Luminescence Spectroscopical Properties of Plagioclase Particles from the Hayabusa Sample Return Mission: An Implication for Study of Space Weathering Processes in the Asteroid Itokawa

AbstractWe report a systematic spectroscopical investigation of three plagioclase particles (RB-QD04-0022, RA-QD02-0025-01, and RA-QD02-0025-02) returned by the Hayabusa spacecraft from the asteroid Itokawa, by means of scanning electron microscopy, cathodoluminescence microscopy/spectroscopy, and micro-Raman spectroscopy. The cathodoluminescence properties are used to evaluate the crystallization effects and the degree of space weathering processes, especially the shock-wave history of Itokawa. They provide new insights regarding spectral changes of asteroidal bodies due to space weathering processes. The cathodoluminescence spectra of the plagioclase particles from Itokawa show a defect-related broad band centered at around 450 nm, with a shoulder peak at 425 nm in the blue region, but there are no Mn- or Fe-related emission peaks. The absence of these crystal field-related activators indicates that the plagioclase was formed during thermal metamorphism at subsolidus temperature and extreme low oxygen fugacity. Luminescence characteristics of the selected samples do not show any signatures of the shock-induced microstructures or amorphization, indicating that these plagioclase samples suffered no (or low-shock pressure regime) shock metamorphism. Cathodoluminescence can play a key role as a powerful tool to determine mineralogy of fine-grained astromaterials.

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Use of pyrite microfabric as a key to tectono-thermal evolution of massive sulphide deposits – an example from Deri, southern Rajasthan, India

Mineralogical Magazine ◽

10.1180/002646198547576 ◽

1998 ◽

Vol 62 (2) ◽

pp. 197-212 ◽

Cited By ~ 10

Author(s):

Anju Tiwary ◽

Mihir Deb ◽

Nigel J. Cook

Keyword(s):

Thermal Evolution ◽

Regional Metamorphism ◽

Massive Sulphide ◽

Ductile Deformation ◽

Sulphide Deposit ◽

Fine Grained ◽

Thermal Metamorphism ◽

Sulphide Ores ◽

History Of ◽

South Delhi Fold Belt

AbstractPyrite is an ubiquitous constituent of the Proterozoic massive sulphide deposit at Deri, in the South Delhi Fold Belt of southern Rajasthan. Preserved pyrite microfabrics in the Zn-Pb-Cu sulphide ores of Deri reveal a polyphase growth history of the iron sulphide and enable the tectono-thermal evolution of the deposit to be reconstructed.Primary sedimentary features in Deri pyrites are preserved as compositional banding. Regional metamorphism from mid-greenschist to low amphibolite facies is recorded by various microtextures of pyrite. Trails of fine grained pyrite inclusions within hornblende porphyroblasts define S1-schistosity. Pyrite boudins aligned parallel to S1 mark the brittle–ductile transformation of pyrite during the earliest deformation in the region. Isoclinal to tight folds (F1 and F2) in pyrite layers relate to a ductile deformation stage during progressive regional metamorphism. Peak metamorphic conditions around 550°C, an estimation supported by garnet–biotite thermometry, resulted in annealing of pyrite grains, while porphyroblastic growth of pyrite (up to 900 µm) took place along the retrogressive path. Brittle deformation of pyrite and growth of irregular pyritic mass around such fractured porphyroblasts characterize the waning phase of regional metamorphism. A subsequent phase of stress-free, thermal metamorphism is recorded in the decussate and rosette textures of arsenopyrite prisms replacing irregular pyritic mass. Annealing of such patchy pyrite provides information regarding the temperature conditions during this episode of thermal metamorphism which is consistent with the hornblendehornfels facies metamorphism interpreted from magnetite–ilmenite geothermometry (550°C) and sphalerite geobarometry (3.5 kbar). A mild cataclastic deformation during the penultimate phase produced microfaults in twinned arsenopyrite prisms.

