Academic literature on the topic 'Permian volcanism'
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Journal articles on the topic "Permian volcanism"
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Tripathi, C. "Volcanism in Gondwanas." Journal of Palaeosciences 36 (December 31, 1987): 285–89. http://dx.doi.org/10.54991/jop.1987.1587.
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In India the Lower Permian event is marked by a major volcanic episode in the Himalayan belt and rift faulting in the Peninsula which gave rise to various Gondwana basins. The Lower Cretaceous major volcanic episode represented by the Rajmahal Trap represents the termination of Gondwana sedimentation. Lower Permian volcanism is represented by the Panjal Volcanics in Kashmir Basin and its equivalent, the Volcanics in Spiti-Zanskar Basin and Rotung Volcanics (Abor Volcanics) in Arunachal Pradesh. In Karakarom Basin of Ladakh, volcanism is associated with Changtash and Aqtash formations of Permian age.
The Agglomeratic Slates in Kashmir are supposed to have originated as explosive volcanism in the form of pyroclastic which was followed later by flows of the Panjal Volcanics represented by subaqueous and subaerial tholeiitic basalt with occasional basaltic, andesitic and rhyolitic volcanics. The Agglomeratic slates are divided into two divisions, the Lower Diamicites and the Upper Pyroclastic. At the base of the Pyroclastic division and at the top of the Diamictite division, we get Eurydesma-Deltopecten Fauna of Lower Permian age. It is thus established that volcanism in Kashmir, Spiti-Zanskar and Ladakh is restricted to Lower Permian only. The sills and dykes associated with the underlying sequence in Syringothyris Limestone and Fenestella Shale in Kashmir, in Lipak and Po Formations in Spiti are related to this volcanism.
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AWDANKIEWICZ, MAREK, RYSZARD KRYZA, and NORBERT SZCZEPARA. "Timing of post-collisional volcanism in the eastern part of the Variscan Belt: constraints from SHRIMP zircon dating of Permian rhyolites in the North-Sudetic Basin (SW Poland)." Geological Magazine 151, no. 4 (September 12, 2013): 611–28. http://dx.doi.org/10.1017/s0016756813000678.
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AbstractThe final stages of the Variscan orogeny in Central Europe were associated with voluminous granitic plutonism and widespread volcanism. Four samples representative of the main rhyolitic volcanic units from the Stephanian–Permian continental succession of the North-Sudetic Basin, in the eastern part of the Variscan Belt, were dated using the SIMS (SHRIMP) zircon method. Three samples show overlapping206Pb–238U mean ages of 294 ± 3, 293 ± 2 and 292 ± 2 Ma, and constrain the age of the rhyolitic volcanism in the North-Sudetic Basin at 294–292 Ma. This age corresponds to the Early Permian – Sakmarian Stage and is consistent with the stratigraphic position of the lava units. The fourth sample dated at 288 ± 4 Ma reflects a minor, younger stage of (sub)volcanic activity in the Artinskian. The silicic activity was shortly followed by mafic volcanism. The rhyolite samples contained very few inherited zircons, possibly owing to limited contribution of crustal sources to the silicic magma, or owing to processes involved in anatectic melting and magma differentiation (e.g. resorption of old zircon by Zr-undersaturated melts). The SHRIMP results and the stratigraphic evidence suggest that the bimodal volcanism terminated the early, short-lived (10–15 Ma) and vigorous stage of basin evolution. The Permian volcanism in the North-Sudetic Basin may be correlated with relatively late phases of the regional climax of Late Palaeozoic volcanism in Central Europe, constrained by 41 published SHRIMP zircon age determinations at 299–291 Ma. The Permian volcanism and coeval plutonism in the NE part of the Bohemian Massif can be linked to late Variscan, post-collisional extension.
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Brown, Derek A., James M. Logan, Michael H. Gunning, Michael J. Orchard, and Wayne E. Bamber. "Stratigraphic evolution of the Paleozoic Stikine assemblage in the Stikine and Iskut rivers area, northwestern British Columbia." Canadian Journal of Earth Sciences 28, no. 6 (June 1, 1991): 958–72. http://dx.doi.org/10.1139/e91-087.
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The Stikine assemblage, the "basement" of Stikinia, extends 500 km along the western flank of the Intermontane Belt, east of younger Coast Belt plutons. Four different stratigraphic successions are characteristic of Lower to Middle Devonian, Carboniferous and Permian rocks in the Stikine and Iskut rivers area. West of Forrest Kerr Creek are penetratively deformed Lower to Middle Devonian island-arc volcaniclastic rocks, coralline limestone, and felsic tuff. Fringing carbonate buildups in an arc setting are best illustrated in the sequence at Round Lake where Lower Carboniferous mafic-dominated, bimodal submarine volcanic rocks grade upward into two distinctive coarse echinoderm limestone units and medial siliceous siltstone and limestone conglomerate. Conodont colour alteration indices for Lower Carboniferous rocks near Newmont Lake indicate an anomalously low-temperature thermal history. Upper Carboniferous–Permian polymictic volcanic conglomerate and Lower Permian limestone overlie these strata there. The Scud River sequence is distinguished by subgreenschist- to greenschist-grade Carboniferous(?) volcanic and sedimentary rocks overlain by a structurally thickened package (greater than 1000 m) of Lower Permian limestone. Local calcalkaline pyroclastic rocks interfinger with limestone near the top of the Scud River sequence. Basinal, shelf, and shallow-water carbonate facies developed in the Early Permian, giving way to calcalkaline volcanism in Late Permian followed by deposition of deep-water chert and argillite.The tectonic setting during the Devonian and Carboniferous is comparable with modern Pacific volcanic arcs and atolls, but there is no modern analogue for the shelf-carbonate accumulation during the Early Permian which characterizes the Stikine assemblage and permits Cordilleran-scale correlations. Permian fusulinid and coral species have very close affinity to those of the McCloud Limestone of the eastern Klamath Mountains, California. Other geologic events common to both Stikinia and the Eastern Klamath terrane are Devonian limestone breccia deposition, Lower Permian limestone accumulation with McCloud faunal affinity, Carboniferous and Permian calcalkaline volcanism, and Upper Permian tuffaceous limestone. Stratigraphic differences include the absence of quartz detritus in Devonian strata and lack of thick Upper Permian volcanic rocks in the Stikine River area.
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Vozárová, Anna, Sergey Presnyakov, Katarína Šarinová, and Miloš Šmelko. "First evidence for Permian-Triassic boundary volcanism in the Northern Gemericum: geochemistry and U-Pb zircon geochronology." Geologica Carpathica 66, no. 5 (October 1, 2015): 375–91. http://dx.doi.org/10.1515/geoca-2015-0032.
