Slab flattening trigger for isotopic disturbance and magmatic flare
... melting in the relaminated schist is hypothesized to have taken place within the magmatic source region to produce S-type granitoids in the eastern domain (Fig. 4). The emplacement of S-type granitoids in the southernmost SNB and adjacent areas occurred during eastward arc migration and at the peak ...
... melting in the relaminated schist is hypothesized to have taken place within the magmatic source region to produce S-type granitoids in the eastern domain (Fig. 4). The emplacement of S-type granitoids in the southernmost SNB and adjacent areas occurred during eastward arc migration and at the peak ...
The origin of Mount St. Helens andesites
... plausibly, the andesites represent mixing between basaltic and dacitic end-member magmas, each of which may be somewhat heterogeneous or vary in composition with time. In this model, efficient mixing must occur in some parts of the magma plumbing system, while some conduits or storage reservoirs mus ...
... plausibly, the andesites represent mixing between basaltic and dacitic end-member magmas, each of which may be somewhat heterogeneous or vary in composition with time. In this model, efficient mixing must occur in some parts of the magma plumbing system, while some conduits or storage reservoirs mus ...
Causes and mechanisms of the 20112012 El Hierro (Canary Islands
... [1] El Hierro eruption started on 10 October 2011 after an unrest episode that initiated on 17 July 2011. This is the first eruption in the Canary Islands that has been tracked in real time. Although being submarine and not directly observable, the data recorded allowed its reconstruction and to iden ...
... [1] El Hierro eruption started on 10 October 2011 after an unrest episode that initiated on 17 July 2011. This is the first eruption in the Canary Islands that has been tracked in real time. Although being submarine and not directly observable, the data recorded allowed its reconstruction and to iden ...
Geol Soc London Spec Publ 204 2002
... commonly driven by gravity acting on the subducting slab (Fig. 4c) and, therefore, most subduction zones are characterized by retreat of the hinge with time, or slab rollback (Fig. 4d). As a result the mantle wedge between the two plates can be replenished by an inflow of hot, undepleted mantle (And ...
... commonly driven by gravity acting on the subducting slab (Fig. 4c) and, therefore, most subduction zones are characterized by retreat of the hinge with time, or slab rollback (Fig. 4d). As a result the mantle wedge between the two plates can be replenished by an inflow of hot, undepleted mantle (And ...
Spring 2009 Showcase Abstracts
... size and frequency of past earthquakes. The pattern of the size and frequency of the last earthquakes are visible when analyzing the area. Lidar is used to measure the fault scarps seen on the forest floor. Lidar is an extremely accurate measuring system of change in ground heights due to natural mo ...
... size and frequency of past earthquakes. The pattern of the size and frequency of the last earthquakes are visible when analyzing the area. Lidar is used to measure the fault scarps seen on the forest floor. Lidar is an extremely accurate measuring system of change in ground heights due to natural mo ...
Quantification of Extraterrestrial Lava Flow Effusion Rates Through
... Mars and Venus, we have determined that all the common flow morphologies (domes, folds and levees) on these planets could have been produced by basalt-like or andesite-like lavas through either continuous or episodic emplacement. The presence of more evolved magma compositions on other planets is no ...
... Mars and Venus, we have determined that all the common flow morphologies (domes, folds and levees) on these planets could have been produced by basalt-like or andesite-like lavas through either continuous or episodic emplacement. The presence of more evolved magma compositions on other planets is no ...
Regional Geology (Wagner) - Western Oregon University
... miles from near the equator to the coast of Oregon. The terrains formed and traveled on the Pacific Plate until they where amalgamated to the North American Plate, creating the Klamath Mountains. After amalgamation the terrains underwent extension to near their present position. Today the Juan De Fu ...
... miles from near the equator to the coast of Oregon. The terrains formed and traveled on the Pacific Plate until they where amalgamated to the North American Plate, creating the Klamath Mountains. After amalgamation the terrains underwent extension to near their present position. Today the Juan De Fu ...
