187,703 research outputs found
Late Precambrian U-Pb titanite age for peak regional metamorphism and deformation (Knoydartian orogeny) in the western Moine, Scotland
No full textThere has been controversy over the number and timing of orogenies in the Precambrian Moine block in the Scottish Caledonides since the earliest radiometric dating in the 1960s. This work challenges a recent hypothesis, that this sector of the Laurentian margin was subjected to continuous crustal extension between greater than 900 and 470 Ma. U-Pb dating (thermal ionization mass spectrometry) of titanite from a calcsilicate pod in the Moine (Morar Group) of the western Highlands gives an age of 737 ñ 5 Ma. The titanite grew from Fe-Ti-bearing detrital minerals during the main progressive, syn-D2, amphibolite-facies (sillimanite zone) regional metamorphism, thus demonstrating that a Neoproterozoic contractional tectonothermal event (Knoydartian orogeny) affected the Moine block following the rift-related emplacement of the West Highland granite gneiss at 873 Ma. We conclude that the Sgurr Beag Thrust, a major tectonic break separating the Morar and Glenfinnan groups of the Moine, is mainly of Neoproterozoic, not Caledonian, age. The early tectonothermal event was succeeded by the Grampian Phase (Caledonian orogeny) at 460-470 Ma
Neoproterozoic to early Paleozoic extensional and compressional history of East Laurentian margin sequences:the Moine Supergroup, Scottish Caledonides
No full textThis work was in part supported by Natural Environment Research Council grant NE/J021822/1, National Science Foundation grant EAR-0087650, and funds from our respective institutions.Neoproterozoic siliciclastic-dominated sequences are widespread along the eastern margin of Laurentia and are related to rifting associated with the breakout of Laurentia from the supercontinent Rodinia. Detrital zircons from the Moine Supergroup, NW Scotland, yield Archean to early Neoproterozoic U-Pb ages, consistent with derivation from the Grenville-Sveconorwegian orogen and environs and accumulation post–1000 Ma. U-Pb zircon ages for felsic and associated mafic intrusions confirm a widespread pulse of extension-related magmatism at around 870 Ma. Pegmatites yielding U-Pb zircon ages between 830 Ma and 745 Ma constrain a series of deformation and metamorphic pulses related to Knoydartian orogenesis of the host Moine rocks. Additional U-Pb zircon and monazite data, and 40Ar/39Ar ages for pegmatites and host gneisses indicate high-grade metamorphic events at ca. 458–446 Ma and ca. 426 Ma during the Caledonian orogenic cycle.The presence of early Neoproterozoic siliciclastic sedimentation and deformation in the Moine and equivalent successions around the North Atlantic and their absence along strike in eastern North America reflect contrasting Laurentian paleogeography during the breakup of Rodinia. The North Atlantic realm occupied an external location on the margin of Laurentia, and this region acted as a locus for accumulation of detritus (Moine Supergroup and equivalents) derived from the Grenville-Sveconorwegian orogenic welt, which developed as a consequence of collisional assembly of Rodinia. Neoproterozoic orogenic activity corresponds with the inferred development of convergent plate-margin activity along the periphery of the supercontinent. In contrast in eastern North America, which lay within the internal parts of Rodinia, sedimentation did not commence until the mid-Neoproterozoic (ca. 760 Ma) during initial stages of supercontinent fragmentation. In the North Atlantic region, this time frame corresponds to a second pulse of extension represented by units such as the Dalradian Supergroup, which unconformably overlies the predeformed Moine succession.Peer reviewe
U-Pn geochronology of deformed metagranites in central Sutherland, Scotland: evidence for widespread late Silurian metamorphism and ductile deformation of the Moine Supergroup during the Caledonian orogeny
No full textWithin the Caledonides of central Sutherland, Scotland, the Neoproterozoic metasedimentary rocks of the Moine Supergroup record NW-directed D2 ductile thrusting and nappe assembly, accompanied by widespread tight-to-isoclinal folding and amphibolite-facies metamorphism. A series of metagranite sheets which were emplaced and penetratively deformed during D2 have been dated using SHRIMP UâPb geochronology. Zircon ages of 424 8 Ma (Vagastie Bridge granite), 420 6 Ma (Klibreck granite) and 429 11 Ma (Strathnaver granite) are interpreted to date emplacement, and hence regional D2 deformation, during
mid- to late Silurian time. Titanite ages of 413 3 Ma (Vagastie Bridge granite) and 416 3 Ma (Klibreck granite) are thought to date post-metamorphic cooling through a blocking temperature of c. 550â 500 8C. A mid- to late Silurian age for D2 deformation supports published models that have viewed the internal ductile thrusts of this part of the orogen as part of the same kinematically linked system of forelandpropagating thrusts as the marginal Moine Thrust Zone. The new data contrast with previous interpretations that have viewed the dominant structures and metamorphic assemblages within the Moine Supergroup as having formed during the early to mid-Ordovician Grampian arcâcontinent orogeny. The mid-to late Silurian D2 nappe stacking event in Sutherland is probably a result of the collision of Baltica with the Scottish segment of Laurentia
U-Pb geochronology of the Fort Augustus granite gneiss: constraints on the timing of Neoproterozoic and Palaeozoic tectonothermal events in the NW Highlands of Scotland
