Workshop Report - Consortium for Ocean Leadership
... the internal structures, melt migration features, and layering was critical, brought together scientists of diverse backgrounds, and fostered multi-disciplinary approaches to mantle dynamics, mantle melting, melt migration and transport processes. The Conference was preceded by a two-day field trip ...
... the internal structures, melt migration features, and layering was critical, brought together scientists of diverse backgrounds, and fostered multi-disciplinary approaches to mantle dynamics, mantle melting, melt migration and transport processes. The Conference was preceded by a two-day field trip ...
Differential preservation in the geologic record of intraoceanic arc
... Records of ancient intraoceanic arc activity, now preserved in continental suture zones, are commonly used to reconstruct paleogeography and plate motion, and to understand how continental crust is formed, recycled, and maintained through time. However, interpreting tectonic and sedimentary records ...
... Records of ancient intraoceanic arc activity, now preserved in continental suture zones, are commonly used to reconstruct paleogeography and plate motion, and to understand how continental crust is formed, recycled, and maintained through time. However, interpreting tectonic and sedimentary records ...
Practice mdtrm
... 90. The speed of light is ____________________ kilometers per second. 91. An emission spectrum is produced by a(n) ____________________ gas under ____________________ pressure. 92. The most dense stars known to exist are called ____________________. 93. The Milky Way is classified as a(n) __________ ...
... 90. The speed of light is ____________________ kilometers per second. 91. An emission spectrum is produced by a(n) ____________________ gas under ____________________ pressure. 92. The most dense stars known to exist are called ____________________. 93. The Milky Way is classified as a(n) __________ ...
Melting of the Uppermost Metasomatized Asthenosphere Triggered
... the Chatan basalt. Chi-square tests for the major elements indicate that crystal fractionation can explain the chemical variations ...
... the Chatan basalt. Chi-square tests for the major elements indicate that crystal fractionation can explain the chemical variations ...
Garnet: Common Mineral, Uncommonly Useful
... garnet grains (FIG. 1F). Garnet has even been documented “when” garnet grows (and the timing of processes that in meteorites (e.g. Krot et al. 1998) and in association with may be linked to it), but also “how fast” and “for how microbial life (Ménez et al. 2012). Indeed, garnet is one of long.” Ague ...
... garnet grains (FIG. 1F). Garnet has even been documented “when” garnet grows (and the timing of processes that in meteorites (e.g. Krot et al. 1998) and in association with may be linked to it), but also “how fast” and “for how microbial life (Ménez et al. 2012). Indeed, garnet is one of long.” Ague ...
here - Lehigh University
... Chapters in Books — Bebout, G. E., 2013, 4.20. Chemical and isotopic cycling in subduction zones, in Rudnick, R. L., ed., 2nd Ed. Volume 4, Treatise on Geochemistry: The Crust, Elsevier, pp. 703-747. Bebout, G. E., 2012, Chapter 9. Metasomatism in subduction zones of subducted oceanic slabs, mantle ...
... Chapters in Books — Bebout, G. E., 2013, 4.20. Chemical and isotopic cycling in subduction zones, in Rudnick, R. L., ed., 2nd Ed. Volume 4, Treatise on Geochemistry: The Crust, Elsevier, pp. 703-747. Bebout, G. E., 2012, Chapter 9. Metasomatism in subduction zones of subducted oceanic slabs, mantle ...
Ophiolite concept and its evolution
... Hess, 1938, 1955) and experimental petrologists (Bowen, 1927, 1928) regarding their close spatial association with volcanic and sedimentary rocks (Young, this volume, Chapter 4; Bernoulli et al., this volume, Chapter 7). While explaining the ophiolitic assemblages as a product of magmatic differenti ...
... Hess, 1938, 1955) and experimental petrologists (Bowen, 1927, 1928) regarding their close spatial association with volcanic and sedimentary rocks (Young, this volume, Chapter 4; Bernoulli et al., this volume, Chapter 7). While explaining the ophiolitic assemblages as a product of magmatic differenti ...
Rare Earth Elements Profile
... The rare earth elements (REE) (sometimes referred to as the rare earth metals) are a group of 17 chemically similar metallic elements, including the 15 lanthanides, scandium and yttrium. The lanthanides are elements spanning atomic numbers 57 (lanthanum, La) to 71 (lutetium, Lu) (Table 1). The lanth ...