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AbstractSeveral magmatic events based on U-Pb zircon geochronology were recognized in the Permian sedimentary succession of the Northern Gemeric Unit (NGU). The Kungurian magmatic event is dominant. The later magmatism stage was documented at the Permian-Triassic boundary. The detrital zircon assemblages from surrounding sediments documented the Sakmarian magmatic age. The post-orogenic extensional/transtensional faulting controlled the magma ascent and its emplacement. The magmatic products are represented by the calc-alkaline volcanic rocks, ranging from basaltic metaandesite to metarhyolite, associated with subordinate metabasalt. The whole group of the studied NGU Permian metavolcanics has values for the Nb/La ratio at (0.44–0.27) and for the Nb/U ratio at (9.55–4.18), which suggests that they represent mainly crustal melts. Magma derivation from continental crust or underplated crust is also indicated by high values of Y/Nb ratios, ranging from 1.63 to 4.01. The new206U–238Pb zircon ages (concordia age at 269 ± 7 Ma) confirm the dominant Kungurian volcanic event in the NGU Permian sedimentary basin. Simultaneously, the Permian-Triassic boundary volcanism at 251 ± 4 Ma has been found for the first time. The NGU Permian volcanic activity was related to a polyphase extensional tectonic regime. Based on the new and previous U-Pb zircon ages, the bulk of the NGU Permian magmatic activity occurred during the Sakmarian and Kungurian. It was linked to the post-orogenic transpression/transtension tectonic movements that reflected the consolidation of the Variscan orogenic belt. The Permian-Triassic boundary magmatism was accompanied by extension, connected with the beginning of the Alpine Wilson cycle.
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Lindgreen, H., and F. Surlyk. "Upper Permian-Lower Cretaceous clay mineralogy of East Greenland: provenance, palaeoclimate and volcanicity." Clay Minerals 35, no. 5 (December 2000): 791–806. http://dx.doi.org/10.1180/000985500547241.
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AbstractThe clay mineralogy of Upper Permian–Lower Cretaceous mudstones from East Greenland has been investigated by X-ray diffraction (XRD), atomic force microscopy (AFM) and thermal analysis in order to evaluate long-term trends in provenance and palaeoclimate and to detect possible volcanic events. The Upper Permian–Lower Triassic mudstones contain illite, chlorite, vermiculite, kaolinite and illite-smectite (I-S), whereas the Rhaetian–Sinemurian mudstones are dominated by kaolinite. Aalenian–Albian mudstones contain kaolinite and large amounts of I-S with ˜80% illite layers. Exceptions are three Kimmeridgian samples, which contain mainly I-S with 30% illite layers, and three Upper Barremian–Lower Aptian samples with large amounts of smectite layers. Discrete clay minerals in the Upper Permian–Jurassic mudstones are largely detrital. The smectite-rich I-S probably reflects episodes of volcanic activity in late Jurassic and late Barremian–early Aptian times. This is the first indication of Mesozoic volcanism from the Mesozoic rift basin of East Greenland. The main sediment source during late Permian–early Cretaceous times was weathered Precambrian and Caledonian crystalline basement. The only possibly climate-induced change is a change from chlorite, illite, vermiculite and kaolinite in Upper Permian–Lower Triassic mudstones to kaolinite and I-S in the Jurassic mudstones and is probably due to an increase in precipitation.
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Francis, E. H. "Mid-Devonian to early Permian volcanism: Old World." Geological Society, London, Special Publications 38, no. 1 (1988): 573–84. http://dx.doi.org/10.1144/gsl.sp.1988.038.01.39.
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ZHU, YONGFENG, SHIHUA SUN, LIBING GU, YOSHIHIDE OGASAWARA, NENG JIANG, and HIROJI HONMA. "Permian volcanism in the Mongolian orogenic zone, northeast China: geochemistry, magma sources and petrogenesis." Geological Magazine 138, no. 2 (March 2001): 101–15. http://dx.doi.org/10.1017/s0016756801005210.
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Lower Permian volcanism was the first magmatic activity to occur after the collision events in the Mongolian orogenic zone, east China. The Permian volcanic rocks are therefore a key to understanding the dynamics of the unified continental lithosphere. The volcanic rocks consist of basic and intermediate rocks. The intermediate rocks with high initial 87Sr/86Sr ratios (0.7051 to 0.7052) and low εNd values (−0.73 to −3.57) generally overlie the basic rocks in the field. The basic rocks have relatively low initial 87Sr/86Sr ratios (0.7034 to 0.7051) and high εNd values (2.72 to −0.10). Two parallel Rb–Sr isochrons give almost the same age, about 270 Ma. One consists of the basic rocks giving an initial isochron 87Sr/86Sr ratio of 0.7035. The other consists of the intermediate rocks and one sample of basalt, which give an initial isochron 87Sr/86Sr value of 0.7051. The strong correlations between SiO2 and other major elements suggest that fractional crystallization played an important role in the magmatic processes. However, fractional crystallization cannot explain the geochemistry of most incompatible trace elements and Sr–Nd isotope characteristics. The positive correlation between Th/Nb and (La/Sm)N ratios demonstrates the direct relation between the enrichment of the light rare earth elements and the contamination of continental sediments. The high contents of large ion lithosphere elements (LILE) in the Permian volcanic rocks may suggest an additional ‘crust + fluid’ component, especially in the intermediate rocks, which are highly enriched in Ba (> 400 ppm) relative to the basic rocks (> 200 ppm). We propose that the subduction slab dropped into depleted mantle and released fluid, which induced the mantle metasomatism and LILE enrichment. The metasomatized mantle partially melted and formed the ‘primary’ magma. This primary magma assimilated with the Proterozoic biotite–quartz schist during its rise, and finally formed the Permian volcanic rocks. Magma assimilated with the Proterozoic biotite–quartz schist in small amounts could have produced the basic rocks, while assimilation of larger amounts of magma (because of longer assimilation time) would generate intermediate rocks.
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Zheng, Binsong, Chuanlong Mou, Renjie Zhou, Xiuping Wang, Zhaohui Xiao, and Yao Chen. "Nature and origin of the volcanic ash beds near the Permian–Triassic boundary in South China: new data and their geological implications." Geological Magazine 157, no. 4 (December 3, 2019): 677–89. http://dx.doi.org/10.1017/s001675681900133x.
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AbstractPermian–Triassic boundary (PTB) volcanic ash beds are widely distributed in South China and were proposed to have a connection with the PTB mass extinction and the assemblage of Pangea. However, their source and tectonic affinity have been highly debated. We present zircon U–Pb ages, trace-element and Hf isotopic data on three new-found PTB volcanic ash beds in the western Hubei area, South China. Laser ablation inductively coupled plasma mass spectrometry U–Pb dating of zircons yields ages of 252.2 ± 3.6 Ma, 251.6 ± 4.9 Ma and 250.4 ± 2.4 Ma for these three volcanic ash beds. Zircons of age c. 240–270 Ma zircons have negative εHf(t) values (–18.17 to –3.91) and Mesoproterozoic–Palaeoproterozoic two-stage Hf model ages (THf2) (1.33–2.23 Ga). Integrated with other PTB ash beds in South China, zircon trace-element signatures and Hf isotopes indicate that they were likely sourced from intermediate to felsic volcanic centres along the Simao–Indochina convergent continental margin. The Qinling convergent continental margin might be another possible source but needs further investigation. Our data support the model that strong convergent margin volcanism took place around South China during late Permian – Early Triassic time, especially in the Simao–Indochina active continental margin and possibly the Qinling active continental margin. These volcanisms overlap temporally with the PTB biocrisis triggered by the Siberian Large Igneous Province. In addition, our data argue that the South China Craton and the Simao–Indochina block had not been amalgamated with the main body of Pangea by late Permian – Early Triassic time.