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Tracing the Life of a Buddhist Literary Apologia: Steps in Preparation for the Study and Translation of Sokdokpa’s Thunder of Definitive Meaning

Religions ◽

10.3390/rel12110933 ◽

2021 ◽

Vol 12 (11) ◽

pp. 933

Author(s):

James Duncan Gentry

Keyword(s):

Tibetan Buddhism ◽

17Th Century ◽

Literary Works ◽

Historical Approach ◽

Fine Grained ◽

History Of ◽

Magnum Opus ◽

Shed Light

This article discusses Buddhist apologetics in Tibet by examining the formation, revision, and reception of the most renowned literary apologia ever written in defense of the Old School of Tibetan Buddhism: Sokdokpa Lodrö Gyeltsen’s early 17th-century magnum opus the Thunder of Definitive Meaning. It reconstructs in broad strokes the history of the Thunder’s reception from the early 17th century to the present and relates this to details in different versions of the Thunder and its addendum to shed light on the process by which this work was composed and edited. By considering this work’s peculiar context of production and history of reception alongside passages it presents revealing how it was conceived and revised, this analysis aims to prepare the ground for its study and translation. In so doing, this discussion attempts to show how a broadly historical approach can work in tandem with a fine-grained philological approach to yield fresh insights into the production and reception of Buddhist literary works that have important ramifications for their understanding and translation.

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Crystallisation of fine- and coarse-grained A-type granite sheets of the Southern Oklahoma Aulacogen, U.S.A.

Earth and Environmental Science Transactions of the Royal Society of Edinburgh ◽

10.1017/s0263593300007331 ◽

2000 ◽

Vol 91 (1-2) ◽

pp. 139-150 ◽

Cited By ~ 11

Author(s):

John P. Hogan ◽

M. Charles Gilbert ◽

Jon D. Price

Keyword(s):

Solidus Temperature ◽

Direct Consequence ◽

Progressive Increase ◽

Coarse Grained ◽

Fine Grained ◽

Mafic Complex ◽

Southern Oklahoma ◽

History Of ◽

Volcanic Pile ◽

Crustal Magma

A-type felsic magmatism associated with the Cambrian Southern Oklahoma Aulacogen began with eruption of voluminous rhyolite to form a thick volcanic carapace on top of an eroded layered mafic complex. This angular unconformity became a crustal magma trap and was the locus for emplacement of later subvolcanic plutons. Rising felsic magma batches ponding along this crustal magma trap crystallised first as fine-grained granite sheets and then subsequently as coarser-grained granite sheets. Aplite dykes, pegmatite dykes and porphyries are common within the younger coarser-grained granite sheets but rare to absent within the older fine-grained granite sheets. The older fine-grained granite sheets typically contain abundant granophyre.The differences between fine-grained and coarse-grained granite sheets can largely be attributed to a progressive increase in the depth of the crustal magma trap as the aulacogen evolved. At low pressures (<200MPa) a small increase in the depth of emplacement results in a dramatic increase in the solubility of H2O in felsic magmas. This is a direct consequence of the shape of the H2O-saturated granite solidus. The effect of this slight increase in total pressure on the crystallisation of felsic magmas is to delay vapour saturation, increase the H2O content of the residual melt fractions and further depress the solidus temperature. Higher melt H2O contents, and an extended temperature range over which crystallisation can proceed, both favour crystallisation of coarser-grained granites. In addition, the potential for the development of late, H2O-rich, melt fractions is significantly enhanced. Upon reaching vapour saturation, these late melt fractions are likely to form porphyries, aplite dykes and pegmatite dykes.For the Southern Oklahoma Aulacogen, the progressive increase in the depth of the crustal magma trap at the base of the volcanic pile appears to reflect thickening of the volcanic pile during rifting, but may also reflect emplacement of earlier granite sheets. Thus, the change in textural characteristics of granite sheets of the Wichita Granite Group may hold considerable promise as an avenue for further investigation in interpreting the history of this rifting event.

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Ultrahigh-temperature metamorphism and decompression history of sapphirine granulites from Rajapalaiyam, southern India: implications for the formation of hot orogens during Gondwana assembly

Geological Magazine ◽

10.1017/s0016756809990100 ◽

2009 ◽

Vol 147 (1) ◽

pp. 42-58 ◽

Cited By ~ 36

Author(s):

T. TSUNOGAE ◽

M. SANTOSH

Keyword(s):

