The Skaergaard Layered Series. Part II
... is not to say that minerals are unaffected; in a dense suspension, some may be deformed, but evidence of this strain is usually weak and may later be erased by recrystallization or annealing. Crystals that grow or recrystallize while magma is being deformed may take on new shapes, sizes, or orientat ...
... is not to say that minerals are unaffected; in a dense suspension, some may be deformed, but evidence of this strain is usually weak and may later be erased by recrystallization or annealing. Crystals that grow or recrystallize while magma is being deformed may take on new shapes, sizes, or orientat ...
38. Site 398 - Deep Sea Drilling Project
... this volume). Consequently, numerous studies support the hypothesis that the initial Eurasian-American continent has been affected, at least locally, by intense fracturing and by an episode of rifting giving rise to subsiding basins filled with Triassic-Liassic evaporites and/or clastic sediments. T ...
... this volume). Consequently, numerous studies support the hypothesis that the initial Eurasian-American continent has been affected, at least locally, by intense fracturing and by an episode of rifting giving rise to subsiding basins filled with Triassic-Liassic evaporites and/or clastic sediments. T ...
Recommendations for Exploration 2013-2014
... The Lavant Lake Gabbro complex has been little studied and may be a worthwhile target for exploration. The northeast trending intrusion occupies large portions of the Townships of Darling, Dalhousie, Lavant, North Sherbrooke and Oso. It has a total length of approximately 45 km and a width of 14.5 k ...
... The Lavant Lake Gabbro complex has been little studied and may be a worthwhile target for exploration. The northeast trending intrusion occupies large portions of the Townships of Darling, Dalhousie, Lavant, North Sherbrooke and Oso. It has a total length of approximately 45 km and a width of 14.5 k ...
Carboniferous and Permian igneous rocks of Great Britain
... Even after the magmatic origin of igneous rocks had become generally accepted, doubts still existed over the mode of emplacement of sheets of basaltic rock. Most were thought to be extrusive lavas, until people began to recognize contact relationships at their upper margins, which showed that they w ...
... Even after the magmatic origin of igneous rocks had become generally accepted, doubts still existed over the mode of emplacement of sheets of basaltic rock. Most were thought to be extrusive lavas, until people began to recognize contact relationships at their upper margins, which showed that they w ...
EPS116_chapter11
... less platy materials and is the most divergent in platy-mineral-rich rocks •The relationship of foliations subparalllel to axial plane of folds is so consistent that it can determine the geometry of folding while field mapping. ii. Relationship with Ductile Shear Zones S-C tectonites- rocks from duct ...
... less platy materials and is the most divergent in platy-mineral-rich rocks •The relationship of foliations subparalllel to axial plane of folds is so consistent that it can determine the geometry of folding while field mapping. ii. Relationship with Ductile Shear Zones S-C tectonites- rocks from duct ...
The Proterozoic Part 1 - University of South Alabama
... • The first evidence of divergent and convergent plate tectonics was during the Paleoproterozoic (2.1 GA) in the Slave Province of the ...
... • The first evidence of divergent and convergent plate tectonics was during the Paleoproterozoic (2.1 GA) in the Slave Province of the ...
Sea-floor basement morphology: Distinguishing
... are two features commonly attributed to hotspot modulation). Much has been learned about the thickness, structure and composition of the oceanic crust where the Mid-Oceanic Ridge axis passes over or near a hotspot-generating anomaly in the mantle below the crust. However, it is the UPPER surface of ...
... are two features commonly attributed to hotspot modulation). Much has been learned about the thickness, structure and composition of the oceanic crust where the Mid-Oceanic Ridge axis passes over or near a hotspot-generating anomaly in the mantle below the crust. However, it is the UPPER surface of ...
The Sveconorwegian magmatic and tectono
... The oldest part consists offelsic and mafic layers, tr ansform ed by bedd ing t ransposit ion into parallelism.They are of unknown age and are of intr usive or ext rusive origin, probably serving as th e basement for metasedimentary rocks. The latt er comprise garnet-silliman ite-cordierite- biot it ...
... The oldest part consists offelsic and mafic layers, tr ansform ed by bedd ing t ransposit ion into parallelism.They are of unknown age and are of intr usive or ext rusive origin, probably serving as th e basement for metasedimentary rocks. The latt er comprise garnet-silliman ite-cordierite- biot it ...
7. Skagit River
... 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 growth of the continent by over 500 km, from a shoreline originally located near modern-day Spokane. This has happened ...
... 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 growth of the continent by over 500 km, from a shoreline originally located near modern-day Spokane. This has happened ...
Differentiated impact melt sheets may be a
... of Ti contents, and corresponding Ti-in-zircon crystallization temperatures (T ), of zircon from throughout the stratigraphy of a differentiated impact melt sheet (Kenny et al., 2016). We appreciate the discussion points presented by Wielicki et al. (2016), and this opportunity to further clarify th ...
... of Ti contents, and corresponding Ti-in-zircon crystallization temperatures (T ), of zircon from throughout the stratigraphy of a differentiated impact melt sheet (Kenny et al., 2016). We appreciate the discussion points presented by Wielicki et al. (2016), and this opportunity to further clarify th ...
