Variscan progradeP-Tevolution and contact metamorphism in metabasites from the Sowia Dolina, Karkonosze-Izera massif, SW Poland

2011 ◽  
Vol 75 (1) ◽  
pp. 185-212 ◽  
Author(s):  
S. Ilnicki
Keyword(s):  
Hydrothermal Activity ◽  
Contact Metamorphism ◽  
Thermal Activity ◽  
Saxothuringian Zone ◽  
History Of ◽  
West Sudetes ◽  
Sw Poland ◽  
Two Stages ◽  
Pressure Changes ◽  
Quantitative Indicators

AbstractSeveral bodies of moderately foliated and porphyroblastic metabasites crop out on the SE side of the metamorphic cover of the Karkonosze granite within metapelites of the Sowia Dolina area (West Sudetes, Saxothuringian zone). Depending on the microstructural setting of the Ca-amphiboles in the rocks, different mineral-chemical trends have been determined for Si,XMg, AlVI,A[Na+K] which serve as semi-quantitative indicators of temperature and pressure changes. Porphyroblasts and prisms oblique to the main foliation in schistose metabasites show zoning from Mg-hornblende and actinolite to tschermakite, and then to Mg-hornblende (or actinolite). Matrix amphiboles and those in pressure shadows around some porphyroblasts have tschermakitic cores and actinolitic rims. Rarely, Ca-amphibole is accompanied in schists by late- to post-tectonic cummingtonite. Thermobarometric calculations involving empirically calibrated amphibole equilibria enable a reconstruction ofP-Tpaths for individual rocks and the unravelling of the metamorphic evolution of the metabasites. Peak metamorphic temperatures of 615–640°C and pressures of 7.3–8.2 kbar were preceded by a variably preserved earlier stage (T = 370–550°C, P = 2.8–6.2 kbar). The final metamorphic episode took place at 450–550°C and 2.5–4.8 kbar and is recorded particularly in rocks close to the Karkonosze pluton. The metabasites shed new light on the history of metamorphism in the Sowia Dolina area. The first two stages ofMP-MTmetamorphism, coeval with Variscan deformation events (continental collision, burial and subsequent exhumation), took place under epidote-amphibolite then amphibolite facies conditions. The last stage partly concurred with the final stages of Variscan deformation and overlapped the onset of thermal activity associated with the Karkonosze granite. This metamorphic event is documented by metabasites (occasionally cummingtonite-bearing) outcropping close to the granite. Finally, a prehnitebearing assemblage reflects retrograde re-equilibration under greenschist/sub-greenschist facies conditions (T<300–350°C,P<2.5–3 kbar), which might also be partly due to hydrothermal activity around the pluton.

Magmatic and post-magmatic phenomena in the Karkonosze granite and its metamorphic envelope (West Sudetes, SW Poland)

2016 ◽  
Vol 66 (3) ◽  
pp. 456-476 ◽  
Author(s):  
Andrzej Kozłowski ◽  
Sławomir Ilnicki ◽  
Witold Matyszczak ◽  
Agnieszka Marcinowska
Keyword(s):  
Geothermal Gradient ◽  
Contact Metamorphism ◽  
Melt And Fluid Inclusions ◽  
Hydrothermal Stage ◽  
Magmatic Stage ◽  
West Sudetes ◽  
Sw Poland ◽  
Chemical Conditions ◽  
Physical And Chemical ◽  
Mineral Changes

