Introduction to Metamorphism
... Cpx + plag ( olivine, ilmenite…) Or any combination of melt + minerals along the liquid line of descent ...
... Cpx + plag ( olivine, ilmenite…) Or any combination of melt + minerals along the liquid line of descent ...
The Sveconorwegian magmatic and tectono
... t he east and nor th. The latest phase of deformation occurred w ith litt le recrystallisat ion, leading to large-scale open to gentle folds wi t h E-W axes and verti cal axial planes.Apart from t his last phase, the deformation proceeded along N-S fold axes, starti ng w it h large-scale recum bent ...
... t he east and nor th. The latest phase of deformation occurred w ith litt le recrystallisat ion, leading to large-scale open to gentle folds wi t h E-W axes and verti cal axial planes.Apart from t his last phase, the deformation proceeded along N-S fold axes, starti ng w it h large-scale recum bent ...
View Entire Bulletin - Ministry of Energy and Mines and Responsible
... Alleyne-Summers Creek system t o the east and the Allison system t o the west. These faults are interpreted to represent an ancient, long-lived r i f t system which determined the extent and distribution of Nicola rocks and along which basins of continental volcanism and sedimentation formed in Earl ...
... Alleyne-Summers Creek system t o the east and the Allison system t o the west. These faults are interpreted to represent an ancient, long-lived r i f t system which determined the extent and distribution of Nicola rocks and along which basins of continental volcanism and sedimentation formed in Earl ...
flow-layering in alpine peridotite-gabbro
... The flow layers in alpine complexes are not nearly as regular and persistent as those formed by crystal settling in the stratiform complexes, and adjoining layers commonly show much more compositional contrast. Features formed by crystal settling have been observed only as rare relicts in chromitite ...
... The flow layers in alpine complexes are not nearly as regular and persistent as those formed by crystal settling in the stratiform complexes, and adjoining layers commonly show much more compositional contrast. Features formed by crystal settling have been observed only as rare relicts in chromitite ...
guide to the geology trail - The Sleeping Giant Park Association
... outcrops located directly on the trail, some may be partially obscured by heavy autumn leaf fall, winter snow and ice, or seasonally active stream flow. Visibility of a few stations may be hampered by dense foliage in summer months. Of course, the number of stations varies from trail to trail and fr ...
... outcrops located directly on the trail, some may be partially obscured by heavy autumn leaf fall, winter snow and ice, or seasonally active stream flow. Visibility of a few stations may be hampered by dense foliage in summer months. Of course, the number of stations varies from trail to trail and fr ...
Late Palaeozoic lam pro phyres and as so ci ated mafic subvolcanic
... with abundant, euhedral dark micas and/or amphiboles, the specific petrographic characteristics of the calc-alkaline lamprophyres that distinguish them from more common rocks of similar bulk composition (e.g., andesites and diorites) include the lack of feldspar phenocrysts, the lack of orthopyroxen ...
... with abundant, euhedral dark micas and/or amphiboles, the specific petrographic characteristics of the calc-alkaline lamprophyres that distinguish them from more common rocks of similar bulk composition (e.g., andesites and diorites) include the lack of feldspar phenocrysts, the lack of orthopyroxen ...
Review of the behavior of plagioclase under metamorphic
... basicand pelitic schistsof the Usu massifin Timor and noted changesin the An content of the plagioclasesover relatively short distances,reflecting a successionof narrow zones of metamorphism.He found the frequency of occurrence of plagioclase betweenAn5 and An2sto be remarkablylow, particularly in t ...
... basicand pelitic schistsof the Usu massifin Timor and noted changesin the An content of the plagioclasesover relatively short distances,reflecting a successionof narrow zones of metamorphism.He found the frequency of occurrence of plagioclase betweenAn5 and An2sto be remarkablylow, particularly in t ...
magnetite and ilmenite from some finnish rocks
... practically unmetamorphosed late Precambrian igneous rocks, the others are metamorphosed Svecofennian deep-seated rocks. In olivine diabase and gabbroanorthosite the Fe-Ti oxides are xenomorphic filling the spaces between other minerals (Fig. 2). Thus, they are formed somewhat later than the other m ...
... practically unmetamorphosed late Precambrian igneous rocks, the others are metamorphosed Svecofennian deep-seated rocks. In olivine diabase and gabbroanorthosite the Fe-Ti oxides are xenomorphic filling the spaces between other minerals (Fig. 2). Thus, they are formed somewhat later than the other m ...
Igneous Environments
... then solidification of the magma into igneous rock. With such a history, igneous systems are best described from the bottom up. Begin with number one at the bottom of this figure. 6. Magma that reaches the surface erupts as lava (molten rock that flows on the surface) or as volcanic ash. Volcanic ash f ...