Southern India ◽

Stability Field ◽

Fine Grained ◽

History Of ◽

Peak Metamorphism ◽

Gondwana Supercontinent ◽

Isothermal Decompression ◽

Ultrahigh Temperature ◽

Late Neoproterozoic ◽

Uht Metamorphism

AbstractSapphirine-bearing Mg–Al granulites from Rajapalaiyam in the southern part of the Madurai Block provide critical evidence for Late Neoproterozoic–Cambrian ultrahigh-temperature (UHT) metamorphism in southern India. Poikiloblastic garnet in quartzo-feldspathic and pelitic granulites contain inclusions of fine-grained subidioblastic to xenoblastic sapphirine associated with quartz, suggesting that the rocks underwent T > 1000°C peak metamorphism. Quartz inclusions in spinel within garnet are also regarded as clear evidence for a UHT condition. Inclusions of orthopyroxene within porphyroblastic garnet in the sapphirine-bearing rocks show the highest Al2O3 content of up to 10.3 wt%, suggesting T = 1050–1070°C and P = 8.5–9.5 kbar. Temperatures estimated from ternary feldspar and other geothermometers (T = 950–1000°C) further support extreme thermal metamorphism in this region. Xenoblastic spinel inclusions in sapphirine coexisting with quartz suggest that the spinel + quartz assemblage pre-dates the sapphirine + quartz assemblage, probably implying a cooling from T ~ 1050°C or an anticlockwise P–T path. The FMAS reaction sapphirine + quartz + garnet → orthopyroxene + sillimanite indicates a cooling from the sapphirine + quartz stability field after the peak metamorphism. Corona textures of orthopyroxene + cordierite (± sapphirine), orthopyroxene + sapphirine + cordierite, and cordierite + spinel around garnet suggest subsequent near-isothermal decompression followed by decompressional cooling toward T = 650–750°C and P = 4.5–5.5 kbar. The sapphirine–quartz association and related textures described in this study have an important bearing on the UHT metamorphism and exhumation history of the Madurai Block, as well as on the tectonic evolution of the continental deep crust in southern India. Our study provides a typical example for extreme metamorphism associated with collisional tectonics during the Late Neoproterozoic–Cambrian assembly of the Gondwana supercontinent.

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Music and cremation rituals in The Netherlands: A fine-grained analysis of a crematorium’s playlist

Digital Scholarship in the Humanities ◽

10.1093/llc/fqy068 ◽

2018 ◽

Vol 34 (4) ◽

pp. 806-817

Author(s):

Doris van der Smissen ◽

Margaret A Steenbakker ◽

Martin J M Hoondert ◽

Menno M van Zaanen

Keyword(s):

The Netherlands ◽

Computational Analysis ◽

Qualitative Approach ◽

Close Reading ◽

Musical Analysis ◽

Fine Grained ◽

History Of ◽

Multi Method Approach ◽

Method Approach

Abstract Although music is an important part of cremation rituals, there is hardly any research regarding music and cremations. This lack of research has inspired the authors to conduct a long-term research project, focusing on musical and linguistic aspects of music played during cremations. This article presents the analysis of a playlist consisting of twenty-five sets of music, each consisting of three tracks, used in a crematorium in the south of The Netherlands from 1986 onward. The main objective is to identify the differences and similarities of the twenty-five sets of musical tracks regarding content and musical properties. Consequently, we aim to provide insight in the history of (music played during) cremation rituals in The Netherlands. To analyze the musical properties of the sets, the authors use both a qualitative approach (close reading and musical analysis) and a computational analysis approach. The article demonstrates that a combination of a close reading and musical analysis and a computational analysis is necessary to explain the differences in properties of the sets. The presented multi-method approach may allow for comparisons against musical preferences in the context of current cremations, which makes it possible to trace the development of music and cremation rituals.

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Mineral assemblages and xenolith cargo in the Storkwitz carbonatite (Delitzsch Complex, Germany)

10.5194/egusphere-egu2020-10678 ◽

2020 ◽

Author(s):

Hripsime Gevorgyan ◽

Sascha Schmidt ◽

Ilja Kogan ◽

Manuel Lapp

Keyword(s):

