• Title/Summary/Keyword: tectonic environment

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The Tectonic Characteristics in the Works of Santiago Calatrava and the Role of Light (산티아고 칼라트라바 건축의 텍토닉 특성과 빛의 역할에 관한 연구)

  • Kim, Chang-Sung
    • KIEAE Journal
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    • v.15 no.2
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    • pp.79-86
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    • 2015
  • Purpose: The concept of the tectonic has researched to find out the identify of modern architecture. The meaning of traditional tectonic knowledge to emphasize structural joints and attention to detail in creativity has developed in various ways in contemporary architecture. The purpose of this study is to analyze the tectonic characteristics and architectural expressions of the light appeared in the works of Santiago Calatrava. Major features in his works could be found is to maximize structural beauties through deducing the architectural images from the nature and expressing the material properties and the kinetic structures, and thus, to ultimately create the functional space and form by connecting the light to the tectonic structure. Method: Accordingly, I tried to analyze the three works of Santiago Calatrava (the Milwaukee Art Museum, the Bodegas Ysios Winery and the City and Arts and Sciences) as following categories - the structural aesthetics, the expression of material properties, the relationship between he kinetic structures and the light. Result: According to the results of the study, Santiago Calatrava tried to create his own architectural aesthetic by combining structural tectonic with nature, material, regional place and culture. He also sought to express the tense and dynamic tectonic rather than the stable one in his works.

Late Cenozoic Metallogeny of Southwest Hokkaido, Japan

  • Watanabe, Yasushi
    • Proceedings of the KSEEG Conference
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    • 2003.04a
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    • pp.3-6
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    • 2003
  • Southwest Hokkaido (Sapporo-Iwanai district) in the Northeast Japan arc (Fig. 1) is one of the best places to test the correlation among tectonic regime, stress field, magmatic style and hydrothermal mineralization. This paper reviews the Miocene to Pleistocene tectonic framework, geology, magmatic style and stress field of southwest Hokkaido, and correlates them with different types of deposits (Kuroko, epithermal base-metal and precious-metal). (omitted)

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Geochemistry of Precambrian Mafic Dikes in Northern Michigan, U.S.A.: Implications for the Paleo-Tectonic Environment (북부 미시간 지역에 분포하는 선캠브리아기의 염기성 암맥에 대한 지화학적인 연구)

  • Wee, Soo Meen
    • Economic and Environmental Geology
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    • v.24 no.4
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    • pp.447-463
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    • 1991
  • Petrological and chemical studies of Precambrian dikes in the southern Lake Superior region were conducted with the objects of evaluating magma source and constraining models for the paleo-tectonic environment. Forty-six samples were analyzed for major, trace, and rare earth elements. Chemical data of the studied dikes are typical of continental tholeiites and showing iron-enrichment fractionation trend. With wallrock contamination carefully evaluated, a series of tectonic discriminating methods utilizing immobile trace elements indicate that the source magma was a high-Ti tholeiitic basalt similar to present-day T-type MORB. Effect of chemical contamination from wallrock assimilation accmulates with increasing differentiation. Evolved rocks show LREE enriched patterns and have enhanced levels of LIL elements (e.g., Rb, K, Ba, Th), but low levels of high field strength elements (e.g., Nb, P, Ti) with respect to their neighboring elements. It is suggested from this study that this enrichment possibly due to a combination of a feature inherited from the subcontinental lithosphere and crustal contamination. Geochemical signatures of these rocks are distinctively different from those of arc-related volcanics. Comparisons with chemistries of modern magmas show a pattern of overlap between Within-plate and ocean-floor characteristics, and chemical signatures of these rocks favor a model of intrusion into a crustal environment undergoing lithospheric attenuation.

