9. Metasomatism and metasomatic rocks
... etc.) components. The acidic metasomatic rocks (or the products of acid leaching) show common enrichment with acid components and depletion of alkalies and alkali earths relative to the initial rocks. Alkaline and basic metasomatism produces the opposite mass exchange. Each of the metasomatic famili ...
... etc.) components. The acidic metasomatic rocks (or the products of acid leaching) show common enrichment with acid components and depletion of alkalies and alkali earths relative to the initial rocks. Alkaline and basic metasomatism produces the opposite mass exchange. Each of the metasomatic famili ...
Mathematical models of the Earth`s density structure and their
... layers. Kennett and Engdahl (1991) compiled the parameterized velocity model IASP91 that summarized travel time characteristics of main seismic phases. Kennett et al. (1995) compiled the AK135-f model by augmenting the AK135 velocity model with the density and Q-model of Montagner and Kennett (1995) ...
... layers. Kennett and Engdahl (1991) compiled the parameterized velocity model IASP91 that summarized travel time characteristics of main seismic phases. Kennett et al. (1995) compiled the AK135-f model by augmenting the AK135 velocity model with the density and Q-model of Montagner and Kennett (1995) ...
Exhumation of high-pressure rocks beneath the Solund Basin
... from its exposure of (i) one of the rare syn-kinematic plutons in the Norwegian Caledonides, the Sogneskollen granodiorite (Skjerlie et al., 2000); (ii) a nearly complete stack of the Caledonian nappes and overlying sediments; and (iii) an excellent structural section from the WGC up through the Upp ...
... from its exposure of (i) one of the rare syn-kinematic plutons in the Norwegian Caledonides, the Sogneskollen granodiorite (Skjerlie et al., 2000); (ii) a nearly complete stack of the Caledonian nappes and overlying sediments; and (iii) an excellent structural section from the WGC up through the Upp ...
Normal faulting in the upper plate of a metamorphic core complex
... and numerous competing models have been proposed for its formation and evolution (e.g., Wernicke, 1981; Miller and Gans, 1983; Lee, 1995). Most of these models have utilized relations in lower plate rocks beneath the northern Snake Range decollement rather than an in depth analysis of upper plate st ...
... and numerous competing models have been proposed for its formation and evolution (e.g., Wernicke, 1981; Miller and Gans, 1983; Lee, 1995). Most of these models have utilized relations in lower plate rocks beneath the northern Snake Range decollement rather than an in depth analysis of upper plate st ...
SESSIONE TS1.3 Processi magmatici e metamorfici nella crosta
... Composition typically ranges from tonalite to granite, but minor dioritic and gabbroic bodies are also present. Magma emplacement took place between 300 and 290 ± 10 Ma during the extensional tectonic stage, following collapse of the Hercynian belt. The heat advected by granitoids was considered res ...
... Composition typically ranges from tonalite to granite, but minor dioritic and gabbroic bodies are also present. Magma emplacement took place between 300 and 290 ± 10 Ma during the extensional tectonic stage, following collapse of the Hercynian belt. The heat advected by granitoids was considered res ...
Exploring Earth: Plate Tectonics
... deep conceptual understanding that is aligned with the standards, key science concepts, and essential features of classroom inquiry (as defined by the National Science Education Standards). In Immersion Units, students learn academic content by working like scientists: making observations, asking qu ...
... deep conceptual understanding that is aligned with the standards, key science concepts, and essential features of classroom inquiry (as defined by the National Science Education Standards). In Immersion Units, students learn academic content by working like scientists: making observations, asking qu ...
Microseismicity and focal mechanisms at the western termination of
... Continental deformation is commonly more complicated than plate tectonics predicts, for it is not limited to narrow boundaries between rigid lithospheric plates, but affects wide areas with horizontal dimensions much larger than the lithosphere thickness (England & Jackson 1989). The strength of con ...
