Scandium mineralizations in southern Norway
... The Kongsberg Silver Works The Kongsberg silver district (Bugge 1917, Ihlen & Nordrum 1986) is located close to the western margin of the Oslo Rift system. The native silver-bearing calcite veins are known to occur where the fracture system intersects "fahlbands", i.e., schistose zones in the Precam ...
... The Kongsberg Silver Works The Kongsberg silver district (Bugge 1917, Ihlen & Nordrum 1986) is located close to the western margin of the Oslo Rift system. The native silver-bearing calcite veins are known to occur where the fracture system intersects "fahlbands", i.e., schistose zones in the Precam ...
Sabzevar Ophiolite, NE Iran - The University of Texas at Dallas
... south and east and the Binalud mountains (Turan block) to the north, and that this small oceanic arc basin existed from at least mid-Cretaceous times. Intraoceanic subduction began before the Albian (100–113 Ma) and was responsible for generating Sabzevar SSZ-related magmas, ultimately forming a mag ...
... south and east and the Binalud mountains (Turan block) to the north, and that this small oceanic arc basin existed from at least mid-Cretaceous times. Intraoceanic subduction began before the Albian (100–113 Ma) and was responsible for generating Sabzevar SSZ-related magmas, ultimately forming a mag ...
GEOLOGIC MAP OF SOUTHEASTERN ALASKA INTRODUCTION
... deformation and (or) metamorphism are poorly known, (2) they are found in geologic units that grade from relatively intact stratigraphic sequences to metamorphic or structural units, or (3) they are known or interpreted to include two or more geologic units of formation rank that are not generally c ...
... deformation and (or) metamorphism are poorly known, (2) they are found in geologic units that grade from relatively intact stratigraphic sequences to metamorphic or structural units, or (3) they are known or interpreted to include two or more geologic units of formation rank that are not generally c ...
EVOLUTION OF THE NORTH AMERICAN CORDILLERA William R
... The indicated time span of 45–65 million years between initial rifting and onset of passive thermotectonic subsidence is comparable to the time span of 55 million years between initial development of Triassic rift basins and the first emplacement of Jurassic oceanic crust along the modern Atlantic c ...
... The indicated time span of 45–65 million years between initial rifting and onset of passive thermotectonic subsidence is comparable to the time span of 55 million years between initial development of Triassic rift basins and the first emplacement of Jurassic oceanic crust along the modern Atlantic c ...
evolution of the north american cordillera
... The indicated time span of 45–65 million years between initial rifting and onset of passive thermotectonic subsidence is comparable to the time span of 55 million years between initial development of Triassic rift basins and the first emplacement of Jurassic oceanic crust along the modern Atlantic c ...
... The indicated time span of 45–65 million years between initial rifting and onset of passive thermotectonic subsidence is comparable to the time span of 55 million years between initial development of Triassic rift basins and the first emplacement of Jurassic oceanic crust along the modern Atlantic c ...
bedrock geology of the piedmont of delaware and adjacent
... with a continental landmass and adjacent forearc basin sediments during the early Paleozoic. As a result of this collision, the rocks are intensely deformed and metamorphosed to the amphibolite and granulite facies. The oldest rocks are Grenville-age layered gneiss, migmatite, and amphibolite that a ...
... with a continental landmass and adjacent forearc basin sediments during the early Paleozoic. As a result of this collision, the rocks are intensely deformed and metamorphosed to the amphibolite and granulite facies. The oldest rocks are Grenville-age layered gneiss, migmatite, and amphibolite that a ...
Rhenium^Osmium Isotope and Platinum
... Combined volumes estimated for the structural components of the Mackenzie LIP indicate that it is one of the most extensive LIPs recognized. The geology and structure of the Muskox intrusion has been described in detail previously (Findlay & Smith,1965; Irvine & Smith, 1967; Francis, 1994) and its s ...
... Combined volumes estimated for the structural components of the Mackenzie LIP indicate that it is one of the most extensive LIPs recognized. The geology and structure of the Muskox intrusion has been described in detail previously (Findlay & Smith,1965; Irvine & Smith, 1967; Francis, 1994) and its s ...
Deep-sea basins of the Atlantic ocean
... earlier than in the Southern one. The oceanic crust began to form, in both regions, in the south , and propagated later to the north [Pushcharovskii, 1994]. The Southern and Northern oceans were connected only in the Albian, that is, 100 million years ago, their isolated development lasting more tha ...
... earlier than in the Southern one. The oceanic crust began to form, in both regions, in the south , and propagated later to the north [Pushcharovskii, 1994]. The Southern and Northern oceans were connected only in the Albian, that is, 100 million years ago, their isolated development lasting more tha ...
Unraveling the alteration history of the basement rocks along the P2
... of Earth Sciences, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada 2Cameco Corporation, Exploration Office, Saskatoon, SK. Canada, S7M 1J3 3Geological Survey of Canada, Booth Street Complex, Ottawa, Ontario ...
