Gotowa bibliografia na temat „Silvio Trentin”

Using unpublished documents, this volume restores the meeting between two masters in a historical and ideal way: Norberto Bobbio and Silvio Trentin. Through the writings which Bobbio dedicated to Trentin between 1954 and 1991, the readers are introduced to Trentin’s world. They gradually discover Trentin’s exemplary biography, his clear moral personality and his commitment to anti-fascism and the Resistance, as well as the great themes of his work as a jurist and political thinker: the criticism of fascism, federalism and the idea of the 'third way'. As Bobbio observes, the fundamental reason why Trentin represents a still valuable example is that, through his life and thought, he has perfectly embodied the conception of politics as a desire of justice, as opposed to the will to dominate.

Per molti anni la figura di Silvio Trentin (1885-1944) è stata dimenticata. Poi, tra gli anni Settanta e gli anni Ottanta del secolo scorso, il profilo di questo originalissimo giurista – e riconosciuto protagonista del vasto e complesso panorama antifascista e resistenziale – ha cominciato ad attrarre l’attenzione di molti studiosi. Concepito in occasione del settantesimo anniversario della morte, questo volume si propone di offrire un ritratto articolato di Trentin, traguardato nelle peculiarità della sua formazione giuridica, nella tenacia delle scelte politiche e nella ricchezza delle relazioni familiari. L’obiettivo non è solo celebrativo; si tratta di ridare alla Repubblica un testimone forte delle tante battaglie che ne hanno preceduto la nascita e che ne possono rianimare tuttora le ragioni.

Giorgio Trentin (1917-2013), primogenito dell’esule antifascista Silvio e fratello del sindacalista Bruno, è stato uno dei massimi conoscitori, appassionati e ‘difensori’ dell’arte incisoria in Italia. Con questo convegno, promosso a pochi mesi dalla sua morte, l’Accademia di Belle Arti di Venezia e il Centro documentazione e ricerca Trentin hanno inteso – incrociando le ricerche di studiosi di diversa estrazione e le testimonianze di chi lo ha conosciuto – restituire unità alle due ‘facce’ della sua figura: da una parte la militanza civile e antifascista, marchio caratteristico e inconfondibile della famiglia, dall’altra l’impegno in campo artistico, che era invece lo spazio individuale di Giorgio o, meglio, la sua personale declinazione di quella militanza comune. Nella tecnica incisoria egli scorgeva, infatti, un paradigma irrinunciabile di rigore morale e di ricerca della verità.

Silvio Trentin (San Donà di Piave, 11 November 1885-Monastier di Treviso, 12 March 1944) was an Italian partisan and jurist. He was Professor of public law at Ca’ Foscari. He participated as a volunteer in the First World War. Deputy since 1919, after the advent of fascism he was part of the constitutional opposition with G. Amendola. Forced into exile (1926), he settled in France, where he carried out an intense publicistic activity and militated in the ranks of Justice and Freedom (1929). After taking part in the French clandestine struggle, he returned to Italy in 1943 and participated in the resistance in the Action Party until his arrest in November of the same year. He died in prison.