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Mineralogy and Geochemistry of Shale Deposits in the Lower Anambra Basin, Nigeria: Implication for Provenance, Tectonic Setting and Depositional Environment

  • Olugbenga Okunlola;Agonsi Udodirim Lydia;Aliyu Ohiani Umaru;Raymond Webrah Kazapoe;Olusegun G. Olisa
    • Economic and Environmental Geology
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    • v.56 no.6
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    • pp.799-816
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    • 2023
  • Mineralogical and geochemical studies of shales within the Lower Anambra Basin was conducted to unravel the depositional environment, provenance, maturity, paleo-weathering conditions, and tectonic settings. Mineralogical studies conducted using X-ray diffraction analysis revealed that the samples were composed of kaolinite, montmorillonite, chlorite, and illite. KaolinIite is the dominant mineral, constituting approximately 41.5% of the bulk composition, whereas the non-clay minerals are quartz, ilmenite, and sillimanite. Geochemical analysis showed a predominance of SiO2, Al2O3, and Fe2O3 contents of the shale samples with mean values of 52.29%, 14.09%, and 6.15% for Imo Shale (IS); 52.31%, 16.70%, and 7.39% for Mamu Shale (MS); 43.21%, 21.33%, and 10.36% for Enugu Shale (ES); 53.35%, 15.64%, and 7.17% for Nkporo Shale (NS); and 51.24%, 17.25%, and 7.78% for Agwu Shale (AS). However, the shales were depleted in Na2O, MgO, K2O, MnO, TiO2, CaO, and P2O5. The trace element ratios of Ni/Co and Cu/Zn of the shale suggest an oxic depositional environment. The average SiO2 vs. Al2O3 ratio of the shales indicated textural maturity. Compared to the PAAS standard, the shales plot below the PAAS value of 0.85, suggesting a high degree of maturity and intensive chemical weathering, further confirmed on a CIA vs. PIA plot. On log (K2O/Na2O) against SiO2 and tectonic setting discriminant function diagrams, the shales plot mostly in the field of passive continental margin tectonic setting. The discriminant function diagrams as well as Al2O3/TiO2 ratio of the shales showed that they were derived from a mixed source (mafic and intermediate igneous rocks).

Sm-Nd Isotopic Study of the Ogcheon Amphibolite, Korea: Priliminary Report (옥천 각섬암의 Sm-Nd 동위원소연구 : 예비보고서)

  • Kwon, Sung-Tack;Lan, Ching-Ying
    • Economic and Environmental Geology
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    • v.24 no.3
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    • pp.277-285
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    • 1991
  • We applied Sm-Nd isotopic system to so-called amphibolites occurring within the Ogcheon group to provide constraints on the age of the metasedimentary rocks and to characterize tectonic environment of basaltic magmatism. An internal mineral isochron age of $677{\pm}91Ma({\sigma})$ was obtained from a coarse-grained, intrusive, amphibolite near Mungyeong. Considering previous studies on the age of the Ogcheon group, we interpret that the isochron represents either early metamorphic or emplacement age. The depositional age of the metasedimentary rocks intruded by the amphibolite would be prior to late Proterozoic. The present study and Cambro-Ordovician fossil evidences of previous workers suggest that both Precambrian and Phanerozoic rocks are present in the Ogcheon group. Positive ${\varepsilon}$ Nd values(+2.4 to +3.5) of four whole rocks indicate mantle origin for the amphibolite. These isotopic data, along with published immobile trace element data of Cluzel et al.(1989), strongly suggest that parental rocks of the amphibolite formed in an intraplate environment rather than in island arc or midocean ridge. The age and tectonic environment of amphibolites in the Ogcheon belt suggest that the basaltic magmatism may be related to the late Proterozoic break-up of a presumed supercontinent, but not to the Triassic(?) collision between North and South China continents.

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Geochemistry of Orthogneisses in the Seungju-Suncheon Area, Korea (승주-순천 지역에 분포하는 정편마암류의 지구화학적 특성)

  • Ahn, Kun-Sang;Oh, Chang-Whan;Park, Bae-Young
    • Journal of the Korean earth science society
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    • v.22 no.3
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    • pp.163-178
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    • 2001
  • Granite gneiss, pophyroblastic gneiss and leucocratic gneiss are widely distributed in the Seungju-Suncheon area, the southwestern part of the Sobacksan Massif, Korea. These orthogneisses show intrusive relationships in outcrops of the study area. This study focuses on the geochemical properties and the tectonic environments for the original rocks of these orthogneisses. The pophyroblastic gneiss is plotted in diorite and granodiorite domain, and granite gneiss and leucocratic gneiss are plotted in both of granodiorite and granite domains on lUGS silica-alkali diagram. Geochemical properies of major elements suggest that these rocks are sub-alkali rock series, and were formed from S-type magma which generated in syn-collision tectonic environment. Discrimination diagrams using HFS elements suggest that original rocks of the three orthogneisses were granitoid of calc-alkali rock series, and were formed in syn-collision environment.

