![2014-Wannamaker-Casc.. - University of Alberta](http://s1.studyres.com/store/data/015537562_1-537b32ab2c24c442e322150c8e7561cd-300x300.png)
2014-Wannamaker-Casc.. - University of Alberta
... Complete sediment offscraping does not appear to occur offshore Oregon. Seismically imaged seaward 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., ...
... Complete sediment offscraping does not appear to occur offshore Oregon. Seismically imaged seaward 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., ...
The Origin, Evolution and Present State of Subcontinental Lithosphere
... composition and evolution remains out of reach. The fact that the average continental crust is > 2.5 Ga whereas the oceanic crust is < 200 Ma tells us that the bulk continental crust (vs. the oceanic crust) is relatively permanent. The prevailing view holds that the subcontinental lithospheric mantl ...
... composition and evolution remains out of reach. The fact that the average continental crust is > 2.5 Ga whereas the oceanic crust is < 200 Ma tells us that the bulk continental crust (vs. the oceanic crust) is relatively permanent. The prevailing view holds that the subcontinental lithospheric mantl ...
STATE GEOLOGICAL MAP OF UKRAINE
... (Uzhotskiy pass) to 1406 m (Pikuy Mountain) high south-westward of which there is extended VolovetskoMizhgirska Verkhovyna and the highest in the territory Polonynskiy Ridge (Polonyna Rivna Mountain of 1479 m height). This part of the area is of medium-mountain type, extensively eroded, with narrow ...
... (Uzhotskiy pass) to 1406 m (Pikuy Mountain) high south-westward of which there is extended VolovetskoMizhgirska Verkhovyna and the highest in the territory Polonynskiy Ridge (Polonyna Rivna Mountain of 1479 m height). This part of the area is of medium-mountain type, extensively eroded, with narrow ...
3 Factors controlling the crustal density structure - diss.fu
... difference in phase proportions and densities calculated by both approaches under the same thermodynamic conditions are generally lower than those generated by uncertainties in temperatures. However, some important differences persist for andesite and basaltic andesite compositions that justify a co ...
... difference in phase proportions and densities calculated by both approaches under the same thermodynamic conditions are generally lower than those generated by uncertainties in temperatures. However, some important differences persist for andesite and basaltic andesite compositions that justify a co ...
Continent–ocean transition and voluminous magmatic underplating
... magmatic underplating and asymmetrical conjugate margins formations are considered as a mirror of complex pre- and syn-rift processes. Key words: crustal structure, East Greenland, ray tracing, rifted margin, underplating. ...
... magmatic underplating and asymmetrical conjugate margins formations are considered as a mirror of complex pre- and syn-rift processes. Key words: crustal structure, East Greenland, ray tracing, rifted margin, underplating. ...
Table of Contents - Society of Economic Geologists
... The voluminous information on Alaskan volcanogenic massive sulfide deposits is brought together in the paper by Newbeny, Crafford, Newkirk, Young, Nelson, and Duke (1997b). Spatially distributed throughout much of Alaska, such deposits provide exciting exploration opportunities for precious and base ...
... The voluminous information on Alaskan volcanogenic massive sulfide deposits is brought together in the paper by Newbeny, Crafford, Newkirk, Young, Nelson, and Duke (1997b). Spatially distributed throughout much of Alaska, such deposits provide exciting exploration opportunities for precious and base ...
subduction to strike-slip transitions on plate boundaries
... southwestern New Zealand to an intra-oceanic transform boundary on the Puysegur Ridge. The transition region evolved from a continental rift connected with an oceanic spreading system in the Eocene and Oligocene, to its present day strike-slip – trench – strike-slip character. The location of the Al ...
... southwestern New Zealand to an intra-oceanic transform boundary on the Puysegur Ridge. The transition region evolved from a continental rift connected with an oceanic spreading system in the Eocene and Oligocene, to its present day strike-slip – trench – strike-slip character. The location of the Al ...
Article
... geometry [1], which the Devonian and Triassic sample sets show in Fig 4. The recycled Devonian sample set is dominated by Precambrian ages with good correlation to the “Cordilleran supersource I”, with lesser fractions derived from Paleozoic arcs. Detrital zircons from the exotic Devonian sample set ...
... geometry [1], which the Devonian and Triassic sample sets show in Fig 4. The recycled Devonian sample set is dominated by Precambrian ages with good correlation to the “Cordilleran supersource I”, with lesser fractions derived from Paleozoic arcs. Detrital zircons from the exotic Devonian sample set ...
lithosphere 2006 - Helsingin yliopisto
... Upper Mantle (part II) (Chair A. Korja) P. Heikkinen, I.T. Kukkonen and FIRE Working Group. FIRE transects: reflectivity of the crust in the Fennoscandian Shield K. Sundblad, M. Beckholmen, O. Nilsen and T. Andersen. Palaeozoic metallogeny of Røros (Norway); a tool for improving Palaeoproterozoic cr ...