AbstractMineralogical studies of the Karkonosze granite (ca. 322-312 Ma) and its surroundings in West Sudetes (SW Poland) have provided data on Nb-Ta-REE minerals from pegmatites in the NE part of the pluton and several new finds of Ag minerals and 15 oxygenic Bi phases, hitherto not reported from the massif. The Karkonosze pegmatites are enriched in HREE as fergusonite-(Y) or xenotime-(Y) appear in almost every studied pegmatite, together with a subordinate assemblage of the aeschynite, euxenite or columbite group. The abundance of LREE minerals such as allanite-( Ce) and the monazite group, correlates inversely with the Nb-Ta-Ti minerals, whilst an early generation of monazite-(Ce) revealed an exceptionally high amount of Nd (up to 22 wt.% of Nd2O3). The physical and chemical conditions during the magmatic and post-magmatic processes were reconstructed and the effects of contact metamorphism in amphibolites from hornfelsed zones examined. Changes in solution composition and concentration at the early magmatic stage (825-920°C), pegmatitic stage overlapping with hydrothermal (560°C which ended at 160-90°C) and clearly hydrothermal stage (400 to 110°C) were studied in detail by means of melt and fluid inclusions in quartz. Furthermore, post-magmatic fluids, including some enriched in Li and B, were identified in rock-forming quartz from the whole pluton. In turn, study of the amphibolites indicates that the pair cummingtonite + anorthite or the presence of Ca-rich plagioclase with actinolite seem to be reliable mineral proxies of the thermal impact of the granitoid body on amphibolites in its envelope. The inferred conditions of the contact processes (450-550°C, 2.5- 4.8 kbar) point to an elevated geothermal gradient (ca. 32-45°C/km) probably reflecting the heat flow induced by the Karkonosze intrusion. Moreover, despite the textural and mineral changes imposed by regional and contact metamorphism, the amphibolites have their pre-metamorphic (magmatic) geochemical features undisturbed.

Hydrothermal activity in the Upper Permian Ravnefjeld Formation of central East Greenland – a study of sulphide morphotypes

1998 ◽  
pp. 81-87
Author(s):  
Jesper Kresten Nielsen ◽  
Mikael Pedersen
Keyword(s):  
Base Metal ◽  
Early Period ◽  
Sedimentary Basins ◽  
Hydrothermal Activity ◽  
Source Rocks ◽  
Upper Permian ◽  
Thermal Activity ◽  
East Greenland ◽  
The North ◽  
Alum Shale

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Kresten Nielsen, J., & Pedersen, M. (1998). Hydrothermal activity in the Upper Permian Ravnefjeld Formation of central East Greenland – a study of sulphide morphotypes. Geology of Greenland Survey Bulletin, 180, 81-87. https://doi.org/10.34194/ggub.v180.5090 _______________ Bituminous shales of the Ravnefjeld Formation were deposited in the subsiding East Greenland basin during the Upper Permian. The shales are exposed from Jameson Land in the south (71°N; Fig. 1) to Clavering Ø in the north (74°20′N) and have attracted considerable attention due to their high potential as hydrocarbon source rocks (Piasecki & Stemmerik 1991; Scholle et al. 1991; Christiansen et al. 1992, 1993a, b). Furthermore, enrichment of lead, zinc and copper has been known in the Ravnefjeld Formation on Wegener Halvø since 1968 (Lehnert-Thiel 1968; Fig. 1). This mineralisation was assumed to be of primary or early diagenetic origin due to similarities with the central European Kupferschiefer (Harpøth et al. 1986). Later studies, however, suggested base metal mineralisation in the immediately underlying carbonate reefs to be Tertiary in age (Stemmerik 1991). Due to geographical coincidence between the two types of mineralisation, a common history is a likely assumption, but a timing paradox exists. A part of the TUPOLAR project on the ‘Resources of the sedimentary basins of North and East Greenland’ has been dedicated to re-investigation of the mineralisation in the Ravnefjeld Formation in order to determine the genesis of the mineralisation and whether or not primary or early diagenetic base metal enrichment has taken place on Wegener Halvø, possibly in relation to an early period of hydrothermal activity. One approach to this is to study the various sulphides in the Ravnefjeld Formation; this is carried out in close co-operation with a current Ph.D. project at the University of Copenhagen, Denmark. Diagenetically formed pyrite is a common constituent of marine shales and the study of pyrite morphotypes has previously been successful from thermalli immature parts of elucidating depositional environment and thermal effects in the Alum Shale Formation of Scandinavia (Nielsen 1996; Nielsen et al. 1998). The present paper describes the preliminary results of a similar study on pyrite from thermally immature parts of the Ravnefjeld Formation which, combined with the study of textures of base metal sulphides in the Wegener Halvø area (Fig. 1), may provide an important step in the evaluation of the presence or absence of early thermal activity on (or below) the Upper Permian sea floor.