... The rare earth elements (REE) (sometimes referred to as the rare earth metals) are a group of 17 chemically similar metallic elements, including the 15 lanthanides, scandium and yttrium. The lanthanides are elements spanning atomic numbers 57 (lanthanum, La) to 71 (lutetium, Lu) (Table 1). The lanth ...
physical, chemical, and chronological characteristics of
... are seen under tectonically active continental regions, such as the Basin and Range, but available evidence indicates that in these continental areas the mantle low-velocity zone begins immediately beneath the Moho, with a high-velocity ‘‘lid’’ similar to that seen in ocean basins notably absent. Lo ...
... are seen under tectonically active continental regions, such as the Basin and Range, but available evidence indicates that in these continental areas the mantle low-velocity zone begins immediately beneath the Moho, with a high-velocity ‘‘lid’’ similar to that seen in ocean basins notably absent. Lo ...
Near-Ultrahigh Pressure Processing of Continental Crust: Miocene
... compositions were measured at Boston University using the remains of thin-section billets. This is not ideal because the samples are contaminated with epoxy from thin-section impregnation, and some include bits of host lava. Billets were first abraded with silicon carbide to remove as much as possib ...
... compositions were measured at Boston University using the remains of thin-section billets. This is not ideal because the samples are contaminated with epoxy from thin-section impregnation, and some include bits of host lava. Billets were first abraded with silicon carbide to remove as much as possib ...
Early Paleozoic Tectonic and Thermomechanical
... Coesite- and diamond-bearing ultrahigh-pressure (UHP) metamorphic rocks represent continental materials that were once subducted to depths of >90 km. Identifying how these rocks were subsequently returned to Earth’s surface has been a major challenge. Opinions on this matter vary widely, ranging fro ...
... Coesite- and diamond-bearing ultrahigh-pressure (UHP) metamorphic rocks represent continental materials that were once subducted to depths of >90 km. Identifying how these rocks were subsequently returned to Earth’s surface has been a major challenge. Opinions on this matter vary widely, ranging fro ...
Volatile Cycling of H2O, CO2, F, and Cl in the HIMU Mantle: A New
... mobility of Pb during subduction zone processing, Pb loss from the slab results in high U/Pb ratios in the subducted slab reservoir, which evolves highly radiogenic Pb-isotope compositions over time [Hofmann and White, 1982; Zindler and Hart, 1986; Hauri and Hart, 1993; Kelley et al., 2005; Hanyu et ...
... mobility of Pb during subduction zone processing, Pb loss from the slab results in high U/Pb ratios in the subducted slab reservoir, which evolves highly radiogenic Pb-isotope compositions over time [Hofmann and White, 1982; Zindler and Hart, 1986; Hauri and Hart, 1993; Kelley et al., 2005; Hanyu et ...
lithosphere 2006 - Helsingin yliopisto
... References of Lithosphere Symposia Publications Pesonen, L.J., Korja, A. and Hjelt, S.-E., 2000 (Eds.). Lithosphere 2000 - A Symposium on the Structure, Composition and Evolution of the Lithosphere in Finland. Programme and Extended Abstracts, Espoo, Finland, October 4-5, 2000. Institute of Seismolo ...
... References of Lithosphere Symposia Publications Pesonen, L.J., Korja, A. and Hjelt, S.-E., 2000 (Eds.). Lithosphere 2000 - A Symposium on the Structure, Composition and Evolution of the Lithosphere in Finland. Programme and Extended Abstracts, Espoo, Finland, October 4-5, 2000. Institute of Seismolo ...
Composition of the Oceanic Crust - DukeSpace
... Intermediate-spreading ridges, with spreading rates between 4 and 8 cm year1, have morphologies that vary between those typical of fast- and slow-spreading ones. Indeed, the intermediate-spreading Juan de Fuca Ridge has segments exhibiting the full range of morphologies (Carbotte et al., 2006; Stak ...
... Intermediate-spreading ridges, with spreading rates between 4 and 8 cm year1, have morphologies that vary between those typical of fast- and slow-spreading ones. Indeed, the intermediate-spreading Juan de Fuca Ridge has segments exhibiting the full range of morphologies (Carbotte et al., 2006; Stak ...
