Calcium isotopic composition of mantle xenoliths and minerals from
... This study presents calcium isotope data for co-existing clinopyroxenes (cpx), orthopyroxenes (opx), and olivine (ol) in mantle xenoliths to investigate Ca isotopic fractionation in the upper mantle. d44/40Ca (d44/40Ca (‰) = (44Ca/40Ca)SAMPLE/ (44Ca/40Ca)SRM915a 1) in opx varies from 0.95 ± 0.05‰ ...
... This study presents calcium isotope data for co-existing clinopyroxenes (cpx), orthopyroxenes (opx), and olivine (ol) in mantle xenoliths to investigate Ca isotopic fractionation in the upper mantle. d44/40Ca (d44/40Ca (‰) = (44Ca/40Ca)SAMPLE/ (44Ca/40Ca)SRM915a 1) in opx varies from 0.95 ± 0.05‰ ...
Tectonic evolution of a continental collision zone
... resulted from this process is sufficiently well constrained [e.g., Searle et al., 1987; Yin et al., 1999; Avouac, 2003] to allow for first order comparisons with physical models. However, at this point, any detailed comparison of numerical experiments and the tectonic evolution of the Himalaya would ...
... resulted from this process is sufficiently well constrained [e.g., Searle et al., 1987; Yin et al., 1999; Avouac, 2003] to allow for first order comparisons with physical models. However, at this point, any detailed comparison of numerical experiments and the tectonic evolution of the Himalaya would ...
Chapter 5. The Eclogite Engine
... tectonic or igneous processes , eventually forming dense eclogite that detaches and sinks into the mantle. It reaches a level of neutral buoyancy and starts to warm up. Eventually it rises and forms a warm fertile patch in the mantle. If the overlying continents have moved off, a midplate magmatic p ...
... tectonic or igneous processes , eventually forming dense eclogite that detaches and sinks into the mantle. It reaches a level of neutral buoyancy and starts to warm up. Eventually it rises and forms a warm fertile patch in the mantle. If the overlying continents have moved off, a midplate magmatic p ...
extra revision sheet grade 7 Q 4 Multiple Choice Identify the choice
... ____ 26. Ice, wind, water, gravity, plants, and animals are all agents of a. oxidation. c. differential weathering. b. desertification. d. physical weathering. ...
... ____ 26. Ice, wind, water, gravity, plants, and animals are all agents of a. oxidation. c. differential weathering. b. desertification. d. physical weathering. ...
a short story about the geological history of the pamir
... The Tadjik sedimentary basin is divided into two domains by the Vakhsh and Trans-Alai overthrusts. The “Tien Shan” domain comprises the South Tien Shan and the central and western parts of the Tadjik Depression. The “Outer Pamir” domain includes the Pamir Alai region and the eastern part of the Tadj ...
... The Tadjik sedimentary basin is divided into two domains by the Vakhsh and Trans-Alai overthrusts. The “Tien Shan” domain comprises the South Tien Shan and the central and western parts of the Tadjik Depression. The “Outer Pamir” domain includes the Pamir Alai region and the eastern part of the Tadj ...
GEO144_mid_term_I_so..
... (1) 2 pts. Phanerozoic, marine, sedimentary strata of the same age on different continents can usually be correlated by their fossil assemblages. T/F (1) 2 pts. The percentage of radioactive atoms that decay during one half-life is always the same. T/F (1) 2 pts. After two half-lives there is no lon ...
... (1) 2 pts. Phanerozoic, marine, sedimentary strata of the same age on different continents can usually be correlated by their fossil assemblages. T/F (1) 2 pts. The percentage of radioactive atoms that decay during one half-life is always the same. T/F (1) 2 pts. After two half-lives there is no lon ...
The Patrimonial Value of the Betic Ophiolites: Rocks from the
... The Betic ophiolites consist of numerous tectonic slices of eclogitized mafic and ultramafic rocks together with oceanic metasediments. They form a tectonic Unit of the Mulhacén Complex in the Betic Cordillera (SE Spain), intercalated between two crustal units named Caldera (below) and Sabinas (abov ...
... The Betic ophiolites consist of numerous tectonic slices of eclogitized mafic and ultramafic rocks together with oceanic metasediments. They form a tectonic Unit of the Mulhacén Complex in the Betic Cordillera (SE Spain), intercalated between two crustal units named Caldera (below) and Sabinas (abov ...
Final Exam Study Guide File
... d. how they formed REF: p. 66 OBJ: 3.2 Identify the three major types of rocks and explain how they differ. MSC: knowledge 15. Why are subduction zones not commonly found at convergent continental-continental boundaries? a. Continental lithosphere is too buoyant to be forced down into the mantle. b. ...