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Hrdličková, Kristýna, Altanbaatar Battushig, Pavel Hanžl, Alice Zavřelová, and Jitka Míková. "Lower Permian basaltic agglomerate from the Tsengel River valley, Mongolian Altai." Mongolian Geoscientist 51 (December 21, 2020): 1–11. http://dx.doi.org/10.5564/mgs.v51i0.1457.
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A new occurrence of Permian volcanic and volcaniclastic rocks in the Mongolian Altai south of the Main Mongolian Lineament was described between soums of Tugrug and Tseel in Gobi-Altai aimag. Studied vitrophyric pyroxene basalt lies in a layer of agglomerate and amygdaloidal lavas, which is a part of NE–SW trending subvertical sequence of varicolored siltstones and volcaniclastic rocks in the Tsengel River valley. This high-Mg basalt is enriched in large ion lithophile elements, Pb and Sr and depleted in Nb and Ta. LA-ICP-MS dating on 44 spots reveals several concordia clusters. The whole rock geochemistry of sample fits volcanic arc characteristic in the geotectonic discrimination diagrams. Dominant zircon data yield Upper Carboniferous and Permian magmatic ages 304.4 ± 2.3 and 288.6 ± 1.9 Ma. Two smaller clusters of Upper Devonian (376 ± 4.7 Ma) to Lower Carboniferous ages (351.9 ± 3.5 Ma) indicate probably contamination of ascending magmatic material. Youngest Triassic age found in three morphologically differing grains reflects probably lead loss. Described high-Mg basalt lava represents sub-aerial volcanism in volcanic arc environment developed over the N dipping subduction zone in the southwestern Mongolia in the time span from Uppermost Carboniferous to Permian during terminal stage of its activity.
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HILTON, JASON, WANG SHI-JUN, JEAN GALTIER, IAN GLASSPOOL, and LIL STEVENS. "An Upper Permian permineralized plant assemblage in volcaniclastic tuff from the Xuanwei Formation, Guizhou Province, southern China, and its palaeofloristic significance." Geological Magazine 141, no. 6 (November 2004): 661–74. http://dx.doi.org/10.1017/s0016756804009847.
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A new permineralized fossil plant assemblage is described from volcaniclastic tuff collected in the Upper Permian (Wuchiapigian to Changhsingian) Xuanwei Formation at Shanjiaoshu mine, Guizhou Province, China. The assemblage is fragmentary but contains a small sphenopsid strobilus, a partial strobilus of a lepidodendralean lycopsid, pinnae of the filicalean fern Anachoropteris and a filicalean non-laminate fertile pinna rachis, the marattialean ferns Eoangiopteris, Scolecopteris and Psaronius, hooked stems of probable gigantopterid affinity, and two kinds of cardiocarpalean ovules. This represents the first indisputable evidence of Anachoropteris from the Permian of China, and contrasts with previous evidence from Europe and North America that indicates this genus became extinct during earliest Permian times. The assemblage highlights the persistence of plants from wetland communities and mire ecosystems into the Upper Permian of southern China, and adds further support to the presence of the Ameriosinian phytogeographical realm. This represents the first record of a plant assemblage preserved in volcaniclastic sediments from the Upper Permian of southern China, and in combination with other recently discovered plant assemblages in similar deposits in southern China, suggests volcanism to be an important factor in facilitating permineralized plant preservation in this realm. Although the source of the volcanism that produced the tuff is unknown, its age and location are consistent with the Emishan Large Igneous Province (LIP) of southwest China.
Dissertations / Theses on the topic "Permian volcanism"
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Sbisa', Andrea. "Structure and eruptive history of the Sesia caldera, North West Italy." Doctoral thesis, Università degli studi di Trieste, 2011. http://hdl.handle.net/10077/4560.
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2009/2010Questa tesi di dottorato è focalizzata sui meccanismi dei sistemi magmatici che possono causare super-eruzioni, e ha come oggetto una sezione fossile che comprende le zone Ivrea-Verbano e la zona Serie dei Laghi (Italia, Nord-Ovest). Questa ricerca presenta evidenze di una caldera di età Permiana che espone il sistema magmatico fino alla profondità di 25 km. La correlazione delle età delle rocce vulcaniche e plutoniche della crosta media ed inferiore, mette in luce come queste costituiscano l’esposizione di un sistema magmatico che ha alimentato una caldera, e evidenzia la relazione cause-effetto tra l’intrusione di fusi basaltici derivanti dal mantello e il vulcanesimo acido. L’eruzione associata al collasso della caldera è stata di VEI > a 8 (Newhall and Self, 1982) e caratterizzata da una unica unità eruttiva a composizione riolitica. Il collasso della caldera è avvenuto in un campo vulcanico maturo, probabilmente tagliando il bordo di una caldera precedente. Il maggior volume di lave eruttate è composto da dacite alte in silice, i termini meno evoluti sono andesi-basalti. Le caratteristiche della caldera e del campo vulcanico sono simili a caldere formatesi durante la transizione da un regime tettonico compressionale ad uno estensionale-transpressivo. Il lavoro documenta una struttura interna della caldera simile a quella descritta per la caldera Grizzly Peak Colorado, USA (Fridrich et al., 1991) dove le frane escono come cunei dal “caldera wall” con una geometria simile ad un “albero di natale rovesciato” insieme ad una zonazione tra zone ricche di litici a zone di ignimbrite con pochi litici. Dopo il collasso, il riempimento della caldera è stato intruso direttamente da granito senza alcune evidenze di “caldera floor”. La composizione delle rocce della caldera del Sesia è compatibile con una ibridazione tra fusi basaltici derivanti dal mantello e una o più componenti anatettiche. La comparazione dell’eruzione che ha causato il collasso della caldera con le rocce del plutone sottostante non mette in luce una parentela con la zona superiore (Upper Valle Mosso); si aprono quindi nuove problematiche che richiedono ulteriori studi isotopici. Abbiamo documentato due stadi di alterazione idrotermale nel riempimento della caldera del Sesia, uno a più alta temperatura ed uno seguente a più bassa temperatura. Si può osservare che la circolazione idrotermale ha causato impoverimento di silice e un inizio di metasomatismo della roccia. La disposizione areale delle vene di quarzo e delle zone di silicificazione indicano che la deposizione ha interessato i confini tra materiali a differente porosità, in particolare tra la porosa ignimbrite intracaldera e materiali meno porosi come le rocce del “caldera wall” (grandi frane intracaldera ed il granito che ha intruso la caldera). Non abbiamo osservato alcuni dei fenomeni associati alla circolazione idrotermale nel granito che intrude il riempimento della caldera, perciò riteniamo che il contatto sia stato un importante confine alla circolazione dei fluidi idrotermali che circolavano principalmente nel riempimento della caldera.
XXIII Ciclo
1976
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Van, Noord Kenrick A. A. "Deep-marine sedimentation and volcanism in the Silverwood Group, New England Fold Belt, Australia." Thesis, Queensland University of Technology, 1999.
Find full textAbstract:
In eastern Australia, the New England Fold Belt (NEFB) comprises an ancient convergent margin that was active from the Paleozoic until the late Mesozoic. Considerable effort has been expended in understanding the development of this margin over the past twenty years. However, proposed tectonic models for the orogen have either been too broad, ignoring contradictory local evidence, or too locally specific without paying attention to the 'big picture'. The research presented in this work addresses the issue of appropriate scale and depth of geological detail by studying the NEFB at the terrane-scale. Using one succession, the Silverwood Group of southeast Queensland, this work demonstrates that detailed sedimentological studies and basin analysis at the terrane-scale can help to refine hypotheses regarding the tectonic evolution of the NEFB.
