Spring 2009 Showcase Abstracts
... deposits and abundant vegetative cover. Aeromagnetic mapping techniques have given insight into this once enigmatic area. The Seattle fault zone is segmented and comprised of several east-trending, north-verging splays along a reverse-thrust system. Three distinct magnetic anomalies are associated w ...
... deposits and abundant vegetative cover. Aeromagnetic mapping techniques have given insight into this once enigmatic area. The Seattle fault zone is segmented and comprised of several east-trending, north-verging splays along a reverse-thrust system. Three distinct magnetic anomalies are associated w ...
Fluid release from the subducted Cocos plate and partial melting of
... prevail, so that 2-D modeling of the data appeared generally justified. However, due to the extraordinary length of the two profiles (345 and 635 km) and the complex local and regional geotectonic environment, sections with different mean strike angles were defined along the lines (Figure 5). Detail ...
... prevail, so that 2-D modeling of the data appeared generally justified. However, due to the extraordinary length of the two profiles (345 and 635 km) and the complex local and regional geotectonic environment, sections with different mean strike angles were defined along the lines (Figure 5). Detail ...
Fluid release from the subducted Cocos plate and
... prevail, so that 2-D modeling of the data appeared generally justified. However, due to the extraordinary length of the two profiles (345 and 635 km) and the complex local and regional geotectonic environment, sections with different mean strike angles were defined along the lines (Figure 5). Detail ...
... prevail, so that 2-D modeling of the data appeared generally justified. However, due to the extraordinary length of the two profiles (345 and 635 km) and the complex local and regional geotectonic environment, sections with different mean strike angles were defined along the lines (Figure 5). Detail ...
Igneous rocks - HEDCen Science
... • How are igneous rocks formed? • How does magma differ from lava? • What two criteria are used to classify igneous rocks? • How does the rate of cooling of magma influence the crystal size of minerals in igneous rocks? • How is the mineral makeup of an igneous rock related to Bowen’s reaction serie ...
... • How are igneous rocks formed? • How does magma differ from lava? • What two criteria are used to classify igneous rocks? • How does the rate of cooling of magma influence the crystal size of minerals in igneous rocks? • How is the mineral makeup of an igneous rock related to Bowen’s reaction serie ...
Pseudotachylytes, related fault rocks, asperities, and crustal structures in the
... the metamorphic belt are strongly deformed and retrogressively metamorphosed, giving rise to a N-S striking tonalite mylonite zone up to ca. 2 km wide (western-margin mylonite zone). The prominent foliations of the metamorphic rocks are steeply inclined to the east, except in the southern area of th ...
... the metamorphic belt are strongly deformed and retrogressively metamorphosed, giving rise to a N-S striking tonalite mylonite zone up to ca. 2 km wide (western-margin mylonite zone). The prominent foliations of the metamorphic rocks are steeply inclined to the east, except in the southern area of th ...
07 Chapter 7_Metamorphism and Metamorphic Rocks
... During mountain building, rocks subjected to differential stress are shortened in the direction that pressure is applied and lengthened in the direction perpendicular to that force. ...
... During mountain building, rocks subjected to differential stress are shortened in the direction that pressure is applied and lengthened in the direction perpendicular to that force. ...
Erosion, Himalayan Geodynamics, and the Geomorphology of
... observed very young metamorphism nor the geophysical data from Nanga Parbat which show the massif to be developed atop weak crust that is hot, dry, and thin by overthickened Himalayan standards (Meltzer et al., 1998; Park and Mackie, 2000). Coupled thermal-mechanical-erosional modeling (Koons , 1998 ...
... observed very young metamorphism nor the geophysical data from Nanga Parbat which show the massif to be developed atop weak crust that is hot, dry, and thin by overthickened Himalayan standards (Meltzer et al., 1998; Park and Mackie, 2000). Coupled thermal-mechanical-erosional modeling (Koons , 1998 ...
Petrogenesis of Mafic to Felsic Plutonic Rock Associations: the Calc
... melts in equilibrium with mafic, refractory granulite residues by fluid-absent breakdown. Such thermal extremes are generally visualized as occurring in the deep crust and require heat input through under- or intraplating of mantle-derived basaltic magmas (e.g. Clemens, 1990; Vielzeuf et al., 1990). ...
