Time-Space Development of an External Brine
... Volcanic rocks were erupted into the shallow basin, eventually building a topographic high, as shown by (1) interfingering of the lower volcanic flows with the basin margin Boyer Ranch Formation, (2) the presence of rare pillow structures in the lower portions of the volcanic pile and the absence of ...
... Volcanic rocks were erupted into the shallow basin, eventually building a topographic high, as shown by (1) interfingering of the lower volcanic flows with the basin margin Boyer Ranch Formation, (2) the presence of rare pillow structures in the lower portions of the volcanic pile and the absence of ...
7. Skagit River
... skyrocketed in the l970’s with the publication of the first guidebooks to the mountains here. Over the last two decades, commercial outfitters have become an increasing presence, catering to national and international clientelle. In numerous areas, it has been necessary to restrict the number of visit ...
... skyrocketed in the l970’s with the publication of the first guidebooks to the mountains here. Over the last two decades, commercial outfitters have become an increasing presence, catering to national and international clientelle. In numerous areas, it has been necessary to restrict the number of visit ...
Ophiolites and Their Origins
... ated with seafloor spreading prior to 170 Ma because no 1980s. Observations of in situ oceanic crust in spreading oceanic lithosphere older than this age is preserved in the environments within the upper plates of subduction zones modern oceans. The occurrence of sheeted dikes, side-byin the western ...
... ated with seafloor spreading prior to 170 Ma because no 1980s. Observations of in situ oceanic crust in spreading oceanic lithosphere older than this age is preserved in the environments within the upper plates of subduction zones modern oceans. The occurrence of sheeted dikes, side-byin the western ...
eastern european alpine system and the carpathian
... which lay between the European and African plate. In Late Jurassic time the three fragments of continental crust were separated by narrow zones of oceanic crust and palinspastic reconstructions of the continental fragments indicate they were considerably larger than their present size and had differ ...
... which lay between the European and African plate. In Late Jurassic time the three fragments of continental crust were separated by narrow zones of oceanic crust and palinspastic reconstructions of the continental fragments indicate they were considerably larger than their present size and had differ ...
Clarification of Pasha Rift Structure in Pasha-Ladoga
... (deGroot-Hedlin and Constable, 1990) algorithm was used for the 2D inversion. We applied the joint TE + TM inversion because it allowed inclusion of both polarization information, which is superior for medium with horizontal heterogeneities. The model mesh was constructed with an incremental factor ...
... (deGroot-Hedlin and Constable, 1990) algorithm was used for the 2D inversion. We applied the joint TE + TM inversion because it allowed inclusion of both polarization information, which is superior for medium with horizontal heterogeneities. The model mesh was constructed with an incremental factor ...
PDF
... Accretionary prisms are mostly composed of recycled continental crust in the form of clastic sediments, shed from the overriding plate and thus are mostly MORN. Accretionary prisms are cemented to arcs when these collide to form accretionary orogens such as the western N. America cordillera (Dickins ...
... Accretionary prisms are mostly composed of recycled continental crust in the form of clastic sediments, shed from the overriding plate and thus are mostly MORN. Accretionary prisms are cemented to arcs when these collide to form accretionary orogens such as the western N. America cordillera (Dickins ...
the massabesic gneiss complex, new hampshire
... MORBs representing the initiation of ocean basin development. The leading edge of this landmass, of which the Massabesic Gneiss Complex is the only observable remnant, collided with Laurentia during the Acadian Orogeny. The inboard, thicker, more continental trailing-edge, that is, platform Avalon ( ...
... MORBs representing the initiation of ocean basin development. The leading edge of this landmass, of which the Massabesic Gneiss Complex is the only observable remnant, collided with Laurentia during the Acadian Orogeny. The inboard, thicker, more continental trailing-edge, that is, platform Avalon ( ...
Deep structures and breakup along volcanic rifted margins: insights
... Norwegian volcanic rifted margin. A surprising high-velocity lower crustal dome marked by a strong amplitude reflection (T Reflection) is described below the north Gjallar Ridge (NGR) near the volcanic plateau formed during the late Paleocene – Early Eocene breakup. Faulting along the NGR occurs dur ...
... Norwegian volcanic rifted margin. A surprising high-velocity lower crustal dome marked by a strong amplitude reflection (T Reflection) is described below the north Gjallar Ridge (NGR) near the volcanic plateau formed during the late Paleocene – Early Eocene breakup. Faulting along the NGR occurs dur ...
here - W. Steven Holbrook
... crustal reflectivity (e.g., Mooney and Brocher, 1987), is conspicuously lacking in the Aleutian arc. MCS profiles acquired across and along the arc during our experiment (Bangs et al., 1995; McGeary and Aleutian Working Group, 1996) show little intracrustal reflectivity, despite the recording of dee ...
