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Journal articles on the topic 'Porphyry'
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1
Гарин, С. В. "Minimal Categorical System and Predication Theory In Porphyry." Logical Investigations 23, no. 1 (May 4, 2017): 140–50. http://dx.doi.org/10.21146/2074-1472-2017-23-1-140-150.
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The article considers some problematic aspects of Porphyry’s typology of Aristotle’s categories and the theory of predication. Minimal (_________) class of categories in Porphyry is revealed. The work has shed some light on the opposition between $\textit{explanation}$ and $\textit{description}$ (__________ / ___________) within the framework of ancient categorical logic. A fourfold pattern of predication theory in Porphyry is described. The study aims to illuminate the development of Porphyry’s predication theory towards the archaic doctrine of quantifiers. Particular attention is paid to Porphyry’s account of semantic relation between sets. The paper represents Porphyry’s nine kinds of class / item relationships. The article focuses on the awakening of academic interest to the logical heritage of Porphyry.
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Proctor, Travis W. "Daemonic Trickery, Platonic Mimicry: Traces of Christian Daemonological Discourse in Porphyry’s De Abstinentia." Vigiliae Christianae 68, no. 4 (September 18, 2014): 416–49. http://dx.doi.org/10.1163/15700720-12341180.
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Porphyry of Tyre’s discussion of daemons and animal sacrifice in De Abstinentia strays from traditional Platonic formulations of daemonic involvement in the Graeco-Roman cult. As a result, scholars have struggled to identify the intellectual pedigree for Porphyry’s daemonology. By contrast, I propose that Porphyry draws upon Christian Platonic daemonologies, best represented in the writings of Origen of Alexandria. To substantiate this hypothesis, I first outline the dissonance between Porphyry’s daemonology and his Hellenic predecessors, before outlining the several daemonological tenets he shares with Christian writers. Second, I note the extensive conceptual commonalities between Origen and Porphyry’s respective daemonologies, Finally, I reexamine Porphyry’s attribution of his daemonology to “certain Platonists,” a claim which, when read in light of Porphyry’s Vita Plotini, places Origen squarely within the intellectual circles from which Porphyry was drawing his daemonological discourse.
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Ramelli, Ilaria L. E. "Plagues and Epidemics Caused by D(a)emons in Origen and Porphyry and Potential Interrelations." Vox Patrum 78 (June 15, 2021): 89–120. http://dx.doi.org/10.31743/vp.12302.
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This essay will address how Origen, an early Christian writer, theologian, and pastor, referred to plagues, epidemics, and misfortunes, and how he construed these phenomena in his theology, literary works, and pastoral practice. A comparison with Porphyry will be offered, who likely drew part of his daemonology from Origen. Those responsible for plagues in both Origen’s philosophical theology and in Porphyry’s philosophy are δαίμονες (demons or fallen angels for Origen, daemons for Porphyry; Origen knew and referred to the two views). Porphyry’s attribution of his daemonology to “certain Platonists” who “divulged” these theories probably alludes to Origen and situates Origen within the Platonic school. I suspect that Porphyry was influenced by Origen’s demonology in general and possibly by On Daemons, if his. Porphyry’s terminology of “divulging” corresponds to that used in his anecdote about Origen who, notwithstanding the oath not to divulge Ammonius’ esoteric doctrines, nevertheless did so in On Daemons and The King Is the Only Creator. This indirectly confirms that Porphyry was speaking of the same Origen. Porphyry’s conviction that evil daemons are responsible for plagues, epidemics, and natural disasters is the same as Origen’s in Contra Celsum, which Porphyry knew. Origen was aware that spiritual plagues are worse than physical ones, that misfortunes mostly befall the just, and took over Jesus’ criticism of the ancient view of misfortunes as divine punishments for an individual or his parents or ancestors.
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Callanan, Christopher K. "A rediscovered text of Porphyry on mystic formulae." Classical Quarterly 45, no. 1 (May 1995): 215–30. http://dx.doi.org/10.1017/s0009838800041811.
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Students of later Platonism know well the significant role Porphyry played in the development of what we now call Neoplatonism. His own biography of Plotinus makes clear that we probably owe the very existence of the majority of Plotinus' written works to Porphyry's nagging. Having cajoled the master into penning a large number of works during his latter years, Porphyry then edited and published them, giving them the title Enneads which they have since borne. We must, of course, take Porphyry's claims regarding the importance of his own influence with a grain of salt. Still, with the sole exception of Plato himself, no figure in the Platonic tradition had ever enjoyed Plotinus' good fortune in the transmission of his complete works, and none would again, for which we clearly have Porphyry to thank.
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Redwood, Stewart D. "The Origin of the Porphyry Deposit Name: From Shellfish, Tyrian Purple Dye, and Imperial Rome to the World’s Largest Copper Deposits." SEG Discovery, no. 118 (July 1, 2019): 1–15. http://dx.doi.org/10.5382/segnews.2019-118.fea.
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Abstract The porphyry deposit name has a long and fascinating etymological history of over 3,000 years. “Porphyry” is derived from the ancient Greek word porphyra (πoρϕύρα), or purple. It was originally applied to a rare purple dye, Tyrian purple, extracted by the Phoenicians from murex shells. It was later applied to a prized purple porphyritic rock, Imperial Porphyry or Porfido rosso attico, quarried by the Romans from Mons Porphyrites in the Eastern Red Sea hills of Egypt from the first to fifth centuries A.D., and used as a monumental stone in Imperial Rome and Byzantium (Istanbul). The name evolved in the field of igneous petrology to include all rocks with a porphyritic texture, regardless of their color. Mining of the first porphyry copper deposits, which were originally called disseminated or low-grade copper deposits, started in 1905. As a result of the close spatial and genetic relationship to porphyry stocks, they became known as porphyry copper deposits. The term was first used by W. H. Emmons in his 1918 textbook The Principles of Economic Geology, but it was originally used more as an engineering and economic description, as in Parsons’ 1933 book The Porphyry Coppers. It was slow to catch on in the geological literature. It was first used in the title of a paper in Economic Geology in 1947 but did not gain widespread use until the 1970s, following the publication of seminal papers on porphyry models and genesis by Lowell and Guilbert (1970) and Sillitoe (1972, 1973).
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Menn, Stephen. "On the Title of Porphyry’s Categories Commentary Πρὸς Γεδάλειον." Phronesis 62, no. 3 (June 6, 2017): 355–62. http://dx.doi.org/10.1163/15685284-12341331.
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Simplicius cites Porphyry’s lost greater commentary on the Categories by the name of its addressee: Πρὸς Γεδάλειον. It has been assumed that we know nothing about Gedalius, and even suggested that he may have been a fictional construct. But his name is Jewish, and Porphyry had no reason to make up a Jewish addressee. It was extremely rare for Greek pagan texts to be dedicated to a Jewish addressee. But Porphyry had an unusual degree of involvement with Judaism. I collect the evidence, and make a tentative proposal about the context for Porphyry’s dedicating this work to Gedalius.
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Svetlov, Roman, and Dmitry Shmonin. "Porphyry, Chaldaism, Judaism." ΣΧΟΛΗ. Ancient Philosophy and the Classical Tradition 17, no. 2 (2023): 866–74. http://dx.doi.org/10.25205/1995-4328-2023-17-2-866-874.
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The article seeks to explain the issue of why Porphyry of Tire, the first thinker introducing the discourses of the «Chaldean oracles» into Platonism, did not integrate Chaldaism and Judaism in his ideas on the nature of barbarian "theologies". For example, Julian the Apostate had accomplished such integration in his “political theology”. In the authors' opinion the reason for Porphyry's caution was his assessment of theurgy and its role in the genuine piety. The well-known discussion on the efficacy of theurgy in Porphyry's «Letter to Anebon» and «On the Egyptian Mysteries» of Iamblichus shows us two different modes of understanding of the Chaldean wisdom. Meantime, focusing on Iamblichus' approaches, Julian achieved this integration.
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Muscolino, Giuseppe. "Porphyry and Black Magic." International Journal of the Platonic Tradition 9, no. 2 (September 11, 2015): 146–58. http://dx.doi.org/10.1163/18725473-12341313.
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In the De abstinentia (ii, 41, 5) Porphyry is the first philosopher to give an exact definition of goeteia or black magic saying: “All black magic is accomplished through the opposite sort [i.e. evil] daemons.This paper will be presented in two parts: in the first part, there is the description about the difference between Magic—the sacred science of the Persian Magi (De abstinentia iv, 16, 1)—, and the black magic (De abstinentia ii, 41, 5); in the second part, using Porphyry’s definition of black magic and other philological data, it’s shown that Porphyry was not merely a philosopher interested in black magic in a theoretical manner, but also a practicing sorcerer.
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Vashchenko, Priest Andrey. "Features of the ecclesiological discourse of St Porphyry Kavsokalivit." Issues of Theology 4, no. 3 (2022): 539–48. http://dx.doi.org/10.21638/spbu28.2022.312.
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The paper analyzes the approach of St Porphyry Kavsokalivit to ecclesiological issues, in particular his central statement, “The Church is eternal and uncreated”. An attempt to determine the origins and logical justification of this concept is made. The emergence of St Porphyry’s unusual theological formula relates to the literal interpretation of the New Testament metaphor of the Church as the Body of Christ (Eph 1:23, 1 Cor 12). A specific feature of St Porphyry’s ecclesiological discourse is the affirmation of sameness of the Church and Christ, the Church and God, the Church and the Holy Trinity. The relationship of his theological ideas with the ecclesiological constructions of some Christian writers (St Epiphanius of Cyprus) is also shown. Along with the original approach from a theological point of view, St Porphyry Kavsokalivit is quite traditional when he talks about the Church in practical terms, about its significance for salvation and the canonical structure of Christianity. The St Porphyry’s idea of Church is more mystical than theological. His thought is based not on rationalization, but on a subjective experience of the “churchness”. Given the dogmatic uncertainty in ecclesiology in the Orthodox Church, the contradictory and unusual concept of the eternal and uncreated Church of St Porphyry can be qualified as a private theological opinion.
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Costa, Cristina D'Ancona. "Porphyry, Universal Soul and the Arabic Plotinus." Arabic Sciences and Philosophy 9, no. 1 (March 1999): 47–88. http://dx.doi.org/10.1017/s0957423900002605.