Abstract The Kalgoorlie gold camp in the Yilgarn craton of Western Australia comprises the supergiant Golden Mile and the smaller Mt. Charlotte, Mt. Percy, and Hidden Secret deposits. Since the camp’s discovery in 1893, ~1,950 metric tons (t) of Au have been produced from a total estimated endowment of ~2,300 t. The camp is located within Neoarchean rocks of the Kalgoorlie terrane, within the Eastern Goldfields superterrane of the eastern Yilgarn craton. Gold mineralization is distributed along an 8- × 2-km, NNW-trending corridor, which corresponds to the Boulder Lefroy-Golden Mile fault system. The host stratigraphic sequence, dated at ca. 2710 to 2660 Ma, comprises lower ultramafic and mafic lava flow rocks, and upper felsic to intermediate volcaniclastic, epiclastic, and lava flow rocks intruded by highly differentiated dolerite sills such as the ca. 2685 Ma Golden Mile Dolerite. Multiple sets of NNW-trending, steeply dipping porphyry dikes intruded this sequence from ca. 2675 to 2640 Ma. From ca. 2685 to 2640 Ma, rocks of the Kalgoorlie gold camp were subjected to multiple deformation increments and metamorphism. Early D1 deformation from ca. 2685 to 2675 Ma generated the Golden Mile fault and F1 folds. Prolonged sinistral transpression from ca. 2675 to 2655 Ma produced overprinting, NNW-trending sets of D2-D3 folds and faults. The last deformation stage (D4; < ca. 2650 Ma) is recorded by N- to NNE-trending, dextral faults which offset earlier structures. The main mineralization type in the Golden Mile comprises Fimiston lodes: steeply dipping, WNW- to NNW-striking, gold- and telluride-bearing carbonate-quartz veins with banded, colloform, and crustiform textures surrounded by sericite-carbonate-quartz-pyrite-telluride alteration zones. These lodes were emplaced during the earlier stages of regional sinistral transpression (D2) as Riedel shear-type structures. During a later stage of regional sinistral transpression (D3), exceptionally high grade Oroya-type mineralization developed as shallowly plunging ore shoots with “Green Leader” quartz-sericite-carbonate-pyrite-telluride alteration typified by vanadium-bearing muscovite. In the Hidden Secret orebody, ~3 km north-northwest of the Golden Mile, lode mineralization is a silver-rich variety characterized by increased abundance of hessite and petzite and decreased abundance of calaverite. At the adjacent Mt. Charlotte deposit, the gold-, silver-, and telluride-bearing lodes become subordinate to the Mt. Charlotte-type stockwork veins. The stockwork veins occur as planar, 2- to 50-cm thick, auriferous quartz-carbonate-sulfide veins that define steeply NW- to SE-dipping and shallowly N-dipping sets broadly coeval with D4 deformation. Despite extensive research, there is no consensus on critical features of ore formation in the camp. Models suggest either (1) distinct periods of mineralization over a protracted, ca. 2.68 to 2.64 Ga orogenic history; or (2) broadly synchronous formation of the different types of mineralization at ca. 2.64 Ga. The nature of fluids, metal sources, and mineralizing processes remain debated, with both metamorphic and magmatic models proposed. There is strong evidence for multiple gold mineralization events over the course of the ca. 2.68 to 2.64 orogenic window, differing in genesis and contributions from either magmatic or metamorphic ore-forming processes. However, reconciling these models with field relationships and available geochemical and geochronological constraints remains difficult and is the subject of ongoing research.

Abstract The Brucejack intermediate-sulfidation epithermal Au-Ag deposit, located 65 km north of Stewart, BC, forms part of a well-mineralized, structurally controlled, north-south gossanous trend associated with Early Jurassic intrusions straddling the Late Triassic-Early Jurassic Stuhini-Hazelton Group unconformity in the Sulphurets mineral district. Mining of the deposit commenced in mid-2017 after a long history of exploration dating back to the 1880s. Mineralization is hosted in deformed Lower Jurassic island-arc volcanic rocks of the Hazelton Group exposed on the eastern limb of the Cretaceous McTagg anticlinorium. High-grade Au-Ag mineralization was formed from ~184 to 183 Ma in association with a telescoped, multipulsed magmatic-hydrothermal system beneath an active local volcanic center. Precious metal mineralization occurs as coarse aggregates of electrum and silver sulfosalts in steeply dipping, E- to SE-trending quartz-carbonate vein stockwork zones cutting low-grade intrusion-related phyllic alteration. Epithermal vein development is interpreted to have occurred during the waning stages of Early Jurassic sinistral transpression in a compressive arc environment, followed by a limited Cretaceous deformation overprint.