Revised history of Izanagi-Pacific ridge subduction
... 85 Ma, which is more than double the fastest current spreading rate globally (approximately 15 cm/yr between the Pacific and Nazca plates). We propose that sub-parallel subduction of the I-P midocean ridge beneath Japan at 60-55 Ma resulted in nearly simultaneous slab break-off along the length of t ...
... 85 Ma, which is more than double the fastest current spreading rate globally (approximately 15 cm/yr between the Pacific and Nazca plates). We propose that sub-parallel subduction of the I-P midocean ridge beneath Japan at 60-55 Ma resulted in nearly simultaneous slab break-off along the length of t ...
Geosci Ques
... Feedback: Geologists can predict fairly well nowadays when a volcano is about to go off. Also, volcanoes create a lot of damage such as landslides, release of poisonous gasses, and tsunamis. 10) T/F: Volcano eruptions are unpredictable and even the best geologists can’t predict when one will go off ...
... Feedback: Geologists can predict fairly well nowadays when a volcano is about to go off. Also, volcanoes create a lot of damage such as landslides, release of poisonous gasses, and tsunamis. 10) T/F: Volcano eruptions are unpredictable and even the best geologists can’t predict when one will go off ...
Tracing the evolving flux from the subducting plate in the Tonga
... variations in this flux should have a major effect on arc geochemistry. Hole et al. (1984), and more recently Plank and Langmuir (1993) and Johnson and Plank (1999), suggested that the REE characteristics of many arc lavas are derived from the sediments being subducted in the adjacent trench. In the ...
... variations in this flux should have a major effect on arc geochemistry. Hole et al. (1984), and more recently Plank and Langmuir (1993) and Johnson and Plank (1999), suggested that the REE characteristics of many arc lavas are derived from the sediments being subducted in the adjacent trench. In the ...
Classification of magmatic rocks
... C. The role of deformation Exploiting shear zones is an alternate way to bring the magmas to the surface. It’s basically quite similar to dykes, except that tectonic deformation in the shear zone will help to build the pressure and move the magmas upwards. At high structural levels, the shear zones ...
... C. The role of deformation Exploiting shear zones is an alternate way to bring the magmas to the surface. It’s basically quite similar to dykes, except that tectonic deformation in the shear zone will help to build the pressure and move the magmas upwards. At high structural levels, the shear zones ...
Subduction of the Rivera plate beneath the Jalisco block as imaged
... Another seismic study at the northern terminus of the MAT (Brown, 2007) shows that the oceanic crust underplates the continental crust north of Bahía de Banderas at depths of 30 km to its top, at a distance of 135 km from the trench. MAGNETOTELLURIC SURVEY Magnetotelluric (MT) surveys have been exte ...
... Another seismic study at the northern terminus of the MAT (Brown, 2007) shows that the oceanic crust underplates the continental crust north of Bahía de Banderas at depths of 30 km to its top, at a distance of 135 km from the trench. MAGNETOTELLURIC SURVEY Magnetotelluric (MT) surveys have been exte ...
Geology
... Showa-machi 3173-25, Kanazawa-ku, Yokohama, Japan Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Natsushima 2-15, Yokosuka, Japan ...
... Showa-machi 3173-25, Kanazawa-ku, Yokohama, Japan Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Natsushima 2-15, Yokosuka, Japan ...
Evolutionary cycles during the Andean orogeny
... rebound of the slab tip (owing to lack of further slab pull), flat subduction and termination of subduction-related magmatism. Rapid subduction leads to shallow overriding of the detached slab fragment. Eclogitization of the gradually steepening slab tip at depth and subsequent slab pull permits ast ...
... rebound of the slab tip (owing to lack of further slab pull), flat subduction and termination of subduction-related magmatism. Rapid subduction leads to shallow overriding of the detached slab fragment. Eclogitization of the gradually steepening slab tip at depth and subsequent slab pull permits ast ...
13 Comparison of Rock Deformation Strain and Volcanic Hazard
... common geological process leads to the development of these features on a regional scale. This is reinforced by the fact that the best-fit kernel in the extensional-arc domain is elongate parallel to the Shimabara-Beppu graben, and some volcanoes in this domain (e.g., Akai and Omine) lie along fault ...