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Scholars working in the field of Graeco-Arabic Neoplatonism often discuss the role Porphyry, the editor of Plotinus, must be credited with in the formation of the Arabic Plotiniancorpus. A note in thiscorpusapparently suggests that Porphyry provided a commentary to the so-calledTheology of Aristotle, i.e., parts of some treatises ofEnneadsIV-VI. Consequently, Porphyry has been considered as responsible for the (sometimes relevant) doctrinal shifts which affect the Arabic Plotinian paraphrase with respect to the original text. This article aims at submitting this hypothesis to trial on a specific doctrinal point where Porphyry parts company with Plotinus: the relationship between the Demiurgic Intellect and World Soul. The ancient doxographical sources testify that Porphyry, in his conviction to be in agreement with Plotinus, in fact parted company with him in so far as he merged the World Soul into the Demiurgic Intellect, while Plotinus always kept them apart. There are in theEnneadssome baffling passages where the role of Intellect as the Demiurge of the sensible world is not clearly distinguishable from the role of World Soul. Notwithstanding that, these passages in the Arabic paraphrase do not bear any trace of the characteristically Porphyrian merging of World Soul into Intellect. The Arabic paraphrase of Plotinus’ writings never confuses Intellect and World Soul, as Porphyry did. This fact seems to disprove, at least on this point, the hypothesis of Porphyry's intervention as the explanation for the doctrinal differences between the original Plotinus’ text and its Arabic tradition.
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Greenwood, David Neal. "Porphyry, Eusebius, and Epistemology." Ancient Philosophy 43, no. 2 (2023): 517–37. http://dx.doi.org/10.5840/ancientphil202343229.
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I argue for the authenticity of a fragment found in Eusebius, PE i 2.2-5, and sometimes attributed to Porphyry of Tyre. I argue against the case for non-Porphyrian authorship that has become dominant in recent years, employing evidence that highlights congruity with generally accepted Porphyrian works. This allows me to move on to an initial reconstruction of Porphyry’s religious epistemology, and to assess what that means in his historical context.
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Soloviev, Roman. "Special features of the genre of the "Vita Plotini": who was Porphyry referring to?" St. Tikhons' University Review. Series III. Philology 73 (December 30, 2022): 84–102. http://dx.doi.org/10.15382/sturiii202273.84-102.
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The article presents the analysis of genre dominants of "The Life of Plotinus" by Porphyry and analyses the polemical sources of the text. Having established the lack of research on the genre of the text in the modern bibliography, the author places the Life of Plotinus into the range of the late antique biographies, and determines the main characteristics of the analyzed text. The title of the text indicates Porphyry's dual purpose: to introduce the reader to the personality of Plotinus, whom Porphyry deliberately presents as theios aner, and also to present Plotinus' 54 treatises within the coherent system of the Enneads. The dual task is also reflected in the structure of the Life. Reconstructing the image of Porphyry in the text, the author of the article highlights the techniques that create the image of the author of Plotinus' Life. Emphasizing his own place in the hierarchy of the school is caused by the polemic both within the Neoplatonic school (with the earlier edition of Plotinus' treatises by Amelius; this is shown through the analysis of the introduction of the Life of Plotinus) and outside it. The author establishes the pragmatics of the key episodes of the text and shows that the text is built around a constructed hierarchy of testimonies: from the fellow student, Amelius, to the Oracle of Apollo. By highlighting the essential attributes of the hero of the biography, the author illustrates the dynamism of Porphyry's conception: Vita Plotini is not only an introduction to the edition, but also a didactic text, depicting a contemporary who has achieved the goal of human life. In the final part of the article, the author analyses the approaches to the identification of the opponents of Porphyry in the literature and sets forth his own hypothesis: the text was created in opposition to the school of Origen and to the image of the scholarch, which was drawn by Gregory the Wonderworker and Eusebius of Caesarea. The hypothesis of Porphyry's response to the Christian texts is grounded by the new lexical similarities with Origen.
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Tomadaki, Maria. "An unpublished poem on Porphyry." Byzantinische Zeitschrift 111, no. 3 (September 1, 2018): 777–92. http://dx.doi.org/10.1515/bz-2018-0021.
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Abstract This paper offers an editio princeps, an English translation and a commentary of an interesting epigram on Porphyry, the commentator of Aristotle. The epigram was transcribed in Vat. Reg. 166 by Ioannes Malaxos (16th c.) and is ascribed to Petros Servilos, a poet unknown from other sources. The paper discusses the poem’s manuscript context, as well as its authorship, genre, content and function. Further, it attempts to shed light on the poem’s relation to Porphyry’s philosophy and his reception in Byzantine poetry.
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Goulet, Richard. "Cinq nouveaux fragments nominaux du traité de Porphyre “Contre les chrétiens”." Vigiliae Christianae 64, no. 2 (2010): 140–59. http://dx.doi.org/10.1163/157007209x439238.
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AbstractFirst publication of five fragments from Porphyry’s treatise Against the Christians discovered in Michael Psellus, Michael Glykas and Damascenus Studites. These objections are explicitly attributed to Porphyry and bear on biblical verses known to have been attacked by this opponent to christianity.
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MIGACHEV, Igor, Vadim ZVEZDOV, and Olga MININA. "Formational types of porphyry copper deposits and their ore-magmatic systems." Domestic geology, no. 1 (March 21, 2022): 26–48. http://dx.doi.org/10.47765/0869-7175-2022-10002.
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Two individual ore-formational types have been identified within the porphyry copper family: the gold-copper-porphyry and molybdenum-copper-porphyry ones. The fundamental difference between them lies in their geotectonic position that determines the origin and composition of fertile magmatic source, as well as other features the composition of ore-bearing porphyry intrusions, the mineralogical and geochemical features of ores, and the pattern of metasomatic and ore zonation. In this study, we investigated porphyry copper ore-magmatic systems with complex metallogeny, or complex porphyry copper systems (CPCS), where porphyry copper deposits constitute the core elements spatially associated with mineralization of other ore-formational types. Based on a set of conjugated and combined types of ore mineralization we established the differences between diorite-related gold-copper-porphyry CPCS, formed in basaltic volcano-plutonic belts, and granodiorite-monzonite-related molybdenum-copper-porphyry CPCS, formed in andesite belts. These differences confirm the validity of the distinction of the two ore-formational types of deposits of the porphyry-copper family.
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Kaczynski, Jerzy, Göran Hansson, and Sven Wallerstedt. "Increased Porphyrins in Primary Liver Cancer Mainly Reflect a Parallel Liver Disease." Gastroenterology Research and Practice 2009 (2009): 1–6. http://dx.doi.org/10.1155/2009/402394.
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Hepatic porphyries have been associated with an increased risk of primary liver cancer (PLC), which on the other hand may cause an increased porphyrin production. To evaluate the role of an underlying liver disorder we analyzed porphyrins in patients with hepatocellular carcinoma (HCC)(n=65), cholangiocellular carcinoma(n=3), or suspected PLC, which turned out to be metastases(n=18)or a benign disorder(n=11). None of the patients had a family history of porphyry or clinical signs of porphyry. Increased aminolevulinic acid or porphyrin values were common not only in patients with PLC (43%) but also in metastatic (50%) and benign (64%) liver disorders. The corresponding proportion for HCC patients with liver cirrhosis (55%) was higher(P<.05)than in those without cirrhosis (17%). We conclude that symptomatic porphyries are unusual in PLC, whereas elevated urinary and/or faecal porphyrins are common, primarily reflecting a parallel liver disease and not the PLC.
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Viltanioti, Irini-Fotini. "Porphyry’s Real Powers in Proclus’ Commentary on Plato’s Timaeus." International Journal of the Platonic Tradition 11, no. 1 (April 18, 2017): 26–45. http://dx.doi.org/10.1163/18725473-12341363.
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In his Commentary on the Timaeus, Porphyry of Tyre argued against the second-century Platonist Atticus’ thesis that the creation in Plato’s Timaeus was a process from a point of time. This paper focuses on the summary of one of Porphyry’s arguments against this thesis exposed in Book 2 of Proclus’ Commentary on the Timaeus. It argues that Proclus does justice to Porphyry’s views and that the argument points to a classification of powers in Porphyry’s metaphysics that has so far been neglected by scholars.
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Xu, Qinglin, Yonggang Sun, Guangzhou Mao, Wei Xin, and Yanqian Yang. "Petrogenesis of the Ore-Related Intrusions of the Aikengdelesite Mo (–Cu) and Halongxiuma Mo Deposits: Implication for Geodynamic Evolution and Mineralization in the East Kunlun Orogen, Northwest China." Minerals 13, no. 3 (March 22, 2023): 447. http://dx.doi.org/10.3390/min13030447.
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The East Kunlun Orogenic Belt (EKOB) is the most important Triassic polymetallic metallogenic belt in China. A study about the petrogenesis of the ore-related intrusions is of great significance to the geodynamic evolution of orogenic belts. In this study, analysis of U–Pb zircon dating, whole-rock major and trace element compositions, and zircon Hf isotopes for the granitoids hosting the Aikengdelesite Mo (–Cu) and Halongxiuma Mo deposits in the EKOB are studied to determine their chronology and petrogenesis. Zircon date results show that the Aikengdelesite granite porphyry and the Halongxiuma granodiorite porphyry formed at 244.2 ± 1.7 Ma and 230.0 ± 1.0 Ma respectively. All samples of the Aikengdelesite granite porphyry and the Halongxiuma granodiorite porphyry which have high SiO2 and K2O contents, and low MgO and Cr, belong to the high-K calc-alkaline series. The Aikengdelesite granite porphyry samples show I-type geochemical affinities, whereas the Halongxiuma granodiorite porphyry samples are A-type granitoids. They all show negative zircon εHf(t) values (−7.4 to −3.3 and −3.7 to −2.5). We suggest that the Aikengdelesite granite porphyry may have been derived from the lower continental crust. While the Halongxiuma granodiorite porphyry could have formed by partial melting of basic lower crustal materials. By combining the results of this study with previous data, two magmatic and mineralization peak periods (278–237 Ma and 230–210 Ma) were observed in the Paleo-Tethys of the EKOB. Porphyry–skarn deposits occurring in the first episode were formed in the setting of an active continental margin related to the Paleo-Tethys Ocean plate subduction (e.g., Aikengdelesite porphyry deposit), while deposits occurring in the second episode were formed in a post-collisional setting (e.g., Halongxiuma porphyry deposit).