The Silverwood Group (Keinjan terrane), located approximately 140 km southwest of Brisbane, Australia, is a succession of arc-related basins that developed within an ancient intraoceanic island-arc during the mid-Cambrian to Late Devonian. From the base of the succession, the group consists of five formations totalling -9700 m. These include the Risdon Stud Formation (2500 m), Connolly Volcanics (2400 m), Bald Hill Formation (2450 m), Ormoral Volcanics (600 m) and the Bromley Hills Formation (1700 m). The Long Mountain Breccia Member (300m) is a separate unit which forms the lower part of the Bromley Hills Formation. The entire succession has been thrust west over the Late Devonian to Early Carboniferous Texas beds. Elsewhere, the Silverwood Group is unconformably overlain by and faulted against Early to Late Permian units including the Rokeby beds, Wallaby beds, Tunnel beds, Fitz Creek beds, Eight Mile Creek beds, Rhyolite Range beds and Condamine beds. Of these Permian units, all but the Condamine beds form part of the Wildash Succession. To the west, southwest and south, the Silverwood Group is intruded by the Late Triassic Herries and Stanthorpe Adamellites. All of these sequences and the two plutonic intrusives are unconformably overlain by the Jurassic sediments of the Marburg Sandstone.
The Silverwood Group and Texas beds consist of various lithologies including grey, purple- grey, green and green-grey volcaniclastic conglomerates, sandstones, siltstones or mudstones, massive and laminated chert, polymict or monomict breccias, muddy breccias, muddy sandstones, and volcanic rocks. Volcanic rocks include various tholeiitic metabasites, dolerite, meta-andesites and infrequent metadacite. In the Silverwood Group, these volcanic rocks are often accompanied by mafic pyroclastic rocks (e.g. peperite and hyaloclastite). Facies analyses of these lithologies has led to the recognition of 19 deep-marine turbiditic and volcanic/volcaniclastic facies that were deposited by three main processes: i) gravity-flow processes (e.g. low- and high-density volcaniclastic turbidites and mass-flows), ii) chemical/biological processes (siliceous oozes- chert) and iii) direct initiation by volcanic processes (e.g. flows, hypabyssal intrusions and associated pyroclastic facies).
For the Silverwood Group, the defined facies occur in distinct vertical associations that form recognisable 3rd and 4th-order architectural elements such as channel, levee, suprafan lobe, outer-fan, basin plain, mass transport complex, volcanic flows, syn-sedimentary sills and syn-sedimentary emergent cryptodomes. These architectural elements are represented in a series of deep-marine depositional environments including slope, shelf-edge failure, submarine-fan and subaqueous basaltic volcanoes. The Risdon Stud Formation and parts of the Connolly Volcanics were deposited along a 'normal' clastic or mud, mud/sand-rich and/or sand/mud-rich slope. Both upper and lower slope environments are represented and in both formations, the slope is speculated to have faced eastwards and prograded away from an active arc located west. Sediments from both successions accumulated at palaeodepths of 1200 to 2000 m.
Although sediments from the upper part of the Bald Hill Formation were also deposited on a slope, these sequences have subsequently collapsed into the depocentre to form extensive slump deposits accompanied by olistoliths of older arc crust. The lower part of the Bald Hill Formation formed by similar processes, although the failure was far more extensive (>20 km along strike). This latter part of the formation is interpreted to be a major shelf-edge failure succession. Upper parts of the Bald Hill Formation also accumulated at palaeodepths of 1200 to 2000 m, but the deposition of these sediments occurred farthest from the shelf and at the greatest depth compared to the Risdon Stud Formation and Connolly Volcanics. Lower parts of the Bald Hill Formation were deposited at palaeodepths of approximately 1700 m.
Subaqueous basaltic volcanoes are prominent in the Connolly Volcanics, Bald Hill Formation and Ormoral Volcanics. In the Bald Hill Formation, igneous rocks were emplaced into the shelf-edge failure succession as a series of syn-sedimentary sills and cryptodomes. These high-level hypabyssal rocks occasionally became emergent above the sediment-water interface, whereupon they were partially resedimented. In some parts of the Bald Hill Formation, the hypabyssal intrusions were blanketed by basin plain deposits that are contemporaneous with the slumps and olistoliths in the upper part of the formation. The intrusive rocks were emplaced at 1700 m palaeodepth.
Unlike the Bald Hill Formation, the Ormoral Volcanics and lower parts of the Connolly Volcanics form thick accumulations of extrusive volcanic and pyroclastic rocks that built a significant volcanic pile. Volcanic and pyroclastic facies within these successions were deposited proximal to their source (0-10 km of vent). Extrusive rocks within the Ormoral Volcanics are thought to be derived from intrabasinal fissure-vents located at palaeodepths of 1700 to 3100 m. Igneous rocks from the Connolly Volcanics, Bald Hill Formation and Ormoral Volcanics have the petrological and geochemical characteristics of back-arc basin basalts (BAB) that were sourced from undepleted to slightly enriched Fertile MORB Mantle-wedge (FMM). The FMM material was variably enriched in trace elements by fluids derived from the subducting slab prior to emplacement of the igneous rocks. Immediately following emplacement, these rocks were hydrothermally metamorphosed under conditions of low-pressure and transitional low to high-temperature (200-300 °C). By contrast, igneous rocks within the Texas beds lack enrichment in subduction components and are characteristic of N-MORB.
The Bromley Hills Formation is a sand-rich point-source submarine fan deposited at palaeodepths of 500 to 2000 m. The fan was initiated by a mass transport complex resulting from subaerial collapse of a basaltic-andesitic stratovolcano. The submarine fan is characterised by two repetitive stages of retrogressive sedimentation during which channel-levee elements (inner-fan channels) are overlain by suprafan lobe elements (mid-fan) and then by outer-fan deposits as sea-level rises within the depocentre. Both inner-fan channels and suprafan lobes show centralised stacking patterns with limited lateral migration that indicate the depocentre was laterally restricted during sedimentation (e.g. submarine ridges). The Bromley Hills Formation exhibits all the characteristics typical of an active margin fan that formed by a combination of tectonic stage initiation followed by eustatically controlled regressive deposition.
Volcaniclastic sediments of the Silverwood Group range in composition from lithic to lithic- feldspathic wackes and arenites, although they are mainly lithic or feldspathic-lithic wackes and arenites. Many samples are tuffaceous (25-75% pyroclasts), particularly those from the Connolly Volcanics, Ormoral Volcanics and Bromley Hills Formation. Samples in the Bald Hills Formation and Texas beds can be classified as quartz-rich. The majority of the Silverwood Group was sourced from an undissected intraoceanic island-arc, although sediments within the Bald Hill Formation exhibit a provenance that is characteristic of uplift within the arc (recorded as a 'strike-slip continental arc' model). Epiclastic sediments from the Texas beds were sourced from a transitional to dissected continental arc.