... d. how they formed REF: p. 66 OBJ: 3.2 Identify the three major types of rocks and explain how they differ. MSC: knowledge 15. Why are subduction zones not commonly found at convergent continental-continental boundaries? a. Continental lithosphere is too buoyant to be forced down into the mantle. b. ...
Bulletin 41 Geology of Puertecito Quadrangle, Socorro County, New
... physiographic province adjacent to the northern and western margins of the Basin and Range province. The center of the area is approximately 21 miles north-northwest of Magdalena, New Mexico. Mapped units include the Abo, Yeso, and San Andres formations, of Permian age; the Triassic Chinle formation ...
... physiographic province adjacent to the northern and western margins of the Basin and Range province. The center of the area is approximately 21 miles north-northwest of Magdalena, New Mexico. Mapped units include the Abo, Yeso, and San Andres formations, of Permian age; the Triassic Chinle formation ...
The Oceanic Lithosphere
... features, thermal subsidence, etc. Ship-mounted systems allow for surveys of large areas of the seafloor, but near-bottom instruments mounted on deep-tow systems, remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs) provide highresolution images to study in detail volcanic and ...
... features, thermal subsidence, etc. Ship-mounted systems allow for surveys of large areas of the seafloor, but near-bottom instruments mounted on deep-tow systems, remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs) provide highresolution images to study in detail volcanic and ...
The Caribbean Ocean Plateau – an overview
... Sinton et al., (1998) the Caribbean Plate was located over the Galapagos Hot Spot at 90 Ma. Widespread but apparently smaller volume magmatism occurred at ~76 Ma with still younger volcanism occurring locally in the Dominican Republic. The 76 Ma magmatism may have been the result of extension during ...
... Sinton et al., (1998) the Caribbean Plate was located over the Galapagos Hot Spot at 90 Ma. Widespread but apparently smaller volume magmatism occurred at ~76 Ma with still younger volcanism occurring locally in the Dominican Republic. The 76 Ma magmatism may have been the result of extension during ...
Dismantling the Deep Earth: Geochemical
... A.) Interested in the 87Sr/86Sr (and Nd, Pb) of only the high 3He/4He mantle, so examine only the lavas with the highest 3He/4He from hotspots that have high 3He/4He. B.) High 3He/4He lavas from some environments may be contaminated by shallow reservoirs and their 87Sr/86Sr (and Nd, Pb) may not repr ...
... A.) Interested in the 87Sr/86Sr (and Nd, Pb) of only the high 3He/4He mantle, so examine only the lavas with the highest 3He/4He from hotspots that have high 3He/4He. B.) High 3He/4He lavas from some environments may be contaminated by shallow reservoirs and their 87Sr/86Sr (and Nd, Pb) may not repr ...
Upper plate proxies for flat-slab subduction processes in southern
... process are not well understood. We explore the record of flat-slab subduction in southern Alaska by integrating stratigraphic, provenance, geochronologic, and thermochronologic data from the region directly above and around the perimeter of ongoing flat-slab subduction. These datasets document a chan ...
... process are not well understood. We explore the record of flat-slab subduction in southern Alaska by integrating stratigraphic, provenance, geochronologic, and thermochronologic data from the region directly above and around the perimeter of ongoing flat-slab subduction. These datasets document a chan ...
PDF
... have been significantly thicker beneath what is oceanic ridge spreading at a half rate of 2-3 that these are generally sites of subduction initianow the frontal arc. cm/yr. These rates, patterns of faulting in the tion has been made by Casey and Dewey (1984) These parameters indicate that between 1, ...
... have been significantly thicker beneath what is oceanic ridge spreading at a half rate of 2-3 that these are generally sites of subduction initianow the frontal arc. cm/yr. These rates, patterns of faulting in the tion has been made by Casey and Dewey (1984) These parameters indicate that between 1, ...
"postorogenie" magmatism
... tures, and thus are compositionally similar to suites found in extensional regimes. We propose that thinning of the lithospheric mantle, which may be an automatic response to orogenie lithospheric thicken· ing, is responsible for these magmatic suites. Mantle lithospheric thinning moves the asthenos ...
... tures, and thus are compositionally similar to suites found in extensional regimes. We propose that thinning of the lithospheric mantle, which may be an automatic response to orogenie lithospheric thicken· ing, is responsible for these magmatic suites. Mantle lithospheric thinning moves the asthenos ...
A new model of lunar crust: asymmetry in crustal composition... Tomoko Arai , Hiroshi Takeda , Akira Yamaguchi
... some rocks enriched in alkali elements, termed alkali-suite rocks. There is another outstanding group, called KREEP, which is extremely enriched in alkalis and incompatible trace elements, such as K, rare earth elements (REEs) and P. They occur as impact melt rocks and basalts. The isotopic ages of ...
... some rocks enriched in alkali elements, termed alkali-suite rocks. There is another outstanding group, called KREEP, which is extremely enriched in alkalis and incompatible trace elements, such as K, rare earth elements (REEs) and P. They occur as impact melt rocks and basalts. The isotopic ages of ...