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BUCHKO, INNA VLADIMIROVNA, and IVAN ALEXANDROVICH YATSENKO. "FORECASTING GEOCHEMICAL PREREQUISITES FOR DETECTING THE PORPHYROUS SYSTEM IN THE KOMSOMOLSK REGION OF KHABAROVSK REGION." Messenger AmSU, no. 93 (2021): 126–30. http://dx.doi.org/10.22250/jasu.93.26.
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The information on the results of geological exploration work to identify the porphyry system in the Komsomolsk region of the Khabarovsk Territory is given. It is shown that copper-molybdenum-porphyry mineralization is associated with the type of porphyry deposits by a porphyry stock surrounded by fields of hydrothermal-metasomatic alteration. The possibilities of the object of the gold-rare metal type are substantiated.
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Murad, Fida, Abdul Ghaffar, Innayat Ullah, Abdul Shakoor Mastoi, and Muhammad Tariq Zaman. "The Alteration and Mineralization Characteristics of Miocene Porphyry Cu-Au Deposits of Chagai Magmatic Belt, District Chagai, Balochistan, Pakistan." International Journal of Economic and Environmental Geology 12, no. 1 (June 8, 2021): 1–8. http://dx.doi.org/10.46660/ijeeg.vol12.iss1.2021.550.
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Subduction related Miocene porphyry type deposits are found in the east-west trending Chagai magmatic belt (CMB) in Pakistan's western margin, Balochistan. This arc exists on the west segment of the Tethyan metallogenic belt in the south-west of Pakistan. Tethyan metallogenic belt is widely spread over 12,000 km from east to west direction from Indochina, Tibet, Pakistan, Iran, Turkey and Alpine mountain range in Europe. During the last thirty to forty years several porphyry deposits have been reported in the Chagai magmatic arc, including the very large Reko Diq H14-H15, large Saindak, Tanjeel, H35, H8 and medium Dasht-e-Kain porphyry deposits and many small porphyry copper deposits. These porphyry deposits were developed within the phase of calc-alkaline type magmatism in the Chagai arc. Tonalite, quartz diorite, and monzonite host the porphyry deposits within the adjacent sedimentary wall rock units of Sinjrani Volcanic Group, Juzzak, Saindak, and Amalaf Formations. The concentric zonal pattern of hydrothermal alteration in these porphyry deposits of the Chagai magmatic arc follows the world's major porphyry deposits' alteration pattern. Zones of hydrothermal alteration from distal to proximal part includesa potassic alteration, sericitic-clay-chlorite alteration, sericitic alteration, argillic alteration and propylitic alteration. Major ore mineralization in these deposits is of copper, gold, silver, molybdenum, and minor constituents of other base metals that have been reported to occur within hydrothermal alteration zones in the Miocene porphyry Chagai magmatic arc
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Pribavkin, S. V., A. V. Коrovko, and I. A. Gottman. "Geological structure and petrology of the Nizhne-Sinyachikhinsky granitoid massif (Alapayevsk-Sukhoi Log porphyry copper zone, the Middle Urals)." LITHOSPHERE (Russia) 20, no. 2 (April 25, 2020): 212–23. http://dx.doi.org/10.24930/1681-9004-2020-20-2-212-223.
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Research subject. The geological structure and rock composition of the Nizhne-Sinyachikhinsky plagiogranite massif, which is part of the Alapaevsk-Sukholozhsky zone, is promising for the Cu(Au,Mo)-porphyric mineralization type, were studied. The aim was to determine the formation features of these rocks and compare them with the productive granitoids of Ural porphyry deposits of similar age. Materials and methods. The mineral composition of the rocks was determined using a JEOL JSM 6790LV scanning electron microscope with an INCA Energy 450 X-Max 80 EDS spectrometer and a CAMECA SX-100 electron microprobe analyser. The rock composition was obtained by X-ray fluorescence spectrometry on a SRM-35 and XRF-1800 spectrometers with the titrimetric determination of FeO. The concentrations of rare and rare-earth elements were determined on an ELAN 9000 inductively coupled plasma mass spectrometer at the Geoanalitik Center for Collective Use of the Ural Branch of the Russian Academy of Sciences. Results. For the first time, an early tonalite-plagiogranite series was identified in the structure of the massif. This series is represented by tonalites of the hypabyssal appearance, broken through by the dikes of plagiogranite-porphyry. It was shown that the separation of plagiogranite-porphyry melts from magmas of the mafic composition occurred at the base of the island-arc construction, and their crystallisation was carried out in an intermediate chamber at a pressure of 1.8–2.3 kbar. In contrast, the plagiogranites of the main phase of the massif were separated from the parent melt in an intermediate chamber located at the level of the upper crust, and their crystallisation occurred at a pressure of 1.5–2.0 kbar. Conclusions. A comparison of the main phase plagiogranites and the isolated early-series plagiogranite-porphyry indicates their similar composition, as well as their similarity in age with the granitoids of the Southern Urals, productive in terms of the porphyry mineralisation type. The concentrations of F, Cl and S in the apatites and amphiboles of the rocks under study is an argument in favour of their belonging to andesitoid formations that are productive in terms of the Cu (Au)-porphyry mineralisation type. The absence of the sulphide mineralisation of this type can be explained by a more significant depth of rock formation and their erosion section.
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Lin, Bin, Juxing Tang, Pan Tang, Georges Beaudoin, Crystal Laflamme, Faqiao Li, Wenbao Zheng, et al. "MULTIPULSED MAGMATISM AND DURATION OF THE HYDROTHERMAL SYSTEM OF THE GIANT JIAMA PORPHYRY Cu SYSTEM, TIBET, CHINA." Economic Geology 119, no. 1 (January 1, 2024): 201–17. http://dx.doi.org/10.5382/econgeo.5054.
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Abstract Jiama is the largest porphyry-skarn ore system in the Gangdese metallogenic belt, Tibet. It is composed of porphyry Cu-Mo, Cu-polymetallic skarn, Cu-Pb-Zn manto, and distal vein Au orebodies with associated Ag, W, and Bi. However, the precise timing of the magmatism and hydrothermal events at Jiama remains obscure. Here, using high-precision chemical abrasion-isotope dilution-thermal ionization mass spectrometry (CA-ID-TIMS) U-Pb zircon dating of ore-bearing and post-ore intrusions, we accurately constrain the lifespan of magmatism and hydrothermal mineralization. Monzogranite porphyry dikes are cut by Cu-Mo vein mineralization in the deeper part of the system, indicating that they were emplaced pre-ore, and yield a crystallization age of 15.534 ± 0.007 Ma (mean square of weighted deviates [MSWD] = 0.99, n = 6). A granodiorite porphyry that cuts the monzogranite porphyry and hosts vein and disseminated chalcopyrite and molybdenite is considered synchronous with ore and yields a crystallization age of 15.368 ± 0.007 Ma (MSWD = 1.01, n = 5). These two phases of intrusions are cut by quartz-diorite porphyry bodies, which yield a crystallization age of 15.076 ± 0.006 Ma (MSWD = 0.13, n = 6) and contain weak, subeconomic Cu and almost no molybdenum mineralization. A post-ore barren quartz monzonite porphyry yields a crystallization age of 14.925 ± 0.006 Ma (MSWD = 1.12, n = 6). The lifespan of magmatism at Jiama is thus about 0.61 m.y. The difference with previous molybdenite Re-Os isochron ages from the porphyry (14.7 ± 0.3 Ma), hornfel (14.7 ± 0.4 Ma), and skarn (15.4 ± 0.2 Ma) suggests that high-precision chronology is required to decipher accurate timing of mineralization in porphyry systems such as Jiama. The 40Ar/39Ar ages of hydrothermal biotite coexisting with molybdenite in monzogranite porphyry and hornfels are 15.25 ± 0.17 Ma (MSWD = 1.6) and 15.25 ± 0.24 Ma (MSWD = 0.14), respectively, slightly younger than the granodiorite porphyry and older than weakly mineralized quartz diorite porphyry, which represents the time of the ore-forming hydrothermal event. Thus, Jiama is the product of pulsed magmatism during which a short-lived hydrothermal event formed the giant Cu polymetallic system.
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Zheng, Yulin, Changqing Zhang, Fudong Jia, Huan Liu, and Qinggao Yan. "Apatite and Zircon Geochemistry in Yao’an Alkali-Rich Porphyry Gold Deposit, Southwest China: Implications for Petrogenesis and Mineralization." Minerals 11, no. 11 (November 20, 2021): 1293. http://dx.doi.org/10.3390/min11111293.
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The Yao’an gold deposit is located in the middle of the Jinshajiang-Ailaoshan alkali-rich metallogenic belt, and this belt hosts many porphyry-type Cu-Au-Mo deposits formed at 46–33 Ma. Yao’an porphyry gold-mineralization is intimately associated with biotite syenite porphyry, whereas the contemporaneous quartz syenite porphyry is barren. In this study, we compared the major and trace elements of apatite and zircon and isotopic compositions of zircon from the biotite syenite porphyry and quartz syenite porphyry, to explore their geochemical differences that may affect their mineralization potential. The results show that both porphyries were derived from the partial melting of the thickened lower crust, which has been modified by slab-derived fluids, but has different mineral crystallization sequences, magma fluid activities, and magma oxidation states, respectively. REE contents in apatite and zircon can be used to reveal the crystallization sequence of minerals. A rapid decrease of (La/Yb)N ratio in apatite from both porphyries may be caused by the crystallization of allanite. Large variation of Cl contents and negative correlation between F/Cl and (La/Yb)N in apatite from fertile porphyry indicate that it has experienced the exsolution of Cl-bearing hydrothermal fluid. Higher Y/Ho and lower Zr/Hf in zircon from fertile porphyry indicate a stronger fluid activity than barren porphyry. The high S, V, As contents, δEu, low δCe in apatite, as well as high Ce4+/Ce3+ and log(fO2) estimated from zircon geochemistry from fertile porphyry, indicate high a oxidation state of fertile porphyry, similar to other fertile porphyries in this metallogenic belt. High fluid activity and fluid exsolution are conducive to the migration and enrichment of metal elements, which are very important for mineralization. High oxygen fugacity inhibits the precipitation of metal in the form of sulfide, thereby enhancing the mineralization potential of rock. Therefore, the exsolution of Cl-bearing hydrothermal fluid and high oxygen fugacity are the key factors promoting mineralization in Yao’an area.
