Lewisian, Torridonian and Moine Rocks of Scotland
... third group, the Sleat Group, is only exposed on the Isle of Skye and is rather more enigmatic. The Moine Supergroup was also deposited during the early Neoproterozoic, and is now exposed to the east of the Moine Thrust Belt. Rocks considered to correlate with the Moine are also exposed on the Shetl ...
... third group, the Sleat Group, is only exposed on the Isle of Skye and is rather more enigmatic. The Moine Supergroup was also deposited during the early Neoproterozoic, and is now exposed to the east of the Moine Thrust Belt. Rocks considered to correlate with the Moine are also exposed on the Shetl ...
Lesson Plan: Earthquakes - Didattica Orizzonte Scuola
... severe at its centre. > The higher on the Richter scale, the more severe the earthquake is. > The level of development – the more developed the nation, the more likely to have the resources and technology for monitoring, prediction and response. > The population density - the more densely populated ...
... severe at its centre. > The higher on the Richter scale, the more severe the earthquake is. > The level of development – the more developed the nation, the more likely to have the resources and technology for monitoring, prediction and response. > The population density - the more densely populated ...
ch 4
... all) of these plutons appear to have intruded along fault zones, shear zones or other tectonic features. They characteristically rose to shallow depths, and were frequently accompanied by surface volcanism. Much of that volcanism appears to have been relatively explosive in character. Because these ...
... all) of these plutons appear to have intruded along fault zones, shear zones or other tectonic features. They characteristically rose to shallow depths, and were frequently accompanied by surface volcanism. Much of that volcanism appears to have been relatively explosive in character. Because these ...
Dynamic models of continental rifting with melt generation
... been applied successfully for the explanation of volcanic sequences at volcanic rich rifted continental margins (White et al., 1987; White and McKenzie, 1989). Given the extreme variability of abundance or absence of volcanic rocks at passive continental margins, and, at the same time the rather uni ...
... been applied successfully for the explanation of volcanic sequences at volcanic rich rifted continental margins (White et al., 1987; White and McKenzie, 1989). Given the extreme variability of abundance or absence of volcanic rocks at passive continental margins, and, at the same time the rather uni ...
Chapter 21: Metamorphism
... – Metamorphic pattern is simpler than the structural one • Pattern of increasing metamorphic grade from both directions toward the core area • Most orogenic belts have several episodes of deformation and metamorphism, creating a more complex polymetamorphic pattern • Associated with continental coll ...
... – Metamorphic pattern is simpler than the structural one • Pattern of increasing metamorphic grade from both directions toward the core area • Most orogenic belts have several episodes of deformation and metamorphism, creating a more complex polymetamorphic pattern • Associated with continental coll ...
Genesis of the Neogene to Quaternary volcanism in the Carpathian
... later on. Mixing between mantle-derived magmas and lower-crustal melts was an important process at the first stage of the silicic and calc-alkaline magmatism in the Northern Pannonian Basin. However, the crustal component gradually decreased with time, which is consistent with magmatic activity in a ...
... later on. Mixing between mantle-derived magmas and lower-crustal melts was an important process at the first stage of the silicic and calc-alkaline magmatism in the Northern Pannonian Basin. However, the crustal component gradually decreased with time, which is consistent with magmatic activity in a ...
Chemical weathering in Malay Peninsula and North Borneo: Clay
... Southeast Asia in the northeastern Borneo, indicate that the rapid uplift during the late Miocene controlled the final mountain landscape of North Borneo, becoming one of major controlling factors on the chemical weathering. There is no significant difference in geological settings (bedrock litholog ...
... Southeast Asia in the northeastern Borneo, indicate that the rapid uplift during the late Miocene controlled the final mountain landscape of North Borneo, becoming one of major controlling factors on the chemical weathering. There is no significant difference in geological settings (bedrock litholog ...
Introduction to Metamorphism
... – Metamorphic pattern is simpler than the structural one • Pattern of increasing metamorphic grade from both directions toward the core area • Most orogenic belts have several episodes of deformation and metamorphism, creating a more complex polymetamorphic pattern • Associated with continental coll ...
... – Metamorphic pattern is simpler than the structural one • Pattern of increasing metamorphic grade from both directions toward the core area • Most orogenic belts have several episodes of deformation and metamorphism, creating a more complex polymetamorphic pattern • Associated with continental coll ...
GEOLOGY, ORE DEPOSITS, AND MINERAL POTENTIAL OF THE
... The writer first began geologic studies on the Seward Peninsula in 1952; between 1960 and 1971 he was continuously engaged in studies of the geology and mineral resources of the region for the U.S. Geological Survey, first in the detailed geologic mapping of the region around the Lost River tin-tung ...
