Isostasy, dynamic topography, and the elevation of the Apennines of
... quantify the relative contribution of isostatic and dynamic components, providing new insights on the range of subduction processes contributing to the topography and vertical motion of the Apennines mountain belt. 2. Isostasy, elevation and uplift rate The elevation of a mountain belt and rate of s ...
... quantify the relative contribution of isostatic and dynamic components, providing new insights on the range of subduction processes contributing to the topography and vertical motion of the Apennines mountain belt. 2. Isostasy, elevation and uplift rate The elevation of a mountain belt and rate of s ...
46_1996_Ilg et al_GSABull_Tectonic evolution in GC
... Suite.” The Brahma Schist consists of mafic to intermediate-composition metavolcanic rocks that have yielded an age of 1750 Ma. The Rama Schist consists of felsic metavolcanic rocks that have yielded an age of 1742 Ma. On the basis of the presence of relict pillow structures, interlayering of metavo ...
... Suite.” The Brahma Schist consists of mafic to intermediate-composition metavolcanic rocks that have yielded an age of 1750 Ma. The Rama Schist consists of felsic metavolcanic rocks that have yielded an age of 1742 Ma. On the basis of the presence of relict pillow structures, interlayering of metavo ...
A Geochemical Classification for Granitic Rocks
... This geochemical classification of granitic rocks is based upon three variables. These are FeO/(FeO + MgO) = Fe-number [or FeOtot/(FeOtot + MgO) = Fe∗], the modified alkali–lime index (MALI) (Na2O + K2O – CaO) and the aluminum saturation index (ASI) [Al/(Ca – 1·67P + Na + K)]. The Fe-number (or Fe∗) ...
... This geochemical classification of granitic rocks is based upon three variables. These are FeO/(FeO + MgO) = Fe-number [or FeOtot/(FeOtot + MgO) = Fe∗], the modified alkali–lime index (MALI) (Na2O + K2O – CaO) and the aluminum saturation index (ASI) [Al/(Ca – 1·67P + Na + K)]. The Fe-number (or Fe∗) ...
Geodynamics of the South China Sea
... of the SCS located north of chron C12, where chrons 15 to 17 were previously identified, is not oceanic but thinned continental crust intruded by volcanic elongated features emplaced 17–22 Ma ago. Based on magnetic anomaly identifications, the end of the SCS spreading could be either 15.5, 20.5 Ma (Br ...
... of the SCS located north of chron C12, where chrons 15 to 17 were previously identified, is not oceanic but thinned continental crust intruded by volcanic elongated features emplaced 17–22 Ma ago. Based on magnetic anomaly identifications, the end of the SCS spreading could be either 15.5, 20.5 Ma (Br ...
Geology of the Pothook Alkalic Copper
... margins of the breccia, fragments are larger and more angular, and the breccia grades into a crackle zone with unrotated fragmentsin a disrupted stockworkof iron oxide sulphide veins. As such, the hydrothermal breccia and veins are interpreted to be geneticallyrelated. The mineralizing episode that ...
... margins of the breccia, fragments are larger and more angular, and the breccia grades into a crackle zone with unrotated fragmentsin a disrupted stockworkof iron oxide sulphide veins. As such, the hydrothermal breccia and veins are interpreted to be geneticallyrelated. The mineralizing episode that ...
New Investigations of Basement to the Western Athabasca Basin
... leucogranite. In general, the granodioritic to tonalitic rocks constitute a larger proportion of the felsic gneiss although proportions are variable. ...
... leucogranite. In general, the granodioritic to tonalitic rocks constitute a larger proportion of the felsic gneiss although proportions are variable. ...
Nappes of the southern Tien Shan
... The southern Tien Shan is a folded area with widespread Paleozoic nappes. The ensembles of nappes distributed in Uzbekistan, Tajikistan, Kyrgyzstan, and China are described, and their structural similarity and distinctions in different parts of the area are shown. Nappes of the southern Tien Shan oc ...
... The southern Tien Shan is a folded area with widespread Paleozoic nappes. The ensembles of nappes distributed in Uzbekistan, Tajikistan, Kyrgyzstan, and China are described, and their structural similarity and distinctions in different parts of the area are shown. Nappes of the southern Tien Shan oc ...
tsunamiDescription
... the frictional forces between the two stuck plates. When this happens, the overriding plate snaps back into an unrestrained position. This sudden motion is the cause of the tsunami - because it gives an enormous shove to the ...
... the frictional forces between the two stuck plates. When this happens, the overriding plate snaps back into an unrestrained position. This sudden motion is the cause of the tsunami - because it gives an enormous shove to the ...
Practising science: reading the rocks and ecology
... connected tasks. The first is observation: they observe the natural world and the space beyond it, and both describe and record what they see. Second, they construct hypotheses to explain what they see. Third, they carry out experiments where possible to test their hypotheses. Finally they communica ...
... connected tasks. The first is observation: they observe the natural world and the space beyond it, and both describe and record what they see. Second, they construct hypotheses to explain what they see. Third, they carry out experiments where possible to test their hypotheses. Finally they communica ...
uLearn Activity Guides and Resources
... The uLearn library contains a great many informative resources to help introduce tectonics, how they work, how they affect the landscape and what impact they have on people. This is just a small selection of the resources available on this subject. There are too many to easily list in one place, bu ...
... The uLearn library contains a great many informative resources to help introduce tectonics, how they work, how they affect the landscape and what impact they have on people. This is just a small selection of the resources available on this subject. There are too many to easily list in one place, bu ...
Essentials of Geology, 11e
... Critical thinking and discussion questions. Use complete sentences, correct spelling, and the information presented in Chapter 1 to answer the questions below. 59) Aside from near oceanic trenches, most earthquakes originate at depths of 100 kilometers or less. Considering the physical properties of ...