Abstract The Dolores project is located in the Sierra Madre Occidental mountain range of northern Mexico, near the historic mining district of Dolores in the state of Chihuahua. Exploratory drilling by Minefinders Corporation, Ltd., began in 1996 and has resulted in the discovery of one of Mexico's largest undeveloped gold-silver deposits. The regional geologic history of the area is dominated by three phases of volcanism: (1) A period of intermediate composition volcanism that resulted in deposition of voluminous andesitic flows and volcaniclastics interlayered with lesser amounts of felsic ash (the Lower volcanic series). This occurred from ˜46 to 35 Ma, (2) The first phase was closely followed by eruption of dominantly felsic ash flow tuffs and flows of rhyolitic to latitic composition (the Upper volcanic series), which occurred between ˜35 and 27 Ma, (3) Finally, intermittent eruption of basaltic andesite in thin flows occurred from <27 to 3 Ma. Deposition of the Baucarit Formation, a conglomeratic basin-fill sedimentary unit with thin interlayers of basalt, also occurred in down-dropped basins during the Pliocene to Pleistocene, or approximately 5 to 1 m.y. ago. Definitive age dates for the mineralization at Dolores have yet to be established. Ages of vein-style Ag-Au mineralization throughout the Sierra Madre Occidental are reported to be between about 49 to 27 Ma (Clark et al., 1979). Geologic observations at Dolores suggest that mineralization occurred following the episode of voluminous andesitic volcanism and generally at the same time as deposition of the overlying latitic pyroclastic tuffs of the Lower volcanic series, because mineralization and alteration are generally confined to the andesites and the lowermost portion of the volcaniclastic rocks. It follows that the Dolores mineralization occurred prior to deposition of the Upper volcanic series and dates from about 38 to 35 Ma of age. Within the district, regional north-northwest-trending structures controlled emplacement of a series of porphyritic andesitic to latitic dikes and sills in conjunction with emplacement of several larger hypabyssal north-northwest-elongate, domal intrusive bodies that formed during deposition of the Lower volcanic series. Epithermal, low-sulfidation fluids, believed to be associated with the waning stages of the intrusive episode, deposited quartz-adularia and precious metals. Wider zones of mineralization formed within areas of higher permeability and where boiling and episodic hydrothermal brecciation were focused in areas of greater structural complexity. Consequently, the mineralization occurs both within high-level stockworks, breccias, and disseminations formed near the contact of the felsic volcaniclastic rocks with the underlying andesites and within more tightly confined north-northwest-trending feeders that continue to depth. Gold predominates in the higher levels of the system and can be found across widths of 100 m or more at an average grade of from 1 to up to 2 g/t. Mineralized feeders occur below these zones and can be from 2 to more than 20 m in width, with gold content of up to 10 to more than 200 g/t and silver content of 1 to more than 5 kg/t. In the studied resource area, Ag/Au ratios appear to be zoned about a central domal intrusive and vary from about 100:1 near the intrusive to less than 10:1 to the north and south. Trace element geochemistry includes variable Hg, As, and Sb in the higher elevations with increasing amounts of Pb, Zn, and minor Cu at depth. A combined program of reverse circulation and core drilling totaling 61,441 m in 291 holes has revealed mineralization that occurs within an area that is approximately 2,800 m long by more than 600 m across. Additional drill intercepts and surface geochemical assays outside of this area indicate the potential to increase the resource base throughout an overall area that is approximately 4,000 m by 1,200 m. A resource study within the most densely drilled 1,900 by 300 m area was completed in 2000. Economic analysis, based on work by a major international engineering firm, indicates that a bulk-minable resource of approximately 67 Mt, at a gold equivalent (Aueq) grade of 1.85 g/t, can be developed by open-pit mining methods. The total calculated resource within the study area is 100.1 Mt containing 2.45 Moz of gold and 129.7 Moz of silver, or 4.62 Moz of Aueq at a 60:1 ratio.

The Jarvis Peak Quadrangle in southwestern most Utah encompasses the southern portion of the Beaver Dam Mountains and lies within the transition zone between the Colorado Plateau and Basin and Range physiographic provinces. The Beaver Dam Mountain uplift isa northwest-trending, doubly-plunging anticline bounded on the east by the Shivwits syncline. These major folds were developed during the late Mesozoic-early Cenozoic Sevier-Laramide orogeny and are truncated on the east by the Grand Wash-Reef Reservoir-Gunlock fault zone. The Grand Wash fault is a major normal fault that extends southward from the quadrangle to the Grand Canyon. Late Cenozoic (late Miocene to quaternary) extension also caused gravity sliding and attenuation faulting along both sides of the range. The stratigraphic section exposed in the quadrangle ranges in age from Precambrian to Triassic and totals approximately 14,000 feet. The Silurian and Ordovician are the only periods not represented. Surficial units include Quaternary-Tertiary and Quaternary alluvial gravels, pediments, talus, colluvium and landslide materials. Commodities mined from or occurring in the quadrangle include lead, zinc, silver, copper, gallium, germanium, gypsum and sand and gravel.

