Verkhoyansk Project Final Report - IIS Windows Server
... in order to examine all the principal lithologic units that characterize each structural domain within the thrust belt. We had Russian geological maps of covering most of our transects at 1:200,000 scale (Ferdman et al. 1963; Losev et al. 1970; Starnikov, 1983; Yan-Shin-Tshin, 1971), as well as a co ...
... in order to examine all the principal lithologic units that characterize each structural domain within the thrust belt. We had Russian geological maps of covering most of our transects at 1:200,000 scale (Ferdman et al. 1963; Losev et al. 1970; Starnikov, 1983; Yan-Shin-Tshin, 1971), as well as a co ...
Crust recycling in the sources of two parallel volcanic chains in
... obscured and recycled crustal sources are difficult to distinguish from crustal contamination. We show major, trace element and Sr–Nd–Hf isotopic compositions for two parallel chains of Cenozoic volcanoes from Shandong Province, North China, which are free of crustal contamination and show clear evid ...
... obscured and recycled crustal sources are difficult to distinguish from crustal contamination. We show major, trace element and Sr–Nd–Hf isotopic compositions for two parallel chains of Cenozoic volcanoes from Shandong Province, North China, which are free of crustal contamination and show clear evid ...
Characterization of crustal-scale structures interpreted from
... intersection of two regional crustal structures and chalcopyrite, bornite, pyrite, and magnetite ...
... intersection of two regional crustal structures and chalcopyrite, bornite, pyrite, and magnetite ...
precambrian geology of the truchas peaks region, north
... Facies changes shown by rocks of the Truchas Range suggest variable environments of deposition for the Truchas Group. At the southern end of the range, the stratigraphic section is dominated by thick turbiditic and reduced (graphitic) metashale. Quartzite beds contain accessory magnetite, rather tha ...
... Facies changes shown by rocks of the Truchas Range suggest variable environments of deposition for the Truchas Group. At the southern end of the range, the stratigraphic section is dominated by thick turbiditic and reduced (graphitic) metashale. Quartzite beds contain accessory magnetite, rather tha ...
Chapter 4 Marine Sedimentation
... Shelf sediments Geologic controls of continental shelf sedimentation must be considered in terms of a time frame. • For a time frame up to 1000 years, waves, currents and tides control sedimentation. • For a time frame up to 1,000,000 years, sea level lowered by glaciation controlled sedimentation ...
... Shelf sediments Geologic controls of continental shelf sedimentation must be considered in terms of a time frame. • For a time frame up to 1000 years, waves, currents and tides control sedimentation. • For a time frame up to 1,000,000 years, sea level lowered by glaciation controlled sedimentation ...
Garzione, C. N., P. Molnar, J. C. Libarkin, and B. J. MacFadden (2007), Reply to Comment on
... occurred by lower crustal flow (Husson and Sempere, 2003), but we imagine that this process would have been aided by the removal of mantle lithosphere beneath the Eastern Cordillera and/or southern Altiplano and Puna through the development of greater gravitational potential energy per unit area bet ...
... occurred by lower crustal flow (Husson and Sempere, 2003), but we imagine that this process would have been aided by the removal of mantle lithosphere beneath the Eastern Cordillera and/or southern Altiplano and Puna through the development of greater gravitational potential energy per unit area bet ...
Geology
... understood, though such crust mostly forms at convergent plate margins today. It is thus imperative to study modern intra-oceanic arcs, such as those common in the western Pacific Ocean. New seismic studies along the representative Izu-Bonin intra-oceanic arc provide unique along-strike images of ar ...
... understood, though such crust mostly forms at convergent plate margins today. It is thus imperative to study modern intra-oceanic arcs, such as those common in the western Pacific Ocean. New seismic studies along the representative Izu-Bonin intra-oceanic arc provide unique along-strike images of ar ...
Ultrahigh-pressure metamorphism: tracing continental crust into the
... partitioning and fluid channelling, significant volumes of subducted crust may remain unreacted (i.e. metastable) even at conditions as high as 700‡C and 3 GPa ^ with implications as to geophysical modeling; (ii) subducted continental crust shows no isotopic or geochemical evidence of interaction wi ...
... partitioning and fluid channelling, significant volumes of subducted crust may remain unreacted (i.e. metastable) even at conditions as high as 700‡C and 3 GPa ^ with implications as to geophysical modeling; (ii) subducted continental crust shows no isotopic or geochemical evidence of interaction wi ...
Generation of new continental crust by sublithospheric silicic
... Fig. 1. Panel showing the main differences between the two models for the generation of the continental crust. The basalt input model (a) needs of two important additional processes to achieve the final composition represented by the bulk continental crust: 1: sinking of an ultramafic residue, not exi ...
