Late Precambrian Stratigraphy and Structure of the North
... correlations (Føyn 1969; Siedlecka & Siedlecki 1972) it is thought that glacial and fluvial deposits of the lower Laksefjord Group, resting on crystalline rocks belonging to the Fennoscandian Shield at Laksefjord (Føyn 1960; Laird 1972), constitute the oldest record of the Late Precambrian depositio ...
... correlations (Føyn 1969; Siedlecka & Siedlecki 1972) it is thought that glacial and fluvial deposits of the lower Laksefjord Group, resting on crystalline rocks belonging to the Fennoscandian Shield at Laksefjord (Føyn 1960; Laird 1972), constitute the oldest record of the Late Precambrian depositio ...
Document
... The new observations support the model of basal shear at Moho i.e. mantle moved faster than crust due to active mantle upwelling ...
... The new observations support the model of basal shear at Moho i.e. mantle moved faster than crust due to active mantle upwelling ...
Structural evolution and strike-slip tectonics off - Archimer
... faulting has controlled the forearc basin evolution since the Late Miocene. The Mentawai Fault Zone extends up to the north of Simeulue Island and was most probably connected farther northwards to the Sumatran Fault Zone until the end of the Miocene. Since then, this northern branch jumped westwards ...
... faulting has controlled the forearc basin evolution since the Late Miocene. The Mentawai Fault Zone extends up to the north of Simeulue Island and was most probably connected farther northwards to the Sumatran Fault Zone until the end of the Miocene. Since then, this northern branch jumped westwards ...
Non-chondritic sulphur isotope composition of the terrestrial mantle
... lack of correlation between d34S and 206Pb/204Pb (Supplementary Fig. 5), together with the preservation of the trends between d34S and Sr–Nd isotopes, argue in favour of relatively sulphur-poor HIMU and LOMU endmembers, overprinted by the contribution of a sulphur-rich enriched-mantle component. In ...
... lack of correlation between d34S and 206Pb/204Pb (Supplementary Fig. 5), together with the preservation of the trends between d34S and Sr–Nd isotopes, argue in favour of relatively sulphur-poor HIMU and LOMU endmembers, overprinted by the contribution of a sulphur-rich enriched-mantle component. In ...
Earth,Tests,Ch14
... geographic location of the associated volcanic arc? Also, if the angle of a subducting plate changed over time, how would this be expressed by the spatial distribution and ages of volcanic rocks produced by the subduction zoned? Diff: 3 ...
... geographic location of the associated volcanic arc? Also, if the angle of a subducting plate changed over time, how would this be expressed by the spatial distribution and ages of volcanic rocks produced by the subduction zoned? Diff: 3 ...
Geology of Nevada - Nevada Bureau of Mines and Geology
... oceanic plates, expressed in folds, thrust faults, strikeslip faults, normal faults, igneous intrusions, volcanism, metamorphism, and sedimentary basins, are recorded in the rocks. Nevada rocks document volcanic and intrusive igneous activity intermittently and repeatedly from earliest geologic hist ...
... oceanic plates, expressed in folds, thrust faults, strikeslip faults, normal faults, igneous intrusions, volcanism, metamorphism, and sedimentary basins, are recorded in the rocks. Nevada rocks document volcanic and intrusive igneous activity intermittently and repeatedly from earliest geologic hist ...
COMPOSITION, STRUCTURE AND EVOLUTION OF THE
... The metamorphic core complex of Naxos is an elongated, structural dome, which is made of three subdomes separated by a high - strain - zone and pinched synforms. The core complex consists of a migmatite core mantled by metasediments (mainly marble and schists). Non - metamorphic units, limestones, o ...
... The metamorphic core complex of Naxos is an elongated, structural dome, which is made of three subdomes separated by a high - strain - zone and pinched synforms. The core complex consists of a migmatite core mantled by metasediments (mainly marble and schists). Non - metamorphic units, limestones, o ...
2307501 Basin analysis
... (B) If the block extrudes with a rotational component into a weak oceanic crust (a transtensional setting), a sedimentary basin forms at the end of the strike-slip fault. Examples include the Yinggehai Basin, which is related to the extrusion of the Indochina Block, and the Gulf of California, which ...
... (B) If the block extrudes with a rotational component into a weak oceanic crust (a transtensional setting), a sedimentary basin forms at the end of the strike-slip fault. Examples include the Yinggehai Basin, which is related to the extrusion of the Indochina Block, and the Gulf of California, which ...