... of Earth Sciences, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada 2Cameco Corporation, Exploration Office, Saskatoon, SK. Canada, S7M 1J3 3Geological Survey of Canada, Booth Street Complex, Ottawa, Ontario ...
as a PDF
... have enough data to determine the main features of the deep structure of the granite body studied, we have measured complementary gravity and magnetic data in the area. The 1:500 000 Bouguer anomaly map (without topographic correction) shows that the region of study is located in an area characteriz ...
... have enough data to determine the main features of the deep structure of the granite body studied, we have measured complementary gravity and magnetic data in the area. The 1:500 000 Bouguer anomaly map (without topographic correction) shows that the region of study is located in an area characteriz ...
A review of the isotopic and trace element evidence for
... been different on Eoarchean to Hadean Earth was a hotter mantle, an atmosphere that was less oxidizing, and lithosphere that was bombarded more frequently by meteorites. A hotter mantle existed in the Archean because Earth is now and was then cooling, radioactive decay produced more heat in the past ...
... been different on Eoarchean to Hadean Earth was a hotter mantle, an atmosphere that was less oxidizing, and lithosphere that was bombarded more frequently by meteorites. A hotter mantle existed in the Archean because Earth is now and was then cooling, radioactive decay produced more heat in the past ...
Geochemistry, Geophysics, Geosystems
... in regions where the crust is divided in three layers, and two crustal rheologies in regions where the crystalline crust consists of two layers. The rheology of diabase is assigned to the Gulf of Mexico with one crystalline crust layer of an oceanic type (Table 1). We do not specify any rheology for ...
... in regions where the crust is divided in three layers, and two crustal rheologies in regions where the crystalline crust consists of two layers. The rheology of diabase is assigned to the Gulf of Mexico with one crystalline crust layer of an oceanic type (Table 1). We do not specify any rheology for ...
Wolverine Deposit Stratigraphy and Shale Relationships
... consists of either carbonaceous shale or carbonate-exhalite and these are conformably overlain, in turn, by carbonaceous shale interlayered with rhyolitic siltstone and iron formation, rhyolite siltstone breccias, and upper carbonaceous shale, all being capped by basalt, mafic volcaniclastic rocks, ...
... consists of either carbonaceous shale or carbonate-exhalite and these are conformably overlain, in turn, by carbonaceous shale interlayered with rhyolitic siltstone and iron formation, rhyolite siltstone breccias, and upper carbonaceous shale, all being capped by basalt, mafic volcaniclastic rocks, ...
Ophiolite concept and its evolution
... gabbros are the early phases to solidify with more differentiated intrusions and volcanic rocks developing later and intruding into these already formed denser rocks. He offered this interpretation to refute Staub’s (1922) idea of gravity-driven separation and differentiation of magma during develop ...
... gabbros are the early phases to solidify with more differentiated intrusions and volcanic rocks developing later and intruding into these already formed denser rocks. He offered this interpretation to refute Staub’s (1922) idea of gravity-driven separation and differentiation of magma during develop ...
Philippine Sea Plate inception, evolution, and consumption with
... 60–55 Ma likely triggered the Oki-Daito plume occurrence, Mesozoic proto-PSP splitting, shortening and then failure across the paleo-transform boundary between the proto-PSP and the Pacific Plate, Izu-Bonin-Mariana subduction initiation and ultimately PSP inception. (2) The initial splitting phase o ...
... 60–55 Ma likely triggered the Oki-Daito plume occurrence, Mesozoic proto-PSP splitting, shortening and then failure across the paleo-transform boundary between the proto-PSP and the Pacific Plate, Izu-Bonin-Mariana subduction initiation and ultimately PSP inception. (2) The initial splitting phase o ...
Mantle-driven deformation of orogenic zones and clutch tectonics
... Earth processes such as mantle convection: if there is no mechanical connection, plate tectonics is either independent or, at a minimum, does not have a simple relationship to mantle convection. This basic realization has recently emerged as one of the most fundamental problems of modem tectonics. I ...
... Earth processes such as mantle convection: if there is no mechanical connection, plate tectonics is either independent or, at a minimum, does not have a simple relationship to mantle convection. This basic realization has recently emerged as one of the most fundamental problems of modem tectonics. I ...
- BIROn - Birkbeck Institutional Research Online
... focus of increased volcanic activity (Sissingh, 2003). Uplift of the Vosges-Black Forest dome commenced between 19-20 Ma; this has been attributed to lithospheric flexuring in the Alpine foreland (Schumacher, 2002; Dèzes et al., 2004). Minor volcanic activity within the Upper Rhine graben, including ...