Chapter 16. Island Arc Magmatism
... 1. The crustal portion of the subducted slab 1a Altered oceanic crust (hydrated by circulating seawater, and metamorphosed in large part to greenschist facies) 1b Subducted oceanic and forearc sediments 1c Seawater trapped in pore spaces 2. The mantle wedge between the slab and the arc crust ...
... 1. The crustal portion of the subducted slab 1a Altered oceanic crust (hydrated by circulating seawater, and metamorphosed in large part to greenschist facies) 1b Subducted oceanic and forearc sediments 1c Seawater trapped in pore spaces 2. The mantle wedge between the slab and the arc crust ...
Structure
... layer as it intersects with a horizontal surface • Dip – is measured at right angles to strike and is the amount of tilting of the formation (angle at which the bed is inclined from the horizontal) ...
... layer as it intersects with a horizontal surface • Dip – is measured at right angles to strike and is the amount of tilting of the formation (angle at which the bed is inclined from the horizontal) ...
Geological Society of America Bulletin - User Web Pages
... Figure 3. (A) Tangtse pluton NW of the Muglib pluton (34°03′30″N, 78°14′00″E) showing dark screens of country rock within the pluton, and boudinaged leucogranite dikes in the distance, NW of the pluton and parallel to the dextral Pangong strand of the Karakoram shear zone, on the right-hand-side. Al ...
... Figure 3. (A) Tangtse pluton NW of the Muglib pluton (34°03′30″N, 78°14′00″E) showing dark screens of country rock within the pluton, and boudinaged leucogranite dikes in the distance, NW of the pluton and parallel to the dextral Pangong strand of the Karakoram shear zone, on the right-hand-side. Al ...
2015 PA SE Reg
... Carboniferous time e. The Caledonides mountain range matches up across the two continents in both placement and age 3. Which of the following was not part of Gondwana? a. Eurasia b. Africa c. India d. Australia e. Antarctica 4. Which of the following statements about paleomagnetism, with respect to ...
... Carboniferous time e. The Caledonides mountain range matches up across the two continents in both placement and age 3. Which of the following was not part of Gondwana? a. Eurasia b. Africa c. India d. Australia e. Antarctica 4. Which of the following statements about paleomagnetism, with respect to ...
Geochemistry of an island-arc plutonic suite
... intrusive phases) along Wadi Dabr. The young gabbros comprise olivine gabbro, norite, gabbro and anorthositic gabbro. They caused a thermal metamorphic effect up to hornblende hornfels-facies. In addition, the Wadi Dabr intrusive complex, young gabbros and ophiolitic melange are also invaded by late ...
... intrusive phases) along Wadi Dabr. The young gabbros comprise olivine gabbro, norite, gabbro and anorthositic gabbro. They caused a thermal metamorphic effect up to hornblende hornfels-facies. In addition, the Wadi Dabr intrusive complex, young gabbros and ophiolitic melange are also invaded by late ...
Precambrian Rocks of Northern Arizona
... intruded by massive quartz diorite and granitic pegmatite and aplite. The pegmatites, typically pink, were assigned to two generations, the older one being folded with the schist, and the younger one cutting both the schist and the quartz diorite. Noble suggested that the older rocks now represented ...
... intruded by massive quartz diorite and granitic pegmatite and aplite. The pegmatites, typically pink, were assigned to two generations, the older one being folded with the schist, and the younger one cutting both the schist and the quartz diorite. Noble suggested that the older rocks now represented ...
modern and ancient incompatible element-poor adakite
... beneath the Quaternary arc at the latitude of NLV, may be responsible for the elevated slab-component of NLV magmas. Oceanic transform faults commonly host serpentinized peridotite bodies, which can liberate vast amounts of fluids during subduction, up to an order of magnitude higher than altered oc ...
... beneath the Quaternary arc at the latitude of NLV, may be responsible for the elevated slab-component of NLV magmas. Oceanic transform faults commonly host serpentinized peridotite bodies, which can liberate vast amounts of fluids during subduction, up to an order of magnitude higher than altered oc ...
Non-ideal Subduction
... the sediments deposited during the orogeny. The Antler foredeep (between the thrust front and the miogeocline) records the sediments derived from the mountain building event that occurred as the deep‐water sediment overrode the shallow sediments. In the foredeep, we see both sediments derived ...
... the sediments deposited during the orogeny. The Antler foredeep (between the thrust front and the miogeocline) records the sediments derived from the mountain building event that occurred as the deep‐water sediment overrode the shallow sediments. In the foredeep, we see both sediments derived ...
06 Chapter 6_Sedimentary Rocks
... – Mud-sized particles (less than 1/16 mm) in thin layers that are called lamina صفيحة – Most common sedimentary rock – They exhibit fissility (التفسخcan be split) ...
... – Mud-sized particles (less than 1/16 mm) in thin layers that are called lamina صفيحة – Most common sedimentary rock – They exhibit fissility (التفسخcan be split) ...