... Continental deformation is commonly more complicated than plate tectonics predicts, for it is not limited to narrow boundaries between rigid lithospheric plates, but affects wide areas with horizontal dimensions much larger than the lithosphere thickness (England & Jackson 1989). The strength of con ...
BERYLLIUM RESOURCES IN NEW MEXICO AND ADJACENT
... Beryllium (Be) is a strategic element that is becoming more important in our technological society, because it is six times stronger than steel, has a high melting point, a high heat capacity, is non-sparking, is transparent to X-rays, and when alloyed with other metals it prevents metal fatigue fai ...
... Beryllium (Be) is a strategic element that is becoming more important in our technological society, because it is six times stronger than steel, has a high melting point, a high heat capacity, is non-sparking, is transparent to X-rays, and when alloyed with other metals it prevents metal fatigue fai ...
Did westward subduction cause Cretaceous
... The North American portion of the Cordilleran orogen extends continuously from Alaska to southern Mexico, and from east to west over much of its length the orogen comprises an easterly vergent fold-thrust belt, a complexly deformed metamorphic hinterland that collapsed gravitationally, and an interl ...
... The North American portion of the Cordilleran orogen extends continuously from Alaska to southern Mexico, and from east to west over much of its length the orogen comprises an easterly vergent fold-thrust belt, a complexly deformed metamorphic hinterland that collapsed gravitationally, and an interl ...
The Russian Far East is a territory where young geological
... expert in geodynamics, petrology, and mineralogy and focuses on reconstruction of geodynamic environments of Earth’s crust evolution in ocean-continent transition zone. In addition, Academician Khanchuk is a recognized authority in fundamental and applied problems of the Pacific margins geology. ...
... expert in geodynamics, petrology, and mineralogy and focuses on reconstruction of geodynamic environments of Earth’s crust evolution in ocean-continent transition zone. In addition, Academician Khanchuk is a recognized authority in fundamental and applied problems of the Pacific margins geology. ...
Alps vs. Apennines - Dipartimento di Scienze della Terra
... monocline, the dip of the slab, the depth of the basal decollement, the PTt paths, the nature and thickness of the upper and lower plates, thermal state, seismicity, stress field, backarc basin development or not, etc. In this article only the most significative of these parameters will be discussed ( ...
... monocline, the dip of the slab, the depth of the basal decollement, the PTt paths, the nature and thickness of the upper and lower plates, thermal state, seismicity, stress field, backarc basin development or not, etc. In this article only the most significative of these parameters will be discussed ( ...
GEOLOGIC MAP OF SOUTHEASTERN ALASKA INTRODUCTION
... particular unit in this category are generally similar in lithic type, stratigraphic position, and age of deposition and are, unless otherwise noted, interpreted to be generally correlative. Such strata generally constitute formations, lithic components of formations or groups, or unnamed geologic u ...
... particular unit in this category are generally similar in lithic type, stratigraphic position, and age of deposition and are, unless otherwise noted, interpreted to be generally correlative. Such strata generally constitute formations, lithic components of formations or groups, or unnamed geologic u ...
Setting Based Classification
... • Occurs in areas that have not experienced significant deformation or orogeny • Restricted to large, relatively undisturbed ...
... • Occurs in areas that have not experienced significant deformation or orogeny • Restricted to large, relatively undisturbed ...
Southern Urals CONTENTS Age and tectonic/structural setting
... Initiation of the ‘Urals Palaeocean’ started at ca. 460 ma (O2-3) was marked by sub-alkaline basalts and cherts in its first stage (the epicontinental rifting referred to in Savlieva & Nesbit 1998). The geochemical signature (REE) of these volcanics is interpreted as either MORB or sub-alkaline depe ...
... Initiation of the ‘Urals Palaeocean’ started at ca. 460 ma (O2-3) was marked by sub-alkaline basalts and cherts in its first stage (the epicontinental rifting referred to in Savlieva & Nesbit 1998). The geochemical signature (REE) of these volcanics is interpreted as either MORB or sub-alkaline depe ...