... Fig. 1. Panel showing the main differences between the two models for the generation of the continental crust. The basalt input model (a) needs of two important additional processes to achieve the final composition represented by the bulk continental crust: 1: sinking of an ultramafic residue, not exi ...
Conductive structures in southernmost Africa: a magnetometer array
... three time sequences are presented and used in locating the edges of the conductive region. Six sets of maps of Fourier transform amplitudes and phases, at periods for which the events supply adequate energy, show anomalies related to currents flowing in three conductive structures. These are the co ...
... three time sequences are presented and used in locating the edges of the conductive region. Six sets of maps of Fourier transform amplitudes and phases, at periods for which the events supply adequate energy, show anomalies related to currents flowing in three conductive structures. These are the co ...
Spatial, temporal and geochemical evolution of
... Tauride platform (Şengör and Yılmaz, 1981). The Izmir–Ankara suture zone includes two different tectonostratigraphic units. In its northwestern and western parts, it consists of a wild-flysch sequence (Bornova flysch of Okay and Siyako, 1993), which contains abundant platform type carbonate olistholit ...
... Tauride platform (Şengör and Yılmaz, 1981). The Izmir–Ankara suture zone includes two different tectonostratigraphic units. In its northwestern and western parts, it consists of a wild-flysch sequence (Bornova flysch of Okay and Siyako, 1993), which contains abundant platform type carbonate olistholit ...
CHAPTER 7 - SYNTHESIS
... In order to analyze the evolution of the stress field in even more detail, additional information would be required on: - Exact dating of Tertiary sediments especially in the smaller basins, would improve the data set and enable lateral extension of the areas for which trajectories of Shmax can be r ...
... In order to analyze the evolution of the stress field in even more detail, additional information would be required on: - Exact dating of Tertiary sediments especially in the smaller basins, would improve the data set and enable lateral extension of the areas for which trajectories of Shmax can be r ...
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... determined under the stations is divided into three-dimensional blocks (see Paper I). The lateral size of blocks is determined essentially by the station distribution: in spite of a concentration of stations in central Europe on the one hand, in Scandinavia, on the other, some important gaps, in par ...
... determined under the stations is divided into three-dimensional blocks (see Paper I). The lateral size of blocks is determined essentially by the station distribution: in spite of a concentration of stations in central Europe on the one hand, in Scandinavia, on the other, some important gaps, in par ...
Chapter 5
... marks the lithosphere-asthenosphere boundary. In the crust large movements happens so slowly (low strain rates) that they can be measured only over a hundred or more years. ...
... marks the lithosphere-asthenosphere boundary. In the crust large movements happens so slowly (low strain rates) that they can be measured only over a hundred or more years. ...
Provenance characteristics of the Brumunddal sandstone in the Oslo
... stage. The composite Larvik pluton in the Vestfold graben intruded in this stage, and has been dated to 298-292 Ma by ID-TIMS U-Pb on zircons (Dahlgren et al., 1996, 1998, Dahlgren 2010). In the subsequent central volcano stage, volcanic activity was concentrated in distinct volcaniccentres with l ...
... stage. The composite Larvik pluton in the Vestfold graben intruded in this stage, and has been dated to 298-292 Ma by ID-TIMS U-Pb on zircons (Dahlgren et al., 1996, 1998, Dahlgren 2010). In the subsequent central volcano stage, volcanic activity was concentrated in distinct volcaniccentres with l ...
Science
... basement drilling is a positive correlation between recovery and crustal age (Fig. 3). The increased recovery in older crust is probably due to increased lithification of the basement. Interflow sediments and breccias recover poorly when unlithified, but can be recovered easily when compacted and ce ...
... basement drilling is a positive correlation between recovery and crustal age (Fig. 3). The increased recovery in older crust is probably due to increased lithification of the basement. Interflow sediments and breccias recover poorly when unlithified, but can be recovered easily when compacted and ce ...
Slab flattening trigger for isotopic disturbance and magmatic flare
... Continental arc magmatism is widely regarded to reflect melting of the mantle wedge by addition of fluids produced through metamorphism of trench sediments and oceanic crust in moderately to steeply dipping subduction zones (e.g., Bebout, 1991). In contrast, shallow subduction is commonly invoked to ...
... Continental arc magmatism is widely regarded to reflect melting of the mantle wedge by addition of fluids produced through metamorphism of trench sediments and oceanic crust in moderately to steeply dipping subduction zones (e.g., Bebout, 1991). In contrast, shallow subduction is commonly invoked to ...
Introduction - Beck-Shop
... processes in the generation of particular rock suites exposed at Earth’s surface. Alternative models for crustal growth place greater importance on basaltic magmatism related to superplume events and the accretion of oceanic plateaus to continents. Oceanic plateaus cover about 3% of modern Earth’s s ...
