Manea et al., 2006. - Centro de Geociencias
... We present a model of the subducting Cocos slab beneath Central Mexico, that provides an explanation for stresses causing the occurrence of the majority of the intraslab earthquakes which are concentrated in a long flat segment. Based on the recently developed thermal models for the Central Mexico s ...
... We present a model of the subducting Cocos slab beneath Central Mexico, that provides an explanation for stresses causing the occurrence of the majority of the intraslab earthquakes which are concentrated in a long flat segment. Based on the recently developed thermal models for the Central Mexico s ...
majalah perdana
... m. Lithological classification, alteration zonation, and mineralisation have been refined with the new exploration results. Lithological classification differentiates the units based on genesis, relation to mineralisation event, and grain size. Two main groups of lithology are diorites and breccias. ...
... m. Lithological classification, alteration zonation, and mineralisation have been refined with the new exploration results. Lithological classification differentiates the units based on genesis, relation to mineralisation event, and grain size. Two main groups of lithology are diorites and breccias. ...
Vertical stretching and crustal thickening at Nanga Parbat, Pakistan
... [2] There are now good descriptions of the active deformation that affects the upper continental crust during orogenesis. Most of this strain is represented by seismogenic faulting together with aseismic deformations, principally represented by folds but also by minor structures such as pressure sol ...
... [2] There are now good descriptions of the active deformation that affects the upper continental crust during orogenesis. Most of this strain is represented by seismogenic faulting together with aseismic deformations, principally represented by folds but also by minor structures such as pressure sol ...
Late Variscan (Carboniferous to Permian) environments in the
... layers in some places, characterize the Cisuralian (lower cycle) throughout these tectonic units (the Laas Formation in the Drauzug, the Werchzirm Formation in the Gurktal Nappe). In most cases, these sediments overlie with angular unconformity the Variscan crystalline basement (the Gailtal metamorp ...
... layers in some places, characterize the Cisuralian (lower cycle) throughout these tectonic units (the Laas Formation in the Drauzug, the Werchzirm Formation in the Gurktal Nappe). In most cases, these sediments overlie with angular unconformity the Variscan crystalline basement (the Gailtal metamorp ...
Magnetization of the oceanic crust
... There is much evidence that very young crust has an anomalously high magnetization intensity, and that some form of decay of magnetization takes place within a few Myr. Bott & Hutton (1970) have inverted magnetic anomalies over the Sheba ridge in order to obtain magnetizations of the ocean floor. Th ...
... There is much evidence that very young crust has an anomalously high magnetization intensity, and that some form of decay of magnetization takes place within a few Myr. Bott & Hutton (1970) have inverted magnetic anomalies over the Sheba ridge in order to obtain magnetizations of the ocean floor. Th ...
THE AGUABLANCA Ni–Cu–PGE DEPOSIT, SOUTHWESTERN
... The Aguablanca Ni–Cu–PGE ore deposit, in southwestern Iberia, has a magmatic origin, and has been reworked by later skarn-related hydrothermal activity. Base-metal sulfides are associated with igneous cumulates displaying subvertical layering consisting of gabbro, norite and dolerite, with fragments ...
... The Aguablanca Ni–Cu–PGE ore deposit, in southwestern Iberia, has a magmatic origin, and has been reworked by later skarn-related hydrothermal activity. Base-metal sulfides are associated with igneous cumulates displaying subvertical layering consisting of gabbro, norite and dolerite, with fragments ...
Petrology and Geochemistry of the Nipissing Gabbro
... (after Lightfoot et al., 1993) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 A1.8c. Sketch map showing the locations of samples referred to in MRD 19. Basswood Lake Intrusion (after Lightfoot et al., 1993) . . . . . . ...
... (after Lightfoot et al., 1993) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 A1.8c. Sketch map showing the locations of samples referred to in MRD 19. Basswood Lake Intrusion (after Lightfoot et al., 1993) . . . . . . ...
Chapter 21: Metamorphism
... • Contact effects overprinted on an earlier low-grade regional orogenic metamorphism ...
... • Contact effects overprinted on an earlier low-grade regional orogenic metamorphism ...
a short story about the geological history of the pamir
... western parts of the Tadjik Depression. The “Outer Pamir” domain includes the Pamir Alai region and the eastern part of the Tadjik Depression. Paleomagnetic measurements in both areas show large declination anomalies in the outer Pamir domain, but not in the Tien Shan domain. The facies zones in the ...
