Magma genesis, plate tectonics, and chemical
... also provide clues about the nature of the source material at (volume 25, numbers 2, 3, 5, and 6, 1987). Volcanoes have played a significant role in the development depth. The theme common to the different parts of this review of geology sinceAbraham Werner at the beginning of the last relates to th ...
... also provide clues about the nature of the source material at (volume 25, numbers 2, 3, 5, and 6, 1987). Volcanoes have played a significant role in the development depth. The theme common to the different parts of this review of geology sinceAbraham Werner at the beginning of the last relates to th ...
Acrobat PDF file - 1 Mb (text and Table 1)
... along axis. Hypotheses for focused solid or liquid upwelling beneath ridge segments make specific predictions regarding the spatial variation of mantle lineation or the distribution of melt migration features. These predictions were directly tested by drilling. We discovered that penetrative mantle ...
... along axis. Hypotheses for focused solid or liquid upwelling beneath ridge segments make specific predictions regarding the spatial variation of mantle lineation or the distribution of melt migration features. These predictions were directly tested by drilling. We discovered that penetrative mantle ...
Synthesis of Existing Structural Data for the Auckland Volcanic Field
... Figure 16. Extent of simple and complex structural zones in the Waitemata Group of the Auckland area................................................................................................................ 44 Figure 17. Palaeocurrent directions in the Waitemata Group. ........................ ...
... Figure 16. Extent of simple and complex structural zones in the Waitemata Group of the Auckland area................................................................................................................ 44 Figure 17. Palaeocurrent directions in the Waitemata Group. ........................ ...
Introduction to Metamorphism
... Temperature distribution within 1-km thick vertical dike and in country rocks (initially at 0οC) as function of time. Curves are labeled in years. The model assumes an initial intrusion temperature of 1200oC and cooling by conduction only. ...
... Temperature distribution within 1-km thick vertical dike and in country rocks (initially at 0οC) as function of time. Curves are labeled in years. The model assumes an initial intrusion temperature of 1200oC and cooling by conduction only. ...
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) . . . . . . ...
papua new guinea
... the once-beautiful New Britain town of Rabaul was destroyed by the Tuvurvur eruption. CLIMATE ...
... the once-beautiful New Britain town of Rabaul was destroyed by the Tuvurvur eruption. CLIMATE ...
secondary planar structural elements
... In strain terms these types of fabrics correspond to constriction, flattening, and intermediate strains with k values near 1. A secondary fabric expressed through the preferred orientation of the individual minerals constituting the rock is the most distinctive feature that separates metamorphic roc ...
... In strain terms these types of fabrics correspond to constriction, flattening, and intermediate strains with k values near 1. A secondary fabric expressed through the preferred orientation of the individual minerals constituting the rock is the most distinctive feature that separates metamorphic roc ...
Geology and gold mineralization of mesozoic rocks in the Pine
... Native gold occurs in quartz-sulfide veins along the margins of pyrite and chalcopyrite grains or as inclusions in pyrite grains. There is a general positive correlation between gold and copper grades in the Wheeler Mine, but the gold/copper ratio increases upward in the mine over 200 m. The mineral ...
... Native gold occurs in quartz-sulfide veins along the margins of pyrite and chalcopyrite grains or as inclusions in pyrite grains. There is a general positive correlation between gold and copper grades in the Wheeler Mine, but the gold/copper ratio increases upward in the mine over 200 m. The mineral ...
Geophysics and Tectonics of the Snake River Plain, Idaho
... density of this basalt has not been determined. The dry bulk density of forty-nine samples of basalt flows of the Quaternary Snake River Group on the eastern Snake River Plain averaged 2.55 grams per cubic centimeter, and seven samples of basalt flows of the Miocene Columbia River Basalt Group north ...
... density of this basalt has not been determined. The dry bulk density of forty-nine samples of basalt flows of the Quaternary Snake River Group on the eastern Snake River Plain averaged 2.55 grams per cubic centimeter, and seven samples of basalt flows of the Miocene Columbia River Basalt Group north ...
Mechanisms for folding of high-grade rocks in extensional tectonic
... 3e– g). A-type subduction (Bradbury and Nolen-Hoeksema, 1985; Etheridge et al., 1987), a similar process except that there has not been previous subduction of oceanic crust, has also been proposed for regional extension and basin formation in some Archaean and Proterozoic terrains. Under high-grade ...