Plastic deformations in kyanites by tectonometamorphic processes: a single-crystal X-ray diffraction study

2009 ◽  
Vol 73 (3) ◽  
pp. 359-371 ◽  
Author(s):  
G. D. Gatta ◽  
N. Rotiroti ◽  
M. Zucali
Keyword(s):  
Single Crystal ◽  
X Ray Diffraction ◽  
Plastic Deformations ◽  
X Ray ◽  
Deformational History ◽  
Significant Difference ◽  
Elliptical Section ◽  
History Of ◽  
Diffraction Patterns ◽  
Two Stages

AbstractThe crystalch emistry and crystal structure of naturalky anite crystals from the Eclogitic Micaschists Complex of the Sesia-Lanzo Zone, Western Italian Alps, have been investigated by means of optical microscopy, wavelength dispersive X-ray microanalysis, and single-crystal X-ray diffraction. The association of kyanite + garnet + phengitic-mica + chloritoid suggests that the eclogite-facies stages occurred at P ≤ 2.1 GPa and T ≤ 650ºC. Kyanite grains are large (cm-sized) porphyroblasts grown dynamically during one of the deformational events related to the subduction of the Austroalpine continentalcr ust. Under the polarizing microscope, kyanite grains show almost homogeneous cores, whereas rims are sometimes symplectitic aggregates of quartz and kyanite, confirming at least two stages of growth most likely related to the multistage deformational history of these rocks. Chemical analysis shows that Fe3+ is the major substituting cation for Al3+, ranging between 0.038 and 0.067 a.p.f.u.The single-crystal X-ray diffraction investigation of the kyanites shows severely textured patterns on the (h0l)*-plane. Such evidence is not observed in the unwarped diffraction patterns on (0kl)* and (hk0)*. The most significant difference between the structuralp arameters refined in this study, with respect to those of previously published unstrained gem-quality crystals, concerns the displacement parameters. The anisotropic displacement ellipsoids of all the atomic sites are significantly larger than those previously described, and systematically oriented with the largest elliptical section almost perpendicular to [010]. The larger ellipsoids in the kyanite crystal investigated here reflect the displacement of the centre of gravity of the electron distribution, rather than an anomalous atomic thermal motion. The magnitude and orientation of the displacement parameters and the textured/strained diffraction pattern may be the result of two combined effects: (1) that the kyanite crystals are actually composed of several blocks; (2) the crystals are affected by a pervasive residual strain, as a result of tectonometamorphic plastic deformations and re-crystallization.

scholarly journals HISTORY OF DEVELOPING THE CONCEPT OF «LARGE SOCIAL GROUPS». PART 1: PERIOD FROM THE MID-19th CENTURY TO THE MID-1930-Х YEARS OF SOCIAL PSYCHOLOGY DEVELOPMENT

2020 ◽  
pp. 390-418
Author(s):  
Ю.В. Ковалева
Keyword(s):  
Social Psychology ◽  
Social Life ◽  
Social Groups ◽  
Social Situation ◽  
Social Phenomena ◽  
Psychological Study ◽  
The Social ◽  
History Of ◽  
The One ◽  
Two Stages