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Zhang, Peng, Zhuang Li, Feng Zhao, and Xinkai Liu. "Petrogenesis and Tectonic Implications of the Granite Porphyry in the Sinongduo Ag-Pb-Zn Deposit, Central Tibet: Constraints from Geochronology, Geochemistry, and Sr-Nd Isotopes." Minerals 14, no. 7 (July 12, 2024): 710. http://dx.doi.org/10.3390/min14070710.
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The Paleocene ore deposits related to the India–Asia continental collision are widely distributed in the Gangdese metallogenic belt. Among these, Sinongduo is the first discovered epithermal Ag-Pb-Zn deposit in the Lhasa terrane. However, there is still controversy over the ore-forming magma in this deposit. This study mainly reports new zircon U-Pb isotopic ages, whole-rock geochemistry, and Sr-Nd isotopic data for the granite porphyry from the Sinongduo deposit, aiming to discuss the petrogenesis and tectonic setting of the granite porphyry and its genetic link between the Ag-Pb-Zn mineralization. The results show that zircon U-Pb analyses yield ages of 62.9 ± 0.5 Ma and 59.0 ± 0.7 Ma for the granite porphyry, indicating that it formed during the Paleocene period. The timing of the granite porphyry intrusion is contemporaneous with the mineralization, suggesting that it is most likely the ore-forming magma in the Sinongduo deposit. The granite porphyry has high SiO2 and K2O, moderate Al2O3, and low Na2O, CaO, and FeOT contents, and it displays significant enrichments in LREEs and LILEs and depletions in HREEs and HFSEs, with negative Eu anomaly. The granite porphyry is a peraluminous series and can be classified as S-type granite. Moreover, the granite porphyry shows relatively high ratios of (87Sr/86Sr)i and low values of εNd(t). The geochemical and isotopic compositions of the granite porphyry from the Sinongduo area are similar to those of the upper continental crust, which suggests that the granite porphyry was most likely derived from the melting of the upper continental crust in the Lhasa terrane during the India–Asia collisional tectonic setting.
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An, Weicai, Chunji Xue, Yun Zhao, and Chao Li. "Two Periods of Porphyry Cu Mineralization and Metallogenic Implications in the Tuwu–Yandong Belt (NW China), Based on Re–Os Systematics of Molybdenite." Minerals 12, no. 9 (September 5, 2022): 1127. http://dx.doi.org/10.3390/min12091127.
Full textAbstract:
The Tuwu–Yandong belt contains five porphyry Cu deposits (Fuxing, Yandong, Tuwu, Linglong, and Chihu), constituting the largest Cu metallogenic belt in Northwest China. However, the metallogenic framework for porphyry Cu deposits in the belt remains controversial. Rhenium-osmium dating of molybdenite from the Tuwu, Linglong, and Chihu deposits and comparisons with previous geochronological data of five deposits suggest that two episodes (335–330 Ma and 323–315 Ma) of porphyry Cu–Mo mineralization occurred in the Tuwu–Yandong belt, and the metals were mainly sourced from the mantle. Moreover, combined with the geodynamic framework of this belt, the compressional environment may be more favorable for porphyry Cu mineralization, and further exploration into the Early Carboniferous porphyry Cu deposits in this belt is expected.
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Economou-Eliopoulos, Maria, Federica Zaccarini, and Giorgio Garuti. "Fertility Indicators for Porphyry-Cu-Au+Pd±Pt Deposits: Evidence from Skouries, Chalkidiki Peninsula, Greece, and Comparison with Worldwide Mineralizations." Minerals 13, no. 11 (November 6, 2023): 1413. http://dx.doi.org/10.3390/min13111413.
Full textAbstract:
The research interest for many authors has been focused on the origin, recovery, and exploration of critical metals, including platinum-group elements (PGEs), with the aim of finding new potential sources. Many giant porphyry Cu deposits are well known around the Pacific Rim, in the Balkan–Carpathian system, Himalayas, China, and Malaysia. However, only certain porphyry Cu-Au deposits are characterized by the presence of significant Pd and Pt contents (up to 20 ppm). This contribution provides new analytical data on porphyry-Cu-Au±Pd±Pt deposits from the Chalkidiki Peninsula and an overview of the existing geochemical characteristics of selected porphyry-Cu deposits worldwide in order to define significant differences between PGE-fertile and PGE-poor porphyry-Cu intrusions. The larger Mg, Cr, Ni, Co, and Re contents and smaller LILE elements (Ba and Sr) in fertile porphyry-Cu-Au-(PGE) reflect the larger contribution from the mantle to the parent magmas. In contrast, the smaller Mg, Cr, Ni, Co, and Re contents and larger Ba and Sr in PGE-poor porphyry-Cu-Mo deposits from the Chalkidiki Peninsula (Vathi, Pontokerasia, and Gerakario) and Russia–Mongolia suggest the presence of parent magmas with a more crustal contribution. Although there is an overlap in the plots of those elements, probably due to the evolution of the ore-forming system, consideration of the maximum contents of Mg, Cr, Ni, and Co is proposed. Magnetite which separated from the mineralized Skouries porphyry of Greece showed small negative Eu anomalies (Eu/Eu* ≥ 0.55), reflecting a relatively high oxidation state during the cooling of the ore-forming system. The relatively high, up to 6 ppm (Pd+Pt), and low Cr content towards the transition from the porphyry to epithermal environment, coupled with the occurrence of Pd, Te, and Se minerals (merenskyite, clausthalite), and tetrahedrite–tennantite in fertile porphyry Cu deposits (Elatsite deposit, Bulgaria), reflect a highly fractionated ore-forming system. Thus, in addition to the crustal and mantle recycling, metasomatism, high oxidation state, and abundant magmatic water, other factors required for the origin of fertile porphyry-Cu deposits are the critical degree of mantle melting to release Pt and Pd in the ore-forming fluids and the degree of fractionation, as reflected in the mineral chemistry and geochemical data.
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Galanopoulos, Evangelos, Panagiotis Voudouris, Constantinos Mavrogonatos, Paul Spry, Craig Hart, Vasilios Melfos, Federica Zaccarini, and Dimitrios Alfieris. "A New Porphyry Mo Mineralization at Aisymi-Leptokarya, South-Eastern Rhodope, North-East Greece: Geological and Mineralogical Constraints." Geosciences 8, no. 12 (November 24, 2018): 435. http://dx.doi.org/10.3390/geosciences8120435.
Full textAbstract:
A new porphyry Mo prospect has been discovered in the Aisymi-Leptokarya area, along the southern margin of the Byala Reka–Kechros metamorphic dome, south-eastern (SE) Rhodope metallogenic zone. The study area is dominated by an Oligocene felsic dike complex, which hosts the porphyry Mo mineralization and intrudes into upper Eocene sandstones-marls and the Leptokarya monzodiorite pluton. The Aisymi-Leptokarya felsic dike complex displays a rhyodacitic to dacitic composition with post-collisional affinities. The porphyry Mo mineralization occurs in the form of porphyry-style quartz stockworks in the felsic dike complex associated with potassic alteration characterized by hydrothermal K-feldspar. The ore minerals consist mainly of pyrite, molybdenite, kesterite, bismuthinite and galena within both the stockwork and the rock matrix. Bulk ore analyses indicate enrichment in Mo (up to 215 ppm), Se (up to 29 ppm), Bi (up to 8 ppm) and Sn (up to 14 ppm) in the porphyry quartz veins. Late-stage, north-east (NE-) and north-west (NW-)trending milky quartz intermediate-sulfidation epithermal veins with base metals, crosscut previous vein generations and are characterized by Ag, Sn and Te anomalies. The Aisymi-Leptokarya porphyry Mo prospect is set in a back-arc geotectonic regime and shares similarities to other post-subduction porphyry molybdenum deposits elsewhere.
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Sellew, Philip. "Achilles or Christ? Porphyry and Didymus in Debate over Allegorical Interpretation." Harvard Theological Review 82, no. 1 (January 1989): 79–100. http://dx.doi.org/10.1017/s0017816000016035.
Full textAbstract:
Porphyry of Tyre, the disciple of Plotinus who composed his massive workAgainst the Christiansunder Diocletian, has attracted much attention in recent years as perhaps the most formidable intellectual opponent of the early church. Modern scholars continue to be impressed by Porphyry's knowledge, resourcefulness, and the evident respect shown him by such figures as Jerome and Augustine. Because his literary remains are both fragmentary and disputed, moreover, any new information about Porphyry's views is of considerable importance. Just such a discovery provides the occasion for this essay. Among the papyrus codices found in an ammunition dump near Toura, Egypt, during World War II, were several previously unknown works of Origen and Didymus the Blind.
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Tang, Yuyu, Hua Kong, Biao Liu, Qi Zong, Qianhong Wu, Hua Jiang, and Fucheng Tan. "Geochronology, Whole-Rock Geochemistry, and Sr–Nd–Hf Isotopes of Granitoids in the Tongshanling Ore Field, South China: Insights into Cu and W Metallogenic Specificity." Minerals 12, no. 7 (July 15, 2022): 892. http://dx.doi.org/10.3390/min12070892.