3 Types of Metamorphism
... • Rocks are metamorphosed over large areas that are the size of many states or even several countries ...
... • Rocks are metamorphosed over large areas that are the size of many states or even several countries ...
Dynamic lithosphere within the Great Basin
... overthickened crust that supported the Nevadaplano [Coney and Harms, 1984]. Core complex formation typifies deformation during this period [Dickinson, 2002, 2006]. The second extensional phase began 18– 16 Ma [e.g., Noble, 1972] and was driven by a reorganization of the Pacific-Farallon-North America ...
... overthickened crust that supported the Nevadaplano [Coney and Harms, 1984]. Core complex formation typifies deformation during this period [Dickinson, 2002, 2006]. The second extensional phase began 18– 16 Ma [e.g., Noble, 1972] and was driven by a reorganization of the Pacific-Farallon-North America ...
IgPetMORB13
... Hafnium Paradox: MORB's have 176Hf/177Hf ratios indicating derivation from a source with a long term Lu/Hf ratio greater than chondrites, yet they have a measured Lu/Hf ratio lower than chondrites. One way of explaining this is to have garnet in the mantle residue with a complementary high Lu/Hf rat ...
... Hafnium Paradox: MORB's have 176Hf/177Hf ratios indicating derivation from a source with a long term Lu/Hf ratio greater than chondrites, yet they have a measured Lu/Hf ratio lower than chondrites. One way of explaining this is to have garnet in the mantle residue with a complementary high Lu/Hf rat ...
MORB13
... Many MORB basalts (especially EMORB) have (Sm/Yb)n ratios of 1.3 to 1.5, suggesting slight depletion in the heavy rare earths (HREE). This has been interpreted as a residual garnet effect. The effect is small, however, and MORB have relatively high and unfractionated HREE in comparison to all OIB ba ...
... Many MORB basalts (especially EMORB) have (Sm/Yb)n ratios of 1.3 to 1.5, suggesting slight depletion in the heavy rare earths (HREE). This has been interpreted as a residual garnet effect. The effect is small, however, and MORB have relatively high and unfractionated HREE in comparison to all OIB ba ...
Full-text PDF (final published version)
... Continental crust Oceanic crust Bulk silicate earth Core ...
... Continental crust Oceanic crust Bulk silicate earth Core ...
Structural Geology (Geol 305) Semester (071)
... foliation is a term used to describe all type of cleavage slaty, crenulation and it is used also to describe the planar structure in coarser-grained metamorphic rocks, such as schist and gneiss where planar orientation of at least one mineral dominates the fabric (parallel of mica, amphibole, and fl ...
... foliation is a term used to describe all type of cleavage slaty, crenulation and it is used also to describe the planar structure in coarser-grained metamorphic rocks, such as schist and gneiss where planar orientation of at least one mineral dominates the fabric (parallel of mica, amphibole, and fl ...
Chapter 17 Basins in arc-continent collisions
... trench-slope basins following arc-continent collision is biased toward margins that were tectonically accreting for a substantial length of time before collision. If accretionary prism material is preserved in an orogen, it may be difficult to distinguish from volumetrically less important trench-sl ...
... trench-slope basins following arc-continent collision is biased toward margins that were tectonically accreting for a substantial length of time before collision. If accretionary prism material is preserved in an orogen, it may be difficult to distinguish from volumetrically less important trench-sl ...
This PDF file is subject to the following conditions and... Copyright © 2006, The Geological Society of America, Inc. (GSA)....
... below, and Phanerozoic-style plate tectonics, driven by the sinking of cool lithospheric slabs, was a major turning point in the thermal evolution of the Earth. Prior to this transition the formation of stable, long-lived crust was rare; after this transition, the formation and amalgamation of conti ...
... below, and Phanerozoic-style plate tectonics, driven by the sinking of cool lithospheric slabs, was a major turning point in the thermal evolution of the Earth. Prior to this transition the formation of stable, long-lived crust was rare; after this transition, the formation and amalgamation of conti ...
Omarini, Ricardo H., Massimo Gasparon, Angelo
... mechanism is the Alto Paraguay Triassic alkaline magmatism at the border of the Rio Apa block. This area was affected by rifting at about 241 Ma, probably induced by counter-clockwise and clockwise movements (north and south, respectively) hinged at about 20° latitude south and taking place during t ...