... Upper Mantle (part II) (Chair A. Korja) P. Heikkinen, I.T. Kukkonen and FIRE Working Group. FIRE transects: reflectivity of the crust in the Fennoscandian Shield K. Sundblad, M. Beckholmen, O. Nilsen and T. Andersen. Palaeozoic metallogeny of Røros (Norway); a tool for improving Palaeoproterozoic cr ...
1.8 Billion Years of Detrital Zircon Recycling Calibrates a
... geometry [1], which the Devonian and Triassic sample sets show in Fig 4. The recycled Devonian sample set is dominated by Precambrian ages with good correlation to the “Cordilleran supersource I”, with lesser fractions derived from Paleozoic arcs. Detrital zircons from the exotic Devonian sample set ...
... geometry [1], which the Devonian and Triassic sample sets show in Fig 4. The recycled Devonian sample set is dominated by Precambrian ages with good correlation to the “Cordilleran supersource I”, with lesser fractions derived from Paleozoic arcs. Detrital zircons from the exotic Devonian sample set ...
Crustal structure and evolution of the Mariana intra
... crystallized basaltic magmas, and the transformation of crustal materials into upper mantle. All four scenarios probably occur beneath the currently active Mariana arc (Fig. 3). However, neither melts nor serpentinized mantle can cause the observed low mantle velocity on the backarc (eastern) side o ...
... crystallized basaltic magmas, and the transformation of crustal materials into upper mantle. All four scenarios probably occur beneath the currently active Mariana arc (Fig. 3). However, neither melts nor serpentinized mantle can cause the observed low mantle velocity on the backarc (eastern) side o ...
FOSI BeritaSedimentologi BS 23 March2012
... crust then sank of its own accord and pulled the subduction zone across the Banda Sea area in a horseshoe shape. The overlying arc migrated south and east and the northern margin was largely a strike-slip margin. Backarc spreading occurred NW of the arc in the present Banda Sea. Hall (2002) infers t ...
... crust then sank of its own accord and pulled the subduction zone across the Banda Sea area in a horseshoe shape. The overlying arc migrated south and east and the northern margin was largely a strike-slip margin. Backarc spreading occurred NW of the arc in the present Banda Sea. Hall (2002) infers t ...
Abyssal peridotites, very slow spreading ridges and
... almost entirely removed. At the same time, the spatially associated basalts have a large range of compositions, similar to those from the rift valleys, requiring extensive shallowlevel fractional crystallization. Since there is little evidence for magma chambers at these fracture zones, it is conclu ...
... almost entirely removed. At the same time, the spatially associated basalts have a large range of compositions, similar to those from the rift valleys, requiring extensive shallowlevel fractional crystallization. Since there is little evidence for magma chambers at these fracture zones, it is conclu ...
iceland in relation to the mid-atlantic ridge
... units which would produce a lenticular shield-like pile of lavas in a given period of time. ...
... units which would produce a lenticular shield-like pile of lavas in a given period of time. ...
provenance analysis and detrital zircons: keys to - ETH E
... sedimentary rocks in these accretionary complexes permits understanding the Cretaceous to Paleogene geological evolution, the geodynamic context and the tectonic-sedimentation relationships. The multidisciplinary provenance study, including sandstone framework, heavy mineral analysis, in situ U-Pb d ...
... sedimentary rocks in these accretionary complexes permits understanding the Cretaceous to Paleogene geological evolution, the geodynamic context and the tectonic-sedimentation relationships. The multidisciplinary provenance study, including sandstone framework, heavy mineral analysis, in situ U-Pb d ...
Distribution of potassium feldspar polymorphs
... The Loch Ailsh complex, Assynt, Scotland, is a small (4 km by 2"5 km) composite intrusion dominantly of highly feldspathic syenite. The feldspar variation within the mass has been described previously (Parsons, I965) and is summarized here, together with some new rock and separated-feldspar analyses ...
... The Loch Ailsh complex, Assynt, Scotland, is a small (4 km by 2"5 km) composite intrusion dominantly of highly feldspathic syenite. The feldspar variation within the mass has been described previously (Parsons, I965) and is summarized here, together with some new rock and separated-feldspar analyses ...
PDF
... Ma's report, the second shearing strain rate parameter of the strain rate field, as computed by China mainland's GPS data for the 1993e2000 period, shows a large-scale negative value region inside the QinghaieTibet Plate. Most of the fracture zone of the Kunlun Mountain Pass West Ms8.1 earthquake th ...