... common geological process leads to the development of these features on a regional scale. This is reinforced by the fact that the best-fit kernel in the extensional-arc domain is elongate parallel to the Shimabara-Beppu graben, and some volcanoes in this domain (e.g., Akai and Omine) lie along fault ...
LC4
... teams, to complete exam questions and to create a range of revision tools. Students will also complete a written assessment based on a series of examination questions from a range of specimen papers. Gap Analysis Reinforcement Gap This end of module time will be allocated to re-teaching any gaps di ...
... teams, to complete exam questions and to create a range of revision tools. Students will also complete a written assessment based on a series of examination questions from a range of specimen papers. Gap Analysis Reinforcement Gap This end of module time will be allocated to re-teaching any gaps di ...
Geology of Maui
... alkalic cap (most of the volcano’s modern surface) •is still in the postsheild alkalic cap stage •includes Haleakala crater - an erosional feature modified by later eruptions, Last erupted in 1790. ...
... alkalic cap (most of the volcano’s modern surface) •is still in the postsheild alkalic cap stage •includes Haleakala crater - an erosional feature modified by later eruptions, Last erupted in 1790. ...
FORMATION OF MAGMA AND IGNEOUS ROCKS
... Volcanic Rocks – Rocks originating from the eruption of molten material at Earth’s surface. These rocks are also referred to as extrusive rocks. Pyroclastic materials are materials that are explosively ejected from an erupting volcano. Plutonic Rocks – Igneous rocks that solidify below the surface o ...
... Volcanic Rocks – Rocks originating from the eruption of molten material at Earth’s surface. These rocks are also referred to as extrusive rocks. Pyroclastic materials are materials that are explosively ejected from an erupting volcano. Plutonic Rocks – Igneous rocks that solidify below the surface o ...
Intra-Panthalassa Ocean subduction zones revealed by fossil arcs
... Intra-Panthalassa Ocean subduction zones revealed by fossil arcs and mantle structure D. G. van der Meer1,2 *, T. H. Torsvik3,4,5,6 , W. Spakman1 *, D. J. J. van Hinsbergen3,6 and M. L. Amaru1,7 The vast Panthalassa Ocean once surrounded the supercontinent Pangaea. Subduction has since consumed most ...
... Intra-Panthalassa Ocean subduction zones revealed by fossil arcs and mantle structure D. G. van der Meer1,2 *, T. H. Torsvik3,4,5,6 , W. Spakman1 *, D. J. J. van Hinsbergen3,6 and M. L. Amaru1,7 The vast Panthalassa Ocean once surrounded the supercontinent Pangaea. Subduction has since consumed most ...
PDF File - Tulane University
... explosive eruptions that emit silicic pyroclastic material in large-volume eruptions. It is the sudden evacuation of underlying magma chambers that appears to result in the collapse of the volcanoes to form the calderas. The imposing presence of these large mostly andesitic stratovolcanoes led to an ...
... explosive eruptions that emit silicic pyroclastic material in large-volume eruptions. It is the sudden evacuation of underlying magma chambers that appears to result in the collapse of the volcanoes to form the calderas. The imposing presence of these large mostly andesitic stratovolcanoes led to an ...
Modification of the Continental Crust by Subduction Zone
... New whole rock analyses for Uturuncu rocks were performed at Washington State University, Pullman. Major and trace element analyses on 121 samples were performed by X-ray Fluorescence Spectrometry (XRF) on a ThermoARL Advant’XP+ automated sequential wavelength spectrometer (ThermoARL, Waltham, MA, U ...
... New whole rock analyses for Uturuncu rocks were performed at Washington State University, Pullman. Major and trace element analyses on 121 samples were performed by X-ray Fluorescence Spectrometry (XRF) on a ThermoARL Advant’XP+ automated sequential wavelength spectrometer (ThermoARL, Waltham, MA, U ...