Insights into extensional processes during magma assisted rifting
... controlled source seismology, magnetotellurics, gravity surveying, and isotope geochemistry to place new constraints on present day extension in Ethiopia. The south-to-north exposure of progressively evolved stages of rifting means that these results can be used to understand the evolution of riftin ...
... controlled source seismology, magnetotellurics, gravity surveying, and isotope geochemistry to place new constraints on present day extension in Ethiopia. The south-to-north exposure of progressively evolved stages of rifting means that these results can be used to understand the evolution of riftin ...
res terrae - Oulun yliopisto
... and total thickness (Eriksson et al., 2001). Tectonic regimes, which control the formation and evolution of sedimentary basins, were more erratic in terms of origin and rates during the Precambrian (Eriksson et al., 1998, 2004, 2005, 2007). The rates and intensities of processes in Precambrian sedim ...
... and total thickness (Eriksson et al., 2001). Tectonic regimes, which control the formation and evolution of sedimentary basins, were more erratic in terms of origin and rates during the Precambrian (Eriksson et al., 1998, 2004, 2005, 2007). The rates and intensities of processes in Precambrian sedim ...
A long in situ section of the lower ocean crust: results of ODP Leg
... Ocean Drilling Program Leg 176 deepened Hole 735B in gabbroic lower ocean crust by 1 km to 1.5 km. The section has the physical properties of seismic layer 3, and a total magnetization sufficient by itself to account for the overlying lineated sea-surface magnetic anomaly. The rocks from Hole 735B a ...
... Ocean Drilling Program Leg 176 deepened Hole 735B in gabbroic lower ocean crust by 1 km to 1.5 km. The section has the physical properties of seismic layer 3, and a total magnetization sufficient by itself to account for the overlying lineated sea-surface magnetic anomaly. The rocks from Hole 735B a ...
Intrusive igneous rocks include granite.
... The sun consists largely of hydrogen gas. Its energy comes from nuclear fusion of hydrogen to helium. ...
... The sun consists largely of hydrogen gas. Its energy comes from nuclear fusion of hydrogen to helium. ...
the Zero Paradox Noble Gas Mantle
... The greatest strength of using noble gases as tracers of mantle processes is their chemical inertness and volatility. These characteristics result in efficient outgassing of the noble gases during melting, with negligible recycling back into the mantle system, which greatly simplifies their interpre ...
... The greatest strength of using noble gases as tracers of mantle processes is their chemical inertness and volatility. These characteristics result in efficient outgassing of the noble gases during melting, with negligible recycling back into the mantle system, which greatly simplifies their interpre ...
13 Oxygen Isotopes in Zircon - University of Wisconsin
... A relatively new and very promising approach to zircon separation is the Electric Pulse Disintegration (EPD), which uses spark discharges of >100 kV to disaggregate a rock, largely along grain boundaries (Rudashevsky et al. 1995, Saint-Eidukat and Weiblen 1996). This technique can preserve delicate ...
... A relatively new and very promising approach to zircon separation is the Electric Pulse Disintegration (EPD), which uses spark discharges of >100 kV to disaggregate a rock, largely along grain boundaries (Rudashevsky et al. 1995, Saint-Eidukat and Weiblen 1996). This technique can preserve delicate ...
Late Proterozoic – Paleozoic Tectonostratigraphic Development and
... geological structure, lithology and geochronology of the Cadomian Brunovistulicum show a broad fit with the crystalline basement of the Istanbul Zone. Their Gondwana or Baltica affinity is still poorly constrained and remains a matter of discussion. The Vendian and Cambrian sequences recognized in t ...
... geological structure, lithology and geochronology of the Cadomian Brunovistulicum show a broad fit with the crystalline basement of the Istanbul Zone. Their Gondwana or Baltica affinity is still poorly constrained and remains a matter of discussion. The Vendian and Cambrian sequences recognized in t ...
Evolution of the Paleo-Asian Ocean (Altai−Sayan Region, Central
... been integrated after Dobretsov et al. (1995). Fragments detached from Gondwanaland in Early Paleozoic have been postulated not only in Central Asia but also in the Middle East (Cocks, 2001 and the references). However, the breakup processes of Gondwana as well as those of Rodinia are still hypothet ...