Представлен историографический анализ развития понятия большие социальные группы и историко-психологический анализ социальных феноменов , связанных с массовыми общественными явлениями в России. Сформулированы актуальные проблемы психологии больших социальных групп, к которым относятся неоднородность оснований для их выделения, недостаточная дифференцированность со сходными понятиями, неравномерность исследований в различные временные периоды и идеологическая нагруженность их разработки. Данная работа была ответом на необходимость восполнения знаний о процессах в таких группах, происходивших в различные исторические периоды развития социальной психологии, с соответствующим им уровнем научного осмысления, а также обобщением этой целостной картины на уровне современного понимания и формулировка перспективных направлений исследований. Целью исследования является установление связи между определением и основными свойствами понятия «большие социальные группы» (его синонимов, аналогов) и особенностями социальной ситуации в определенный период времени, а также реконструкция социальных процессов данного исторического этапа. Проверялась гипотеза о том, что большие социальные группы как феномены социальной жизни формировались в соответствии с историческим временем, а соответствующее им понятие и его свойства с одной стороны отвечали уровню развития гуманитарного знания, а с другой - пытались удовлетворить общественный и политический запрос в объяснении и управлении социальной ситуацией. Использовались методы историографии социальной психологии и психолого-исторической реконструкции . Первая часть статьи посвящена анализу первых двух этапов развития социальной психологии - с середины XIX до начала XX вв. и в 1920-е гг. XX в. The historiographic analysis of the development of the concept of large social groups and historical and psychological study of social phenomena associated with mass social phenomena was presented. Topical problems of the psychology of large social groups are formulated, including heterogeneity of the grounds for their isolation, insufficient differentiation with similar concepts, uneven research in various periods, and ideological loading of the history of its development. The study's main problem was the need to replenish the processes in such groups that took place in various historical periods of social psychology development as well as a synthesis of this holistic picture at the level of modern understanding and the formulation of promising areas of research. The study's purpose was to establish a connection between the definition and the basic properties of the concept of "large social groups" (and its synonyms, analogs) and the peculiarities of the social situation in a certain period, as well as the reconstruction of social processes of this historical segment. The hypothesis was tested that large social groups as phenomena of social life were formed under the past time. The concept and its properties were corresponding to them, on the one hand, compared to the level of development of humanitarian knowledge. On the other, they tried to satisfy the social and political requests to understand and manage the social situation. Methods of the historiography of the history of social psychology and psychological and historical reconstruction were used. The article's first part was devoted to the analysis of the early two stages of the development of social psychology - from the middle of the XIX to the beginning of the XX centuries and 1920 of the XX century.

scholarly journals Erichthonius or Theseus, who established the Panathenaea?

2021 ◽  
Vol 13 (3) ◽  
pp. 259-268
Author(s):  
Tatiana Borisovna Gvozdeva
Keyword(s):  
Olympic Games ◽  
Urban Community ◽  
Vase Painting ◽  
New Name ◽  
New Information ◽  
History Of ◽  
Two Stages ◽  
Regional Character ◽  
The Olympic Games

The sources know two versions of the establishing of Panathenaia, the main public holiday of the Athenian polis. The earliest version of aition of Panathenaia is associated with the history of the Athenian indigenous king Erichthonius. The son of Gaia and Hephaestus, Erichthonius was raised by the goddess Athena on the Acropolis, and after becoming king of Athens, he dedicated the feast of Panathenaia to the goddess. In the source, he is the first founder of the holiday. However, two types of Panathenaia were known in Athens: the Lesser Panathenaia, which were held annually, and the Greater Panathenaia, which, like the Olympic Games, were held every four years. Gradually, there appear pieces of new information about the history of the establishing of the Panathenaia in the mythological tradition. Now the authors distinguish two stages in the history of the feast, wherein the earlier one was called Athenaia. Gradually Erichthonius was relegated to the background, as founder Athenaeus, whereas the holiday got a new name - Panathenaia. This process was often associated with the synoekismus of Theseus, when he had united all the Athenians into one urban community. The cult of Theseus became especially popular in Athens after the reforms of Cleisthenes. Theseus' exploits are becoming a popular theme in Attic vase painting, especially scenes depicting the struggle, which Theseus was believed to be the founder of in Athens. At the same time, the program of the Panathenaic Games was expanding, the Panathenaia gradually acquired a supra-regional character.