Modification of the Continental Crust by Subduction Zone
... New whole rock analyses for Uturuncu rocks were performed at Washington State University, Pullman. Major and trace element analyses on 121 samples were performed by X-ray Fluorescence Spectrometry (XRF) on a ThermoARL Advant’XP+ automated sequential wavelength spectrometer (ThermoARL, Waltham, MA, U ...
... New whole rock analyses for Uturuncu rocks were performed at Washington State University, Pullman. Major and trace element analyses on 121 samples were performed by X-ray Fluorescence Spectrometry (XRF) on a ThermoARL Advant’XP+ automated sequential wavelength spectrometer (ThermoARL, Waltham, MA, U ...
Measuring Timescales of Magmatic Evolution
... now permit in situ dating of (mainly) zircon and allanite The timescales and rates of magmatic processes are key (e.g. Bourdon et al. 2003). U-series disequilibria in parental pieces of information for understanding and modeling magmas are typically produced during mantle melting; sysmany aspects of ...
... now permit in situ dating of (mainly) zircon and allanite The timescales and rates of magmatic processes are key (e.g. Bourdon et al. 2003). U-series disequilibria in parental pieces of information for understanding and modeling magmas are typically produced during mantle melting; sysmany aspects of ...
Tectonic controls on the nature of large silicic calderas in volcanic arcs
... Cruciani et al. (2005) of convergent margin data (e.g., New Zealand and the Aegean). We defined silicic calderas as having CFEs with compositions of at least 63 wt% SiO2. For calderas with more than one CFE, data from the oldest eruption were used when possible. We included only calderas younger tha ...
... Cruciani et al. (2005) of convergent margin data (e.g., New Zealand and the Aegean). We defined silicic calderas as having CFEs with compositions of at least 63 wt% SiO2. For calderas with more than one CFE, data from the oldest eruption were used when possible. We included only calderas younger tha ...
Answer skills
... such as Andes. The South American Plate (continental plate) collided with the Nazca Plate (oceanic plate) as sinking convective currents pulled them towards each other. The continental plate and the oceanic plate are of different densities. The denser Nazca Plate subducted under the South American P ...
... such as Andes. The South American Plate (continental plate) collided with the Nazca Plate (oceanic plate) as sinking convective currents pulled them towards each other. The continental plate and the oceanic plate are of different densities. The denser Nazca Plate subducted under the South American P ...
Cascade Volcanoes
This article is for the volcanic arc. For the namesake mountain range see Cascade Range.The Cascade Volcanoes (also known as the Cascade Volcanic Arc or the Cascade Arc) are a number of volcanoes in a volcanic arc in western North America, extending from southwestern British Columbia through Washington and Oregon to Northern California, a distance of well over 700 miles (1,100 km). The arc has formed due to subduction along the Cascadia subduction zone. Although taking its name from the Cascade Range, this term is a geologic grouping rather than a geographic one, and the Cascade Volcanoes extend north into the Coast Mountains, past the Fraser River which is the northward limit of the Cascade Range proper.Some of the major cities along the length of the arc include Portland, Seattle, and Vancouver, and the population in the region exceeds 10,000,000. All could be potentially affected by volcanic activity and great subduction-zone earthquakes along the arc. Because the population of the Pacific Northwest is rapidly increasing, the Cascade volcanoes are some of the most dangerous, due to their eruptive history and potential for future eruptions, and because they are underlain by weak, hydrothermally altered volcanic rocks that are susceptible to failure. Consequently, Mount Rainier is one of the Decade Volcanoes identified by the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) as being worthy of particular study, due to the danger it poses to Seattle and Tacoma. Many large, long-runout landslides originating on Cascade volcanoes have inundated valleys tens of kilometers from their sources, and some of the inundated areas now support large populations.The Cascade Volcanoes are part of the Pacific Ring of Fire, the ring of volcanoes and associated mountains around the Pacific Ocean. All of the known historic eruptions in the contiguous United States have been from the Cascade Volcanoes. Two most recent were Lassen Peak in 1914 to 1921 and a major eruption of Mount St. Helens in 1980. It is also the site of Canada's most recent major eruption about 2,350 years ago at the Mount Meager volcanic complex.