... melts in equilibrium with mafic, refractory granulite residues by fluid-absent breakdown. Such thermal extremes are generally visualized as occurring in the deep crust and require heat input through under- or intraplating of mantle-derived basaltic magmas (e.g. Clemens, 1990; Vielzeuf et al., 1990). ...
Durham Research Online
... layered crust both delamination and break-off are feasible. We identify three modes: (1) slab detachment, in which the lithospheric mantle and the crust are strongly coupled, subduction slows down and the slab eventually breaks; (2) delamination of the lithospheric mantle that separates from the cru ...
... layered crust both delamination and break-off are feasible. We identify three modes: (1) slab detachment, in which the lithospheric mantle and the crust are strongly coupled, subduction slows down and the slab eventually breaks; (2) delamination of the lithospheric mantle that separates from the cru ...
- ResearchOnline@JCU
... rocks in the Cajamarca region are related to three major magmatic episodes that intrude and overlie the deformed Cretaceous sedimentary rocks and metamorphic basement. The first of these magmatic episodes occurred during Palaeogene times (57-35 Ma) and resulted in deposition of the Llama-Calipuy Vol ...
... rocks in the Cajamarca region are related to three major magmatic episodes that intrude and overlie the deformed Cretaceous sedimentary rocks and metamorphic basement. The first of these magmatic episodes occurred during Palaeogene times (57-35 Ma) and resulted in deposition of the Llama-Calipuy Vol ...
AbdolnaserFazlnia-Word offic file
... The Mamakan gabbroic intrusions are located in the north of Sanandaj-Sirjan zone (SSZ). The intrusions injected to the Paleozoic platform of the central Iran at 303-298 Ma. These intrusions are divided into the layered and massive gabbros. The layered types consist primarily of gabbros, interspersed ...
... The Mamakan gabbroic intrusions are located in the north of Sanandaj-Sirjan zone (SSZ). The intrusions injected to the Paleozoic platform of the central Iran at 303-298 Ma. These intrusions are divided into the layered and massive gabbros. The layered types consist primarily of gabbros, interspersed ...
Glen Catacol
... The diapir therefore caused brittle and ductile deformation in the country rock and was too cool and too ‘dry' to effect substantial thermal metamorphism and mineralization in the country rock. However, the contacts in the Catacol area differ from this overall interpretation in that the junction is ...
... The diapir therefore caused brittle and ductile deformation in the country rock and was too cool and too ‘dry' to effect substantial thermal metamorphism and mineralization in the country rock. However, the contacts in the Catacol area differ from this overall interpretation in that the junction is ...
Iceland is cool: An origin for the Iceland volcanic province in the
... locus of spreading in Iceland, thought to be consistent with an eastward-migrating plume, and a maximum in crustal thickness and volcanic activity beneath central Iceland. The features quoted are, however, required by the complex tectonic history of the region, which is described in this section. Fo ...
... locus of spreading in Iceland, thought to be consistent with an eastward-migrating plume, and a maximum in crustal thickness and volcanic activity beneath central Iceland. The features quoted are, however, required by the complex tectonic history of the region, which is described in this section. Fo ...
The tectonic evolution of Sabah provides... development. The summary below was compiled... 2.1 TECTONIC EVOLUTION AND BASIN DEVELOPMENT IN SABAH
... (Hutchinson, 1996). During this period, major tectonic event took place with major uplift and erosion which led to the formation of mélange. Patches of Gomantong limestone, of Burdigalian age formed on structural highs during the uplifting events. Similar to the eastern part, the opening of the Sulu ...
... (Hutchinson, 1996). During this period, major tectonic event took place with major uplift and erosion which led to the formation of mélange. Patches of Gomantong limestone, of Burdigalian age formed on structural highs during the uplifting events. Similar to the eastern part, the opening of the Sulu ...
