An immense shield volcano within the Shatsky Rise oceanic plateau
... morphology early in the volcano history. Alternatively, these undulations may simply indicate three-dimensional geometry as the seismic line strays from the buried eruption axis. Nevertheless, the seismic data show that in the upper ∼1.5 s, lava flows evened out the topography to construct the curre ...
... morphology early in the volcano history. Alternatively, these undulations may simply indicate three-dimensional geometry as the seismic line strays from the buried eruption axis. Nevertheless, the seismic data show that in the upper ∼1.5 s, lava flows evened out the topography to construct the curre ...
Tectonic controls on the distribution of large
... subduction of the PSCSP was immediately followed by rotation of Borneo and formation of crustal scale structures, providing conditions in which the slab may have been trapped and heated sufficiently to induce partial melting. It is worth noting that the older systems (e.g. Mount Muro) appear to be l ...
... subduction of the PSCSP was immediately followed by rotation of Borneo and formation of crustal scale structures, providing conditions in which the slab may have been trapped and heated sufficiently to induce partial melting. It is worth noting that the older systems (e.g. Mount Muro) appear to be l ...
Did Paleo-Tethyan anoxia kill arc magma fertility for
... associated epithermal Au ± Cu deposits (Fig. 1), but the majority of known deposits are Cretaceous to Cenozoic in age, and are related to subduction and closure of the Neo-Tethyan ocean basin (Aghazadeh et al., 2015; Richards, 2015b). Examples include the Majdanpek porphyry Cu-Mo-Au deposit in Serbi ...
... associated epithermal Au ± Cu deposits (Fig. 1), but the majority of known deposits are Cretaceous to Cenozoic in age, and are related to subduction and closure of the Neo-Tethyan ocean basin (Aghazadeh et al., 2015; Richards, 2015b). Examples include the Majdanpek porphyry Cu-Mo-Au deposit in Serbi ...
Chapter 3 Igneous Rocks What are Rocks? Rock: any naturally
... material beneath the Earth's surface. Mobility of this liquid within the Earth is controlled by its physical properties, density and viscosity. Being a liquid, it is less dense than solid rock and thus, tends to rise buoyantly within the Earth as long as it is lighter than the surrounding or country ...
... material beneath the Earth's surface. Mobility of this liquid within the Earth is controlled by its physical properties, density and viscosity. Being a liquid, it is less dense than solid rock and thus, tends to rise buoyantly within the Earth as long as it is lighter than the surrounding or country ...
Chapter 3 Igneous Rocks What are Rocks?
... material beneath the Earth's surface. Mobility of this liquid within the Earth is controlled by its physical properties, density and viscosity. Being a liquid, it is less dense than solid rock and thus, tends to rise buoyantly within the Earth as long as it is lighter than the surrounding or country ...
... material beneath the Earth's surface. Mobility of this liquid within the Earth is controlled by its physical properties, density and viscosity. Being a liquid, it is less dense than solid rock and thus, tends to rise buoyantly within the Earth as long as it is lighter than the surrounding or country ...
Document
... This proposal is for the ultra-deep drilling site of a series of IODP proposals in the Izu-Bonin-Mariana (IBM) arc that aim at comprehensive understanding of arc evolution and continental crust formation. We propose to drill a deep hole that penetrates through a complete sequence of intra-oceanic ar ...
... This proposal is for the ultra-deep drilling site of a series of IODP proposals in the Izu-Bonin-Mariana (IBM) arc that aim at comprehensive understanding of arc evolution and continental crust formation. We propose to drill a deep hole that penetrates through a complete sequence of intra-oceanic ar ...
An immense shield volcano within the Shatsky Rise oceanic plateau
... seismic line strays from the buried eruption axis. Nevertheless, the seismic data show that in the upper ⇠1.5 s, lava flows evened out the topography to construct the current shield shape. Although Tamu Massif has a broad, dome shape, there are significant secondary volcanic features. A ⇠1-km tall, ...
... seismic line strays from the buried eruption axis. Nevertheless, the seismic data show that in the upper ⇠1.5 s, lava flows evened out the topography to construct the current shield shape. Although Tamu Massif has a broad, dome shape, there are significant secondary volcanic features. A ⇠1-km tall, ...
Igneous Rocks - FacultyWeb Support Center
... are batholiths (the tip of the iceberg”) Most are granite in composition, but some may be diorite. (mostly sialic magmas, with someintermediate magmas) Most are formed near continental margins during episodes of mountain building or great uplift (during an orogeny or tectonic activity). ...