... crustal reflectivity (e.g., Mooney and Brocher, 1987), is conspicuously lacking in the Aleutian arc. MCS profiles acquired across and along the arc during our experiment (Bangs et al., 1995; McGeary and Aleutian Working Group, 1996) show little intracrustal reflectivity, despite the recording of dee ...
Formation and Exhumation of Ultrahigh
... The earliest models for UHP tectonism assumed that it occurs during subduction of a continental margin because the metamorphic pressure–temperature (P–T) conditions of UHP rocks are typical of subduction zones and not of overthickened continental collision zones, such as the Tibetan Plateau. A secon ...
... The earliest models for UHP tectonism assumed that it occurs during subduction of a continental margin because the metamorphic pressure–temperature (P–T) conditions of UHP rocks are typical of subduction zones and not of overthickened continental collision zones, such as the Tibetan Plateau. A secon ...
Density of Oceanic Crust
... Certain properties of a substance are both distinctive and relatively easy to determine. Density, the ratio between a sample’s mass and volume at a specific temperature and pressure (like standard ambient temperature and pressure), is one such property. Regardless of the size of a sample, the densit ...
... Certain properties of a substance are both distinctive and relatively easy to determine. Density, the ratio between a sample’s mass and volume at a specific temperature and pressure (like standard ambient temperature and pressure), is one such property. Regardless of the size of a sample, the densit ...
Chapter 20: Anorthosites
... Highly felsic nature and their location in continental areas they share with granitoid rocks The felsic mineral, however, is a calcic plagioclase, which, along with associated high-temperature mafic minerals, suggests a stronger similarity to basaltic rocks ...
... Highly felsic nature and their location in continental areas they share with granitoid rocks The felsic mineral, however, is a calcic plagioclase, which, along with associated high-temperature mafic minerals, suggests a stronger similarity to basaltic rocks ...
SGES 1302 Lecture4
... Plate tectonics is a theory of geology that has been developed to explain the observed evidence for large scale motions of the Earth's lithosphere. The theory encompassed and superseded the older theory of continental drift from the first half of the 20th century and the concept of seafloor spreadin ...
... Plate tectonics is a theory of geology that has been developed to explain the observed evidence for large scale motions of the Earth's lithosphere. The theory encompassed and superseded the older theory of continental drift from the first half of the 20th century and the concept of seafloor spreadin ...
The origin and occurrence of
... With one plate acting as a cap over the Martian mantle and no recycling of extruded material the mantle convection would be considerably sluggish (Montesi, 2000), inhibiting plume generation. Yet distinct episodes of early magmatic/tectonic activity that declines with time from early explosive volca ...
... With one plate acting as a cap over the Martian mantle and no recycling of extruded material the mantle convection would be considerably sluggish (Montesi, 2000), inhibiting plume generation. Yet distinct episodes of early magmatic/tectonic activity that declines with time from early explosive volca ...
Gabbroic Pegmatite Intrusions, Iberia Abyssal
... exhumation of mantle rocks was under way by 137 Ma and continued for 10–20 my (Whitmarsh & Wallace, 2001; Manatschal et al., 2002). Site 1070 lies >100 km outboard of Hobby High, with much of the intervening oceanic basement being serpentinized peridotite (Fig. 2). Linear magnetic anomalies in the v ...
... exhumation of mantle rocks was under way by 137 Ma and continued for 10–20 my (Whitmarsh & Wallace, 2001; Manatschal et al., 2002). Site 1070 lies >100 km outboard of Hobby High, with much of the intervening oceanic basement being serpentinized peridotite (Fig. 2). Linear magnetic anomalies in the v ...
Geothermal gradients in continental magmatic arcs: Constraints from
... even if these considerations can be addressed adequately, a more important uncertainty arises from the fact that much of the heat in continental arcs may be advected by magma. The thermal histories that result from such heating are very different from those in classical regional metamorphic terranes ...
... even if these considerations can be addressed adequately, a more important uncertainty arises from the fact that much of the heat in continental arcs may be advected by magma. The thermal histories that result from such heating are very different from those in classical regional metamorphic terranes ...
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 The scope of metamorphic Geology
... experimental studies and through the application of equilibrium thermodynamic principles. Both techniques are used to establish the PT stability range of metamorphic minerals and mineral associations, and provide the basis for the subdivision PT space into distinct metamorphic facies. Most types of ...
... experimental studies and through the application of equilibrium thermodynamic principles. Both techniques are used to establish the PT stability range of metamorphic minerals and mineral associations, and provide the basis for the subdivision PT space into distinct metamorphic facies. Most types of ...
