The Yellowstone Magmatic System from the Mantle Plume to the Upper Crust Hsin-Hua Huang, Fan-Chi Lin, Brandon Schmandt, Jamie Farrell, Robert B. Smith, Victor C. Tsai

The Yellowstone Magmatic System from the Mantle Plume to the Upper Crust Hsin-Hua Huang, Fan-Chi Lin, Brandon Schmandt, Jamie Farrell, Robert B. Smith, Victor C. Tsai PDF Author: Hsin-Hua Huang
Publisher:
ISBN:
Category : Snake River Plain (Idaho and Or.)
Languages : en
Pages : 4

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Book Description
The Yellowstone supervolcano is one of the largest active continental silicic volcanic fields in the world. An understanding of its properties is key to enhancing our knowledge of volcanic mechanisms and corresponding risk. Using a joint local and teleseismic earthquake P-wave seismic inversion, we revealed a basaltic lower-crustal magma body that provides a magmatic link between the Yellowstone mantle plume and the previously imaged upper-crustal magma reservoir. This lower-crustal magma body has a volume of 46,000 cubic kilometers, ~4.5 times that of the upper-crustal magma reservoir, and contains a melt fraction of ~2%. These estimates are critical to understanding the evolution of bimodal basaltic-rhyolitic volcanism, explaining the magnitude of CO2 discharge, and constraining dynamic models of the magmatic system for volcanic hazard assessment.

The Yellowstone Magmatic System from the Mantle Plume to the Upper Crust Hsin-Hua Huang, Fan-Chi Lin, Brandon Schmandt, Jamie Farrell, Robert B. Smith, Victor C. Tsai

The Yellowstone Magmatic System from the Mantle Plume to the Upper Crust Hsin-Hua Huang, Fan-Chi Lin, Brandon Schmandt, Jamie Farrell, Robert B. Smith, Victor C. Tsai PDF Author: Hsin-Hua Huang
Publisher:
ISBN:
Category : Snake River Plain (Idaho and Or.)
Languages : en
Pages : 4

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Book Description
The Yellowstone supervolcano is one of the largest active continental silicic volcanic fields in the world. An understanding of its properties is key to enhancing our knowledge of volcanic mechanisms and corresponding risk. Using a joint local and teleseismic earthquake P-wave seismic inversion, we revealed a basaltic lower-crustal magma body that provides a magmatic link between the Yellowstone mantle plume and the previously imaged upper-crustal magma reservoir. This lower-crustal magma body has a volume of 46,000 cubic kilometers, ~4.5 times that of the upper-crustal magma reservoir, and contains a melt fraction of ~2%. These estimates are critical to understanding the evolution of bimodal basaltic-rhyolitic volcanism, explaining the magnitude of CO2 discharge, and constraining dynamic models of the magmatic system for volcanic hazard assessment.

Scientists See Deeper Yellowstone Magma

Scientists See Deeper Yellowstone Magma PDF Author: Fan-Chi Lin
Publisher:
ISBN:
Category :
Languages : en
Pages : 4

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Beneath Yellowstone

Beneath Yellowstone PDF Author: Eugene D. Humphreys
Publisher:
ISBN:
Category : Geology, Structural
Languages : en
Pages : 7

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The Yellowstone Hotspot

The Yellowstone Hotspot PDF Author: Robert Baer Smith
Publisher:
ISBN:
Category : Calderas
Languages : en
Pages : 122