Late Cretaceous ◽

Early Stage ◽

Soft Rock ◽

Core Material ◽

Compositional Variation ◽

Published Data ◽

Fine Grained ◽

Ultramafic Lamprophyre ◽

The Matrix ◽

History Of

The multi-compositional carbonatite body of Storkwitz is one of several purported diatremes of the Late Cretaceous Delitzsch Complex, which comprises carbonatites and ultramafic lamprophyres emplaced into a heterogeneous series of volcanic and sedimentary rocks of Precambrian to Early Permian age (Kr&#252;ger et al., 2013; Seifert et al., 2000). The Late Cretaceous peneplain is covered with about one hundred meters of Tertiary soft rock. According to R&#246;llig et al. (1990), the Delitzsch Complex developed in six stages: (i) hidden intrusion of a dolomite carbonatite (rauhaugite) that led to the formation of a fenite aureole; (ii) ultramafic and alkaline lamprophyre intrusion (aln&#246;ite, aillikite, monchiquite); (iii) formation of beforsitic diatremes (intrusive breccias), including xenoliths of dolomite carbonatite and ultramafic lamprophyre; (iv) ultramafic and alkali lamprophyres (dykes within diatremes of 3rd&#160;stage); (v) formation of beforsite and (vi) alvikite dykes.The Storkwitz carbonatite is mainly characterized by beforsitic breccias containing abundant angular xenoliths of metasediments form the complete underlying stratigraphic succession, metamorphic and igneous rocks, as well as rounded xenoliths of ultramafic lamprophyre, rauhaugite, fenite, and glimmerite, which suggest the existence of a deep-seated carbonatite pluton (Seifert et al., 2000). It is remarkable that the fenites exhibit a different degree of fenitization and show occurrence of phlogopite in the strongly fenitized samples. The matrix of the Storkwitz carbonatite is mainly composed of ankerite and calcite/siderite, which corresponds to ferro- or silico-carbonatites.Detailed petrographical observations on extensive drill core material, new analyses and a reinterpretation of published data confirm the existence of compositional variation and zonation within the carbonatite body that reflect independent crystallization history and formation due to multiple magmatic events. The different generations of apatite and phlogopite from the early stage of the plutonic dolomite carbonatite through the late-stage beforsite dykes and fine-grained calcite carbonatite veins shed light on the crystallization history and magma development of carbonatites.&#160;References&#160;Kr&#252;ger, J.C., Romer, R.L., K&#228;mpf, H., 2013. Late Cretaceous ultramafic lamprophyres and carbonatites from the Delitzsch Complex, Germany. Chemical Geology, 353, 140-150.R&#246;llig, G., Viehweg, M., Reuter, N., 1990. The ultramafic lamprophyres and carbonatites of Delitzsch/GDR. Zeitschrift f&#252;r Angewandte Geologie, 36, 49-54.Seifert, W., K&#228;mpf, H., Wasternack, J., 2000. Compositional variation in apatite, phlogopite and other accessory minerals of the ultramafic Delitzsch complex, Germany: implication for cooling history of carbonatites. Lithos, 53, 81-100.

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Testing direct dating of Alpine faults by luminescence and ESR

10.5194/egusphere-egu2020-7982 ◽

2020 ◽

Author(s):

Sumiko Tsukamoto ◽

David Tanner ◽

Christian Brandes ◽

Christoph von Hagke

Keyword(s):

Esr Spectra ◽

Fault Gouge ◽

Esr Dating ◽

Fine Grained ◽

Infrared Stimulated Luminescence ◽

Minimum Age ◽

History Of ◽

Recent Earthquakes ◽

Age Range ◽

Saturation Dose

For a better understanding of the recent exhumation history of the Alps and the distribution of palaeo- and recent earthquakes within the orogen, it is important to elucidate the Quaternary activity of major faults. In this study, we test the applicability of luminescence and electron spin resonance (ESR) dating, which have ultralow closure temperatures, to directly date fault gouge of the Simplon Fault. A dark grey to black, fine-grained fault gouge was sampled near Visp, Switzerland, from an outcrop that exposes rocks that formed at ductile/brittle conditions. Quartz and feldspar grains were extracted from the sample; quartz grains were used for ESR dating, whereas feldspar grains were used for infrared stimulated luminescence (IRSL) dating.The IRSL measurements reveal that the natural post-IR IRSL signal, stimulated at 225&#176;C (pIRIR225) was in saturation. The pIRIR225 signal had an extremely low saturation dose, with a characteristic saturation dose (D0) of ~90 Gy. The natural IRSL signal at 50&#176;C (IR50) is about 80 % of the laboratory saturation, so that this signal is presumably in the field saturation. The IR50 also showed a small D0 of ~250 Gy. Although these D0 values are unexpectedly small, the IRSL signals can be used to calculate the minimum age of the last seismic movement of the fault.Both natural and laboratory-irradiated ESR spectra did not contain detectable Ti centre. Therefore, only the Al centre was used for ESR dating. The natural Al centre from the fault was not in saturation, with a preliminary equivalent dose value of ~1500 Gy. Since the last seismogenic movement most likely only partially reset the Al centre, the ESR age can be regarded as the maximum age of the last event.&#160; We show that by combining luminescence and ESR dating, it is possible to narrow down the age range of the last seismic activity on the fault.

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Combining Experiments and Modelling to Understand the Role of Potential Sputtering by Solar Wind Ions

10.5194/egusphere-egu2020-9386 ◽

2020 ◽

Author(s):

Paul Stefan Szabo ◽

Herbert Biber ◽

Noah Jäggi ◽

Matthias Brenner ◽

David Weichselbaum ◽

...