... processes in the generation of particular rock suites exposed at Earth’s surface. Alternative models for crustal growth place greater importance on basaltic magmatism related to superplume events and the accretion of oceanic plateaus to continents. Oceanic plateaus cover about 3% of modern Earth’s s ...
PDF
... 1. Introduction and geologic setting This paper reviews the closing 100 million years of crustal growth in the Arabian–Nubian Shield (ANS), covering the period between 650 Ma and 542 Ma, and describes the late Cryogenian– Ediacaran depositional, structural, metamorphic, intrusive, and mineralization ...
... 1. Introduction and geologic setting This paper reviews the closing 100 million years of crustal growth in the Arabian–Nubian Shield (ANS), covering the period between 650 Ma and 542 Ma, and describes the late Cryogenian– Ediacaran depositional, structural, metamorphic, intrusive, and mineralization ...
Heterogeneous sources for Pleistocene lavas of Marie Byrd Land
... Mountains, resting depositionally upon frost-heaved periglacial surfaces and upon angular glacial boulders that mantle bedrock surfaces at low elevations. Many volcanic exposures consist of delicate tephra, cinder, and splatter forms, not evidently modified by wet-based glacial ice. In addition, a f ...
... Mountains, resting depositionally upon frost-heaved periglacial surfaces and upon angular glacial boulders that mantle bedrock surfaces at low elevations. Many volcanic exposures consist of delicate tephra, cinder, and splatter forms, not evidently modified by wet-based glacial ice. In addition, a f ...
Can progressive melt extraction from a plum
... been depleted in incompatible elements (Polve and Allegre, 1980). We propose that the mantle experiences progressive melt-extraction as flows upward and melts first deep beneath a hotspot, later more shallowly beneath a mid-ocean ridge. During the first stage, plume upwelling and melting creates an ...
... been depleted in incompatible elements (Polve and Allegre, 1980). We propose that the mantle experiences progressive melt-extraction as flows upward and melts first deep beneath a hotspot, later more shallowly beneath a mid-ocean ridge. During the first stage, plume upwelling and melting creates an ...
No. 51. The Sveconorwegian Orogen of southern Scandinavia
... References................................................................................................................................ 80 ...
... References................................................................................................................................ 80 ...
here - GeoCoops
... deep the oceanic plate sinks before it begins to melt and lose its identity as a rigid slab, but we do know that it remains solid far beyond depths of 100 km beneath the Earth’s surface. 11. Subduction zones are one type of CONVERGENT PLATE BOUNDARY, the type of plate boundary that forms where two p ...
... deep the oceanic plate sinks before it begins to melt and lose its identity as a rigid slab, but we do know that it remains solid far beyond depths of 100 km beneath the Earth’s surface. 11. Subduction zones are one type of CONVERGENT PLATE BOUNDARY, the type of plate boundary that forms where two p ...
Mantle temperature control on composition of arc magmas along the
... Abundant volcanism in the Central Kamchatka Depression (CKD) adjacent to the Kamchatka–Aleutian Arc junction occurs where the Pacific slab edge is subducting beneath Kamchatka. Here we summarize published data on CKD rocks and demonstrate a systematic south-to-north change of their compositions from ...
... Abundant volcanism in the Central Kamchatka Depression (CKD) adjacent to the Kamchatka–Aleutian Arc junction occurs where the Pacific slab edge is subducting beneath Kamchatka. Here we summarize published data on CKD rocks and demonstrate a systematic south-to-north change of their compositions from ...
Subduction of the Rivera plate beneath the Jalisco block as imaged
... Another seismic study at the northern terminus of the MAT (Brown, 2007) shows that the oceanic crust underplates the continental crust north of Bahía de Banderas at depths of 30 km to its top, at a distance of 135 km from the trench. MAGNETOTELLURIC SURVEY Magnetotelluric (MT) surveys have been exte ...
... Another seismic study at the northern terminus of the MAT (Brown, 2007) shows that the oceanic crust underplates the continental crust north of Bahía de Banderas at depths of 30 km to its top, at a distance of 135 km from the trench. MAGNETOTELLURIC SURVEY Magnetotelluric (MT) surveys have been exte ...
Baltic Shield
The Baltic Shield (sometimes referred to as the Fennoscandian Shield) is located in Fennoscandia (Norway, Sweden and Finland), northwest Russia and under the Baltic Sea. The Baltic Shield is defined as the exposed Precambrian northwest segment of the East European Craton. It is composed mostly of Archean and Proterozoic gneisses and greenstones which have undergone numerous deformations through tectonic activity (see Geology of Fennoscandia map [1]). The Baltic Shield contains the oldest rocks of the European continent. The lithospheric thickness is about 200-300 km. During the Pleistocene epoch, great continental ice sheets scoured and depressed the shield's surface, leaving a thin covering of glacial material and innumerable lakes and streams. The Baltic Shield is still rebounding today following the melting of the thick glaciers during the Quaternary Period.