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Book Description
Direct evidence for a plume-plate interaction as the mechanism responsible for the Yellowstone-Snake River Plain (YSRP), 16 Ma volcanic system is observation of a linear age-progression of silicic volcanic centers along the Snake River Plain 800 km to the Yellowstone caldera-- the track of the Yellowston hotspot. Caldera-forming rhyolitic volcanism, active crustal deformation, extremely high heat flow (30 times the continental average), and intensive earthquake activity in Yellowstone National Park mark the surface manifestations of the hotspot. Anomalously low, P-wave velocities in the upper-crust of the Yellowstone caldera are interpreted as solidified but still hot granitic rocks, partial melts, hydrothermal fluids and sediments. Unprecedented deformation of the Yellowstone caldera of up to 1 m of uplift from 1923 to 1984, followed by subsidence of as much as ~12 cm from 1985 to 1991, clearly reflects a giant caldera unrest. The regional signature of the Yellowstone hotspot is highlighted by an anomalous, 600 m high, topographic bulge centered on the caldera and that extends across a ~600 km-wide region. We suggest that this feature reflecs long-wavelength tumescence of the hotspot. Yellowstone is also the center of a +20 m geoid anomaly, the largest in North America, and extends ~500 km laterally from the caldera, similar in width to the geoid anomalies of many oceanic hotspots and swells. The 16 Ma trace of the Yellowstone hotspot, the seismically quiescent Snake River Plain, is surrounded by "bow-wave" or parabolic shaped regions of earthquakes and high topography. Whereas systematic topographic decay along the Snake River Plain, totaling 1,300 m, fits a model of lithospheric cooling and subsidence which is consistent with passage of the North American plate across a mantle heat source. We note that the rate of 4.5 cm/yr silicic, volcanic age progression of the YSRP includes a component of southwest motion of the North American plate, modeled at ~2.5 cm/yr, and a component of concomitant crustal extension estimated to be 1 to 2 cm/yr. The USRP also exhibits anomalous crustal structure which we believe is inherited from magmatic and thermal processes associated which the Yellowstone hotspot. This includes a thin, 2-5 km-thick surface layer compses of basalts and rhyolites and an unusually high-velocity, 6.5 km/s, mid-crustal mafic layer that we suggest reflects extinct "Yellowstone" magma systems that have replaced much of the normal granite upper-crust. Direct evidence for a mantle connection for the YSRP system is from anomalously low, P-wave velocities which extend from the crust to depths of ~200km. These properties and the kinematics of teh YSRP are consistent with an analytic model for plume-plate interaction that produces a "bow-wave" or parabolic patter of upper-mantle flow southwesterly from the hotspot, similar to the systematic patterns of regional topography and seismicity. Our unified model for the origin of the YSRP is consistent with the geologic evidence where basaltic magmas ascend from a mantle plume to interact with a silicic-rich continental crust producing partial melts of rhyolite composition and the characteristic caldera-forming volcanism of Yellowstone. Cooling and contraction of the lithosphere follows the passage of the plate over the hotspot with continuing episodic eruptions of mantle-derived basalts along the SRP.

Upper-mantle Origin of the Yellowstone Hotspot

Upper-mantle Origin of the Yellowstone Hotspot PDF Author: Robert L. Christiansen
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 12

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Book Description
Fundamental features of the geology and tectonic setting of the northeast-propagating Yellowstone hotspot are not explained by a simple deep-mantle plume hypothesis and, within that framework, must be attributed to coincidence or be explained by auxiliary hypotheses. These features include the persistence of basaltic magmatism along the hotspot track, the origin of the hotspot during a regional middle Miocene tectonic reorganization, a similar and coeval zone of northwestward magmatic propagation, the occurrence of both zones of magmatic propagation along a first-order tectonic boundary, and control of the hotspot track by preexisting structures. Seismic imaging provides no evidence for, and several contraindications of, a vertically extensive plume-like structure beneath Yellowstone or a broad trailing plume head beneath the eastern Snake River Plain. The high helium isotope ratios observed at Yellowstone and other hotspots are commonly assumed to arise from the lower mantle, but upper-mantle processes can explain the observations. The available evidence thus renders an upper-mantle origin for the Yellowstone system the preferred model; there is no evidence that the system extends deeper than 200 km, and some evidence that it does not. A model whereby the Yellowstone system reflects feedback between upper-mantle convection and regional lithospheric tectonics is able to explain the observations better than a deep-mantle plume hypothesis. --Abstract.