Formations of the Silverwood Group were mostly deposited in a series of intra-arc basins within an ancient intra-oceanic island arc, although the lowermost formation developed in a marginal basin (Risdon Stud Formation). All of the basins were located east of the active arc (behind the arc), keeping in mind the present location of the Group relative to the Texas-Coffs Harbour megafold. The entire succession formed during four-phases of arc-related basin development that coincide with major changes in the strain regime of the arc. From the base of the succession, these changes are: I) mid Cambrian to late Silurian marginal basin sedimentation- relative compression within the arc (Risdon Stud Formation), II) late Silurian to Early Devonian intra-arc rifting- relative extension within the arc (Connolly Volcanics), Ill) Early to early Middle Devonian basin collapse followed by intra-arc rifting- relative extension to compression (Bald Hill Formation and Ormoral Volcanics) and IV) early Middle to Late Devonian intra-arc submarine fan sedimentation- relative compression (Bromley Hills Formation).
Comparing the Silverwood Group against equivalent terranes of Cambrian to Devonian age within the New England Fold Belt (NEFB) suggests that the Gamilaroi terrane, Calliope Volcanic Assemblage, Willowie Creek beds and Silverwood Group all formed as one intraoceanic island-arc during the Early to Late Devonian. Prior to this, significant differences in the sedimentological evolution of these terranes suggests that they occupied different positions relative to each other within the one arc. It is proposed that the NEFB formed as a result of dual west-directed subduction zones during the Cambrian to Middle Devonian period. During this time, a single intraoceanic island-arc located seaward of the Australian craton developed above a west-directed subduction zone. This arc was separated from the craton by a marginal sea. A second west-directed subduction zone was located beneath a continental arc developed on the Australian craton. Cambrian to Early Devonian terranes within and along the Peel Fault are proposed to form a part of the ancient subduction zone present beneath the intraoceanic island-arc (Weraerai and Djungati terranes). Collision of the intraoceanic island-arc occurred during the Late Devonian, at which point west-directed subduction occurred beneath the Australian craton and the accreted intraoceanic island-arc. Following collision, a new continental volcanic arc was established that was active during the Late Devonian to Early Carboniferous.
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Wallis, Susan M. "Petrology and geochemistry of Upper Carboniferous-Lower Permian volcanic rocks in Scotland." Thesis, University of Edinburgh, 1989. http://hdl.handle.net/1842/13183.
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Mujdrica, Stefan. "Gold-bearing volcanic breccia complexes related to carboniferous-permian magmatism, North Queensland, Australia." Thesis, Rhodes University, 1994. http://hdl.handle.net/10962/d1005577.
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Gold-bearing volcanic breccia complexes are the major sources of gold in the Tasman Fold Belt System in north Queensland. The Tasman Fold Belt System represents the site of continental accretion as a series of island-arcs and intra-arc basins with accompanying thick sedimentation, volcanism, plutonism, tectonism and mineralisation. In north Queensland, the fold belt system comprises the Hodgkinson-Broken River Fold Belt, Thomson Fold Belt, New England Fold Belt and the Georgetown Inlier. The most numerous ore deposits are associated with calc-alkaline volcanics and granitoid intrusivesof the transitional tectonic stage of the fold belt system. The formation and subsequent gold mineralisation of volcanic breccia complexes are related to Permo-Carboniferous magmatism within the Thomson Fold Belt and Georgetown Inlier. The two most important producing areas are at Mount Leyshon and Kidston mines, which are high tonnage, low-grade gold deposits. The Mount Leyshon breccia complex was emplaced along the contact between CambroOrdovician metasedimentary and metavolcanic rocks, and Ordovician-Devonian I-type granitoids of the Lolworth-Ravenswood Block. The Kidston breccia complex is located on a major lithological contact between the Early to Middle Proterozoic . Einasleigh Metamorphics and the Silurian-Devonian Oak River Granodiorite. The principal hosts to the gold mineralisation at the Mount Leyshon and Kidston deposits, are breccia pipes associated with several episodes of porphyry intrusives. The goldbearing magmatic-hydrothermal and phreatomagmatic breccias post-date the development of a porphyry-type protore. The magmatic-hydrothermal breccias were initially emplaced without the involvement of meteoric-hydrothermal fluids, within a closed system. Later magma impulses reached higher levels in the cooled upper magma chamber, where meteoric water invaded the fracture system. This produced an explosive emplacement of phreatomagmatic breccias, as seen at Mount Leyshon. Widespread sericitisation and pyrite mineralisation are common, with cavity fill, disseminated and fracturelveincontrolled gold and base metal sulphides. The Kidston and Mount Leyshon breccia complexes have hydrothermal alteration and mineralisation characteristics of the 'Lowell-Guilbert Model'. However, the argillic zone is generally not well defined. The gold travelled as chloride complexes with the hydrothermal fluids before being deposited into cavities and fractures of the breccias. Later stage epithermal deposits formed at the top of the breccia complexes that were dominantly quartz-adularia-sericite-type. The erosion, collapse and further intrusion of later porphyry phases allowed the upper parts of the breccia complexes to mix with the lower hydrothermal systems. Exploration for gold-related volcanic breccia complexes is directed at identifying hydrothermal alteration. This is followed by detailed ground studies including geological, mineralogical, petrological and geochemical work, with the idea of constructing a 'model' that can be tested with subsequent subsurface work (e.g. drilling). Geomorphology, remote sensing, geochemistry, geophysics, petrology, isotopes and fluid inclusions are recommended exploration techniques for the search of gold-bearing volcanic breccia complexes. Spectral remote sensing has especially become an important tool for the detection of hydrothermal alteration. Clay and iron minerals of the altered rock, within the breccia complexes, have distinctive spectral characteristics that can be recognisable in multispectral images from the Landsat thematic mapper. The best combination of bands, when using TM remote sensing for hydrothermally altered rock, are 3/5/7 or 4/5/7. The breccia complexes have exploration signatures represented as topographic highs, emplaced within major structural weaknesses, associated I-type granitic batholiths, early potassic alteration with overprint of sericitic alteration, and an associated radiometric high and magnetic low. The exploration for gold-bearing volcanic breccia complex deposits cannot be disregarded, because of the numerous occurrences that are now the major gold producers in north Queensland.
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Martin, Philippe. "Le volcanisme Permien d'arc insulaire des Klamath orientales (Californie, USA) : pétrogenèse et implications géodynamiques." Nancy 1, 1989. http://www.theses.fr/1989NAN10068.
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L'étude pétrographique et géochimique du volcanisme sub-aérien de la partie supérieure de la série de Redding (Klamath orientales) qui appartient à un système d'arc insulaire intra-océanique permien moyen-permien sup, montre que l'évolution de l'arc permien par rapport à l'arc siluro-dévonien copley-Balaklada se marque principalement par un approfondissement des sources magmatiques et une plus grande contribution sédimentaire à la source
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Chauvet, François. "La marge continentale sud-téthysienne en Oman : structure et volcanisme au Permien et au Trias." Phd thesis, Université Joseph Fourier (Grenoble), 2007. http://tel.archives-ouvertes.fr/tel-00202524.