The LaRonde Zone 5 (LZ5) mine is part of the Doyon-Bousquet-LaRonde mining camp and is located in the southern part of the Abitibi greenstone belt in northwestern Quebec. The LZ5 deposit consists of three stacked mineralized corridors: Zone 4, Zone 4.1, and Zone 5. Zones 4 and 4.1 are discontinuous satellite mineralized corridors, whereas Zone 5 represents the main mineralized body. The mineralized zones of the LZ5 deposit and adjacent Ellison property (Ellison A and B zones) are hosted in the strongly-deformed, 2699-2695 Ma transitional to calcalkaline, intermediate to felsic, volcanic and volcaniclastic rocks of the Bousquet Formation upper member, which is part of the Blake River Group (2704-2695 Ma). Zones 4, 4.1, and 5 at the LZ5 mine are hosted in intermediate volcanic and volcaniclastic rocks of the Westwood andesitic to rhyodacitic unit (unit 5.1a), which forms the base of the upper member of the Bousquet Formation. The Ellison Zone A is hosted higher up in the stratigraphic sequence within a newly described intermediate volcanic unit. The Ellison Zone B is hosted in felsic volcanic and volcaniclastic rocks of the Westwood feldsparphyric rhyolite dome (subunit 5.3a-(b)). Mineralization in all three zones of the LZ5 deposit consists of discordant networks of millimeter- to centimeter-thick pyrite ±chalcopyrite ±sphalerite ±pyrrhotite veins and veinlets (10-20 % of the volume of the rock) and, to a lesser extent, very finely disseminated pyrite and boudinaged veins (less than or equal to 5 vol. % each) in strongly altered host rocks. Gold commonly occurs as microscopic inclusions in granoblastic pyrite and at the triple junction between recrystallized grains. The veins, stockworks, and disseminations were intensely folded and transposed in the steeply south-dipping, east-west trending S2 foliation. The vein network is at least partly discordant to the stratigraphy. A distal alteration halo envelops the LZ5 mineralized corridors and consists of a sericite-carbonate-chlorite- feldspar ±biotite assemblage. A proximal sericite-carbonate-chlorite-pyrite-quartz- feldspar-biotite ±epidote alteration assemblage is present within the LZ5 mineralized zones. A local proximal alteration assemblage of sericite-quartz-pyrite is also locally developed within Zone 4 and Zone 5 of the LZ5 deposit. Mass gains in Fe2O3 (t) and K2O, and mass losses in CaO, MgO, Na2O, and locally SiO2, are characteristic of the LZ5 alteration zones. The Ellison zone A and B are similar to LZ5 in terms of style of mineralization, but thin (10-20 cm) veins or bands of semi-massive to massive, finely recrystallized disseminated pyrite (0.1-1 mm) are distinctive. Chalcopyrite and sphalerite are also slightly more abundant in the mineralized corridors of the Ellison property and are usually associated with elevated gold grades. The zones are also slightly richer than at LZ5 in terms of gold and silver content, but narrower and less continuous in general. The Ellison Zone A is characterized by gains in Fe2O3 (t) and K2O and losses in CaO, MgO, Na2O, and SiO2. Gains in Fe2O3 (t) and local gains in K2O, MgO, and MnO, and losses in CO2, Na2O, P2O5, and SiO2, characterize the felsic host rocks of the Zone B corridor. The style of mineralization at LZ5 (pyrite ±chalcopyrite veins and veinlets, ±disseminated pyrite with low base metal content), its setting (i.e. in rocks of intermediate composition at the base of the upper member of the Bousquet Formation), and the geometry of its ore zones (stacked lenses of sulfide veins and veinlets, without massive sulfide lenses) differ from the other major deposits of the Doyon-Bousquet-LaRonde mining camp. Despite these differences, this study indicates that the LZ5 and Ellison mineralized corridors are of synvolcanic hydrothermal origin and have most likely been formed by convective circulation of seawater below the seafloor. An influx of magmatic fluids from the Mooshla synvolcanic intrusive complex or its parent magma chamber could explain the Au enrichment at LZ5, as has been suggested for other deposits of the camp. Evidence for a pre-deformation synvolcanic mineralization at LZ5 includes ductile deformation and recrystallization of the sulfides, the stacked nature of its ore zones, subconcordant alteration halos that envelop the mineralized corridors, evidence that the mineralized system was already active when the LZ5 lenses were deposited and control on mineralization by primary volcanic features such as the permeability and porosity of the volcanic rocks.