Subduction factory 2. Are intermediate
... between the patterns of intermediate-depth seismicity and the locations of predicted hydrous minerals: Earthquakes occur in subducting slabs where dehydration is expected, and they are absent from parts of slabs predicted to be anhydrous. We propose that a subducting oceanic plate can consist of fou ...
... between the patterns of intermediate-depth seismicity and the locations of predicted hydrous minerals: Earthquakes occur in subducting slabs where dehydration is expected, and they are absent from parts of slabs predicted to be anhydrous. We propose that a subducting oceanic plate can consist of fou ...
A long in situ section of the lower ocean crust: results of ODP Leg
... 18 km east of the present-day transform-slip zone and 95 km south of the SW Indian Ridge axis. At the time of accretion, however, it was only about 15 km from the active transform fault as there was subsequent transtensional extension across the transform due to a spreading direction change [6]. The ...
... 18 km east of the present-day transform-slip zone and 95 km south of the SW Indian Ridge axis. At the time of accretion, however, it was only about 15 km from the active transform fault as there was subsequent transtensional extension across the transform due to a spreading direction change [6]. The ...
9.2 Metallic mineral occurrences in the shield and deposit types
... sizes of trial excavations, the ancient miners effectively differentiated between bull and goldbearing quartz veins; and exploration was so comprehensive that it is almost a truism that an ancient trial pit or excavation can be found at any outcrop of quartz vein in the shield that shows promise for ...
... sizes of trial excavations, the ancient miners effectively differentiated between bull and goldbearing quartz veins; and exploration was so comprehensive that it is almost a truism that an ancient trial pit or excavation can be found at any outcrop of quartz vein in the shield that shows promise for ...
Fluorine and Chlorine in Granitoids from the Basin and Range
... Analysis of fluorine and chlorine in 228 samples of granitoids' from the Basin and Range province of the western United States suggests that at least three types of granitoids can be distinguished: (1) fluorine-poor granitoids of the northwestern Great Basin (mean F = 0.041 wt %, maximum = 0.11 wt % ...
... Analysis of fluorine and chlorine in 228 samples of granitoids' from the Basin and Range province of the western United States suggests that at least three types of granitoids can be distinguished: (1) fluorine-poor granitoids of the northwestern Great Basin (mean F = 0.041 wt %, maximum = 0.11 wt % ...
Tectónica e Bacias
... Olsen (1997) subdivided the synrift strata of central Atlantic margin rift basins into four tectonostratigraphic (TS) packages (Fig. 3.3.1.6, 3.3.1.8). An individual TS package consists of all or part of a tripartite stratigraphic succession, is separated from other packages by unconformities or cor ...
... Olsen (1997) subdivided the synrift strata of central Atlantic margin rift basins into four tectonostratigraphic (TS) packages (Fig. 3.3.1.6, 3.3.1.8). An individual TS package consists of all or part of a tripartite stratigraphic succession, is separated from other packages by unconformities or cor ...
Tectonic controls on the nature of large silicic calderas in volcanic arcs
... regions of local extension (Table 2). Of the calderas with rhyolitic eruptions, however, 77% are located in extensional regimes. As for backarc stress regimes (Table 1), which we assume to characterize the overall stress state of the arc, the lack of calderas in arcs with the most extension (backarc ...
... regions of local extension (Table 2). Of the calderas with rhyolitic eruptions, however, 77% are located in extensional regimes. As for backarc stress regimes (Table 1), which we assume to characterize the overall stress state of the arc, the lack of calderas in arcs with the most extension (backarc ...
Lithospheric Layering in the North American Craton
... have made common conversion point (CCP) stacked Ps and Sp receiver function image volumes to determine, in more detail and higher resolution than previously obtained, the crustal thickness and the depth to the Moho and lithosphere-asthenosphere boundary (LAB) throughout the Western U.S. Individual r ...
... have made common conversion point (CCP) stacked Ps and Sp receiver function image volumes to determine, in more detail and higher resolution than previously obtained, the crustal thickness and the depth to the Moho and lithosphere-asthenosphere boundary (LAB) throughout the Western U.S. Individual r ...