... been integrated after Dobretsov et al. (1995). Fragments detached from Gondwanaland in Early Paleozoic have been postulated not only in Central Asia but also in the Middle East (Cocks, 2001 and the references). However, the breakup processes of Gondwana as well as those of Rodinia are still hypothet ...
Megaregolith evolution and cratering cataclysm models—Lunar
... sampled by Apollo/Luna. Reported lunar meteorite data do not show the spike. Asteroid data show a broader, milder peak, spreading from about 4.2 to 3.5 Gyr. These data suggest either that the spike in Apollo impact melt ages is associated with unique lunar front side events, or that the lunar meteor ...
... sampled by Apollo/Luna. Reported lunar meteorite data do not show the spike. Asteroid data show a broader, milder peak, spreading from about 4.2 to 3.5 Gyr. These data suggest either that the spike in Apollo impact melt ages is associated with unique lunar front side events, or that the lunar meteor ...
evolution of the north american cordillera
... ways, as the Atlantic and Indian oceans opened to disrupt Pangea by seafloor spreading. Alpine-Himalayan evolution has involved the successive juxtaposition of disparate continental blocks (e.g., Africa, India, Australia against Eurasia) at suture belts marking the former positions of trenches where ...
... ways, as the Atlantic and Indian oceans opened to disrupt Pangea by seafloor spreading. Alpine-Himalayan evolution has involved the successive juxtaposition of disparate continental blocks (e.g., Africa, India, Australia against Eurasia) at suture belts marking the former positions of trenches where ...
EVOLUTION OF THE NORTH AMERICAN CORDILLERA William R
... ways, as the Atlantic and Indian oceans opened to disrupt Pangea by seafloor spreading. Alpine-Himalayan evolution has involved the successive juxtaposition of disparate continental blocks (e.g., Africa, India, Australia against Eurasia) at suture belts marking the former positions of trenches where ...
... ways, as the Atlantic and Indian oceans opened to disrupt Pangea by seafloor spreading. Alpine-Himalayan evolution has involved the successive juxtaposition of disparate continental blocks (e.g., Africa, India, Australia against Eurasia) at suture belts marking the former positions of trenches where ...
History of Earth
The history of Earth concerns the development of the planet Earth from its formation to the present day. Nearly all branches of natural science have contributed to the understanding of the main events of the Earth's past. The age of Earth is approximately one-third of the age of the universe. An immense amount of biological and geological change has occurred in that time span.Earth formed around 4.54 billion years ago by accretion from the solar nebula. Volcanic outgassing probably created the primordial atmosphere, but it contained almost no oxygen and would have been toxic to humans and most modern life. Much of the Earth was molten because of frequent collisions with other bodies which led to extreme volcanism. One very large collision is thought to have been responsible for tilting the Earth at an angle and forming the Moon. Over time, the planet cooled and formed a solid crust, allowing liquid water to exist on the surface.The first life forms appeared between 3.8 and 3.5 billion years ago. The earliest evidences for life on Earth are graphite found to be biogenic in 3.7-billion-year-old metasedimentary rocks discovered in Western Greenland and microbial mat fossils found in 3.48-billion-year-old sandstone discovered in Western Australia. Photosynthetic life appeared around 2 billion years ago, enriching the atmosphere with oxygen. Life remained mostly small and microscopic until about 580 million years ago, when complex multicellular life arose. During the Cambrian period it experienced a rapid diversification into most major phyla. More than 99 percent of all species, amounting to over five billion species, that ever lived on Earth are estimated to be extinct. Estimates on the number of Earth's current species range from 10 million to 14 million, of which about 1.2 million have been documented and over 86 percent have not yet been described.Geological change has been constantly occurring on Earth since the time of its formation and biological change since the first appearance of life. Species continuously evolve, taking on new forms, splitting into daughter species, or going extinct in response to an ever-changing planet. The process of plate tectonics has played a major role in the shaping of Earth's oceans and continents, as well as the life they harbor. The biosphere, in turn, has had a significant effect on the atmosphere and other abiotic conditions on the planet, such as the formation of the ozone layer, the proliferation of oxygen, and the creation of soil.