scholarly journals Comprehensive Rehabilitation After Reconstruction of the Anterior Cruciate Ligament

2021 ◽  
Vol 11 (8) ◽  
pp. 182-193
Author(s):  
Dawid Besztak ◽  
Karina Szczypiór-Piasecka ◽  
Alicja Mińko ◽  
Krzysztof Antczak
Keyword(s):  
Anterior Cruciate Ligament ◽  
Knee Joint ◽  
Cruciate Ligament ◽  
Treatment Options ◽  
Rehabilitation Process ◽  
History Of ◽  
Comprehensive Rehabilitation ◽  
Anterior Cruciate ◽  
Two Stages ◽  
Hospital Rehabilitation

Introduction: The knee joint is the second most frequently injured joint. Anterior cruciate ligament (ACL) injury is a relatively common injury to the inner part of the knee joint, mainly related to contact sports. Its rupture leads to instability of the entire joint. Two treatment options are possible: operative or conservative. Each of them is related to an appropriate rehabilitation process. The aim of this study was to define a comprehensive rehabilitation plan in patients after ACL rupture and meniscal suturing.Materials and methods: The work was written based on the medical history of the patient who was diagnosed with complete rupture of ACL, and then reconstruction was performed with the harvesting of a semitendinous and slender muscle graft.Results: The rehabilitation process can be divided into two stages: hospital and post-hospital. Rehabilitation in hospital conditions begins on the zero day after arthroscopy. The main goals of rehabilitation include: increasing the range of mobility, no myofascial dysfunctions, no thromboembolic complications, and the ability to self-service.Conclusion: Rehabilitation is an indispensable element of the treatment of patients after ACL reconstruction. Early initiation of rehabilitation brings tangible benefits during treatment and return to full physical fitness.

«(Великая) культурная революция» в приграничных к СССР районах КНР: ХулунБуир, провинция Хэйлунцзян (1966–1976 гг.)

2020 ◽  
pp. 127-134
Author(s):  
Ochirov Ts. Solbonovich ◽  
Keyword(s):  
Cultural Revolution ◽  
Industrial Development ◽  
Political Campaigns ◽  
Contemporary History ◽  
Initial Stage ◽  
History Of ◽  
Oriental Studies ◽  
Two Stages ◽  
The Given ◽  
The Cultural Revolution

The research of the problems of the contemporary history of the NorthEastern China including the analysis of ideological and political campaigns of the second half of the XX century is one of the high-potential fields of the Oriental studies in our country. The article focuses on the period of the (Great) ‘Cultural Revolution’ (1966–1976) at bordering USSR Chinese regions — Heilongjiang province and Khulun-Buir aimak of the autonomous region of Inner Mongolia. The goals of the study are set in concurrence with chronological order of the events: the ‘cultural revolution’ in the above mentioned regions had two stages. The study is based on the works of the Chinese historians. The given research highlights the specific features of the initial stage of the “cultural revolution” including the criticism of the party officials, establishment of revolution committees and running a political campaign ‘vasu’; considers the Soviet-Chinese conflict at the Daman island in 1969 to be a factor in the following political stabilization of the bordering territories; examines the movement for restoration of the party apparatus and the boost in the industrial development in 1970s of the last century.

scholarly journals U-Pb monazite ages of the Kabanga mafic-ultramafic intrusions and contact aureoles, central Africa: Geochronological and tectonic implications