... western parts of the Tadjik Depression. The “Outer Pamir” domain includes the Pamir Alai region and the eastern part of the Tadjik Depression. Paleomagnetic measurements in both areas show large declination anomalies in the outer Pamir domain, but not in the Tien Shan domain. The facies zones in the ...
Distribution of potassium feldspar polymorphs
... be either monoclinic orthoclase or triclinic microcline, usually showing the characteristic cross-hatched twinning, is familiar to petrologists. The physical factors controlling the presence of either polymorph are, however, unclear. Experimental studies of ordering in synthetic albitic alkali felds ...
... be either monoclinic orthoclase or triclinic microcline, usually showing the characteristic cross-hatched twinning, is familiar to petrologists. The physical factors controlling the presence of either polymorph are, however, unclear. Experimental studies of ordering in synthetic albitic alkali felds ...
What controls the occurrence of shallow intraplate earthquakes? Yoshihisa Iio
... process is thought to be in accordance with the concept of the partial collision proposed by Hashimoto and Matsu’ura (2004), since a part of the relative plate motion velocity is consumed in internal deformation within the intraplate crust. This stress build-up process is not apparent in Fig. 2, sin ...
... process is thought to be in accordance with the concept of the partial collision proposed by Hashimoto and Matsu’ura (2004), since a part of the relative plate motion velocity is consumed in internal deformation within the intraplate crust. This stress build-up process is not apparent in Fig. 2, sin ...
Magmatic Apatite: A Powerful, Yet Deceptive
... elongate). Equant apatite is generally defi ned by wellformed crystal faces (FIG. 1), and is often easily recognized by its hexagonal shape. This habit is interpreted to have grown under near-equilibrium conditions. Less commonly, equant apatite occurs with no well-formed crystal faces as an interst ...
... elongate). Equant apatite is generally defi ned by wellformed crystal faces (FIG. 1), and is often easily recognized by its hexagonal shape. This habit is interpreted to have grown under near-equilibrium conditions. Less commonly, equant apatite occurs with no well-formed crystal faces as an interst ...
Georgian Bay Geological Synthesis, Grenville Province: Explanatory
... The Grenville Front marks the northwest limit of penetrative Grenvillian metamorphism and deformation and truncates structural trends in the adjacent structural provinces, although locally some of these rocks can be traced across the Grenville Front for short distances (10 to 30 km, Easton 1992). It ...
... The Grenville Front marks the northwest limit of penetrative Grenvillian metamorphism and deformation and truncates structural trends in the adjacent structural provinces, although locally some of these rocks can be traced across the Grenville Front for short distances (10 to 30 km, Easton 1992). It ...
Bulletin of the Geological Society of Denmark, Vol. 39/3-4 pp. 179-197
... Most of the rest of the terrane was metamorphosed to granulite facies, with peak metamorphic conditions on Nordlandet estimated to have been 800 50°C and 7.9 1.0 kbar (Nutman et al. 1989, Riciputi et af. 1990). There was retrogression to amphibolite facies over large areas (Garde 1989,1990), at leas ...
... Most of the rest of the terrane was metamorphosed to granulite facies, with peak metamorphic conditions on Nordlandet estimated to have been 800 50°C and 7.9 1.0 kbar (Nutman et al. 1989, Riciputi et af. 1990). There was retrogression to amphibolite facies over large areas (Garde 1989,1990), at leas ...
Use of Hydrothermal Mineralogy and Geological Structures in
... Generally, permeability is low in the West field and its distribution is strongly controlled by the lithostratigraphic contacts, fractured lava and fault zones. The fault zones show higher permeability with wells drilled within the structures having larger total mass outputs with some wells producin ...
... Generally, permeability is low in the West field and its distribution is strongly controlled by the lithostratigraphic contacts, fractured lava and fault zones. The fault zones show higher permeability with wells drilled within the structures having larger total mass outputs with some wells producin ...
Geology of Southwestern Alaska (3.0MB, PDF)
... part, on Precambrian basement , and locally overlain by Cretaceous and Tertiary volcanic and sedimentary rocks. The Farewell terrane is divided into two distinctive sequences: (1) the White Mountain sequence , which consists of Middle Cambrian through Middle Devonian stable continental margin deposi ...