Keyword(s):

Solar Wind ◽

Solar System ◽

Surface Composition ◽

Space Weathering ◽

Mineral Surfaces ◽

Multiply Charged ◽

History Of ◽

System 2 ◽

Sputtering Yields ◽

Weathering Effects

In the absence of a protecting atmosphere, the surfaces of rocky bodies in the solar system are affected by significant space weathering due to the exposure to the solar wind [1]. Fundamental knowledge of space weathering effects, such as optical changes of surfaces as well as the formation of an exosphere is essential for gaining insights into the history of planetary bodies in the solar system [2]. Primarily the exospheres of Mercury and Moon are presently of great interest and the interpretation of their formation processes relies on the understanding of all space weathering effects on mineral surfaces.Sputtering of refractory elements by solar wind ions is one of the most important release processes. We investigate solar wind sputtering by measuring and modelling the sputtering of pyroxene samples as analogues for the surfaces of Mercury and Moon [3, 4]. These measurements with thin film samples on Quartz Crystal Microbalance (QCM) substrates allow recording of sputtering yields in-situ and in real time [5]. For the simulation of kinetic sputtering from the ion-induced collision cascade we use the software SDTrimSP with adapted input parameters that consistently reproduce measured kinetic sputtering yields [4, 6].This study focuses on investigating the potential sputtering of insulating samples by multiply charged ions [7]. Changes of these sputtering yields with fluence are compared to calculations with a model based on inputs from SDTrimSP simulations. This leads to a very good agreement with steady-state sputtering yields under the assumption that only O atoms are sputtered by the potential energy of the ions. The observed decreasing sputtering yields can be explained by a partial O depletion on the surface [4]. Based on these findings expected surface composition changes and sputtering yields under realistic solar wind conditions can be calculated. Our results are in line with previous investigations (see e.g. [8, 9]), creating a consistent view on solar wind sputtering effects from experiments to established modelling efforts.&#160;References:[1]&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; B. Hapke, J. Geophys. Res.: Planets, 106, 10039 (2001).[2]&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; P. Wurz, et al., Icarus, 191, 486 (2007).[3]&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; P.S. Szabo, et al., Icarus, 314, 98 (2018).[4]&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; P.S. Szabo, et al., submitted to Astrophys. J. (2020).[5]&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; G. Hayderer, et al., Rev. Sci. Instrum., 70, 3696 (1999).[6]&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; A. Mutzke, et al., &#8220;SDTrimSP Version 6.00&#8220;, IPP Report, (2019).[7]&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; F. Aumayr, H. Winter, Philos. Trans. R. Soc. A, 362, 77 (2004).[8]&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; H. Hijazi, et al., J. Geophys. Res.: Planets, 122, 1597 (2017).[9]&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; S.T. Alnussirat, et al., Nucl. Instrum. Methods Phys. Res. B, 420, 33 (2018).

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SPACE, POWER AND HEALING IN EQUATORIAL AFRICA Colonial Rule and Crisis in Equatorial Africa: Southern Gabon ca. 1850–1940. CHRISTOPHER GRAY. Rochester NY: University of Rochester Press, 2002. Pp. xxii+275. $65 (ISBN 1-58046-048-8).

The Journal of African History ◽

10.1017/s0021853704000350 ◽

2005 ◽

Vol 46 (1) ◽

pp. 139-143

Author(s):

FLORENCE BERNAULT

Keyword(s):

Physical Environment ◽

Colonial Rule ◽

Anglophone Literature ◽

Fine Grained ◽

Equatorial Africa ◽

Political Resources ◽

Land Disputes ◽

History Of ◽

The One ◽

Ideological Construction

THE Anglophone literature has conceptualized the history of the African ‘space’ through two major approaches. Fine-grained reconstructions of land disputes have helped to illuminate colonial changes in the political and economic control over residential and productive units, and to assess the local (im)possibilities for Africans of accumulating landed property and/or penetrating the new plantation and market economy. More recently, environmental studies have encouraged historians to uncover how fundamental alterations in the relationships between communities and their physical environment have been shaping ancient and recent struggles for identities and socio-political resources. Meanwhile, renewed attention to cognitive notions of space by anthropologists on the one hand, and literary critics on the other, has delineated deep structuring principles in the ideological construction of space among Africans and colonizers. Few historians have followed through, however, and historicized such imaginaries. Among those who have done so, and have traced people's conceptual, commemorative and moral visions of land, fewer still have ventured beyond the boundaries of specific locales and societies. By reconstructing a longue durée history of the disruptions in both the physical and cognitive spaces of the Gabonese rainforest, Chris Gray's book stands as a major attempt to bridge these gaps.

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