... then solidification of the magma into igneous rock. With such a history, igneous systems are best described from the bottom up. Begin with number one at the bottom of this figure. 6. Magma that reaches the surface erupts as lava (molten rock that flows on the surface) or as volcanic ash. Volcanic ash f ...
T.Y.B.Sc. Geology
... B) Role of weathering in sedimentation: (5 Lectures) a) Surface processes of rock weathering b) Chemistry of the weathering processes & mobility of oxides c) Mineral stability series C) Dispersal of sediments: (4 Lectures) a) Dynamics of transportation b) Concept of dispersal based on: size, roundne ...
... B) Role of weathering in sedimentation: (5 Lectures) a) Surface processes of rock weathering b) Chemistry of the weathering processes & mobility of oxides c) Mineral stability series C) Dispersal of sediments: (4 Lectures) a) Dynamics of transportation b) Concept of dispersal based on: size, roundne ...
petrology of the sthathbogie batholith: a cordierite-bearing
... sedimentary rocks on the southern side of the granite are truncated by the contact. However, the strike of the sedimentary rocks appears to be deflected near the western end of the batholith (Vandenberg & Garratt 1976), with the divergence becoming apparent within 20 km of the granite contact (Fig. ...
... sedimentary rocks on the southern side of the granite are truncated by the contact. However, the strike of the sedimentary rocks appears to be deflected near the western end of the batholith (Vandenberg & Garratt 1976), with the divergence becoming apparent within 20 km of the granite contact (Fig. ...
Chapter 4. TTG & Genesis of the Continental Crust
... TTG gneiss intruded by late granite (highly deformed) ...
... TTG gneiss intruded by late granite (highly deformed) ...
precambrian geology of the truchas peaks region, north
... disseminated carbonaceous material. Carbon (as graphite) is so abundant that even thin sections of this rock are black. The unit is exceedingly fine-grained; quartz and foliated muscovite crystals rarely exceed .03 mm in size. As units of the Rinconada Formation are followed north through a series o ...
... disseminated carbonaceous material. Carbon (as graphite) is so abundant that even thin sections of this rock are black. The unit is exceedingly fine-grained; quartz and foliated muscovite crystals rarely exceed .03 mm in size. As units of the Rinconada Formation are followed north through a series o ...
geology
... contact metasomatism fluids from the magma carry chemicals into the surrounding rock; the chemistry of the country rock is changed. Contact metasomatism is more commonly produced by wet granitic magmas than by dry gabbroic magmas. Limestones react with the acidic magmatic fluids. This causes a reduc ...
... contact metasomatism fluids from the magma carry chemicals into the surrounding rock; the chemistry of the country rock is changed. Contact metasomatism is more commonly produced by wet granitic magmas than by dry gabbroic magmas. Limestones react with the acidic magmatic fluids. This causes a reduc ...
- ResearchOnline@JCU
... northern Peru: Implications for magmatic controls on the formation of porphyry Cu-Au deposits. C.1 Abstract Tertiary igneous rocks in the Cajamarca mining district range from medium to high-K, tholeiitic to calc-alkaline and are predominantly metaluminous. Palaeogene felsic rocks (57-43 Ma) are inte ...
... northern Peru: Implications for magmatic controls on the formation of porphyry Cu-Au deposits. C.1 Abstract Tertiary igneous rocks in the Cajamarca mining district range from medium to high-K, tholeiitic to calc-alkaline and are predominantly metaluminous. Palaeogene felsic rocks (57-43 Ma) are inte ...
UNITED STATES DEPARTMENT OF THE INTERIOR CECIL D
... cut by ravines and gullies on steeper slopes. These merge a t lower elevations into small valleys occupied by streams. The area has an annual rainfall of 18 to 38 cm and receives 76 to 86 cm of snow (Hopkins and others, 1955). Permafrost is continuous except locally along larger streams, in the vici ...
... cut by ravines and gullies on steeper slopes. These merge a t lower elevations into small valleys occupied by streams. The area has an annual rainfall of 18 to 38 cm and receives 76 to 86 cm of snow (Hopkins and others, 1955). Permafrost is continuous except locally along larger streams, in the vici ...
Distribution of potassium feldspar polymorphs
... material of adularia habit and slight obliquity in a pressure vessel with a temperature gradient.) The factors controlling the presence of either polymorph can, at present, be established only from studies of the distribution of these feldspars in natural rocks, and such evidence is summarized by Ma ...