... 3e– g). A-type subduction (Bradbury and Nolen-Hoeksema, 1985; Etheridge et al., 1987), a similar process except that there has not been previous subduction of oceanic crust, has also been proposed for regional extension and basin formation in some Archaean and Proterozoic terrains. Under high-grade ...
Evolution of Metamorphic Belts - CiteSeerX
... a pair. The latter belt is always on the Pacific Ocean side. They were probably formed in different phases of the same cycle of orogeny. Their origin is discussed. Regional metamorphism under higher rock pressures appears to have taken place in later geological times. The metamorphic facies series o ...
... a pair. The latter belt is always on the Pacific Ocean side. They were probably formed in different phases of the same cycle of orogeny. Their origin is discussed. Regional metamorphism under higher rock pressures appears to have taken place in later geological times. The metamorphic facies series o ...
Tectonostratigraphic Terranes and Tectonic Evolution of Mexico
... the morphotectonic provinces and the modern plate tectonic framework of the region. Next, we present data for 17 terranes that, except for North America, are named after indigenous cultures. Terrane descriptions are based on published and unpublished geophysical and geologic data of all types, utili ...
... the morphotectonic provinces and the modern plate tectonic framework of the region. Next, we present data for 17 terranes that, except for North America, are named after indigenous cultures. Terrane descriptions are based on published and unpublished geophysical and geologic data of all types, utili ...
Lower Continental Crust. - UCSB Earth Science
... (1990) assembled a database of rock compositions from Archean and post-Archean terrains recrystallized at >0.6 GPa. Huang et al. (2013) updated this database and added a compilation of amphibolite-facies samples. We augmented their granulite data with additional analyses from the literature, and her ...
... (1990) assembled a database of rock compositions from Archean and post-Archean terrains recrystallized at >0.6 GPa. Huang et al. (2013) updated this database and added a compilation of amphibolite-facies samples. We augmented their granulite data with additional analyses from the literature, and her ...
Transfer of melts in the sub-arc mantle: Insights from high
... Caledonia lies astride the Tropic of Capricorn and possesses an oceanic tropical climate with highly seasonal rainfall. The unusual geological history of New Caledonia has allowed the archipelago to maintain a unique flora and fauna preserving characteristics of an ancient Gondwanian ecosystem (Pira ...
... Caledonia lies astride the Tropic of Capricorn and possesses an oceanic tropical climate with highly seasonal rainfall. The unusual geological history of New Caledonia has allowed the archipelago to maintain a unique flora and fauna preserving characteristics of an ancient Gondwanian ecosystem (Pira ...
Rutile in eclogites as a mineral resource in the Sunnfjord
... of high-grade, high-quality ilmenite deposits as well as good rutile deposits. Particular focus has been given to rutilebearing eclogites in the Sunnfjord region of western Norway, due to a combination of factors such as high rutile content over significant volumes of rock and favourable rutile grai ...
... of high-grade, high-quality ilmenite deposits as well as good rutile deposits. Particular focus has been given to rutilebearing eclogites in the Sunnfjord region of western Norway, due to a combination of factors such as high rutile content over significant volumes of rock and favourable rutile grai ...
The life cycle of suprasubduction zone ophiolites
... to all such ophiolites. This sequence includes the following: (1) birth, which entails the formation of the ophiolite above a nascent or reconfigured subduction zone; this stage is typically characterized by the eruption of arc tholeiite lavas and the formation of layered gabbros and sheeted dike co ...
... to all such ophiolites. This sequence includes the following: (1) birth, which entails the formation of the ophiolite above a nascent or reconfigured subduction zone; this stage is typically characterized by the eruption of arc tholeiite lavas and the formation of layered gabbros and sheeted dike co ...
Shervais, J.W., 2001, Birth, Death, and Resurrection: The Life Cycle
... to all such ophiolites. This sequence includes the following: (1) birth, which entails the formation of the ophiolite above a nascent or reconfigured subduction zone; this stage is typically characterized by the eruption of arc tholeiite lavas and the formation of layered gabbros and sheeted dike co ...
... to all such ophiolites. This sequence includes the following: (1) birth, which entails the formation of the ophiolite above a nascent or reconfigured subduction zone; this stage is typically characterized by the eruption of arc tholeiite lavas and the formation of layered gabbros and sheeted dike co ...
Crustal Evolution of the GreatBasin and the Sierra
... of thousands of cubic kilometers of ash-flow deposits, making it one of the greatest manifestations of prolonged ash-flow volcanism in the terrestrial rock record. Some individual calderas are exposed east to west across three or four mountain ranges. Simplecooling-unit outflow tuff sheets cover are ...