Formation of metamorphic core complexes in non-over - HAL-Insu
... extensive parametric study by Tirel et al. (2008) demonstrated that in the case of an orogenic crust with a commonly inferred rheological structure, three conditions should be satisfied: (1) the initial ...
... extensive parametric study by Tirel et al. (2008) demonstrated that in the case of an orogenic crust with a commonly inferred rheological structure, three conditions should be satisfied: (1) the initial ...
Plume mantle source heterogeneity through time: Insights from the
... the CCOP results from the accretion of two separated Late Cretaceous oceanic plateaus, related to two independent hot spots. ...
... the CCOP results from the accretion of two separated Late Cretaceous oceanic plateaus, related to two independent hot spots. ...
accepted manuscript
... The EW-trending Xiaohuangshan ophiolite mélange (about 22 km long and 6 km wide) is situated in the Xiaohuangshan fault (TXF) (Fig. 3). A matrix of various schists contains about fifty exotic lenticular blocks that are mainly harzburgites and dunites, and a few olivine pyroxenites, pyroxenites, ande ...
... The EW-trending Xiaohuangshan ophiolite mélange (about 22 km long and 6 km wide) is situated in the Xiaohuangshan fault (TXF) (Fig. 3). A matrix of various schists contains about fifty exotic lenticular blocks that are mainly harzburgites and dunites, and a few olivine pyroxenites, pyroxenites, ande ...
6 Metamorphic Rocks
... of experimental apparatus is shown here. Small samples of pulverized rock are placed in a tiny metal capsule about the size of a vitamin pill. The capsule is usually made of gold or some other noble metal that remains stable at high temperature.This small capsule is then placed inside a “bottle” wit ...
... of experimental apparatus is shown here. Small samples of pulverized rock are placed in a tiny metal capsule about the size of a vitamin pill. The capsule is usually made of gold or some other noble metal that remains stable at high temperature.This small capsule is then placed inside a “bottle” wit ...
Structural development of the Mid-Tertiary Doi Suthep Metamorphic
... schist, suggest peak metamorphic grades in the amphibolite facies. The generally medium- to coarse-grained textures also suggest a high metamorphic grade. This interpretation is consistent with relations farther south, in the Doi Inthanon area. There, metasedimentary rocks form a thick mantle over a ...
... schist, suggest peak metamorphic grades in the amphibolite facies. The generally medium- to coarse-grained textures also suggest a high metamorphic grade. This interpretation is consistent with relations farther south, in the Doi Inthanon area. There, metasedimentary rocks form a thick mantle over a ...
(Neoproterozoic-Paleozoic) and plate reconstructions
... Late Paleozoic. These data along with an extensive published paleomagnetic database for the cratons of Laurentia, Baltica, Siberia, and Gondwana are the basis for the presented paleotectonic reconstructions. The migrations of those Arctida tectonic blocks that lack paleomagnetic data are reconstruct ...
... Late Paleozoic. These data along with an extensive published paleomagnetic database for the cratons of Laurentia, Baltica, Siberia, and Gondwana are the basis for the presented paleotectonic reconstructions. The migrations of those Arctida tectonic blocks that lack paleomagnetic data are reconstruct ...
A New Mineral Province for PGEs, Au, Sc, Cu, Ni, Technology Metals
... A new Silurian-Devonian metallogenic province has been discovered in Australia using spinifex biogeochemistry. Targets include PGE, Sc, REE, HFSE, Cu, Au and possibly diamond. Intrusions are surrounded by REEY-rich fenite alteration zones and may be capped by metal-rich laterite. ...
... A new Silurian-Devonian metallogenic province has been discovered in Australia using spinifex biogeochemistry. Targets include PGE, Sc, REE, HFSE, Cu, Au and possibly diamond. Intrusions are surrounded by REEY-rich fenite alteration zones and may be capped by metal-rich laterite. ...
Baltic Shield
The Baltic Shield (sometimes referred to as the Fennoscandian Shield) is located in Fennoscandia (Norway, Sweden and Finland), northwest Russia and under the Baltic Sea. The Baltic Shield is defined as the exposed Precambrian northwest segment of the East European Craton. It is composed mostly of Archean and Proterozoic gneisses and greenstones which have undergone numerous deformations through tectonic activity (see Geology of Fennoscandia map [1]). The Baltic Shield contains the oldest rocks of the European continent. The lithospheric thickness is about 200-300 km. During the Pleistocene epoch, great continental ice sheets scoured and depressed the shield's surface, leaving a thin covering of glacial material and innumerable lakes and streams. The Baltic Shield is still rebounding today following the melting of the thick glaciers during the Quaternary Period.