... material of adularia habit and slight obliquity in a pressure vessel with a temperature gradient.) The factors controlling the presence of either polymorph can, at present, be established only from studies of the distribution of these feldspars in natural rocks, and such evidence is summarized by Ma ...
7. Skagit River
... stretches back hundreds of millions of years into geologic time. This is the story of the geologic evolution of the Pacific Northwest, one of the most persistant enigmas in North American geology. Over the last two hundred million years, that course of geologic evolution has included the westward gro ...
... stretches back hundreds of millions of years into geologic time. This is the story of the geologic evolution of the Pacific Northwest, one of the most persistant enigmas in North American geology. Over the last two hundred million years, that course of geologic evolution has included the westward gro ...
Generation of high-silica rhyolite: A Nd, Sr, and O isotopic study of
... Guadalajara, Mexico (Fig. t). Like several other silicic caldera complexes, it lies slightly north of the main trend of cinder cones and active stratovolcanoes that define the Mexican Neovolcanic Belt (Ferriz and Mahood 1986). All nearby exposures are of Tertiary and Quaternary lavas and tufts (Gilb ...
... Guadalajara, Mexico (Fig. t). Like several other silicic caldera complexes, it lies slightly north of the main trend of cinder cones and active stratovolcanoes that define the Mexican Neovolcanic Belt (Ferriz and Mahood 1986). All nearby exposures are of Tertiary and Quaternary lavas and tufts (Gilb ...
English - SciELO Colombia
... The lithosphere is the outer «rigid» layer of the earth, which is fragmented into a number of «rigid» tectonic plates floating on a viscous asthenosphere; the latter on geological time intervals behaves as a fluid. According to the plate-tectonics theory, thermally driven convection currents is one ...
... The lithosphere is the outer «rigid» layer of the earth, which is fragmented into a number of «rigid» tectonic plates floating on a viscous asthenosphere; the latter on geological time intervals behaves as a fluid. According to the plate-tectonics theory, thermally driven convection currents is one ...
Geology and petrology of the felsic intrusions in the
... Scriptie voorgelegd tot het behalen van de graad Van Master of Science in de geologie ...
... Scriptie voorgelegd tot het behalen van de graad Van Master of Science in de geologie ...
`granitic` laver of the crust in the southern norwegian precambrian
... more obscure but whose layering is most likely inherited from original supracrustal rocks constitute the predominant rock type at deeper levels. In central Telemark, DoNs (1960, p. 56) has described the contact between the supracrustal rocks and the underlying granitic gneisses as being gradational ...
... more obscure but whose layering is most likely inherited from original supracrustal rocks constitute the predominant rock type at deeper levels. In central Telemark, DoNs (1960, p. 56) has described the contact between the supracrustal rocks and the underlying granitic gneisses as being gradational ...
The lithosphere and the soil as power equipment and hazard
... 12.5. Deforestation in Amazonia ................................................................................... 171 References ............................................................................................................................ 173 ...
... 12.5. Deforestation in Amazonia ................................................................................... 171 References ............................................................................................................................ 173 ...
Weathering
Weathering is the breaking down of rocks, soil and minerals as well as artificial materials through contact with the Earth's atmosphere, biota and waters. Weathering occurs in situ, roughly translated to: ""with no movement"" , and thus should not be confused with erosion, which involves the movement of rocks and minerals by agents such as water, ice, snow, wind, waves and gravity and then being transported and deposited in other locations.Two important classifications of weathering processes exist – physical and chemical weathering; each sometimes involves a biological component. Mechanical or physical weathering involves the breakdown of rocks and soils through direct contact with atmospheric conditions, such as heat, water, ice and pressure. The second classification, chemical weathering, involves the direct effect of atmospheric chemicals or biologically produced chemicals also known as biological weathering in the breakdown of rocks, soils and minerals. While physical weathering is accentuated in very cold or very dry environments, chemical reactions are most intense where the climate is wet and hot. However, both types of weathering occur together, and each tends to accelerate the other. For example, physical abrasion (rubbing together) decreases the size of particles and therefore increases their surface area, making them more susceptible to rapid chemical reactions. The various agents act in concert to convert primary minerals (feldspars and micas) to secondary minerals (clays and carbonates) and release plant nutrient elements in soluble forms.The materials left over after the rock breaks down combined with organic material creates soil. The mineral content of the soil is determined by the parent material, thus a soil derived from a single rock type can often be deficient in one or more minerals for good fertility, while a soil weathered from a mix of rock types (as in glacial, aeolian or alluvial sediments) often makes more fertile soil. In addition, many of Earth's landforms and landscapes are the result of weathering processes combined with erosion and re-deposition.