... of thousands of cubic kilometers of ash-flow deposits, making it one of the greatest manifestations of prolonged ash-flow volcanism in the terrestrial rock record. Some individual calderas are exposed east to west across three or four mountain ranges. Simplecooling-unit outflow tuff sheets cover are ...
STP 3 & 4 2.5S.1 Basic Geologic and Seismic Information
... The Gulf Coastal Plain Physiographic Province (Figure 2.5S.1-6 [Reference 2.5S.112]) extends southeast and east from the edge of the Edwards Plateau, (Figure 2.5S.16 [Reference 2.5S.1-12]), 200 to 300 mi to the shore of the Gulf of Mexico. The Gulf Coastal Plain has been divided into three sub-provi ...
... The Gulf Coastal Plain Physiographic Province (Figure 2.5S.1-6 [Reference 2.5S.112]) extends southeast and east from the edge of the Edwards Plateau, (Figure 2.5S.16 [Reference 2.5S.1-12]), 200 to 300 mi to the shore of the Gulf of Mexico. The Gulf Coastal Plain has been divided into three sub-provi ...
.USGS
... particle size size from from clay clay to to in front front of of the the ice ice sheet. sheet. Deposits Deposits of of till till are are boulders, was boulders, was deposited deposited under under the the ice ice or or directly directly in the most the most extensive extensive glacial glacial depos ...
... particle size size from from clay clay to to in front front of of the the ice ice sheet. sheet. Deposits Deposits of of till till are are boulders, was boulders, was deposited deposited under under the the ice ice or or directly directly in the most the most extensive extensive glacial glacial depos ...
Salt Plugs in the Eastern Zagros, Iran: Results of
... Range and the Persian Gulf Platform. Khalij-e Fars is a shallow epicontinental sea with water depths of less than 100 m. Jazirehye Qesh is the largest shore island near the coast. The smaller offshore islands (Hormoz, Larak, Hengam, etc.) are salt plugs, partly fringed by the recent or subrecent cor ...
... Range and the Persian Gulf Platform. Khalij-e Fars is a shallow epicontinental sea with water depths of less than 100 m. Jazirehye Qesh is the largest shore island near the coast. The smaller offshore islands (Hormoz, Larak, Hengam, etc.) are salt plugs, partly fringed by the recent or subrecent cor ...
STP 3 & 4 2.5S.1 Basic Geologic and Seismic Information
... The Gulf Coastal Plain Physiographic Province (Figure 2.5S.1-6 [Reference 2.5S.112]) extends southeast and east from the edge of the Edwards Plateau, (Figure 2.5S.16 [Reference 2.5S.1-12]), 200 to 300 mi to the shore of the Gulf of Mexico. The Gulf Coastal Plain has been divided into three sub-provi ...
... The Gulf Coastal Plain Physiographic Province (Figure 2.5S.1-6 [Reference 2.5S.112]) extends southeast and east from the edge of the Edwards Plateau, (Figure 2.5S.16 [Reference 2.5S.1-12]), 200 to 300 mi to the shore of the Gulf of Mexico. The Gulf Coastal Plain has been divided into three sub-provi ...
101 - Durham University Community
... the scenario that we may imperceptibly treat some authority interpretations as facts or as being correct without questioning. This is unhealthy and inhibits the advance of our science. What is worse is the situation when we recognize the errors in the authority interpretations, we do not have the co ...
... the scenario that we may imperceptibly treat some authority interpretations as facts or as being correct without questioning. This is unhealthy and inhibits the advance of our science. What is worse is the situation when we recognize the errors in the authority interpretations, we do not have the co ...
Lecture 19: Mantle Plumes - Earth and Atmospheric Sciences
... continents, recycling of oceanic crust, continental crust, mantle plumes, and oceanic island basalts may all be part of a grand geochemical cycle. Tectonic erosion of continental crust in subduction zones and delamination of continental crust may be alternative mechanisms for deep recycling of conti ...
... continents, recycling of oceanic crust, continental crust, mantle plumes, and oceanic island basalts may all be part of a grand geochemical cycle. Tectonic erosion of continental crust in subduction zones and delamination of continental crust may be alternative mechanisms for deep recycling of conti ...
Geology of Great Britain
The geology of Great Britain is renowned for its diversity. As a result of its eventful geological history, Great Britain shows a rich variety of landscapes across the constituent countries of England, Wales and Scotland. Rocks of almost all geological ages are represented at outcrop, from the Archaean onwards.