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La formation de la chaîne de montagne d'Oman est associée à l'inversion tectonique de la marge continentale arabe qui bordait la partie sud de l'océan Néotéthys entre la fin du Paléozoïque et le Crétacé supérieur. Les unités sous-ophiolitiques des montagnes d'Oman sont étudiées dans le but de caractériser les différents stades de formation de ce segment de marge néotéthysien. L'étude se focalise sur les périodes d'activité volcanique du Permien et du Trias qui ont accompagné la formation de la marge arabe et dont les témoins sont retrouvés sur l'ensemble du domaine sud téthysien (Himalaya, Oman, Méditerranée orientale).Une reconstitution syn-rift de la plate-forme continentale omanaise est proposée au Permien moyen sur la base de nouvelles observations structurales et stratigraphiques menées dans les massifs du Saih Hatat et du Jabal Akhdar. L'analyse structurale porte en particulier sur les structures extensives synsédimentaires permiennes, et sur la comparaison à l'échelle régionale des variations latérales de faciès et d'épaisseur (Formation Saiq, massifs du Jabal Akhdar et du Saih Hatat). Les structures extensives indiquent des directions d'étirement principalement orientées ENE-WSW. Une composante d'étirement NS est observée localement et associée à des mouvements de très faible ampleur. Le dépliage des séries déformées de la plate-forme indique que ces directions d'extensions correspondent aux directions principales des variations d'épaisseur et de faciès des séries permiennes. Ceci suggère qu'elles représentent les témoins inversés des structures majeures qui ont contrôlé la plate-forme arabe. Les structures observées sont contemporaines de l'épisode volcanique intraplaque du Murghabien, et correspondent à un épisode tectonique court (< 5 Ma).
Le volcanisme du Trias moyen-supérieur omanais met en place de faibles volumes de laves sur différentes parties de la marge continentale arabe. Il est contemporain d'une remobilisation de la marge, associée à des soulevements locaux, et à des glissements gravitaires de la couverture sédimentaire. L'analyse géochimique montre qu'il s'agit d'un magmatisme intraplaque, qui a probablement subi une contamination crustale. Les compositions isotopiques (Nd, Pb) des laves triasiques sont comparables à celles des laves alcalines du Permien, suggèrant une remobilisation du manteau hérité (principalement de l'épisode Permien) plutôt que l'intervention d'un nouveau point chaud.
Finalement, il est proposé un modèle polyphasé pour la formation et l'évolution de la marge continentale omanaise. La formation initiale correspondrait à une marge volcanique associée au point chaud Permien centré sur les trapps du Panjal. Les orientations des structures observées indiquent que ce segment de marge pourrait être situé à l'extrémité septentrionale de l'ouverture Inde-Madagascar/Arabie-Afrique. La remobilisation et le volcanisme triasique pourraient être générés par une réorganisation cinématique du domaine téthysien, lors du début de la collision des blocs cimmériens (Iran) avec la Laurasia.
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Nmila, Abderrahim. "L'empreinte du volcanisme dns le remplissage permien du bassin de lodeve. Etude petrographique et geochimique. Implication metallogenique." Paris 6, 1995. http://www.theses.fr/1995PA066788.
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L'etude petrographique realisee sur l'ensemble des unites lithologiques du bassin permien de lodeve met en evidence le role important du volcanisme dans le remplissage sedimentaire. Ce volcanisme a affinite rhyolitique s'exprime d'une part par des niveaux bien individualises de cinerites (dans le permien gris, gris et rouge et rouge inferieur) et de tuffites (dans le permien rouge superieur), mais aussi par un epandage quasi continu de produits fins, dilues dans les depots et facilement alterables. Il impliquerait l'existence et la proximite d'un important massif volcanique dont l'activite explosive s'est manifestee tout au long de la sedimentation du bassin de lodeve. L'etude geochimique de ces depots volcanoclastiques completee par une etude typologiques des zircons indique une evolution de la nature de ce volcanisme depuis un pole calco-alcalin de type premier cycle de corse durant le permien gris et le permien gris et rouge jusqu'a un pole alcalin de type deuxieme cycle de corse ou de l'esterel durant le permien rouge. La contribution des produits volcaniques dans le remplissage du bassin de lodeve, peut etre estimee a environ 30% ; la finesse de ces reliques volcaniques et leur forte composante vitreuse, ajoutee a l'evolution de leur chimisme au cours du temps, permettent d'expliquer les differentes transformations mineralogiques observees dans les depots. Cet apport volcanique, synchrone avec la sedimentation, serait en particulier a l'origine d'une mise a disposition d'un important stock en uranium dans le bassin de lodeve. La reprise de cet uranium par les differentes phases d'alterations et de circulation hydrothermales aurait conduit aux gisements encore actuellement en exploitation dans le bassin de lodeve
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Benzakour, Abderrahim. "Le volcanisme permien des Vosges du Nord : un témoin d'une évolution dans le cycle orogénique varisque de l'Europe occidentale." Nancy 1, 1988. http://www.theses.fr/1988NAN10252.
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Cette thèse présente une étude pétrographique et géochimique des roches volcaniques (diabases, trachy-andésites, rhyodacites, rhyolites, ignimbrites) permienne des Vosges du Nord en vue de connaître les relations pétrogénétiques entre les différents faciès et le cadre géodynamique de leur mise en place. Deux séries calcoalcalines sont distinguées et l'enrichissement en K::(2)O qui représente un caractère généralisé de ces roches est discuté
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Benzakour, Abderrahim. "Le Volcanisme permien des Vosges du nord un témoin d'une évolution dans le cycle orogénique varisque de l'Europe occidentale /." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37611828d.
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Ouazzani, Hassane. "Quelques formations volcaniques et hypo-volcaniques tardi-collisionnelles d'age stephano-permien des Alpes, du Massif Central et du Bassin Sarro-Lorrain : Exemples d'une dynamique lithosphérique en milieu intraplaque continental." Nancy 1, 1989. http://www.theses.fr/1989NAN10025.
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Les produits des magmatismes permo-stéphaniens s'organisent soit en séries différenciées d'origine mantellique soit en séries acides d'origine crustale, ils sont d'affinité calco-calcaire à sub-alcaline potassique, ils sont associés généralement aux bassins intracrustaux tardi-varisque et ont certainement joué un rôle important dans la génèse et la mise en place des volcanismes étudiés. Des processus interactifs entre la croûte et le manteau sont responsables de l'enrichissement de la source magmatique en élèments incompatibles
Books on the topic "Permian volcanism"
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1927-, Harrison R. K., ed. Petrology of lower permian volcanic rocks from the Larne No.2 (Geothermal) Borehole, Co. Antrim, Northern Ireland. London: H.M.S.O., 1985.
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Keith, Harrison Ronald, ed. Petrology of lower Permian volcanic rocks from the Larne no. 2 (Geothermal) borehole, Co. Antrim, Northern Ireland. London: H.M.S.O., 1985.
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Jackowicz, Elżbieta. Permskie skały wulkaniczne północnej części monokliny przedsudeckiej =: Permian volcanic rocks from the northern part of the Fore-Sudetic Monocline. Warszawa: Państwowy Instytut Geologiczny, 1994.
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Hallam, Tony. Catastrophes and Lesser Calamities. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780198524977.001.0001.