... part, on Precambrian basement , and locally overlain by Cretaceous and Tertiary volcanic and sedimentary rocks. The Farewell terrane is divided into two distinctive sequences: (1) the White Mountain sequence , which consists of Middle Cambrian through Middle Devonian stable continental margin deposi ...
9.2 Metallic mineral occurrences in the shield and deposit types
... pit mine that extracts lower grade ore for processing at the Bulghah heap-leach facility and higher grade ore that is trucked to the Sukhaybarat CIL plant. Al Amar is an underground mine extracting gold-rich polymetallic ore and producing gold doré and copper and zinc concentrates that are sold to t ...
... pit mine that extracts lower grade ore for processing at the Bulghah heap-leach facility and higher grade ore that is trucked to the Sukhaybarat CIL plant. Al Amar is an underground mine extracting gold-rich polymetallic ore and producing gold doré and copper and zinc concentrates that are sold to t ...
thesis
... Krill & Zwaan (1987) suggesting that the SIP represents the root zone of a palaeorift related to continental break-up and formation of the Iapetus Ocean. Elvevold & Reginiussen (1994) considered a rift related origin for all the intrusions based on the results that the rocks of the SIP have alkaline ...
... Krill & Zwaan (1987) suggesting that the SIP represents the root zone of a palaeorift related to continental break-up and formation of the Iapetus Ocean. Elvevold & Reginiussen (1994) considered a rift related origin for all the intrusions based on the results that the rocks of the SIP have alkaline ...
Intrusive igneous rocks include granite.
... cause pollution, but the are relatively cheap and easy to use. ...
... cause pollution, but the are relatively cheap and easy to use. ...
The origin of metamorphic core complexes and detachment faults
... out. Nfibelek has shown that the dip of one such large normal fault varied less than 10° in this entire depth range. If arrays of such faults are involved, they are spaced 15-40 km apart. There is a complete lack of seismological evidence for active large-area, low-angle (i.e. less than 30° dip), cr ...
... out. Nfibelek has shown that the dip of one such large normal fault varied less than 10° in this entire depth range. If arrays of such faults are involved, they are spaced 15-40 km apart. There is a complete lack of seismological evidence for active large-area, low-angle (i.e. less than 30° dip), cr ...
Relationship between Moldanubicum, the Kutn· Hora Crystalline
... Institute of Geology and Palaentology, Charles University, Albertov 6, 128 43 Praha 2, Czech Republic The Moldanubian Zone, forming a highly metamorphosed root of the Variscan orogenic belt in Central Europe, is surrounded by several different lithotectonic units within the Bohemian Massif. These un ...
... Institute of Geology and Palaentology, Charles University, Albertov 6, 128 43 Praha 2, Czech Republic The Moldanubian Zone, forming a highly metamorphosed root of the Variscan orogenic belt in Central Europe, is surrounded by several different lithotectonic units within the Bohemian Massif. These un ...
Three lithospheric transects across the Alps and their forelands
... the “Western” and “Eastern” Alps, corresponding to the western limit of the Austroalpine nappes of the Eastern Alps (mapped as “Apulian Plate north of the Periadriatic Line” in Fig. 1) that runs almost perpendicular across the E-W-strike of the present-day Eastern Alps (Fig. 1). This most important ...
... the “Western” and “Eastern” Alps, corresponding to the western limit of the Austroalpine nappes of the Eastern Alps (mapped as “Apulian Plate north of the Periadriatic Line” in Fig. 1) that runs almost perpendicular across the E-W-strike of the present-day Eastern Alps (Fig. 1). This most important ...
V. C. Summer Nuclear Station, Units 2 and 3 COL Application
... The Blue Ridge is divided into western and eastern portions. The western Blue Ridge consists of an assemblage of Middle Proterozoic crystalline continental (Grenville) basement rock nonconformably overlain by Late Proterozoic to Early Paleozoic rift-facies sedimentary rock (Reference 279). The basem ...
... The Blue Ridge is divided into western and eastern portions. The western Blue Ridge consists of an assemblage of Middle Proterozoic crystalline continental (Grenville) basement rock nonconformably overlain by Late Proterozoic to Early Paleozoic rift-facies sedimentary rock (Reference 279). The basem ...
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.