A normalised seawater strontium isotope curve: possible
... its sedimentary cover (87 Sr/86 Sr ∼0.712: Palmer and Edmond, 1989; Peucker-Ehrenbrink and Miller, 2006). The 87 Sr/86 Sr signatures of these two isotopic end members indicate that about twice as much ocean Sr derives from river runoff (RR) than from hydrothermal exchange (MI). Because seafloor spre ...
... its sedimentary cover (87 Sr/86 Sr ∼0.712: Palmer and Edmond, 1989; Peucker-Ehrenbrink and Miller, 2006). The 87 Sr/86 Sr signatures of these two isotopic end members indicate that about twice as much ocean Sr derives from river runoff (RR) than from hydrothermal exchange (MI). Because seafloor spre ...
Rhenium^Osmium Isotope and Platinum-Group Element
... rock differentiation series from dunite cumulates, peridotites, pyroxenites, and gabbros, to granophyres. Second, it is one of the most ultramafic large layered intrusions so far recognized on Earth and has been considered to be related in space and time to the extensive 127 Ga giant Mackenzie dyke ...
... rock differentiation series from dunite cumulates, peridotites, pyroxenites, and gabbros, to granophyres. Second, it is one of the most ultramafic large layered intrusions so far recognized on Earth and has been considered to be related in space and time to the extensive 127 Ga giant Mackenzie dyke ...
chapter 3
... island group. It has not been dismembered to the degree seen in the Napeequa, and contains fewer ultramafic sections. A good case can be advanced (but not resolved) that the Alexander, Wrangell and Chilliwack Terranes were amalgamated by Late Triassic time. Because all of these are older than the Bri ...
... island group. It has not been dismembered to the degree seen in the Napeequa, and contains fewer ultramafic sections. A good case can be advanced (but not resolved) that the Alexander, Wrangell and Chilliwack Terranes were amalgamated by Late Triassic time. Because all of these are older than the Bri ...
Kimberlites and Lamproites: Primary Sources of Diamond
... On the basis of this evidence, it is now believed that some diamonds are derived by the disaggregation of such source rocks. Thus, the recognition of purple subcalcic chrome pyrope xenocrysts, known colloquially as GI0 garnets, in kimberlites Is commonly regarded as a key indicator for the presence ...
... On the basis of this evidence, it is now believed that some diamonds are derived by the disaggregation of such source rocks. Thus, the recognition of purple subcalcic chrome pyrope xenocrysts, known colloquially as GI0 garnets, in kimberlites Is commonly regarded as a key indicator for the presence ...
Commentary on schematic geological map of Antarctica Scale 1:10
... has been, the fact that only about 2% of the continent's bedrock is not covered by ice , and thus accessible to surface examination . A subsidiary problem is the difficult access to these outcrops , many of which are in large cliff faces (Fig.l) or isolated nunataks adjacent to which the ice surface ...
... has been, the fact that only about 2% of the continent's bedrock is not covered by ice , and thus accessible to surface examination . A subsidiary problem is the difficult access to these outcrops , many of which are in large cliff faces (Fig.l) or isolated nunataks adjacent to which the ice surface ...
Large igneous province
A large igneous province (LIP) is an extremely large accumulation of igneous rocks, including liquid rock (intrusive) or volcanic rock formations (extrusive), when hot magma extrudes from inside the Earth and flows out. The source of many or all LIPs is variously attributed to mantle plumes or to processes associated with plate tectonics. Types of LIPs can include large volcanic provinces (LVP), created through flood basalt and large plutonic provinces (LPP). Eleven distinct flood basalt episodes occurred in the past 250 million years, creating volcanic provinces, which coincided with mass extinctions in prehistoric times. Formation depends on a range of factors, such as continental configuration, latitude, volume, rate, duration of eruption, style and setting (continental vs. oceanic), the preexisting climate state, and the biota resilience to change.