... are batholiths (the tip of the iceberg”) Most are granite in composition, but some may be diorite. (mostly sialic magmas, with someintermediate magmas) Most are formed near continental margins during episodes of mountain building or great uplift (during an orogeny or tectonic activity). ...
magma intrusion in `proto-caldera caldera` systems: example from
... shaped faults (Fig. 5). The horse-shoe shaped faults define the apical graben which usually has a mean diameter approximately half of that of the subvolcanic reservoir (Walter and Troll 2001). Due to the strongest extension occurring in the apical graben, slumping of large blocks and subsidence take ...
... shaped faults (Fig. 5). The horse-shoe shaped faults define the apical graben which usually has a mean diameter approximately half of that of the subvolcanic reservoir (Walter and Troll 2001). Due to the strongest extension occurring in the apical graben, slumping of large blocks and subsidence take ...
The Geological and Tectonic Framework of Europe
... the upper mantle, and is a rheologically more rigid layer lying above a more plastic layer of the upper mantle, known as the asthenosphere. The lithosphere is divided into several major tectonic plates that move relative to one another, and interact and deform, especially around their margins. Oroge ...
... the upper mantle, and is a rheologically more rigid layer lying above a more plastic layer of the upper mantle, known as the asthenosphere. The lithosphere is divided into several major tectonic plates that move relative to one another, and interact and deform, especially around their margins. Oroge ...
Travel Time Tomographic Imaging of Shallow Fore
... fore-arc basin structure at the Cascadia subduction zone using first-arrival travel times from two multichannel seismic (MCS) profiles acquired with an 8-km long streamer in the frame of the 2012 Cascadia Ridge to trench program. The first profile extends offshore Gray’s Harbor in Washington and the ...
... fore-arc basin structure at the Cascadia subduction zone using first-arrival travel times from two multichannel seismic (MCS) profiles acquired with an 8-km long streamer in the frame of the 2012 Cascadia Ridge to trench program. The first profile extends offshore Gray’s Harbor in Washington and the ...
Slide 1 - Global Heat Flow Database
... In all cases, the high HFD belt coincides with the zone of active volcanism and the amplitude of the HFD anomaly appears to correlate with the angle of subduction. Variable width of the high HFD zones is interpreted to be related to differences in thickness and composition of the local crust, and to ...
... In all cases, the high HFD belt coincides with the zone of active volcanism and the amplitude of the HFD anomaly appears to correlate with the angle of subduction. Variable width of the high HFD zones is interpreted to be related to differences in thickness and composition of the local crust, and to ...
- Wiley Online Library
... thrust fault vergence and decreased P-wave velocities suggest the presence of a subduction sediment channel 1 km in thickness under the coast [Gulick et al., 1998; Trehu et al., 2012; McNeill et al., 2013]. Sediment compaction and clay dehydration can release large amounts of fluids to distances app ...
... thrust fault vergence and decreased P-wave velocities suggest the presence of a subduction sediment channel 1 km in thickness under the coast [Gulick et al., 1998; Trehu et al., 2012; McNeill et al., 2013]. Sediment compaction and clay dehydration can release large amounts of fluids to distances app ...
Advances in Environmental Biology
... rocks (with associated pyroclastic and volcaniclastic successions) along the active margin of the Iranian plate. Although magmatic activity continued from the Cretaceous to recent times, the peak activity in the Urumieh– Dokhtar Magmatic Assemblage occurred in Eocene times [13]. The magmatic activit ...
... rocks (with associated pyroclastic and volcaniclastic successions) along the active margin of the Iranian plate. Although magmatic activity continued from the Cretaceous to recent times, the peak activity in the Urumieh– Dokhtar Magmatic Assemblage occurred in Eocene times [13]. The magmatic activit ...
2014-Wannamaker-Casc.. - University of Alberta
... thrust fault vergence and decreased P-wave velocities suggest the presence of a subduction sediment channel 1 km in thickness under the coast [Gulick et al., 1998; Trehu et al., 2012; McNeill et al., 2013]. Sediment compaction and clay dehydration can release large amounts of fluids to distances app ...
... thrust fault vergence and decreased P-wave velocities suggest the presence of a subduction sediment channel 1 km in thickness under the coast [Gulick et al., 1998; Trehu et al., 2012; McNeill et al., 2013]. Sediment compaction and clay dehydration can release large amounts of fluids to distances app ...
EENS 2120 Petrology Prof. Stephen A. Nelson Igneous Rocks of the
... origin of granitic rocks (known as the "Granite Controversy"). One group referred to themselves as the granitizationists and argued that granitic rocks were produced by ultrametamorphism at high temperatures and pressures in the Earth's crust. The other group, referred to as the magmatists, argued t ...
... origin of granitic rocks (known as the "Granite Controversy"). One group referred to themselves as the granitizationists and argued that granitic rocks were produced by ultrametamorphism at high temperatures and pressures in the Earth's crust. The other group, referred to as the magmatists, argued t ...