2019 ◽  
Vol 131 (11-12) ◽  
pp. 1857-1870 ◽  
Author(s):  
Jian-Wei Zi ◽  
Birger Rasmussen ◽  
Janet R. Muhling ◽  
Wolfgang D. Maier ◽  
Ian R. Fletcher
Keyword(s):  
Central Africa ◽  
Layered Intrusion ◽  
Thermal Anomaly ◽  
Contact Metamorphism ◽  
Contact Aureole ◽  
East African ◽  
Metamorphic History ◽  
History Of ◽  
Rodinia Assembly ◽  
Contact Aureoles

AbstractMafic-ultramafic rocks of the Kabanga-Musongati alignment in the East African nickel belt occur as Bushveld-type layered intrusions emplaced in metasedimentary sequences. The age of the mafic-ultramafic intrusions remains poorly constrained, though they are regarded to be part of ca. 1375 Ma bimodal magmatism dominated by voluminous S-type granites. In this study, we investigated igneous monazite and zircon from a differentiated layered intrusion and metamorphic monazite from the contact aureole. The monazite shows contrasting crystal morphology, chemical composition, and U-Pb ages. Monazite that formed by contact metamorphism in response to emplacement of mafic-ultramafic melts is characterized by extremely high Th and U and yielded a weighted mean 207Pb/206Pb age of 1402 ± 9 Ma, which is in agreement with dates from the igneous monazite and zircon. The ages indicate that the intrusion of ultramafic melts was substantially earlier (by ∼25 m.y., 95% confidence) than the prevailing S-type granites, calling for a reappraisal of the previously suggested model of coeval, bimodal magmatism. Monazite in the metapelitic rocks also records two younger growth events at ca. 1375 Ma and ca. 990 Ma, coeval with metamorphism during emplacement of S-type granites and tin-bearing granites, respectively. In conjunction with available geologic evidence, we propose that the Kabanga-Musongati mafic-ultramafic intrusions likely heralded a structurally controlled thermal anomaly related to Nuna breakup, which culminated during the ca. 1375 Ma Kibaran event, manifested as extensive intracrustal melting in the adjoining Karagwe-Ankole belt, producing voluminous S-type granites. The Grenvillian-aged (ca. 990 Ma) tin-bearing granite and related Sn mineralization appear to be the far-field record of tectonothermal events associated with collision along the Irumide belt during Rodinia assembly. Since monazite is a ubiquitous trace phase in pelitic sedimentary rocks, in contact aureoles of mafic-ultramafic intrusions, and in regional metamorphic belts, our study highlights the potential of using metamorphic monazite to determine ages of mafic-ultramafic intrusions, and to reconstruct postemplacement metamorphic history of the host terranes.

Reproductive cycle of purple clam, Amiantis purpurata (Bivalvia: Veneridae) in northern Patagonia (Argentina)

2005 ◽  
Vol 85 (2) ◽  
pp. 367-373 ◽  
Author(s):  
Enrique M. Morsan ◽  
Marina A. Kroeck
Keyword(s):  
Reproductive Cycle ◽  
Continuous Process ◽  
Early Summer ◽  
Maturation Stage ◽  
Reproductive Pattern ◽  
Oocyte Diameter ◽  
Histological Techniques ◽  
Northern Patagonia ◽  
History Of ◽  
Quantitative Indicators

The reproductive cycle of the purple clam (Amiantis purpurata) northern Patagonian population was studied throughout a 19-month period (September 1993–March 1995) using standard histological techniques and quantitative indicators (oocyte diameter distributions, oocytes per ocular field and relative oocyte area). In this species gametogenesis is a continuous process involving a complete gonadal restitution after the end of the reproductive season (no resting period). The proliferation phase occurs during the coldest half of the year (April to September) and maturation takes place during spring (September to December). Several partial emissions of gametes, with subsequent restitution of the gametogenic series, occur during the summer months. During the total maturation stage, oocytes never filled the whole alveolar area: maximum per cent of alveolar sections occupied by oocytes (46%) was observed in late spring–early summer. Implications of the reproductive pattern in the context of palaeogeographic history of northern Patagonia, and the isolation of this population are discussed.

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