... The writer first began geologic studies on the Seward Peninsula in 1952; between 1960 and 1971 he was continuously engaged in studies of the geology and mineral resources of the region for the U.S. Geological Survey, first in the detailed geologic mapping of the region around the Lost River tin-tung ...
The Cordilleran Ribbon Continent of North America
... depositional basement to Medial Basin and Cassiar Platform is a distinct, in part, Grenvillian-aged basement. Precambrian crystalline rocks crop out within the pericratonic assemblages in British Columbia, including, from south to north, the Priest River Complex (Idaho), the Monahsee Complex, the Ma ...
... depositional basement to Medial Basin and Cassiar Platform is a distinct, in part, Grenvillian-aged basement. Precambrian crystalline rocks crop out within the pericratonic assemblages in British Columbia, including, from south to north, the Priest River Complex (Idaho), the Monahsee Complex, the Ma ...
Petrological models of magma evolution and deep crustal structure
... Seismic experiments imaging the deep crustal structure beneath hotspot tracks and oceanic plateaus indicate unusually high seismic velocities (V, = 7.3-7.8 km/s) at the base of the crust. These high-velocity ‘layers’, up to 10 km thick, are generally interpreted as large igneous intrusions. In this ...
... Seismic experiments imaging the deep crustal structure beneath hotspot tracks and oceanic plateaus indicate unusually high seismic velocities (V, = 7.3-7.8 km/s) at the base of the crust. These high-velocity ‘layers’, up to 10 km thick, are generally interpreted as large igneous intrusions. In this ...
The evolving nature of terrestrial crust from the Hadean, through the
... continental lithosphere. Here I review the geological, geochemical and basic geophysical data that hold key information regarding Archaean crust formation and preservation. This insight is then contrasted with the data for the preceding Hadean and following Palaeoproterozoic, both often portrayed as ...
... continental lithosphere. Here I review the geological, geochemical and basic geophysical data that hold key information regarding Archaean crust formation and preservation. This insight is then contrasted with the data for the preceding Hadean and following Palaeoproterozoic, both often portrayed as ...
Geology of Southern California
... Mesozoic plutonic rocks similar to granite (red) and associated metamorphosed volcanic and sedimentary rocks (green) of about the same age. Vast exposures of lightcolored granitic rock can be seen throughout the high country of the southern Sierra Nevada and also make up many of the prominent peaks ...
... Mesozoic plutonic rocks similar to granite (red) and associated metamorphosed volcanic and sedimentary rocks (green) of about the same age. Vast exposures of lightcolored granitic rock can be seen throughout the high country of the southern Sierra Nevada and also make up many of the prominent peaks ...
How Plate-forming Processes Explain Structure and Shortening in
... Estimates of crustal shortening were obtained from an analysis of about 50 geological cross‐sections from 30 collision belts (Figure 2). Each section was constructed and restored using balancing techniques constrained by stratigraphic data from wells, seismic reflection profiles and field geologica ...
... Estimates of crustal shortening were obtained from an analysis of about 50 geological cross‐sections from 30 collision belts (Figure 2). Each section was constructed and restored using balancing techniques constrained by stratigraphic data from wells, seismic reflection profiles and field geologica ...
Is the rate of supercontinent assembly changing with time?
... 900–700, and 300–200 Ma. There is no simple relationship in craton collision frequency or average plate velocity between supercontinent assemblies and breakups. Assembly of Nuna at 1700–1500 Ma correlates with very low collision rates, whereas assemblies of Rodinia and Gondwana at 1000–850 and 650–3 ...
... 900–700, and 300–200 Ma. There is no simple relationship in craton collision frequency or average plate velocity between supercontinent assemblies and breakups. Assembly of Nuna at 1700–1500 Ma correlates with very low collision rates, whereas assemblies of Rodinia and Gondwana at 1000–850 and 650–3 ...
Workshop on the Rio Grande Rift
... bringing traditional geoscientists and remote sensing scientists together in fruitful exchange, outlining a . research approach to the RGR, and identifying significant problems to be worked on. However, the workshop was much less successful in identifying ways in which remote sensing could be utiliz ...
... bringing traditional geoscientists and remote sensing scientists together in fruitful exchange, outlining a . research approach to the RGR, and identifying significant problems to be worked on. However, the workshop was much less successful in identifying ways in which remote sensing could be utiliz ...
Tectonic stress field of the continental United States
... indicators. Previously, in the eastern United States we used fault offsets of Tertiary or Quaternary age as compiled by Prowell (1983). We have now restricted our consideration to faults in the eastern United States that show offsets of Miocene or younger strata. The age criteria for geological data ...