... mechanism is the Alto Paraguay Triassic alkaline magmatism at the border of the Rio Apa block. This area was affected by rifting at about 241 Ma, probably induced by counter-clockwise and clockwise movements (north and south, respectively) hinged at about 20° latitude south and taking place during t ...
Deposition of the Early to Late Permian Whitehill Formation during a
... The black, laminated, carbonaceous shales of the Whitehill Formation were deposited in a very young, underfilled foreland basin under anoxic bottom conditions. A sea-level highstand, basin tectonics, and climate were the controlling factors - interplay of which resulted in bounding conditions for or ...
... The black, laminated, carbonaceous shales of the Whitehill Formation were deposited in a very young, underfilled foreland basin under anoxic bottom conditions. A sea-level highstand, basin tectonics, and climate were the controlling factors - interplay of which resulted in bounding conditions for or ...
Evolution of the Neogene-Pleistocene Basins of Macedonia
... basins in Macedonia. Polyphase Neogene deformation manifested by relative vertical displacement creating topographic relief, and in some regions associated with volcanic activity, directly influenced the gradual formation of the grabens and the type of sedimentary deposits in the basins. From the mi ...
... basins in Macedonia. Polyphase Neogene deformation manifested by relative vertical displacement creating topographic relief, and in some regions associated with volcanic activity, directly influenced the gradual formation of the grabens and the type of sedimentary deposits in the basins. From the mi ...
The evolving nature of terrestrial crust from the Hadean, through the
... Van Kranendonk (2010) and Kamber (2010), juvenile crustal segments exist, which have formed very rapidly, apparently without the involvement of much pre-existing, significantly older crustal nuclei. It will be argued that these juvenile continental remnants differ markedly from how continental lithos ...
... Van Kranendonk (2010) and Kamber (2010), juvenile crustal segments exist, which have formed very rapidly, apparently without the involvement of much pre-existing, significantly older crustal nuclei. It will be argued that these juvenile continental remnants differ markedly from how continental lithos ...
Author`s personal copy - Laboratoire de Planétologie et
... trench and explain the occurrence of alkaline magmatism in the backarc region at 12 Ma. Concerning the post-plateau event, the hypothesis of a slab window related to the SCR-1 segment is consistent in time and space (Gorring et al., 2003; Guivel et al., 2006). Along the western border of the MLBA, t ...
... trench and explain the occurrence of alkaline magmatism in the backarc region at 12 Ma. Concerning the post-plateau event, the hypothesis of a slab window related to the SCR-1 segment is consistent in time and space (Gorring et al., 2003; Guivel et al., 2006). Along the western border of the MLBA, t ...
The mechanics of progressive deformation in crustal plates
... mapped by oil explorationists and the continued use of their maps today is a testament to their skill. The compilation by Van Bemmelen, "The Geology of Indonesia", first published in 1949, stands as a tribute to the work done by these early explorers and remains one of the most authoritative sources ...
... mapped by oil explorationists and the continued use of their maps today is a testament to their skill. The compilation by Van Bemmelen, "The Geology of Indonesia", first published in 1949, stands as a tribute to the work done by these early explorers and remains one of the most authoritative sources ...
New Tectonic Map of Georgia (Explanatory Note)
... 33]. The existence of deep faults, which in many cases were overlain by sedimentary cover of different thickness, was established on the basis of different geological (structural, sedimentary, magmatic etc.) and geophysical (gravimetric, magnetic, seismic and other) signs. For the first time for Geo ...
... 33]. The existence of deep faults, which in many cases were overlain by sedimentary cover of different thickness, was established on the basis of different geological (structural, sedimentary, magmatic etc.) and geophysical (gravimetric, magnetic, seismic and other) signs. For the first time for Geo ...
ppt
... by fractional crystallization) is indicated by the arrow. Different primary magmas (to the left) are distinguished by vertical variations in K2O at low SiO2. After Gill, 1981, Orogenic ...
... by fractional crystallization) is indicated by the arrow. Different primary magmas (to the left) are distinguished by vertical variations in K2O at low SiO2. After Gill, 1981, Orogenic ...
Provenance (geology)
Provenance in geology, is the reconstruction of the history of sediments movements over time. The Earth is not a static but a dynamic planet, all rocks are subject to transition between the three main rock types, which are sedimentary, metamorphic, and igneous rocks (the rock cycle). Rocks exposed to the surface, sooner or later, are broken down into sediments. Sediments are expected to be able to provide evidence of the erosion history of their parent source rocks. The purpose of provenance study is to restore the tectonic, paleo-geographic and paleo-climatic history.