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In Catastrophes and Lesser Calamities, renowned geologist Tony Hallam takes us on a tour of the Earth's history, and of the cataclysmic events, as well as the more gradual extinctions, that have punctuated life on Earth throughout the past 500 million years. While comparable books in this field of study tend to promote only one likely cause of mass extinctions, such as extraterrestrial impact, volcanism, and or climatic cooling, Catastrophes and Lesser Calamities breaks new ground, as the first book to attempt an objective coverage of all likely causes, including sea-level and climatic changes, oxygen deficiency in the oceans, volcanic activity, and extraterrestrial impact. Hallam focuses on the so-called 'big five' mass extinctions, at the end of the Ordovician, Permian, Triassic, and Cretaceous periods, and the later Devonian, and he also includes less well-known examples where relevant. He devotes attention especially to the attempts by geologists to distinguish true catastrophes from more gradual extinction events, and he concludes with a discussion of the evolutionary significance of mass extinctions, and on the influence of Homo sapiens in causing extinctions within the last few thousand years, both on land and in the seas.
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Harrison, R. K. Petrology of Lower Permian Volcanic Rocks from the Larne No. 2 (Geothermal) Borehole, Co. Antrim, Northern Ireland (BGS Reports). Stationery Office Books, 1986.
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Harrison, R. K. Petrology of Lower Permian Volcanic Rocks from the Larne No. 2 (Geothermal) Borehole, Co. Antrim, Northern Ireland (BGS Reports). Stationery Office Books, 1986.
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Sheppard, Charles. 2. Ancient reefs and islands. Oxford University Press, 2014. http://dx.doi.org/10.1093/actrade/9780199682775.003.0002.
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‘Ancient reefs and islands’ illustrates that the present day ecology and organization of species on a reef and their behaviour—basically how a reef works—is the result of a very long heritage. Limestone-deposited structures of the Pre-Cambrian, Cambrian, Ordovician, Carboniferous, Permian, Triassic, and Cretaceous periods, the organisms that created them (including ancestors of today’s sponges and corals), and key extinctions are described along with the three different kinds of coral islands seen around the tropical world: coral cays, islands with a solid limestone core, and volcanic or basaltic islands fringed with coral reef. The future of current reef systems, the effects of ocean changes, and the resulting impact on humanity are considered.
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Jovic, Sebastián Miguel. Geología y metalogénesis de las mineralizaciones polimetálicas del área El Tranquilo (Cerro León), sector central del Macizo del Deseado, provincia de Santa Cruz. Editorial de la Universidad Nacional de La Plata (EDULP), 2010. http://dx.doi.org/10.35537/10915/4346.
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La presente investigación tiene como eje principal el estudio detallado de las mineralizaciones y la geología de un área del Macizo del Deseado con características geológicas y metalogénicas únicas. La elección del área del El Tranquilo o también conocido como “anticlinal” El Tranquilo, como zona de estudio, se ha basado en el reducido conocimiento y la presencia características atípicas en las mineralizaciones y la escasa representación, en el Macizo del Deseado, de las rocas y unidades geológicas aflorantes. La investigación ha sido realizada en tres etapas: una primera con recopilación de antecedentes y trabajo de campo, una segunda analítica con trabajos de laboratorio y una tercera etapa interpretativa. Se realizó el procesado de imágenes satelitales (TM, SPOT, IKONOS) y se ejecutaron mapeos geológico-estructurales de detalle y semidetalle (con elaboración de una cartografía digital), descripción de testigos de sondeos (gran parte de los 30.000 metros de las perforaciones ejecutadas en la propiedad minera), se realizaron estudios petrográficos, calcográficos, de rayos X, determinaciones geoquímicas, estudios de inclusiones fluidas, de microscopía electrónica, microsonda electrónica, determinaciones geocronológicas y análisis de isótopos estables e inestables. Además se participó de otros trabajos complementarios realizados durante las distintas etapas de exploración minera, tales como geoquímica de suelos, muestras de trincheras y relevamientos magnetométricos y geoeléctricos terrestres y la interpretación, para la zona de trabajo, de estudios previos de magnetometría aérea y líneas sísmicas. El área del “anticlinal” El Tranquilo, está caracterizada por la presencia de rocas y unidades geológicas con escasa representación en el Macizo del Deseado, y representa una “ventana geológica” que permite el estudio del intervalo Triásico superior - Jurásico inferior, períodos que se encuentran poco expuestos en esta provincia geológica. La secuencia estratigráfica de este sector se inicia con las sedimentitas continentales, areniscas a areniscas conglomerádicas con intercalaciones de pelitas, del Grupo El Tranquilo, del Triásico medio a superior (Jalfin y Herbst 1995). Por encima, se presentan las rocas volcaniclásticas de la Formación Roca Blanca (Herbst, 1965), del Jurásico inferior. Esta es la litología más desarrollada en el área y está compuesta por tufitas, areniscas y sabulitas ricas en componentes volcánicos. Intruyendo a las sedimentitas continentales y a las tufitas, se disponen rocas básicas a intermedias del Jurásico inferior, que se presentan como filones capa de diabasa en el sector este del área y como pórfidos andesíticos de formas subcirculares en el sector noroeste, de la Formación Cerro León (Panza, 1995 y de Barrio et al., 1999). En los sectores norte y noreste del área afloran volcánitas del Jurásico medio a superior, basaltos y andesitas de la Formación Bajo Pobre, y en el sector sudoriental pequeños asomos de ignimbritas riolíticas del Grupo Bahía Laura (Panza, 1995). Estas unidades se encuentran parcialmente cubiertas por el Basalto Las Mercedes del Cretácico superior y el Basalto Cerro del Doce correspondiente al Eoceno (Panza, 1982) y finalizan esta secuencia sedimentos modernos, aluviales, coluviales y de bajos. En la presente investigación se determinó la presencia de niveles ignimbríticos ácidos y coladas basálticas intercaladas en las tufitas de la Formación Roca Blanca. A partir de las edades obtenidas, relaciones estratigráficas y composición se desvincula a los intrusivos dioríticos de la Formación Cerro León y se los asocia con el magmátismo de la Formación La Leona (Jurásico inferior). Los basaltos aflorantes en el área presentan características de basaltos continentales que se corresponden a los primeros indicios del magmatismo sinextensional jurásico y representan magmas básicos de origen mantélico que alcanzaron la superficie. Se los desvinculan de la Formación Bajo Pobre por ser ligeramente más antiguos al estar intercalados entre las tufitas de la Formación Roca Blanca (Jurásico inferior) y por presentar diferentes características isotópicas y petrogenéticas. Se define así una nueva unidad formacional para estas rocas denominándolas Formación El Piche. Los pórfidos andesíticos de la Formación Cerro León y las andesitas de la Formación Bajo Pobre presentan similitudes geoquímicas, isotópicas, petrogenéticas y edades semejantes, por lo que se interpreta un mismo origen para estas rocas, siendo los pórfidos andesíticos partes de los conductos de emisión de las coladas andesíticas. A diferencia del resto del Macizo del Deseado donde predomina casi por completo deformación con comportamiento netamente frágil, en el área de estudio se reconoció deformación tanto dúctil como frágil en las secuencias triásicas y jurásicas. Los rasgos