Subduction and the rock record: Concepts developed
... significantly, the paper explained the association of low geothermal gradients and the metamorphism. The paper also pointed out the difficult tectonic problem of the exhumation of the high P-T rocks, a problem still vigorously debated today, and proposed a tectonic model explaining the exhumation of ...
... significantly, the paper explained the association of low geothermal gradients and the metamorphism. The paper also pointed out the difficult tectonic problem of the exhumation of the high P-T rocks, a problem still vigorously debated today, and proposed a tectonic model explaining the exhumation of ...
Characterizing the hypersiliceous rocks of Belgium used in (pre
... silicified quartz sand deposits, better known as sedimentary quartzites or orthoquartzites (Krynine 1941, 1948), in which the components are made up of quartz grains originating from weathered and transported pre-existing rock. Also excluded from this definition are very pure metamorphic quartzites ...
... silicified quartz sand deposits, better known as sedimentary quartzites or orthoquartzites (Krynine 1941, 1948), in which the components are made up of quartz grains originating from weathered and transported pre-existing rock. Also excluded from this definition are very pure metamorphic quartzites ...
Lecture 18
... Trough. On the other hand, the deeper reservoir seems to be sam- lower mantle is primitive and pled exclusively, or nearly so, where there is independent evi- has bulk Earth characteristics, dence for major mantle upwelling in the form of mantle plumes. e.g., eNd = 0. The geophysical evidence for th ...
... Trough. On the other hand, the deeper reservoir seems to be sam- lower mantle is primitive and pled exclusively, or nearly so, where there is independent evi- has bulk Earth characteristics, dence for major mantle upwelling in the form of mantle plumes. e.g., eNd = 0. The geophysical evidence for th ...
Three geological sections across South Sumatra
... Netherlands East Indies between 1927 and 1933, which methodical survey, the results of which have been published in the Explanations to the Geol. Map of Sumatra, scale 1 : 200.000 1 ), in a certain way may be considered as a continuation of the explorations made previously by A. TOBLER 2) and others ...
... Netherlands East Indies between 1927 and 1933, which methodical survey, the results of which have been published in the Explanations to the Geol. Map of Sumatra, scale 1 : 200.000 1 ), in a certain way may be considered as a continuation of the explorations made previously by A. TOBLER 2) and others ...
11. GEODYNAMIC EVOLUTION OF THE CÔTE D`IVOIRE
... unconformities capping the Early Cretaceous deformed sequences are not thought to be coeval at all ODP sites. A progressive southward migration of the active transform may have been initiated in early Albian times, when continental breakup occurred within the adjacent rifted Ivorian Basin. The early ...
... unconformities capping the Early Cretaceous deformed sequences are not thought to be coeval at all ODP sites. A progressive southward migration of the active transform may have been initiated in early Albian times, when continental breakup occurred within the adjacent rifted Ivorian Basin. The early ...
Deep structure of the Mid Norway rifted margin
... form area and the Jurassic basins on the Halten Terrace involves the successive development of two generations of extensional detachments and their interaction with a deep-seated, antiformal culmination interpreted here as a metamorphic core complex. Denudation of the core complex was related to lar ...
... form area and the Jurassic basins on the Halten Terrace involves the successive development of two generations of extensional detachments and their interaction with a deep-seated, antiformal culmination interpreted here as a metamorphic core complex. Denudation of the core complex was related to lar ...
Meso- and Cenozoic Tectonics of the Central Asian Mountain Belt
... tion" of the Indian plate into the Eurasian plate. The new model is based on the hypothesis of a complex interaction of lithospheric plates and mantle-plume magmatism. Compilation and comparison of new and published structural, geomorphological, paleomagnetic, isotopic, fission-track, and plume magm ...
... tion" of the Indian plate into the Eurasian plate. The new model is based on the hypothesis of a complex interaction of lithospheric plates and mantle-plume magmatism. Compilation and comparison of new and published structural, geomorphological, paleomagnetic, isotopic, fission-track, and plume magm ...
Spreading Continents Kick-Started Plate Tectonics Plate tectonics
... that no convective stresses act on the lid, allowing us to isolate the dynamic effect of the continent. A ...
... that no convective stresses act on the lid, allowing us to isolate the dynamic effect of the continent. A ...
Provenance (geology)
Provenance in geology, is the reconstruction of the history of sediments movements over time. The Earth is not a static but a dynamic planet, all rocks are subject to transition between the three main rock types, which are sedimentary, metamorphic, and igneous rocks (the rock cycle). Rocks exposed to the surface, sooner or later, are broken down into sediments. Sediments are expected to be able to provide evidence of the erosion history of their parent source rocks. The purpose of provenance study is to restore the tectonic, paleo-geographic and paleo-climatic history.