7 Volcano-tectonic Interactions in Kyushu and Implications for Future
... Many previous workers have noted that most of the arc volcanoes in Kyushu (with the exception of Unzen) lie in a region generally above the 100 km contour of the subducting slab. Due to a southward increase in back-arc extension rate and southward steepening of the subducting slab, there is a south ...
... Many previous workers have noted that most of the arc volcanoes in Kyushu (with the exception of Unzen) lie in a region generally above the 100 km contour of the subducting slab. Due to a southward increase in back-arc extension rate and southward steepening of the subducting slab, there is a south ...
Metamorphism and tectonics
... series; whereas others are associated with so much magmatic activity that they may be considered to belong to the “regional – contact” type of metamorphism of Spear (1993). Examples of these two cases include: 1- The Himalayas (which have an inverted metamorphic gradient in which the Sill zone overl ...
... series; whereas others are associated with so much magmatic activity that they may be considered to belong to the “regional – contact” type of metamorphism of Spear (1993). Examples of these two cases include: 1- The Himalayas (which have an inverted metamorphic gradient in which the Sill zone overl ...
Plate Tectonics in a Nutshell Name
... or rocks, when later exposed by erosion, commonly form cores of many great mountain ranges [such as the Sierra Nevada (California) or the Andes (South America)] that are created along the subduction zones where the plates converge. 14. Some of the molten rock may reach the Earth’s surface to erupt a ...
... or rocks, when later exposed by erosion, commonly form cores of many great mountain ranges [such as the Sierra Nevada (California) or the Andes (South America)] that are created along the subduction zones where the plates converge. 14. Some of the molten rock may reach the Earth’s surface to erupt a ...
Silicic Magmatism and the Volcanic–Plutonic Connection
... all samples for which SiO2 was reported. These arrays support field observations by showing strong biases of volcanic rocks toward low-silica compositions and plutonic rocks toward high-silica compositions. Volcanic peak at ~54 wt% SiO2 represents the Columbia River basalts (western USA), which are ...
... all samples for which SiO2 was reported. These arrays support field observations by showing strong biases of volcanic rocks toward low-silica compositions and plutonic rocks toward high-silica compositions. Volcanic peak at ~54 wt% SiO2 represents the Columbia River basalts (western USA), which are ...
Abstract
... What are phenocrysts, and what do they signify? In both plutonic and volcanic rocks, crystals that are much larger than their surrounding matrix are generally interpreted as having grown early in a magma’s crystallization history (e.g., Harker and Marr 1891; Crosby 1900; Kelley and Branson 1947; Ver ...
... What are phenocrysts, and what do they signify? In both plutonic and volcanic rocks, crystals that are much larger than their surrounding matrix are generally interpreted as having grown early in a magma’s crystallization history (e.g., Harker and Marr 1891; Crosby 1900; Kelley and Branson 1947; Ver ...
pdf file - Pacific Northwest Geodetic Array
... Please send your comments and/or additions to this draft! RATIONALE Subduction zones are the most dynamic tectonic environments on earth. The fastest relative plate motions and the highest mass fluxes of sediment, magma, and related fluids into the continental crust and mantle occur at subduction zo ...
... Please send your comments and/or additions to this draft! RATIONALE Subduction zones are the most dynamic tectonic environments on earth. The fastest relative plate motions and the highest mass fluxes of sediment, magma, and related fluids into the continental crust and mantle occur at subduction zo ...
chapter 2
... The Cache Creek Connection The Stikine (stih-keen’) Terrane (Stikinia, named for the Stikine River in northwest British Columbia) is a typical collection of Late Paleozoic to Mid-Jurassic island-arc rocks, not at all unlike Quesnellia to the south. It consists of a succession of island-arc complexes ...
... The Cache Creek Connection The Stikine (stih-keen’) Terrane (Stikinia, named for the Stikine River in northwest British Columbia) is a typical collection of Late Paleozoic to Mid-Jurassic island-arc rocks, not at all unlike Quesnellia to the south. It consists of a succession of island-arc complexes ...
Reassessment of the historical seismic activity with major impact on
... distribution pattern of some low seismic intensity anomalies in the vicinity of Sete Cidades and/or Furnas volcanoes allowed constraining the epicentral locations of the 1852, 1932 and 1935 earthquakes. Concerning the seismic swarms associated with volcanic phenomena, it is clear that the distributi ...
... distribution pattern of some low seismic intensity anomalies in the vicinity of Sete Cidades and/or Furnas volcanoes allowed constraining the epicentral locations of the 1852, 1932 and 1935 earthquakes. Concerning the seismic swarms associated with volcanic phenomena, it is clear that the distributi ...
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.