CHAPTER 5 Mafic-ultramafic complexes
... Nevertheless, it was recognized by the conference delegates that contacts between mappable units are commonly faulted and whole sections may be missing and any given ophiolite may be incomplete or dismembered. The Penrose definition came out of the widely accepted view that ideal oceanic crust had a ...
... Nevertheless, it was recognized by the conference delegates that contacts between mappable units are commonly faulted and whole sections may be missing and any given ophiolite may be incomplete or dismembered. The Penrose definition came out of the widely accepted view that ideal oceanic crust had a ...
A new look at the Altaids: A superorogenic complex in northern and
... evolved along two major arc systems, both in part rifted from the Siberian Craton. Throughout the evolution of the system there were no continental or arc collisions until the system was sealed by its final collision with the intermediate units in the late Palaeozoic and the closure of the Khangai-K ...
... evolved along two major arc systems, both in part rifted from the Siberian Craton. Throughout the evolution of the system there were no continental or arc collisions until the system was sealed by its final collision with the intermediate units in the late Palaeozoic and the closure of the Khangai-K ...
Deep submergence potential science
... velocities, is primarily controlled by the degree of cementation and hydrothermal deposition in this void space. So far, the relationships between such large scale porosity and seismic structure have been investigated primarily by appeal to ophiolite sequences (sediments, lavas, feeder dikes, underl ...
... velocities, is primarily controlled by the degree of cementation and hydrothermal deposition in this void space. So far, the relationships between such large scale porosity and seismic structure have been investigated primarily by appeal to ophiolite sequences (sediments, lavas, feeder dikes, underl ...
Ghikas et al.IGR2010
... Agios Nikolaos Formation (ANF) and a rift assemblage, both of which display ENEvergent thrust faults, shear zones, and folds. The ANF comprises schistose mudstone with pebbles, cobbles, and boulders of arenite and wacke derived from the crystalline basement of Pelagonia. Imbricated along ENE-directe ...
... Agios Nikolaos Formation (ANF) and a rift assemblage, both of which display ENEvergent thrust faults, shear zones, and folds. The ANF comprises schistose mudstone with pebbles, cobbles, and boulders of arenite and wacke derived from the crystalline basement of Pelagonia. Imbricated along ENE-directe ...
Great Lakes tectonic zone
The Great Lakes tectonic zone is bounded by South Dakota at its tip and heads northeast to south of Duluth, Minnesota, then heads east through northern Wisconsin, Marquette, Michigan, and then trends more northeasterly to skim the northern-most shores of lakes Michigan and Huron before ending in the Sudbury, Ontario, Canada, area.During the Late Archean Era the Algoman orogeny added landmass to the Superior province by volcanic activity and continental collision along a boundary that stretches from present-day South Dakota, U.S., into the Lake Huron region near Sudbury, Ontario, Canada.This crustal boundary is the Great Lakes tectonic zone. It is 1,400 km (870 mi) long, and separates the older Archean gneissic terrane to the south from younger Late Archean greenstone-granite terrane to the north.The zone is characterized by active compression during the Algoman orogeny (about 2,700 million years ago), a pulling-apart (extensional) tectonics (2,450 to 2,100 million years ago), a second compression during the Penokean orogeny (1,900 to 1,850 million years ago), a second extension during Middle Proterozoic time (1,600 million years ago) and minor reactivation during Phanerozoic time (the past 500 million years).Collision began along the Great Lakes tectonic zone (GLTZ) with the Algoman mountain-building event and continued for tens of millions of years. During the formation of the GLTZ, the gneissic Minnesota River Valley subprovince was thrust up onto the Superior province's edge as it consumed the Superior province's oceanic crust. Fragmentation of the Kenorland supercontinent began 2,450 million years ago and was completed by 2,100 million years ago. The Wyoming province is the continental landmass that is hypothesized to have rifted away from the southern Superior province portion of Kenorland, before moving rapidly west and docking with the Laurentia supercontinent 1,850 to 1,715 million years ago. Sedimentation from the GLTZ-rifting environment continued into the Penokean orogeny, which is the next major tectonic event in the Great Lakes region. Several earthquakes have been documented in Minnesota, Michigan's Upper Peninsula and Sudbury in the last 120 years along the GLTZ.