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Sphene U-Pb ages of the granodiorites from Gimcheon, Seongju and Anui areas of the middle Yeongnam Massif (영남육괴 중부 김천, 성주 및 안의지역 화강섬록암의 스핀 U-Pb 연대)

  • Park Kye-Hun;Lee Ho-Sun;Cheong Chang-Sik
    • The Journal of the Petrological Society of Korea
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    • v.14 no.1
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    • pp.1-11
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    • 2005
  • Sphene U-Pb ages were determined for the granodiorites from Gimcheon, Seongju and Anui areas of the middle Yeongnam massif. The determined ages were in the narrow range of 195.7±2.4∼200.8±1.9(2σ) Ma that are approximately coincident with the boundary between Triassic and Jurassic. Even though the studed plutons are aerially separated, they reveal quite similar major element compositions and almost identical ages, suggesting that they were generated from the similar source materials under the identical tectonic environment and thus they can be considered to form a single suite. Considering the age and spatial distribution of the Triassic to Lower Jurassic plutons of the Yeongnam Massif and Okcheon Belt, it seems that there were episodic changes in tectonic environment in both areas with relatively short intervals. In general, the compressive environment of active continental margin was prevailed. However, the tensional environment of within-plate was also appeared several times intermittently. In conclusion, Yeongnam Massif and Okcheon Belt experienced distinct tectonic environments during Triassic to Lower Jurassic, providing important clue to reveal the crustal evolution of the Korean Peninsula.

Geological Structures of the Hadong Northern Anorthosite Complex and its surrounding Area in the Jirisan Province, Yeongnam Massif, Korea (영남육괴 지리산지구에서 하동 북부 회장암복합체와 그 주변지역의 지질구조)

  • Lee, Deok-Seon;Kang, Ji-Hoon
    • The Journal of the Petrological Society of Korea
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    • v.21 no.3
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    • pp.287-307
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    • 2012
  • The study area, which is located in the southeastern part of the Jirisan province of the Yeongnam massif, Korea, consists mainly of the Precambrian Hadong northern anorthosite complex (HNAC) and the Jirisan metamorphic rock complex (JMRC) and the Mesozoic granitoids which intrude them. Its tectonic frame is built into NS trend, unlike the general NE-trending tectonic frame of Korean Peninsula. This paper researched the structural characteristics at each deformation phase to clarify the geological structures associated with the NS-trending tectonic frame which was built in the HNAC and JMRC. The result indicates that the geological structures of this area were formed at least through three phases of deformation. (1) The $D_1$ deformation formed the $F_1$ sheath or "A"-type folds in the HNAC and JMRC, and the $S_{0-1}$ composite foliation and the $S_1$ foliation and the $D_1$ ductile shear zone which are (sub)parallel to the axial plane of $F_1$ fold, and the $L_1$ stretching lineation which is parallel to the $F_1$ fold axis owing to the large-scale top-to-the SE shearing on the $S_0$ foliation. (2) The $D_2$ deformation (re)folded the $D_1$ structural elements under the EW-trending tectonic compression environment, and formed the NS-trending $F_2$ open, tight, isoclinal, intrafolial folds with the $S_{0-1-2}$ composite foliation and the $S_2$ foliation and the $D_2$ ductile shear zone with S-C-C' structure and the $L_2$ stretching lineation which is (sub)parallel to the axial plane of $F_2$ fold. The extensive $D_2$ ductile shear zone (Hadong shear zone) of NS trend was persistently developed along the eastern boundary of HNAC and JMRC which would be to the limb of $F_2$ fold on a geological map scale. The Hadong shear zone is no less than 1.4 km width, and was formed in the mylonitization process which produced the mylonitic structure and the stretching lineation with the reduction of grain size during the $F_2$ passive folding. (3) The $D_3$ deformation formed the EW-trending $F_3$ kink or open fold under the NS-trending tectonic compression environment and partially rearranged the NS-trending pre-$D_3$ structural elements into (E)NE or (W)NW direction. The regional trend of $D_1$ tectonic frame before the $D_2$ deformation would be NE-SW unlike the present, and the NS-trending tectonic frame in the HNAC and JMRC like the present was formed by the rearrangement of the $D_1$ tectonic frame owing to the $F_2$ active and passive folding. Based on the main intrusion age of (N)NE-trending basic dyke in the study area, these three deformation events are interpreted to have occurred before the Late Paleozoic.

