst., 6, Q04003, doi:10.1029/2004GC000784.
Figure 4. Gravity map of the South Atlantic [Sandwell and Smith, 1997] showing the Walvis
Ridge and Rio Grande Rise hot spot system. Radiometric ages for the ridge system are
shown, as listed in Table 1. Rio Grande Rise and bracketed sample number are from
O’Connor and Duncan [1990]; Gough lineament data are from O’Connor and le Roex
[1992]. A variety of sources concur on the age of the Parana and Etendeka volcanics
[Deckart et al., 1998; Morgan, 1971; O’Connor and Duncan, 1990; Renne et al., 1996a,
Figure 5. Gravity map [from Sandwell and Smith, 1997] of the St. Helena hot spot
system. AC-series radiometric dates are from O’Connor and le Roex [1992]; all other
dates are from O’Connor et al. [1999].
Figure 6. Gravity map [from Sandwell and Smith, 1997] of the Great Meteor hot spot system. Radiometric dates
for the New England seamounts are from Duncan [1984]. An age progression from the New England
seamounts to the Corner seamounts and the Great Meteor group has been shown by Tucholke and Smoot
[1990] on the basis of seamount subsidence curves. Ages for White Mountains and Monteregian Hills are given
by Gilbert and Foland [1986].
Figure 7. Gravity map of the Reunion hot spot system
Figure 8. Gravity map of the Kerguelen hot spot
system.
Fig. 13b. Predicted tracks of our fixed (brown) and moving (colored circles) hot spot reconstructions for
the African plate at 10 Myr intervals. The fixed model has difficulty fitting the Ninetyeast Ridge and
New England seamount chain for older times. Assumed present position of hot spots shown as blue
crosses. Also shown are the predicted tracks of Muller et al. [1993] (red lines) at 10 Myr intervals for
our assumed present-day positions.
Large Igneous Provinces
Wall of Dry Falls (about 200 m high), Grand Coulee gorge, Washington, USA,
in the mid-Miocene Columbia River flood basalt province, showing a
section through four pahoehoe lava flow fields (1–4), each the product of a
huge-volume eruption of >1000 km3 of lava. Photo by Self.
Steens Mountain basalt flows, SE Oregon
A flow of the North Atlantic LIP, Hebrides (Fingal’s Cave)
Deccan Traps, 65 Ma Continental Flood Basalt
Fig. 1. Distribution of the 49 hotspots (black circles) from the catalogue used in this paper
[6,11,12] superimposed on a section at (a) 500 km and (b) 2850 km depths through
Ritsema et al.’s tomographic model for shear wave velocity (VS) [25]. Color code from
32% (red hues) to +2% (blue hues) velocity variation. The seven ‘primary’ hotspots
outlined in this paper are shown as red circles with the first letter of their name indicated
Predicted Plume Uplift
Uplift above a plume head, as predicted by Griffiths and Campbell (1991), compared with the
uplift observed at the centre of the Emeishan flood basalt (shown in pink) by He et al. (2003).
The timing and uplift shape predicted by Farnetani and Richards (1994) is similar, but they
predict more uplift because they model a plume head with a higher excess temperature:
350°C as opposed to 100°C. Predicted profiles are given for maximum uplift (t = 0), when the
top of the plume is at a depth of ~250 km, and 2 Myr later (t = 2 Myr), when flattening of the
head is essentially complete. The uplift for the Emeishan flood basalt province is the minimum
average value for the inner and intermediate zones as determined from the depth of erosion
of the underlying carbonate rocks. (Campbell, 2005, Elements)
Bryce, DePaolo, Lassiter, 2005: Hawaiian plume structure, G-cubed 6 (9), 10.1029/2004GC00
Figure 21. Schematic model of the
Hawaiian plume. The central core zone
of the plume is inferred to come from
either the core-mantle boundary or is a
tendril of a basal dense layer that is
entrained by the plume along its axis.
The material in the plume core is highly
heterogeneous, containing materials
that appear to be recycled oceanic
crust as well as material that could be
regarded as approximating ‘‘primitive.’’
An essential aspect of the plume core
mantle is that the character of what is
being melted under the volcanoes
changes with time. The plume material
that is just outside the plume core,
which is referred to in the text as the
‘‘outer core’’ of the plume, is less
heterogeneous than the plume core but
still distinct from the ambient upper
mantle. High 3He/4He is found only in
the plume ‘‘core zone;’’ high 87Sr/86Sr
is found in both the plume core and
‘‘outer core’’ zones.
Figure 1. Vertical section across three-dimensional plumes. (a) Early
stage, (b) formation of a spherical head, (c) large head reaches the
lithosphere, (d) 30 My after, the plume is sheared by the left moving
oceanic lithosphere. (e) Early stage, (f) formation of a ‘spout’, (g) only
a ‘tail’ of plume material reaches the lithosphere, (h) 30 My after.
(i) Horizontal section across a plume tail. Excess potential temperature
contours each 50C (bold +100C, +200C). To visualize the material that
constitutes the plume tail we advect distinct packs of tracers. The initial
pack’s shape (a cube) and dimension (400 km size) are arbitrary, their
horizontal position is indicated in the insert, each color corresponds to a
pack. The hottest part of the plume tail is made of deep material with a
highly irregular, not concentric distribution. (j) Deep mantle
heterogeneities rise like distinct filaments in the plume tail and are
sheared by left moving oceanic lithosphere.