... indicators. Previously, in the eastern United States we used fault offsets of Tertiary or Quaternary age as compiled by Prowell (1983). We have now restricted our consideration to faults in the eastern United States that show offsets of Miocene or younger strata. The age criteria for geological data ...
On the relationship between the Bushveld Complex and its felsic
... magma into the crust undoubtedly causes significant thermal perturbation to the overlying crust. Despite the clear importance of the country rock in modulating the thermal evolution the Bushveld Complex, little is known about the nature and extent of its roof zone. This manuscript details the latera ...
... magma into the crust undoubtedly causes significant thermal perturbation to the overlying crust. Despite the clear importance of the country rock in modulating the thermal evolution the Bushveld Complex, little is known about the nature and extent of its roof zone. This manuscript details the latera ...
Baltica upside down: A new plate tectonic model for Rodinia and the
... These early crust-forming events may in part overlap with formation of calc-alkalic arcs related to subduction of Ægir crust along the continent boundaries. These 690–603 Ma arcs dominate the periGondwana region (Murphy et al., 1999), which formed synchronously with arcs in the Ran and Ægir Seas, in ...
... These early crust-forming events may in part overlap with formation of calc-alkalic arcs related to subduction of Ægir crust along the continent boundaries. These 690–603 Ma arcs dominate the periGondwana region (Murphy et al., 1999), which formed synchronously with arcs in the Ran and Ægir Seas, in ...
Depositional Environment of Cherts of the Sikhote
... terrigenous rocks) indicate that they are derived from overlying Gorbousha Formation. The blocks and fragments of Triassic shallow-marine terrigenous rocks containing the macrofauna fossils (Monotis), are, most likely, derived from the continental margin, under which the Taukha prism was formed. The ...
... terrigenous rocks) indicate that they are derived from overlying Gorbousha Formation. The blocks and fragments of Triassic shallow-marine terrigenous rocks containing the macrofauna fossils (Monotis), are, most likely, derived from the continental margin, under which the Taukha prism was formed. The ...
Lecture 6 - Mantle and Basalts
... contain melt; they ascend by “creep”. Adiabatic melting occurs when rising mantle does not cool along the geotherm, but instead it remains hot. This allows it to reach the mantle solidus that has a shallower slope on the P-T diagram (see diagram below). The melting is eutectic involving olivine, opx ...
... contain melt; they ascend by “creep”. Adiabatic melting occurs when rising mantle does not cool along the geotherm, but instead it remains hot. This allows it to reach the mantle solidus that has a shallower slope on the P-T diagram (see diagram below). The melting is eutectic involving olivine, opx ...
Heterogeneous crustal deformation along the central-northern
... Figure 1 shows displacement rate vectors at all the analyzed sites. More than 10 mm/yr shortening evidently occurs along the Omachi Linear Array. On the other hand, the central part around the Gofukuji Fault does not have so much shortening. Rather, left-lateral shear deformation seems dominant in t ...
... Figure 1 shows displacement rate vectors at all the analyzed sites. More than 10 mm/yr shortening evidently occurs along the Omachi Linear Array. On the other hand, the central part around the Gofukuji Fault does not have so much shortening. Rather, left-lateral shear deformation seems dominant in t ...
Ascent of the ultrahigh-pressure Western Gneiss Region, Norway.
... CALEDONIDES The Scandinavian Caledonides formed from ca. 500 to 350 Ma through a series of collisional events—including the emplacement of multiple ophiolites, and the Laurentia-Baltica collision—separated by intervening extensional phases (Roberts, 2003; Hacker and Gans, 2005); there were at least ...
... CALEDONIDES The Scandinavian Caledonides formed from ca. 500 to 350 Ma through a series of collisional events—including the emplacement of multiple ophiolites, and the Laurentia-Baltica collision—separated by intervening extensional phases (Roberts, 2003; Hacker and Gans, 2005); there were at least ...
the Scanned PDF
... In a recent examination of a granitic intrusion and the associatedcontact relations, a statistical study of the form of zircon provided clear confirmatory evidence of the extent of granitization of the contact rocks adjacent to the instrusion, although the behavior of zircon in this instance, under ...
... In a recent examination of a granitic intrusion and the associatedcontact relations, a statistical study of the form of zircon provided clear confirmatory evidence of the extent of granitization of the contact rocks adjacent to the instrusion, although the behavior of zircon in this instance, under ...
Sedimentary Rocks Lecture-HO
... Sediments are diverse, as are the rocks made from them. Sedimentary rocks divide to groups based on sediments type. 1) Siliciclastics – Made from weathered rock fragments (clasts primarily of silicates). ...
... Sediments are diverse, as are the rocks made from them. Sedimentary rocks divide to groups based on sediments type. 1) Siliciclastics – Made from weathered rock fragments (clasts primarily of silicates). ...
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.