Delny-Mount Sainthill Fault System, eastern Arunta Block, Central
... some 130 km across the Arunta Block, central Aus• tralia. It has a slightly north-of-west trend, from 4 km south of Mount Thring (22 °49'S, 136 °02'E) to 5 km south of Delny Outstation (22 °33'S, 134°49'S) (Figs 1, 2). The deformed nature of the rocks at Mount Saint4iIl was first noted by Smith and ...
... some 130 km across the Arunta Block, central Aus• tralia. It has a slightly north-of-west trend, from 4 km south of Mount Thring (22 °49'S, 136 °02'E) to 5 km south of Delny Outstation (22 °33'S, 134°49'S) (Figs 1, 2). The deformed nature of the rocks at Mount Saint4iIl was first noted by Smith and ...
Deep Mantle Plumes and Geoscience Vision
... 201 Ma, Early Jurassic (e.g., Deckart et al., 1997; Weems and Olsen, 1997, p. 199). But well before the magmatic activity broke out, eastern North America began to pull apart in the extensive system of Triassic, sediment-filled rifts roughly parallel with the coast and with the earlier Paleozoic str ...
... 201 Ma, Early Jurassic (e.g., Deckart et al., 1997; Weems and Olsen, 1997, p. 199). But well before the magmatic activity broke out, eastern North America began to pull apart in the extensive system of Triassic, sediment-filled rifts roughly parallel with the coast and with the earlier Paleozoic str ...
The role of crustal heterogeneity in controlling vertical coupling
... Abstract: Analogue models of polyphase deformation involving crustal differences in strength, thickness and density give insights into lateral and vertical strain propagation during Late Cretaceous shortening and Early Tertiary left-lateral shearing related to the early development of the North Amer ...
... Abstract: Analogue models of polyphase deformation involving crustal differences in strength, thickness and density give insights into lateral and vertical strain propagation during Late Cretaceous shortening and Early Tertiary left-lateral shearing related to the early development of the North Amer ...
Convergent Plate Boundaries - North Coast Distance Education
... An example is the great Alpine fold and thrust belt of southern Europe. The Tyrolean Alps of northern Italy illustrate the results of deformation when plates collide, in this case the African and Eurasian plates. Thick sequences of sedimentary strata, originally deposited on the seafloor, were defor ...
... An example is the great Alpine fold and thrust belt of southern Europe. The Tyrolean Alps of northern Italy illustrate the results of deformation when plates collide, in this case the African and Eurasian plates. Thick sequences of sedimentary strata, originally deposited on the seafloor, were defor ...
`granitic` laver of the crust in the southern norwegian precambrian
... (chemical composition). Less dense migmatitic rocks whose origin is 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 supracrus ...
... (chemical composition). Less dense migmatitic rocks whose origin is 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 supracrus ...
Huismans
... rift, thereby filling basins in P and S during both synrift phases but leaving D underfilled, as in the dynamical models (Fig. 2). Sediments, once deposited, will experience and record extension depending on whether or not stretching of the underlying crust continues. An important test of the model ...
... rift, thereby filling basins in P and S during both synrift phases but leaving D underfilled, as in the dynamical models (Fig. 2). Sediments, once deposited, will experience and record extension depending on whether or not stretching of the underlying crust continues. An important test of the model ...
Great Lakes tectonic zone
The Great Lakes tectonic zone is bounded by South Dakota at its tip and heads northeast to south of Duluth, Minnesota, then heads east through northern Wisconsin, Marquette, Michigan, and then trends more northeasterly to skim the northern-most shores of lakes Michigan and Huron before ending in the Sudbury, Ontario, Canada, area.During the Late Archean Era the Algoman orogeny added landmass to the Superior province by volcanic activity and continental collision along a boundary that stretches from present-day South Dakota, U.S., into the Lake Huron region near Sudbury, Ontario, Canada.This crustal boundary is the Great Lakes tectonic zone. It is 1,400 km (870 mi) long, and separates the older Archean gneissic terrane to the south from younger Late Archean greenstone-granite terrane to the north.The zone is characterized by active compression during the Algoman orogeny (about 2,700 million years ago), a pulling-apart (extensional) tectonics (2,450 to 2,100 million years ago), a second compression during the Penokean orogeny (1,900 to 1,850 million years ago), a second extension during Middle Proterozoic time (1,600 million years ago) and minor reactivation during Phanerozoic time (the past 500 million years).Collision began along the Great Lakes tectonic zone (GLTZ) with the Algoman mountain-building event and continued for tens of millions of years. During the formation of the GLTZ, the gneissic Minnesota River Valley subprovince was thrust up onto the Superior province's edge as it consumed the Superior province's oceanic crust. Fragmentation of the Kenorland supercontinent began 2,450 million years ago and was completed by 2,100 million years ago. The Wyoming province is the continental landmass that is hypothesized to have rifted away from the southern Superior province portion of Kenorland, before moving rapidly west and docking with the Laurentia supercontinent 1,850 to 1,715 million years ago. Sedimentation from the GLTZ-rifting environment continued into the Penokean orogeny, which is the next major tectonic event in the Great Lakes region. Several earthquakes have been documented in Minnesota, Michigan's Upper Peninsula and Sudbury in the last 120 years along the GLTZ.