... Critical thinking and discussion questions. Use complete sentences, correct spelling, and the information presented in Chapter 1 to answer the questions below. 59) Aside from near oceanic trenches, most earthquakes originate at depths of 100 kilometers or less. Considering the physical properties of ...
Absolute migration and the evolution of the Rodriguez
... traces: the Indo-Australian, African and Antarctic plates, yield coincident migration trajectories for the RTJ. The RTJ appears to have been migrating northeasterly since 64 Ma (Chron 28). The migration trajectories do not indicate any major changes that could be related to instability of the RTJ. T ...
... traces: the Indo-Australian, African and Antarctic plates, yield coincident migration trajectories for the RTJ. The RTJ appears to have been migrating northeasterly since 64 Ma (Chron 28). The migration trajectories do not indicate any major changes that could be related to instability of the RTJ. T ...
3.20 Trace Element and Isotopic Fluxes
... and metamorphism along the subduction pathway. The focus in this contribution is largely on the chemical and isotopic tracers commonly employed to elucidate chemical cycling in subduction zones based on study of arc lavas, and on discussion of metamorphic suites for which it is possible to evaluate ...
... and metamorphism along the subduction pathway. The focus in this contribution is largely on the chemical and isotopic tracers commonly employed to elucidate chemical cycling in subduction zones based on study of arc lavas, and on discussion of metamorphic suites for which it is possible to evaluate ...
california state university, northridge rayleigh wave tomography
... divides the North American plate and the Pacific plate. This tectonic system was formed during the Miocene period with the subduction of the Farallon plate and the East Pacific Rise (EPR) beneath California. The Farallon plate was subducting steadily beneath the North American plate from 37 to 30 Ma ...
... divides the North American plate and the Pacific plate. This tectonic system was formed during the Miocene period with the subduction of the Farallon plate and the East Pacific Rise (EPR) beneath California. The Farallon plate was subducting steadily beneath the North American plate from 37 to 30 Ma ...
Geological Survey of Denmark and Greenland. Bulletin 10
... Ultrabasic alkaline magmatic rocks are products of melts generated deep within or at the base of the lithospheric mantle. The magmas may reach the surface to form lavas and pyroclastic deposits; alternatively they crystallise at depth to form dykes or central complexes. The rocks are chemically dist ...
... Ultrabasic alkaline magmatic rocks are products of melts generated deep within or at the base of the lithospheric mantle. The magmas may reach the surface to form lavas and pyroclastic deposits; alternatively they crystallise at depth to form dykes or central complexes. The rocks are chemically dist ...
A synthesis of tectonically-related stratigraphy in the North Atlantic
... terized by volcanic activity and uplift, may have been caused by thermal dorning related to the onset of ...
... terized by volcanic activity and uplift, may have been caused by thermal dorning related to the onset of ...
M44-2002-C24-eng - Publications du gouvernement du Canada
... northern mining community of Flin Flon, Manitoba by working with the local mining and exploration companies to gain a better understanding of the volcanic setting and hydrothermal signatures of the region’s volcanogenic massive sulphide deposits. The Geological Survey of Canada–Manitoba–Saskatchewan ...
... northern mining community of Flin Flon, Manitoba by working with the local mining and exploration companies to gain a better understanding of the volcanic setting and hydrothermal signatures of the region’s volcanogenic massive sulphide deposits. The Geological Survey of Canada–Manitoba–Saskatchewan ...
Analysis of tectonic settings of global superlarge porphyry copper
... higher speed than the West Pacific plate, which is consistent with the results of modern surveying. In normal cases, volcanic effusion at the mid-ocean ridge is a motive force driving ocean tectonic plate subduction, so it is impossible to subduct underneath the continental tectonic plate. Therefore ...
... higher speed than the West Pacific plate, which is consistent with the results of modern surveying. In normal cases, volcanic effusion at the mid-ocean ridge is a motive force driving ocean tectonic plate subduction, so it is impossible to subduct underneath the continental tectonic plate. Therefore ...
Mineralogy Petrology
... composition and an ordered atomic arrangement. It is usually formed by inorganic processes. Let's look at the five parts of this definition: 1.) "Naturally occurring" means that synthetic compounds not known to occur in nature cannot have a mineral name. However, it may occur anywhere, other planets ...
... composition and an ordered atomic arrangement. It is usually formed by inorganic processes. Let's look at the five parts of this definition: 1.) "Naturally occurring" means that synthetic compounds not known to occur in nature cannot have a mineral name. However, it may occur anywhere, other planets ...
Soriano 2012 Journal of Volcanology and Geothermal Research
... 3.2 Los Frailes Formation The Los Frailes Formation is named for exposures on the lower slopes of Cerro de Los Frailes, but extends farther to the north, west and southwest (Fig. 2). It is mainly composed of dacite breccia, lava and pyroclastic rocks that are pale brown to pale grey and amphibole to ...
... 3.2 Los Frailes Formation The Los Frailes Formation is named for exposures on the lower slopes of Cerro de Los Frailes, but extends farther to the north, west and southwest (Fig. 2). It is mainly composed of dacite breccia, lava and pyroclastic rocks that are pale brown to pale grey and amphibole to ...
Tuffaceous Conglomerates
... deposits, with a very small amount of matrix, in accordance with a very concentrated mass flow. The basal clast- supported part seems to be emplaced from a hyperconcentrated flow, upward passing into a viscous, plastic laminar flow, entrained by both the cohesive matrix and the collisional interacti ...
... deposits, with a very small amount of matrix, in accordance with a very concentrated mass flow. The basal clast- supported part seems to be emplaced from a hyperconcentrated flow, upward passing into a viscous, plastic laminar flow, entrained by both the cohesive matrix and the collisional interacti ...
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.