Full textAbstract:
The Qin-Hang Metallogenic Belt (QHMB), an important metallogenic belt in South China, hosts Cu and W–Sn polymetallic deposits. The Tongshanling ore field in the QHMB is characterized by the coexistence of Cu- and W-bearing polymetallic deposits, which are related to granodiorite and granite porphyry. This study examined whole-rock geochemistry, geochronology, and Sr–Nd–Hf isotopes to determine the genetic relationship between diverse ore-related granitoids (i.e., granodiorite and granite porphyry) and Cu–W metallogeny in the Tongshanling ore field. Zircon LA-ICP-MS U–Pb dating shows that the granodiorite and granite porphyry in the Tongshanling ore field were emplaced at 163.7 ± 0.4 Ma to 154.7 ± 0.6 Ma and 161.1 ± 0.3 Ma, respectively. Geochemically, the granodiorites are classified as oxidized I-type, while the highly evolved granite porphyry is reduced A-type. The Lu–Hf isotopic composition of the granodiorites is characterized by εHf(t) values ranging from –10.49 to –4.99 (average = –7.17), with corresponding TDMC ages ranging from 1524 to 1877 Ma (average = 1682 Ma). In contrast, the granite porphyry has higher εHf(t) values (–3.60 to –1.58, average = –2.78) and younger TDMC (1310–1438 Ma, average = 1387 Ma). The εNd(t) values of granodiorite are −8.06 to −7.37 and the two-stage model ages (TDM2) are 1543–1598 Ma, while the granite porphyry has higher εNd(t) values (−3.0 to −3.4) and younger TDM2 ages (1195–1223 Ma). The results show that the granodiorite and granite porphyry were formed from partial melting of different Mesoproterozoic basement rocks under varying degrees of crust–mantle interaction. Granite porphyry underwent well-recorded fractional crystallization. Compared to the Cu-forming granodiorite, the W-forming granite porphyry has a higher differentiation index, higher crystallization temperatures of zircon (average = 708 °C versus 631 °C), and lower oxygen fugacity (median ΔFMQ = –2.21 versus –1.77).
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Prokofiev, Vsevolod Yu, and Vladimir B. Naumov. "Ranges of Physical Parameters and Geochemical Features of Mineralizing Fluids at Porphyry Deposits of Various Types of the Cu−Mo−Au System: Evidence from Fluid Inclusions Data." Minerals 12, no. 5 (April 24, 2022): 529. http://dx.doi.org/10.3390/min12050529.
Full textAbstract:
The paper reviews and summarizes data on the physicochemical parameters and chemical features of mineralizing fluids at porphyry deposits of the Cu–Mo–Au system. The calculated average values and ranges of parameters of the fluids in mineral-hosted fluid inclusions at porphyry deposits are as follows: temperature 90–957 °C, average 388 °C; salinity 0.1–88.0 wt % equiv. NaCl, average 29.4 wt % equiv. NaCl; and density 0.38–1.85 g/cm3, average 0.93 g/cm3. The highest average temperature and the highest maximum homogenization temperatures of the fluids were detected at deposits of the Cu (Au) type, with both values systematically decreasing with the transition to the Cu, Mo (Au), and then to Mo and Au types of porphyry deposits. The situations with the average and maximum salinity values of the fluids and their density are analogous. The data in the literature on the concentrations of some elements are still insufficient to reliably characterize variations in these concentrations at all of the discussed types of porphyry deposits. The highest Cu and Fe concentrations were found in the highest temperature fluids at deposits of the Cu (Au) type. The maximum Mo concentrations were detected in fluids at porphyry Mo deposits, and the highest Ag concentrations occurred at porphyry Au deposits. The chemical composition of the mineralizing fluids is, thus, strongly correlated with the types of the porphyry deposits. The hypothesis is discussed: the geochemical specifics of mineralizing fluids at various types of porphyry deposits of the Cu–Mo–Au system are related to the depths at which fluid separated from the magmatic melt. A scenario is proposed for the separation of mineralizing fluids from granite melt at various depths for fluids that form different types of porphyry deposits.
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Xu, Zhi-Tao, Jing-Gui Sun, Feng-Zhi Lei, Ji-Long Han, and Ke-Yao Zhang. "Geochronology, geochemistry, and Pb–Hf isotopes of mineralization-related magmatism in the Dongyang gold deposit, Fujian Province, southeastern China." Canadian Journal of Earth Sciences 57, no. 5 (May 2020): 553–74. http://dx.doi.org/10.1139/cjes-2019-0006.
Full textAbstract:
The recently discovered Dongyang low-sulphidation epithermal Au deposit is located in Fujian Province. The Au mineralization hosted in rhyolite porphyry and the Lower Jurassic Nayuan Formation continental volcanic rocks is considered to be related to intermediate–acidic intrusions (rhyolite porphyry, quartz diorite porphyry, and dacite porphyry). The zircon U–Pb ages of these samples are 160.3 ± 0.8, 156.6 ± 0.8, and 154.1 ± 0.6 Ma, respectively, and the sulphide Rb–Sr isotope isochron age is 152.4 ± 1.7 Ma, indicating a temporal link between porphyry emplacement and Au mineralization. Porphyries are enriched in large-ion lithophile elements and light rare earth elements and slightly depleted in heavy rare earth elements and high field strength elements, belong to the high-potassium calc-alkaline or shoshonitic series, and show characteristics of volcanic arcs or active continental margins. Moreover, the εHf(t) values of the porphyries range from −11.6 to −7.6, −11.2 to −5.4, and −9.8 to −4.6, respectively. The 208Pb/204Pb, 207Pb/204Pb, and 206Pb/204Pb values of the ore minerals are from 38.417 to 38.406, 15.603, and from 18.179 to 18.175, respectively. Pb and Hf isotopes indicate that the intermediate–acidic magma related to mineralization originated from Mesoproterozoic lower crust. Consequently, these data favour an intermediate–acidic magma origin for Au mineralization in the Dongyang deposit. Integrating new and published data on the tectonic evolution, we suggest that the rhyolite porphyry, quartz diorite porphyry, dacite porphyry, and associated Au mineralization in the Dongyang deposit formed at 160–152 Ma in an extensional environment related to subduction of the Palaeo-Pacific Plate beneath the South China block.
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Dillon, John. "Intellect and the One in Porphyry’s Sententiae." International Journal of the Platonic Tradition 4, no. 1 (2010): 27–35. http://dx.doi.org/10.1163/187254710x492910.
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AbstractThis article seeks to provide some support for the troublesome report of Damascius in the De Principiis that, for Porphyry, the first principle is the Father of the Noetic Triad—and thus more closely implicated with the realm of Intellect and Being than would seem proper for a Neoplatonist and faithful follower of Plotinus. And yet there is evidence from other sources that Porphyry did not abandon the concept of a One above Being. A clue to the complexity of the situation may be provided by a passage from Proclus (In Parm. 1070, 155ff. Cousin) which criticises him for making the One the subject also of the Second Hypothesis of the Parmenides. Here, I consider a series of passages from Porphyry’s Sententiae which seem to indicate a doctrine of the One essentially faithful to that of Plotinus, but modulated in the direction of closer linkage to the levels of reality below it.
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Murad, Fida, Abdul Ghaffar, Inayat Ullah, Abdul Shakoor Mastoi, and Muhammad Tariq Zaman. "The Alteration and Mineralization Characteristics of Miocene Porphyry Cu-Au Deposits of Chagai Magmatic Belt, District Chagai, Balochistan, Pakistan." International Journal of Economic and Environmental Geology 12, no. 1 (February 13, 2024): 1–8. http://dx.doi.org/10.46660/ijeeg.v12i1.139.
Full textAbstract:
Subduction related Miocene porphyry type deposits are found in the east-west trending Chagai magmaticbelt (CMB) in Pakistan's western margin, Balochistan. This arc exists on the west segment of the Tethyan metallogenicbelt in the south-west of Pakistan. Tethyan metallogenic belt is widely spread over 12,000 km from east to westdirection from Indochina, Tibet, Pakistan, Iran, Turkey and Alpine mountain range in Europe. During the last thirty toforty years several porphyry deposits have been reported in the Chagai magmatic arc, including the very large RekoDiq H14-H15, large Saindak, Tanjeel, H35, H8 and medium Dasht-e-Kain porphyry deposits and many small porphyrycopper deposits. These porphyry deposits were developed within the phase of calc-alkaline type magmatism in theChagai arc. Tonalite, quartz diorite, and monzonite host the porphyry deposits within the adjacent sedimentary wallrock units of Sinjrani Volcanic Group, Juzzak, Saindak, and Amalaf Formations. The concentric zonal pattern ofhydrothermal alteration in these porphyry deposits of the Chagai magmatic arc follows the world's major porphyrydeposits' alteration pattern. Zones of hydrothermal alteration from distal to proximal part includes a potassic alteration,sericitic-clay-chlorite alteration, sericitic alteration, argillic alteration and propylitic alteration. Major ore mineralizationin these deposits is of copper, gold, silver, molybdenum, and minor constituents of other base metals that have beenreported to occur within hydrothermal alteration zones in the Miocene porphyry Chagai magmatic arc.
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Han, Chang-Cheng, Xue-Bing Zhang, Shi-Shan Wu, and Ying-Ting Liu. "The Magmatic-Hydrothermal Ore-Forming Processes of the Tonggou Cu-Zn Deposit, NW China: Constraints from Magnetite Chemistry and Fluid Inclusions." Minerals 12, no. 4 (April 15, 2022): 485. http://dx.doi.org/10.3390/min12040485.
Full textAbstract:
The Tonggou deposit is a porphyry Cu and vein-type Cu-Zn mineralization system located in the Bogda Orogenic Belt, north of Eastern Tianshan. Systematic fluid inclusion analyses were performed on granular quartz from the magnetite–quartz stage and pyrite–chalcopyrite–quartz stage from the porphyry Cu mineralization. During the early stage of porphyry Cu mineralization, the ore-forming fluids were at high temperatures (450–501 °C) and high salinity (51.2–55.2 wt.% NaCl equiv.) H2O-NaCl hydrothermal fluids with fluid boiling. These fluids evolved to high temperature (412–450 °C) and intermediate to low salinity (8.3–14.2 wt.% NaCl equiv.) H2O-NaCl hydrothermal fluids during the pyrite–chalcopyrite–quartz stage. In addition, magnetite from the Tonggou deposit was studied as a marker for the ore-forming process evolution of porphyry and vein-type mineralization. Sampled magnetite can be divided into MagI (allotriomorphic magnetite from altered granodiorite), MagII (magnetite from altered granodiorite found in veinlets or as granular aggregates), MagIII (from the magnetite–quartz stage of porphyry mineralization), and MagIV (from the polymetallic sulfide–epidote–quartz stage of vein-type mineralization). Magnetite LA-ICP-MS data indicate a hydrothermal origin. The contents of Ti, Si, Al, and Ta are controlled by temperature, and these elements gradually decrease from MagI to MagIV. Moreover, fO2 has considerable influence on the substitution of Sn, V, and Mn in magnetite, and the contents of these elements generally decrease from MagI to MagIII—increasing only in MagIV. Indeed, high fO2 in the polymetallic sulfide–epidote–quartz stage (MagIV) of vein-type mineralization is shown by the presence of a replacement texture in ilmenite grains within hydrothermal magnetite. On the other hand, magnetite samples from the Tonggou deposit have relatively low Ti + V contents compared to other porphyry Cu deposits—plotting in the skarn field of the (Ti + V) vs. (Ca + Al + Mn) diagram—and shows negative correlations in the (Ti + V) vs. Sn diagram. These data indicate that the porphyry Cu mineralization at Tonggou formed at relatively lower fO2 conditions than the Tonggou vein-type mineralization and other typical porphyry Cu deposits. Finally, porphyry and vein-type mineralization at Tonggou are both sourced from the porphyry system, as a result of ore-forming fluid transfer to a different location.