Unraveling the Physics of the Yellowstone Magmatic System Using Geodynamic Simulations

Unraveling the Physics of the Yellowstone Magmatic System Using Geodynamic Simulations PDF Author: Georg S. Reuber
Publisher:
ISBN:
Category : 3D model
Languages : en
Pages : 17

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Book Description
The Yellowstone magmatic system is one of the largest magmatic systems on Earth, and thus an ideal location to study magmatic processes. Whereas previous seismic tomography results could only image a shallow magma reservoir, a recent study using more seismometers showed that a second and massive partially molten mush reservoir exists above the Moho (Huang et al., 2015). To understand the measurable surface response of this system to visco-elasto-plastic deformation, it is thus important to take the whole system from the mantle plume up to the shallow magma reservoirs into account. Here, we employ lithospheric-scale 3D visco-elasto-plastic geodynamic models to test the influence of parameters such as the connectivity of the reservoirs and rheology of the lithosphere on the dynamics of the system. A gravity inversion is used to constrain the effective density of the magma reservoirs, and an adjoint modeling approach reveals the key model parameters affecting the surface velocity. Model results show that a combination of connected reservoirs with plastic rheology can explain the recorded slow vertical surface uplift rates of around 1.2 cm/year, as representing a long term background signal. A geodynamic inversion to fit the model to observed GPS surface velocities reveals that the magnitude of surface uplift varies strongly with the viscosity difference between the reservoirs and the crust. Even though stress directions have not been used as inversion parameters, modeled stress orientations are consistent with observations. However, phases of larger uplift velocities can also result from magma reservoir inflation which is a short term effect. We consider two approaches: (1) overpressure in the magma reservoir in the asthenosphere and (2) inflation of the uppermost reservoir prescribed by an internal kinematic boundary condition. We demonstrate that the asthenosphere inflation has a smaller effect on the surface velocities in comparison with the uppermost reservoir inflation. We show that the pure buoyant uplift of magma bodies in combination with magma reservoir inflation can explain (varying) observed uplift rates at the example of the Yellowstone volcanic system.

Volcanism and Tectonism in the Columbia River Flood-basalt Province

Volcanism and Tectonism in the Columbia River Flood-basalt Province PDF Author: Stephen P. Reidel
Publisher: Geological Society of America
ISBN: 081372239X
Category : Science
Languages : en
Pages : 403

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Regional Geology of Eastern Idaho and Western Wyoming

Regional Geology of Eastern Idaho and Western Wyoming PDF Author: P. K. Link
Publisher: Geological Society of America
ISBN: 0813711797
Category : Science
Languages : en
Pages : 324

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Ash-flow Tuffs

Ash-flow Tuffs PDF Author: Charles Edward Chapin
Publisher: Geological Society of America
ISBN: 0813721806
Category : Science
Languages : en
Pages : 222

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Glaciers

Glaciers PDF Author: M. J. Hambrey
Publisher:
ISBN: 9780521828086
Category : Science
Languages : en
Pages : 376

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Book Description
Glaciers are among the most beautiful natural wonders on Earth, but for most of us the least known and understood. This book describes how glaciers grow and decay, how they move, and how they influence human civilisation. Today covering a tenth of the Earth's surface, glacier ice has shaped the landscape over millions of years by scouring away rocks, transporting and depositing debris far from its source. Glacier meltwater drives turbines and irrigates deserts, yields mineral-rich soils, and has left us a wealth of valuable sand and gravel. However, glaciers also threaten human property and life. Our future is indirectly bound up with the fate of glaciers and their influence on global climate and sea level. A lively running text develops these themes and is supported by over 200 stunning photographs, taking us from the High-Arctic through North America, Europe, Asia, Africa, New Zealand and South America to the Antarctic.