... focus of increased volcanic activity (Sissingh, 2003). Uplift of the Vosges-Black Forest dome commenced between 19-20 Ma; this has been attributed to lithospheric flexuring in the Alpine foreland (Schumacher, 2002; Dèzes et al., 2004). Minor volcanic activity within the Upper Rhine graben, including ...
structural geology of the western branch of the east african rift
... for this might be the pre-existing heterogeneities at the lithospheric level. The Eastern branch developed in the Pan-African Mozambique Belt, which was a typical subduction/collision orogeny in the Cambrian. Much of the Western branch formed in older, early to middle Proterozoic Belts that, at leas ...
... for this might be the pre-existing heterogeneities at the lithospheric level. The Eastern branch developed in the Pan-African Mozambique Belt, which was a typical subduction/collision orogeny in the Cambrian. Much of the Western branch formed in older, early to middle Proterozoic Belts that, at leas ...
Thematic Article Tethyan ophiolites and Pangea break-up
... Abstract The break-up of Pangea began during the Triassic and was preceded by a generalized Permo-Triassic formation of continental rifts along the future margins between Africa and Europe, between Africa and North America, and between North and South America. During the Middle–Late Triassic, an oce ...
... Abstract The break-up of Pangea began during the Triassic and was preceded by a generalized Permo-Triassic formation of continental rifts along the future margins between Africa and Europe, between Africa and North America, and between North and South America. During the Middle–Late Triassic, an oce ...
Melting Relations of MORB^Sediment Me
... capsule was used to simulate the complex multilayer formed by intense flow within the mantle wedge as predicted by numerical models. A basaltic [mid-ocean ridge basalt (MORB)-derived amphibolite] component was sandwiched between two adjacent layers of a sedimentary (Bt-rich metagreywacke) component. ...
... capsule was used to simulate the complex multilayer formed by intense flow within the mantle wedge as predicted by numerical models. A basaltic [mid-ocean ridge basalt (MORB)-derived amphibolite] component was sandwiched between two adjacent layers of a sedimentary (Bt-rich metagreywacke) component. ...
PDF version - Western Washington University
... the Kohistan arc was an Andean-type continental arc. However, more recent work suggests that this northern collision post-dates collision of Kohistan with India (e.g., Khan et al. 2009, Burg 2011). It is unclear whether the Kohistan arc was ever Andean in nature. The arc was tilted to the north duri ...
... the Kohistan arc was an Andean-type continental arc. However, more recent work suggests that this northern collision post-dates collision of Kohistan with India (e.g., Khan et al. 2009, Burg 2011). It is unclear whether the Kohistan arc was ever Andean in nature. The arc was tilted to the north duri ...
Geology of the Murihiku Area
... terrane in the west and faulted against Dun Mountain Maitai terrane along the northeastern limb of the regional Southland Syncline. The Dun Mountain-Maitai terrane is in turn faulted against the Caples terrane in the northeastern corner of the map area. Dun Mountain - Maitai terrane rocks represent ...
... terrane in the west and faulted against Dun Mountain Maitai terrane along the northeastern limb of the regional Southland Syncline. The Dun Mountain-Maitai terrane is in turn faulted against the Caples terrane in the northeastern corner of the map area. Dun Mountain - Maitai terrane rocks represent ...
40. Evolution of a layered diorite-gabbro to become a layered quartz
... The eastern border of the Wanup pluton along Route 69 contains thick feldspathic bands that alternate with thinner amphibolite bands (Fig 5 c), similar to those at the north end, except that the feldspathic bands are mostly coarser grained with microcline crystals, 1-2 cm long (Fig. 4). These larger ...
... The eastern border of the Wanup pluton along Route 69 contains thick feldspathic bands that alternate with thinner amphibolite bands (Fig 5 c), similar to those at the north end, except that the feldspathic bands are mostly coarser grained with microcline crystals, 1-2 cm long (Fig. 4). These larger ...
The Relevance of Brittle Fault Zones in Tunnel Construction
... (Fig. 2). The Inntal Nappe, Vomperbach Slice Complex and the Thaur, Hauskogel and Hohenegg Slices are part of the Tirolikum, the Lechtal Nappe is part of the Bajuvarikum. Heteroaxial and polyphase folding and thrusting related to various Alpine orogenic phases produced complex structures, with local ...
... (Fig. 2). The Inntal Nappe, Vomperbach Slice Complex and the Thaur, Hauskogel and Hohenegg Slices are part of the Tirolikum, the Lechtal Nappe is part of the Bajuvarikum. Heteroaxial and polyphase folding and thrusting related to various Alpine orogenic phases produced complex structures, with local ...
Geological Society of America Bulletin
... belts. Magmatism during each of these phases produces spatially and temporally associated, mafic-ultramafic to highly evolved rock assemblages. These rock units, which have varying internal structures, geochemical affinities, and age ranges, and originally formed in different geodynamic settings, co ...
... belts. Magmatism during each of these phases produces spatially and temporally associated, mafic-ultramafic to highly evolved rock assemblages. These rock units, which have varying internal structures, geochemical affinities, and age ranges, and originally formed in different geodynamic settings, co ...
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.