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De Haas, Frans. "Did Plotinus and Porphyry disagree on Aristotle's Categories?" Phronesis 46, no. 4 (2001): 492–526. http://dx.doi.org/10.1163/156852801753736517.
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AbstractIn this paper I propose a reading of Plotinus Enneads VI.1-3 \[41-43] On the genera of being which regards this treatise as a coherent whole in which Aristotle's Categories is explored in a way that turns it into a decisive contribution to Plotinus' Platonic ontology. In addition, I claim that Porphyry's Isagoge and commentaries on the Categories start by adopting Plotinus' point of view, including his notion of genus, and proceed by explaining its consequences for a more detailed reading of the Categories. After Plotinus' integration of the Categories into the Platonic frame of thought Porphyry saw the possibilities of exploiting the Peripatetic tradition both as a means to support the Platonic interpretation of the Categories and as a source for solutions to traditional questions. His allegiance to a division of being into ten, and his emphasis on semantics rather than ontology can be explained from this orientation. In the light of our investigation the alleged disagreement between Plotinus and Porphyry on the Categories changes its appearance completely. There are differences, but these can be best explained as confirmation and extension of Plotinus' perspective on the Categories and its role in Platonism.
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Vassileff, Ljuben, and Girgina Stanisheva-Vassileva. "Petrochemical and geodynamic correlation of the porphyry-copper systems in the Eurasian copper belt: the segment Romania – Pakistan." Geologica Balcanica 21, no. 3 (June 30, 1991): 3.—33. http://dx.doi.org/10.52321/geolbalc.21.3.3.
Full textAbstract:
The porphyry-copper systems are represented by ore-bearing magmatic complexes which to a greater or lesser extent are the host rocks of mineralization, and the processes involved in the differential formation of intrusive and subvolcanic bodies are similar to those leading to the release and concentration of useful components during some of the subsequent postmagmatic processes. Producers of porphyry-copper ore are mostly the intermediate and slightly acid rocks, the majority showing some tendency towards increased potassic alkalinity. The magmatic systems involved usually manifest several pulses of different compositions and/or fabric grouped into larger and more complex intrusive centres, sometimes called "batholiths". Copper, however, concentrates in separate, small and relatively late magmatic differentiates of increased acidity. Porphy.ry-copper mineralizations are characteristic of magmatic systems of homodromous evolution during subduction. Porphyry-copper deposits associated with the bimodal basalt-rhyolite magmatism of the epicontinental riftogenesis or with MORB are not known. In the Eurasian copper belt, the porphyry-copper systems are typically associated with massive and disseminated copper (polymetallic) - pyrite (±Au) mineralizations in propylites and secondary quartzites and with copper-gold (±Ag) base-metal veins and skarns. All three types are closely associated in space forming, along with the productive volcano-intrusive centres, an integral polygenic and polyfacial ore-magmatic system. The segment discussed in this study includes 65 deposits located exclusively within the Eurasian Plate active margin and associated with the formation of mature magmatic arcs during the period from the Upper Cretaceous till the Neogene inclusive. The most typical feature of the geodynamic setting is that a number of small continental blocks (micro-continents) have been also involved in the process of ocean (Neotethys) closing accompanying the collision of the major lithospheric plates (the Afro-Arabian and Eurasian ones). These blocks probably broke off the Afro-Arabian Plate and migrated to the north where they stuck to the Eurasian Plate southern margin forming an accretionary collage. The formation of porphyry-copper systems in the magmatic arcs is exclusively a post-accretion process at advanced subduction and collision. An especially characteristic feature is the localization of the largest and best defined deposits inside the accreted exotic blocks. Deposits formed in the back-arc thrust zone of the Eurasian Plate active margin are comparatively less widespread. In Romania, the porphyry-copper systems formed during the Upper Cretaceous and the Neogene are located in a block collage traced back, rather guestionably, to the Gondwana. The porpltyry-copper systems in East Serbia occur in a similar setting. As to the Tertiary deposits in North Macedonia, Krusha Mountain and Halkidiki Peninsula, they definitely belong to the Serbo-Macedonian accreted terrane. On the territory of Bulgaria, the majority of the Upper Cretaceous porphyry-copper deposits are lo;atd in the Central Srednogorie, Sakar Strandja and East-Thracia terranes. Separate deposits are situated (possibly as parts of allochthons) in the Balkaoid's thrust-nappe – back-arc belt. In Turkey (Strandja Mt.), a group of complex copper-molybdenum-tungsten porphyry deposits are located not far away from the Bulgarian ones, again in the East Thracia terrane. Anotller, less conspicuous group of Upper Cretaceous (and m1y be even younger) age is located in the active southern margin of the Eurasian Plate. Further east, all porphyry-copper deposits of the USSR, Iran and Pakistan occur in accreted exotic terranes including those of Lesser Caucasus, Northwest Iran, Central Iran and Hilmend. Local petrochemical correlation is based on the K2O+Na2O/SiO2 diagram on which fields of porphyrycopper deposits from the Circum-Pacific metallogenic belt and from the Caribbean have been plotted prior to analysis. Compared to these plots, the porphyry-copper systems in the Eurasian belt show analogous acidity of magmatism. Alkalinity is variable but generally the Eurasian (Alpine, Mediterranean) belt as compared to the Pacific one is characterized by a pronounced potassic alkilinity (high·potassic calc-alkaline series). This is consistent with the overall Mediterranean petrochemistry. Outside it, e.g. further east in Pakistan, the ore-bearing magmatic complexes are of normal calc-alkaline character. A general petrochemical correlation shows that compared to the Pacific belt the porphyry-copper systems in the Romania-Pakistan segment of the Eurasian copper belt are formed in a mixed geodynamic setting involving both continental and island arcs. It is suggested that the present-day mixing of geodynamic settings is a secondary phenomenon caused by Late Alpine collision processes which have deformed the primary tectonic features and have pushed to the north many of the magmatic arcs involved.
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Cong, Pang, Wang, Tian, Ying, and Huang. "Zircon LA-ICP-MS U-Pb Ages and the Hf Isotopic Composition of the Ore-Bearing Porphyry from the Yanghuidongzi Copper Deposit, Heilongjiang, China, and Its Geological Significance." Minerals 9, no. 11 (November 2, 2019): 676. http://dx.doi.org/10.3390/min9110676.
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The Yanghuidongzi copper deposit is a typical porphyry copper deposit located at the eastern margin of the Xing’anling-Mongolian Orogenic Belt (XMOB). While much attention have been paid to the ore-forming age of the deposit and the magma source of the ore-bearing porphyry, this paper approaches this issue with the methods of the LA-ICP-MS zircon U-Pb dating and Lu-Hf isotopic composition of the Yanghuidongzi porphyry copper deposit. The results reveal that the Yanghuidongzi porphyry copper deposit was formed in the Early Jurassic (189.6 ± 1.0 Ma), which corresponds to the time of magmatic activity in this region. The background studies of ore-forming dynamics indicate that the formation of the Yanghuidongzi copper deposit is related to the subduction of the Paleo-Pacific plate. The Yanghuidongzi ore-bearing porphyry zircons have a positive εHf(t) value (4.4–7.0), a high 176Hf/177Hf ratio (0.282786–0.282854), and a two-stage Hf model ages (TDM2) ranging from 783 Ma to 943 Ma, all of which suggest that the Early Jurassic granodiorite porphyry of the Yanghuidongzi deposit was formed by the partial melting of newly grown crustal material from the depleted mantle in the Neoproterozoic.
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Eliopoulos, D. G., and M. Economou-Eliopoulos. "Palladium and platinum in hydrothermal systems: The case of porphyry-Cu systems and sulfides associated with ophiolite complexes." Bulletin of the Geological Society of Greece 47, no. 4 (December 21, 2016): 1618. http://dx.doi.org/10.12681/bgsg.11002.
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Data on the Pt and Pd contents in sea-floor massive sulfides related to ophiolite complexes indicated elevated Pt contents, up to 1 wt % Pt in sulfides from East Pacific Rise, up to 1000 ppb Pd or Pt in sulfides from mid-Atlantic Ridge and the Pindos ophiolite complex (Greece). Recently, elevated levels of Pd and Pt, have been reported from mineralization associated with alkaline porphyry deposits, such as the Skouries porphyry deposit (Greece), Cordillera of British Columbia, Elatsite (Bulgaria), Santo Tomas II in the Philippines and elsewhere. Current state of knowledge on the solubility of platinum-group elements was applied on hydrothermal systems related to the mineralization in ophiolite complexes and porphyry Cu-Mo-Au±Pd±Pt deposits toward a better understanding of the PGE mineralization in hydrothermal systems and the unknown Pd and Pt potential in porphyry-Cu systems. Ore reserves, mineralogical and geochemical ore data for porphyry-Cu systems are considered to be an encouraging factor for the presence of precious metals. In particular, the occurrence of merenskyite (palladium telluride) associated with chalcopyrite, coupled with the experimental data indicate that porphyry systems are capable to transport significant amounts of Pd and Pt.