No full textThe West Highland granite gneiss suite in Inverness-shire, Scotland, represents a series of S-type, anatectic granites formed by partial melting of host Neoproterozoic metasediments of the Moine Supergroup. U-Pb (SHRIMP) dating of zircons from a member of the suite, the Fort Augustus granite gneiss, indicates that the granitic protolith to the gneiss was intruded at 870 +/- 30 Ma. This is indistinguishable from the published age determined by the same method for the Ardgour granite gneiss at Glenfinnan, thus supporting the assumption that the various members of the West Highland granite gneiss are part of a single intrusive suite. The spread of ages from the zircon cores (1626-947 Ma) is interpreted to indicate a Proterozoic source terrain for the Moine sediments that were later melted to form the granitic protolith. A U-Pb age of 470+/-2 Ma obtained for titanite in the Fort Augustus granite gneiss is interpreted to date amphibolite-facies metamorphism during the early to mid-Ordovician Grampian Orogeny, The emerging similarity in the timing of this event either side of the Great Glen Fault implies that this structure does not juxtapose crustal blocks with significantly different histories with respect to the Grampian Orogeny
Thrust sheet evolution in the Kinlochewe region of the Moine Thrust Zone, N.W. Scotland and the Pelvoux-Brianconnais, French Alps
No full textBalanced and restored cross sections demonstrate a
minimum 16 km shortening below the Moine Thrust and
minimum restored wi1ths of 17 km between the La Meije and
Combeynot Thrusts (external Alps), and 54 km between the
frontal Subbrianconnais Thrust and the western Brianconnais
Zone (internal Alps). Imbricate thrusts within the Moine
Thrust Zone branch off a floor thrust which cuts up
stratigraphic section from basement (Lewisian gneiss) to
Cambrian shelf sediments parallel to the ESE-WNW movement
direction. Cut-off relationships and fold geometries
within the Pelvoux-Brianconnais suggest a change in move-ment direction of thrust sheets during the evolution of the
French Alps from ENE-WSW for the Brianconnais and Sub-brianconnais Zones to ESE-WNW for the External Zones.
Higher thrust sheets are frequently flexured as a
result of slip on lower thrust surfaces (in-sequence
thrusting). Important examples occur of Imver thrust
assemblages which are truncated by higher thrust surfaces
(out-of-sequence thrusting). Strains within thrust sheets
from the Kinlochewe region suggest 0%-20% layer parallel
shortening may develop in the footwall to an abandoned
thrust as a tip strain to a newly developing thrust.
Variations in strain may reflect variable propagation
rates; differential displacement has resulted in differential movement within thrust sheets.
Fault-bend folds (structurally necessary folds) have
developed following slip of thrust sheets across irregular
thrust surfaces and buckle folds have grown during shortening within the sheet. Extensional fault sheets (surge
zones) can be mapped out in the Briancon region which both
truncate and are flexured by thrust structures; important
extensional structures have developed during evolution of
the thrust belt
Un velo di silenzio : l’identità delle comunità monastiche femminili nel tardo Medioevo
No full textThe title of this research is “A veil of silence”, because it aims to investigate the identity and daily life of female religious communities in Italy from an archaeological point of view. Usually, traditional historical studies are based on written sources, often elaborated in an official contexts by religious authority. This kind of documentation describes nunneries from the outside. The chronological range is between the late Middle Ages and the Early Modern Age, from the 13th to the 16th century, when the social role of nuns deeply changed. The “religious women affaire” literally exploded in the 16th century, at the dawn of the Council of Trento, when all nunneries were permanently conformed through standardized and detailed norms, in particular concerning the closure. The area of investigation is the Po Valley and the Adriatic Coast in Northern Italy. The research is based on different sources: historical and archaeological studies, late medieval and early modern texts, archival records, archaeological finds and sequences. Open-source GIS projects had been realised to manage the information.Il titolo di questa ricerca, “Un velo di silenzio”, è ispirato dalla volontà di indagare l’identità e la vita quotidiana delle comunità femminili attraverso la cultura materiale, facendo emergere gli aspetti particolari, altrimenti taciuti dale fonti tradizionali. I testi scritti dell’epoca infatti erano redatti principalmente da esponenti della gerarchia ecclesiastica, che potevano osservare le dinamiche sociali di questi gruppi, solo dall’esterno. I limiti cronologici sono compresi tra il XIII e il XVI secolo, un epoca in cui il ruolo delle monache cambiò profondamente, attraverso la normative promulgate dal Concilio di Trento. Lo spazio geografico della ricerca è compreso tra la valle del Po e l’Arco Alto Adriatico. L’approccio è multidisciplinare. La gestione di una molteplicità di fonti è stata realizzata grazie a progetti GIS open-source
Tendzin, moine tibétain
No full textin Être moine. A. Herrou, D. Iogna-Prat et A. Poujeau (éds.), Hors-série n° 3, Histoire et religions, p. 64.International audienceno abstrac
318. Treverius (S.), moine
No full text318. Treverius (S.), moine. In: Molinier Auguste. Les Sources de l'histoire de France - Des origines aux guerres d'Italie (1494). I. Époque primitive, mérovingiens et carolingiens. Paris : A. Picard et fils, 1901. p. 118
318. Treverius (S.), moine
No full text318. Treverius (S.), moine. In: Molinier Auguste. Les Sources de l'histoire de France - Des origines aux guerres d'Italie (1494). I. Époque primitive, mérovingiens et carolingiens. Paris : A. Picard et fils, 1901. p. 118
Tyrocinium Artis Oratoriæ Sacræ Et Profanæ : In quo dilucidè explicantur, & exemplis additis complanantur, quæ, præsertim Tyronibus hujus Artis, solent negotium facessere
No full textAuctore P. Josepho Moine è Societate JesvSignaturformel: [8], A-Z8, Aa8, Bb7Vorlageform des Erscheinungsvermerks: Solodori, Typis Ursi Heuberger. Anno M. DCC. XIV
- …