... Ma's report, the second shearing strain rate parameter of the strain rate field, as computed by China mainland's GPS data for the 1993e2000 period, shows a large-scale negative value region inside the QinghaieTibet Plate. Most of the fracture zone of the Kunlun Mountain Pass West Ms8.1 earthquake th ...
The global range of subduction zone thermal structures from
... The assumption of full coupling of subducting slab and convecting overlying mantle at 80 km depth with no mantle convection at shallower levels results in a “shelf” in the P–T paths at 80 km (between ∼2 and 2.5 GPa) in which there is an isobaric temperature increase. An average D80 P–T path was calc ...
... The assumption of full coupling of subducting slab and convecting overlying mantle at 80 km depth with no mantle convection at shallower levels results in a “shelf” in the P–T paths at 80 km (between ∼2 and 2.5 GPa) in which there is an isobaric temperature increase. An average D80 P–T path was calc ...
Slab behaviour and its surface expression: new insights
... The Bouguer correction accounts for the gravitational effects of masses between gravity stations and the reference level. For stations on land, this is often performed by subtracting the gravity effect of an infinite slab with a specific density (typically 2670 kg m 3). For stations at sea, the opp ...
... The Bouguer correction accounts for the gravitational effects of masses between gravity stations and the reference level. For stations on land, this is often performed by subtracting the gravity effect of an infinite slab with a specific density (typically 2670 kg m 3). For stations at sea, the opp ...
New Zealand`s Continental Shelf and UNCLOS
... the outer edge of the continental margin. The outer edge of the continental margin is defined by fixed points located either 60 nautical miles from the foot of the continental slope, or where the sediment thickness is at least 1% of the shortest distance to the nearest foot of the continental slope ...
... the outer edge of the continental margin. The outer edge of the continental margin is defined by fixed points located either 60 nautical miles from the foot of the continental slope, or where the sediment thickness is at least 1% of the shortest distance to the nearest foot of the continental slope ...
as a PDF
... the Cleaverville Formation, along the northern coast of Western Australia (Fig. 1a). The age of the Cleaverville Formation of the Gorge Creek Group is estimated to be 3.3–3.2 Gyr on the basis of U-Pb zircon dating (Hickman, 1990). The Formation is composed of weakly metamorphosed greenstone, BIF, mu ...
... the Cleaverville Formation, along the northern coast of Western Australia (Fig. 1a). The age of the Cleaverville Formation of the Gorge Creek Group is estimated to be 3.3–3.2 Gyr on the basis of U-Pb zircon dating (Hickman, 1990). The Formation is composed of weakly metamorphosed greenstone, BIF, mu ...
Subduction cycles under western North America during the
... to test and quantify these concepts. Plate motions in the northeast Pacific and the rates of convergence of these plates with the North American plate during Cretaceous and Tertiary time have been studied in more detail than anywhere else in the world. Radiometric ages for tens of thousands of rocks ...
... to test and quantify these concepts. Plate motions in the northeast Pacific and the rates of convergence of these plates with the North American plate during Cretaceous and Tertiary time have been studied in more detail than anywhere else in the world. Radiometric ages for tens of thousands of rocks ...
Geology 10L Manual - FOG - City College of San Francisco
... Field trip – You must arrange your own transportation to the field trip. Carpools are encouraged! Start making friends now with students with cars. The field trip begins at a time that provides you sufficient time to reach the site from CCSF. Arriving late means you may miss us (if we move) or part ...
... Field trip – You must arrange your own transportation to the field trip. Carpools are encouraged! Start making friends now with students with cars. The field trip begins at a time that provides you sufficient time to reach the site from CCSF. Arriving late means you may miss us (if we move) or part ...
20 Transform Plate Boundaries - North Coast Distance Education
... age of the oceanic crust on either side of the fracture is huge, nearly 50 million years (compare with the map on the inside front cover). The Romanche fracture zone is a series of deep valleys separated by ridges. One narrow ridge rises above sea level to make cluster of small islands—St. Peter and ...
... age of the oceanic crust on either side of the fracture is huge, nearly 50 million years (compare with the map on the inside front cover). The Romanche fracture zone is a series of deep valleys separated by ridges. One narrow ridge rises above sea level to make cluster of small islands—St. Peter and ...
res terrae - Oulun yliopisto
... This thesis comprises six original papers that focus on the sedimentology of the Mesoproterozoic (1.6–1.0 Ga) Telemark basin-fills in southern Norway, known as the Telemark supracrustal rocks. It is made up of an approximately 10-km-thick succession of volcanic-sedimentary rocks that are an integral ...
... This thesis comprises six original papers that focus on the sedimentology of the Mesoproterozoic (1.6–1.0 Ga) Telemark basin-fills in southern Norway, known as the Telemark supracrustal rocks. It is made up of an approximately 10-km-thick succession of volcanic-sedimentary rocks that are an integral ...
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.