Interpretation of Gravity, Magnetic and High-resolution (3.5 kHz) Seismic Data in the Powell Basin, Antarctica (남극 파월분지 지역의 중,자력 및 고해상 (3.5 KHZ) 탄성파 자료 해석)

  • Jin, YoungKeun;Kim, KyuJung;Nam, SangHeon;Kim, YeaDong;Lee, JooHan
    • Journal of the Korean Geophysical Society
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    • v.7 no.1
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    • pp.1-10
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    • 2004
  • Gravity, magnetic and high-resolution seismic surveys were carried out in the Powell Basin to examine tectonic structure and recent sedimentation on Dec. 2002. The trend of negative gravity anomalies along the spreading axis of the Powell Basin changes from northwest to east-west toward south. Both boundaries of the basin with the Antarctic Peninsula and the South Orkey micro-continent show negative magnetic anomalies, which indicates that the boundaries were continental rift areas in the initial stage of spreading. Magnitude of the magnetic anomalies corresponding to the axis of the basin is rather small compared to those of normal spreading axises in other regions. Such small anomalies would be caused by reduction of magnetic strength of oceanic crust below thick sediments due to thermal alternation. High-resolution (3.5 kHz) seismic profiles reveal that top of the South Scotia Ridge is a flat terrain coverd with thin coarse sediments by glacial erosion. Thick oceanic sediments are deposited in the central part of the basin. Little deformation in the oceanic sediments indicates that the Powell Basin has been in stable tectonic environment after spreading of the basin stopped.

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Geochemistry of cordierite-bearing motasedimentary rocks, northern Yeongnam Massif: implications for provenance and tectonic setting

  • Kim, Jeongmin;Moonsup Cho
    • Proceedings of the Mineralogical Society of Korea Conference
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    • 2003.05a
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    • pp.54-54
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    • 2003
  • The metasedimentary rocks together with various granitoids are the main constituents in Taebaeksan gneiss complex, northern Yeongnam Massif. Chemical compositions of sedimentary rocks may reflect the nature of the provenance and could be crucial for understanding the evolution of early continental crust. Previous workers have suggested that the provenance and tectonic studies based on the geochemistry of sediments are applicable to the Precambrian samples. In this study we analyzed the major, trace and REE elements of metasedimentary rocks to understand their provenance and tectonic setting during sedimentation. The overall geochemical characteristics of metasedimentary rocks are similar to those of average shale of the post-Archean. Major element chemistry indicates mature and sorted nature of the sediments. The degree of weathering in the source rocks the is not uniform, as inferred from a large scatter in chemical indices of weathering (CIW). The immobile trace elements such as Th, Sc, and REE can be used to discriminate various sedimentary processes. The Th/sc ratios (0.9 - 4.4) are larger than those of the upper crust and average shale, suggesting that the felsic source predominates. The contents of Ni and Cr and the variations in the ratio of compatible to incompatible elements are similar to the average post-Archean shale. Uniform chondrite-normalized REE pattern with the LREE enrichment (LaN/SmN = 4.9 ${\pm}$ 0.4) and slight negative Eu anomalies (Eu/Eu$\^$*/ = 0.7 ${\pm}$ 0.1) also support this observation. The presence of negative Eu anomaly indicates that intracrustal igneous processes involving plagioclase separation have affected the provenance rocks. The LREE enrichment implies the major role of felsic rocks in source rocks. The eNd (1.9 Ga) values of metasediment rocks vary from 9.4 to 6.7, corresponding to TDM of 2.9 - 2.7 Ga. On the other hand, the 147Sm/144Nd ratios are 0.1079 - 0.1101, corresponding to typical tettigenous sediments. The geochemical features of metasedimentary rocks such as high abundances of large ion lithophile elements, high ratios of Th/Sc and La/Sm, commonly high Th/U ratios, negative Eu anomalies, and negative eNd, suggest a provenance consisting virtually entirely of recycled upper continental crust in passive margin environment. Tectonic discrimination diagrams based upon major element compositions also support this suggestion. In conjunction with igneous activity and metamorphism in the convergent margin setting at 1.8 - 1. 9 Ga, the transition from passive margin to active margin characterize the Paleoproterozoic crustal evolution in northern Yeongnam Massif.

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