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Zhou, Xiong, Yu Zhou, and Yi Zhang. "Further Studies of Ore-Forming Fluid Sources of Bangpu Molybdenum-Copper Polymetallic Deposit, Tibet." Advanced Materials Research 746 (August 2013): 473–77. http://dx.doi.org/10.4028/www.scientific.net/amr.746.473.
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Bangpu molybdenum-copper polymetallic deposit is located in the eastern section of the Gangdese Porphyry Copper Belt of Tibet. It is a typical large porphyry molybdenum copper polymetallic deposit. The isotope study of fluid inclusions H and O in the quartz (calcite) of various mineralization stages shows that, the ore-forming fluid comes mainly from meteoric hydrothermal caused by atmospheric precipitation, which has consistency with ore-forming fluid sources of Gangdese Porphyry Copper Belt. The Mo-Cu phase with low δD value (-140.5 ~ -104.0 ) suggests a large-scale magmatic degassing. The alteration and mineralization have been caused precisely by the degassing, and the obvious O isotope drift occurred being accompanied by alteration-mineralization, so that the fluid has a low δ18O (vary from 5.50 to 9.0 ). The statistical research indicates that, the massive magmatic degassing occurred in Gangdese Porphyry Copper Belt, and was gradually increased from east to west, suggesting the direct impact of the magmatic degassing on the formation of the porphyry copper-gold deposit and molybdenum copper deposit: the stronger the magmatic degassing, the more easily to form the molybdenum-based porphyry deposit, otherwise it will be formed the deposits dominated by Cu and Au.
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Winarno, Tri, Rinal K. Ali, Harrys Simangunsong, and Almiftahurrizqi Almiftahurrizqi. "Characteristics and Genesis of Laterite Bauxite in Sompak District and Surrounding Areas, Landak Regency, West Kalimantan." Indonesian Journal on Geoscience 10, no. 1 (January 5, 2023): 37–49. http://dx.doi.org/10.17014/ijog.10.1.37-49.
Full textAbstract:
West Kalimantan has very large bauxite resources, reaching 2.07 billion tons, equivalent to 57.32% of the total bauxite resources in Indonesia with bauxite reserves of 0.84 billion tons or equivalent to 66.77% of the total national mineral reserves. The researched area covers Sompak District and surrounding areas, Landak Regency, West Kalimantan. This research aims to determine geological conditions, laterization, and characteristics of laterite bauxite in the studied area. Methods used in this research are geological mapping, lateritic mapping, and petrographic and geochemical analyses. The lithology of the researched area is composed of granodiorite, porphyry quartz diorite, granite, porphyry andesite, porphyry basalt, alluvial, and swamp deposits. Laterite profiles in the researched area generally consist of topsoil, latosol, bauxite, and clay zone. The laterite bauxite derived from granodiorite is classified as a medium grade, laterite bauxite from porphyry quartz diorite is classified as high-grade bauxite, laterite bauxite from andesite porphyry is classified as low-medium grade bauxite, and laterite bauxite from porphyry basalt in the studied area is classified as high grade bauxite. Laterite bauxites in the researched area were formed from weathered parent rocks which were intermediate - alkaline igneous rock.
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Granger Cook, John. "Porphyry's Attempted Demolition of Christian Allegory." International Journal of the Platonic Tradition 2, no. 1 (2008): 1–27. http://dx.doi.org/10.1163/187254708x282259.
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AbstractPorphyry wrote the Contra Christianos during the time of the persecutions, and later several Christian rulers consigned it to the flames. In that work Porphyry included a penetrating critique of Christian allegory. Parts of his argument reappeared in the Protestant Reformers and subsequently in modern biblical research. Scholarship on Porphyry's text often is dominated by the historical problems that beset the fragment. Such problems can be temporarily put aside to carefully study the key terms in Porphyry's argument. The net gain of such an approach is to understand the power of the argument and its structure in a clearer light.
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An, Weicai, Chunji Xue, Yun Zhao, Chao Li, Dengfeng Xu, and Bo Chen. "Petrogenesis and Tectonic Implications of Late Carboniferous Intrusions in the Tuwu-Yandong Porphyry Cu Belt (NW China): Constraints from Geochronology, Geochemistry and Sr–Nd–Hf Isotopes." Minerals 12, no. 12 (December 7, 2022): 1573. http://dx.doi.org/10.3390/min12121573.
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The Tuwu-Yandong porphyry Cu belt is located on the southern margin of the Dananhu island arc in eastern Tianshan, constituting the largest Cu metallogenic belt in Northwest China. Two episodes (~334 Ma and ~317 Ma) of porphyry Cu-Mo mineralization in the belt have been recognized, associated with Early and Late Carboniferous felsic intrusions, respectively. The Carboniferous intrusions, therefore, provide a unique opportunity to investigate tectono-magmatic-metallogenic evolution of the belt. New LA–ICP–MS zircon U–Pb dating indicates that the mineralization-related and post-mineralization intrusions (granodiorite porphyry, gabbro, and granite porphyry) were formed at 321.8 ± 3.1 Ma, 313.5 ± 1.2 Ma, and 309.8 ± 2.5 Ma, respectively. The zircon trace element shows that the granodiorite porphyry (Ce4+/Ce3+ ratios, avg. 129, median = 112, n = 15) was likely derived from a more oxidized (and hydrous) magma source than that of the gabbro (Ce4+/Ce3+ ratios, avg. 74, median = 40, n = 15) and granite porphyry (Ce4+/Ce3+ ratios, avg. 100, median = 91, n = 15), being favorable for porphyry copper mineralization. The granodiorite porphyry shows an adakitic affinity (e.g., high Sr/Y ratios and low Y contents) and has high εNd(t) (6.4–6.7), εHf(t) (11.4–14.3), and Mg# values (47.4–58.1) and low (87Sr/86Sr)i (0.703804–0.703953), suggesting that the melt was derived from partial melting of a subducted oceanic slab followed by mantle peridotite interaction. The gabbro exhibits higher Al2O3 (16.5–17.4 wt.%), Cr (107–172 ppm), and Ni (37–77 ppm) contents and εNd(t) (6.6–7.2), εHf(t) (11.6–15.9), and Mg # (53.3–59.9) values, while it has lower (87Sr/86Sr)i values (0.703681–0.703882) than the granodiorite porphyry, indicating a depleted mantle source. The granite porphyry exhibits an affinity with non-fractionated I-type granites and possesses higher SiO2 (71.1–72.0 wt.%) contents, lower but positive εNd(t) (4.8–5.2), εHf(t) (10.3–13.0), and Mg # (38.7–41.0) values, and higher (87Sr/86Sr)i (0.704544–0.704998) than the granodiorite porphyry and gabbro, together with young Nd and Hf model ages, suggesting that the parental magmas originated from the partial melting of a juvenile lower crust. The enrichment in LREEs and LILEs (e.g., Ba, U, K and Sr) and depletion in HFSEs (e.g., Nb, Ta, and Ti) indicate that these intrusive rocks formed in the subduction zone. With the integration of previous studies, it can be inferred that the northward flat subduction of the Kangguer ocean slab at ca. 335–315 Ma caused the formation of the adakites and associated porphyry Cu mineralization in the Tuwu-Yandong belt. After the prolonged flat subduction, slab rollback may have occurred at ca. 314–310 Ma, followed by a “quiet period” before the final closure of the ancient Tianshan Ocean along the Kangguer Fault in this belt.
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Zheng, Shunli, Xiaojia Jiang, and Shunbao Gao. "Spatial Overlay Analysis of Geochemical Singularity Index α-Value of Porphyry Cu Deposit in Gangdese Metallogenic Belt, Tibet, Western China." Applied Sciences 13, no. 18 (September 8, 2023): 10123. http://dx.doi.org/10.3390/app131810123.
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The statistical modeling with ILR-RPCA-back CLR has two problems when dealing with the closure effect of geochemical data. Firstly, after performing isometric logratio (ilr) transformation, robust principal component analysis (RPCA) is employed for processing. The double-plot diagram illustrates that the element sequence transformation occurs in the first and second principal components, while the unique principal component remains unattainable. Secondly, by transforming both the score and load into the centered logratio (CLR) space using the U matrix, it is possible to obtain a score result that corresponds to the original order of elements according to the CLR = ILR·U formula. However, for obtaining a load result that corresponds to the original order of elements, an alternative formula “CLR = UT·ILR” must be used instead. In order to determine the optimal element assemblage for porphyry copper deposits, this study conducted statistical analysis on mineral assemblages from discovered deposits in the Gangdese metallogenic belt and identified Cu, Mo, Au, Ag, W, and Bi as key elements associated with porphyry copper deposits. Subsequently, by analyzing the singularities of the composite elements, the spatial overlay of the combined element is carried out, and concentration-area (C-A) fractal filtering is applied to identify the anomaly and background areas. To facilitate comparison, we conducted an analysis of various mineral and ore deposit types, revealing the following findings: (1) Combination elements exhibit superior recognition capability than single elements in porphyry copper deposits; (2) Skarn-type copper deposits unrelated to porphyry show a high degree of dissimilarity compared to those related to porphyry; (3) this method offers advantages over the single element method in evaluating porphyry gold deposits by reducing anomaly levels and initial investment during the evaluation stage for porphyry copper anomalies; (4) However, this method has limited ability in distinguishing between porphyry copper and molybdenum deposits.
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Shaw, Gregory. "Iamblichus and the Talisman of Gnosis." Gnosis: Journal of Gnostic Studies 2, no. 2 (July 17, 2017): 235–45. http://dx.doi.org/10.1163/2451859x-12340038.
Full textAbstract:
For Neoplatonic philosophers, the Delphic oracle had authoritatively characterized their two great teachers, Iamblichus and Porphyry. Later Platonists cited the Pythia’s oracular pronouncement, “The Syrian is full of god; the Phoenican a polymath” as revealed wisdom. The Syrian Iamblichus, “full of god,” was more highly regarded in Platonic circles than the learned Porphyry, but because Iamblichus’ theurgical Platonism vanished after the sixth century, we are left with only “learned” reports about theurgic divination. Contemporary scholars are polymaths; we are the children of Porphyry. So, when Porphyry asks for a precise definition of theurgic divination, it seems entirely reasonable, and it is hard for us to appreciate Iamblichus’ barbed response. He chastises Porphyry for presuming that divination can be discursively explained and says he needs a talisman (ἀλεξιοφάρµακον) to protect him from his discursive addiction. Divination, he says, can only be known through experiences that awaken the soul to an innate gnosis that precedes dualist thinking. This paper will explore that talismanic gnosis.
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Khosravi, Vahid, Aref Shirazi, Adel Shirazy, Ardeshir Hezarkhani, and Amin Beiranvand Pour. "Hybrid Fuzzy-Analytic Hierarchy Process (AHP) Model for Porphyry Copper Prospecting in Simorgh Area, Eastern Lut Block of Iran." Mining 2, no. 1 (December 21, 2021): 1–12. http://dx.doi.org/10.3390/mining2010001.
Full textAbstract:
The eastern Lut block of Iran has a high potential for porphyry copper mineralization due to the subduction tectonic regime. It is located in an inaccessible region and has harsh arid conditions for traditional mineral exploration campaigns. The objective of this study is to use Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) remote sensing data for porphyry copper exploration in Simorgh Area, eastern Lut block of Iran. Hydrothermal alteration zones such as argillic, phyllic and propylitic zones associated with porphyry copper systems in the study were identified using false color composition (FCC), band ratio (BR), principal component analysis (PCA) and minimal noise fraction (MNF). The thematic alteration layers extracted from FCC, BR, PCA and MNF were integrated using hybrid Fuzzy-AHP model to generate a porphyry copper potential map for the study area. Four high potential zones were identified in the central, western, eastern and northeastern of the study area. Fieldwork was used to validate the approach used in this study. This investigation exhibits that the use of hybrid Fuzzy-AHP model for the identification of hydrothermal alteration zones associated with porphyry copper systems that is typically applicable to ASTER data and can be used for porphyry copper potential mapping in many analogous metallogenic provinces.
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MANSUROV, Mamoy. "GEOCHEMICAL CHARACTERISTICS OF THE MAIN ORE COMPONENTS IN THE GOSHGARCHAY PORPHYRY-EPITHERMAL SYSTEM (LESSER CAUCASUS, AZERBAIJAN)." Visnyk of Taras Shevchenko National University of Kyiv. Geology, no. 3 (102) (2023): 39–45. http://dx.doi.org/10.17721/1728-2713.102.06.
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The article deals with the determining characteristics of ore elements in the Goshgarchay porphyry-epithermal system. The genetic and geochemical characteristics of the main ore components were studied, and close positive and negative relationships between pairs of elements were determined by correlation analysis on the selected elements. According to the results of the cluster analysis, the geochemical associations that allow the localization of the development area of mineralization at different stages of formation of the porphyry-epithermal system were analyzed. The following series of stable elements, which are typical for hydrothermal deposits, are distinguished among the ore elements of the host and ore-bearing intrusive rocks: Cu, Mo, Pb, Zn, Ag, Ni, Co, Mn, Ti, Cr, V, Sr, etc. This group of elements is considered to be the indicator elements of the copper-porphyry deposit within the porphyry-epithermal system. It has been determined that correlations between elements in copper-porphyry mineralization are characterized by a wide range of element impurities. It includes both chalcophile (As, Sb, Cu, Bi, Cd, Ga, In, Ge, Au, Ag, Te) and siderophile (Co, Ni, Mo, Fe, Cr) elements. The range of values of vertical geochemical zonality on individual sections of the deposit allows to assess the level of the erosion truncation of occurrences in the porphyry-epithermal system.
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Guo, Dongwei, Yanhe Li, Chao Duan, Changfu Fan, and Pengcheng Sun. "The Role of Reductive Carbonaceous Surrounding Rocks in the Formation of Porphyry Mo Deposits." Minerals 13, no. 7 (July 17, 2023): 951. http://dx.doi.org/10.3390/min13070951.
Full textAbstract:
Porphyry Mo deposits are the most important type of Mo resource. They result from a high oxygen fugacity of the parent magma, which acts as an effective indicator for evaluating the mineralization. In the ore-forming system of porphyry Mo deposits, sulfur exists mainly as sulfate in highly oxidized magma but as sulfide in ores. What triggers the reduction in the mineralization system that leads to sulfide precipitation has not yet been determined. Most of the previous studies have focused on the origin and evolution of the ore-forming parent magma, and the effects of reductive surrounding rocks on porphyry mineralization have been ignored. In this study, a comprehensive geological–geochemical investigation and review have been performed on the typical porphyry Mo deposits, the Nannihu-Sandaozhuang, Yuchiling, and Shapingou deposits in China, and the Mt. Emmons deposits in America. Black carbonaceous sedimentary layers commonly surround porphyry Mo ores, which are widely altered and discolored during mineralization. CH4 is commonly present in fluid inclusions in the main mineralization stage, and the δ13CV-PDB values of calcite and fluid inclusions from the altered surrounding rocks and ore minerals are generally low and significantly different from those of marine sedimentary carbonate rocks, indicating that the involvement of reductive components from carbonaceous surrounding rocks might be key to the redox state transformation leading to mineral precipitation. On the other hand, the CH4 produced by the thermal decomposition of organic matter or carbonaceous reaction with H2O can diffuse into the ore-forming system along the structural fractures and reduce the SO42− in the ore-forming hydrothermal fluids to form sulfide precipitation without direct contact between the intrusion and the carbonaceous surrounding rocks. Moreover, the CH4 content controls the location of the orebody formation with the high content producing orebodies mainly in the porphyry intrusion, while the low CH4 content results in the orebodies mainly occurring at the contact zone between the porphyry and carbonaceous surrounding rocks. Compared to the magmatic stage of mineralization, the involvement of reductive components in the carbonaceous surrounding rocks during the hydrothermal stage is more favorable for forming giant/large Mo deposits. The highly oxidized porphyry with reductive carbonaceous surrounding rocks or Fe-rich volcanic rocks offers a new indicator for efficiently evaluating porphyry Mo mineralization.
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Verhasselt, Gertjan, and Robert Mayhew. "Porphyry and ancient scholarship on Iliad 10.252–253: Edition, translation and discussion." Trends in Classics 13, no. 2 (November 1, 2021): 437–500. http://dx.doi.org/10.1515/tc-2021-0015.
Full textAbstract:
Abstract In Iliad 10, Odysseus claims that ‘more night has passed | than two parts, but still a third part remains’ (252–253). This gave rise to a Homeric problem, which received a great deal of attention from ancient scholars: If more than two parts of the night have passed, how can a third part remain? The main source for a variety of solutions to it is a lengthy discussion written along the perimeter of three pages of Venetus B, an important manuscript of the Iliad. The source of this text is almost certainly Porphyry’s Homeric Questions. Porphyry presents six different solutions, including those of Apion, Chrysippus and Aristotle (this last a fragment from his lost Homeric Problems), as well as a discussion of Odysseus as astronomer. The present paper includes: a critical edition of this text based on a fresh inspection of the manuscript, yielding new readings; an English translation; notes to the text; and an interpretive essay. The paper demonstrates the limitations of earlier editors of the text, and the hope is that it will serve as an example of how properly to approach and present the fragments of Porphyry’s Homeric Questions. It also turns out that, for quotations from the Iliad and Odyssey, Porphyry often does not provide the text attributed to him in the recent Homer editions of West.
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Jogee, B. A., G. M. Bybee, L. J. Robb, D. L. Reid, H. Minnaar, L. Caricchi, and R. Bolhar. "Assessing the geological relationships between the mafic-ultramafic intrusion in the Haib area and the Vuurdood Subsuite, Richtersveld Subprovince." South African Journal of Geology 127, no. 1 (March 1, 2024): 55–70. http://dx.doi.org/10.25131/sajg.127.0011.
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Abstract The Haib porphyry copper deposit is situated in the Richtersveld Subprovince and is host to unique Palaeoproterozoic porphyry copper mineralisation in Namibia. Several lines of evidence, including machine-learning geothermobarometry, indicate that the deposit is exposed at mid- to upper-crustal levels, as constrained from average pressure and temperature estimates of 4 kbar and 870°C, respectively. The Haib porphyry copper deposit is associated with, and is in close proximity to, a mafic-ultramafic intrusion named the Kokerboom Intrusion (KI) in this study. Together with several other mafic intrusions in this region, these intrusions are known collectively as the Vuurdood Subsuite of the Richtersveld Subprovince. The purpose of this study is to demonstrate a genetic link between the KI and the Vuurdood Subsuite using lithological characteristics, mineral and alteration assemblages, major and trace element geochemistry and U-Pb geochronology. Pyroxenites from the KI contain magmatic sulphides and have a geochemical affinity with shallow plutonic and volcanic rocks of the Haib porphyry, providing a unique mid-crustal perspective on porphyry copper deposit metallogenesis.
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Schöpa, Anne, Catherine Annen, John H. Dilles, R. Stephen J. Sparks, and Jon D. Blundy. "Magma Emplacement Rates and Porphyry Copper Deposits: Thermal Modeling of the Yerington Batholith, Nevada." Economic Geology 112, no. 7 (November 1, 2017): 1653–72. http://dx.doi.org/10.5382/econgeo.2017.4525.
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Abstract Many porphyry copper deposits are associated with granitoid plutons. Porphyry copper deposit genesis is commonly attributed to degassing of pluton-forming intermediate to silicic magma chambers during slow cooling and crystallization. We use numerical simulations of thermal evolution during pluton growth to investigate the links between pluton construction, magma accumulation and solidification, volatile release, and porphyry copper deposit formation. The Jurassic Yerington batholith, Nevada, serves as a case study because of its exceptional exposure, revealing the geometry of three main intrusions. The last intrusion, the Luhr Hill granite, is associated with economic porphyry copper deposits localized over cupolas where dikes and fluid flow were focused. Our simulations for the conceptual model linking porphyry copper deposits with the presence of large, highly molten magma chambers show that the Luhr Hill granite must have been emplaced at a vertical thickening rate of several cm/yr or more. This magma emplacement rate is much higher than the time-averaged formation rates of other batholiths reported in the literature. Such low rates, although common, do not lead to magma accumulation and might be one of the reasons why many granitoid plutons are barren. Based on our results, we formulate the new testable hypothesis of a link between porphyry copper deposit formation and the emplacement time scale of the associated magma intrusion.