estructurales más sobresalientes son: un domamiento regional de entre 15 a 20 km de diámetro, definido por Di Persia (1956) como “anticlinal” El Tranquilo, domamientos y plegamientos con dimensiones menores a 1 km localizados dentro de la antiforma regional, un sistema de fracturas radiales asociado al domamiento y la falla El Tranquilo con un sistema de vetas controladas por fallas. Se determinó que el “anticlinal” El Tranquilo, se formó por el emplazamiento de un cuerpo intrusivo no aflorante del orden de 8 a 10 Km de diámetro y profundidad mínima hasta su techo de 1400 m, subyaciendo al Grupo El Tranquilo y a la Formación Roca Blanca, y generando por su intrusión, el domamiento regional y los domamientos y plegamientos con dimensiones menores a 1 km localizados corresponde a una deformación producida por lacolitos o stocks no aflorantes. En el área de estudio se reconocieron gran cantidad de mineralizaciones, las que totalizan ~80 km lineales de vetas, ubicadas principalmente en el sector central del área. Las vetas se concentran hacia el este de la estructura regional, la falla El Tranquilo, son subparalelas a esta estructura y están emplazadas en las tufitas de la Formación Roca Blanca y pelitas y areniscas del Grupo El Tranquilo. Se han discriminado dos tipos distintos de vetas según su composición y expresión superficial, vetas formadas por importantes zonas de oxidación que representan la expresión superficial de vetas de sulfuros, y vetas, brechas hidrotermales, vetillas y stockworks formados principalmente por cuarzo. A partir de las distintas características observadas y datos obtenidos (composición, signatura geoquímica, mineralogía, datos de inclusiones fluidas, isótopos, controles estructurales y litológicos y edades) se ha podido diferenciar dos estilos de mineralización. La mineralización polimetálica que presenta una compleja mineralogía de sulfuros asociada a una signatura geoquímica de In, Cu, Au, As, Sn, W, Bi, Zn, Pb, Ag, Cd y Sb. Las temperaturas y salinidades de los fluidos indican un sistema epitermal para la formación de estas vetas. Su génesis esta vinculada a los cuerpos intrusivos dioríticos reducidos por sedimentos ricos en materia orgánica, concentrando en los fluidos hidrotermales In, Sn, Ag, W, Bi. Se define a esta mineralización como un depósito epitermal vetiforme polimetálico rico en In semejante a los depósitos de Japón y Bolivia. Las características de esta mineralización y la edad Jurásica inferior (193 Ma) confirman la presencia de un nuevo tipo de deposito epitermal que difiere del clásico modelo de baja sulfuración del Macizo del Deseado y que no se encuentra asociado al importante volcanismo bimodal del Jurásico medio a superior (Complejo Bahía Laura), como la mayoría de las mineralizaciones del Macizo del Deseado. Este hecho potencia el hallazgo de otros tipos de depósitos epitermales polimetálicos, asociados a otras rocas y con diferentes asociaciones metalogénicas. La mineralización argentífera está formada por cuarzo, carbonatos y en menor medida sulfuros y sulfosales con una signatura geoquímica de Ag (Au), Pb, Cu y Zn. Las temperaturas y salinidades de los fluidos indican un sistema epitermal para la formación de estas vetas. Su génesis está vinculada al magmatismo intermedio de las Formaciones Cerro León y Bajo Pobre, atribuyéndole una edad Jurásica media (168 Ma). Según sus características esta mineralización puede ser definida como un depósito epitermal de sulfuración intermedia. Esta mineralización también representa una variación en el modelo de baja sulfuración del Macizo del Deseado, pero está genéticamente asociada al volcanismo bimodal del Complejo Bahía Laura (Fm. Bajo Pobre) por lo que podría incluirse dentro de las mineralizaciones de la Provincia auroargéntifera del Deseado.
Book chapters on the topic "Permian volcanism"
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Tran, Trong-Hoa, Gleb V. Polyakov, Tuan-Anh Tran, Alexander S. Borisenko, Andrey E. Izokh, Pavel A. Balykin, Thi-Phuong Ngo, and Thi-Dung Pham. "Permian – Triassic Pluton – Volcanic Magmatic Associations in the Song Hien Structure, Northeast Vietnam." In Modern Approaches in Solid Earth Sciences, 103–51. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-25235-3_4.
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Speczik, S. "Relation of Permian Base Metal Occurrences to the Variscan Paleogeothermal Field of the Fore-Sudetic Monocline (Southwestern Poland)." In Base Metal Sulfide Deposits in Sedimentary and Volcanic Environments, 12–24. Berlin, Heidelberg: Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/978-3-662-02538-3_2.
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"Permian volcanism." In Dictionary Geotechnical Engineering/Wörterbuch GeoTechnik, 981. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-41714-6_160972.
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Vrzhosek, Alexander A. "Late Permian bimodal volcanism in South Primorye." In Late Palaeozoic and Early Mesozoic Circum-Pacific Events and their Global Correlation, 106–8. Cambridge University Press, 1997. http://dx.doi.org/10.1017/cbo9780511564413.011.
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Racki, Grzegorz, and Paul B. Wignall. "Chapter 10 late permian double-phased mass extinction and volcanism: an oceanographic perspective." In Developments in Palaeontology and Stratigraphy, 263–97. Elsevier, 2005. http://dx.doi.org/10.1016/s0920-5446(05)80010-x.
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Mittal, Tushar, Courtney J. Sprain, Paul R. Renne, and Mark A. Richards. "Deccan volcanism at K-Pg time." In From the Guajira Desert to the Apennines, and from Mediterranean Microplates to the Mexican Killer Asteroid: Honoring the Career of Walter Alvarez. Geological Society of America, 2022. http://dx.doi.org/10.1130/2022.2557(22).
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ABSTRACT The last major mass extinctions in Earth history (e.g., end-Guadalupian, end-Permian, end-Triassic, and end-Cretaceous) are all correlated closely in time with the main-phase eruptions of major flood basalt provinces (Emeishan, Siberian, Central Atlantic Magmatic Province, and Deccan Traps, respectively). The causal relationship between flood volcanism and mass extinction is not clear, but likely involves the climate effects of outgassed volatile species such as CO2, SO2, Cl, F, etc., from some combination of magma and country rocks. In a surprising “coincidence,” the end-Cretaceous (K-Pg boundary) micro-faunal extinction also corresponds precisely in time to what may have been the largest meteor impact of the past billion years of Earth history, the Chicxulub crater at 66.05 Ma. The Deccan Traps eruptions were under way well before K-Pg/Chicxulub time and are most likely the result of the mantle plume “head” that initiated the presently active Reunion hotspot track—thus the Deccan Traps were clearly not generated, fundamentally, by the impact. However, recent high-precision 40Ar/39Ar geochronology indicates that conspicuous changes in basalt geochemistry, lava flow morphology, emplacement mode, and a possible 50% increase in eruption rate at the Lonavala/Wai subgroup transition in the Deccan Traps lava group corresponded, within radioisotopic age precision, to the K-Pg boundary and the Chicxulub impact. This has led to the testable hypothesis that the Mw ~11 seismic disturbance of the Chicxulub impact may have affected the Deccan eruptions. Here we review a broad landscape of evidence regarding Deccan volcanism and its relation to the K-Pg boundary and attempt to define what we see as the most important questions than can and should be answered by further research to better understand both the onshore and largely unknown offshore components of Deccan-related volcanism, and what their climate and environmental impacts at K-Pg time may have been.
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Sial, Alcides Nóbrega, Jiubin Chen, Cristoph Korte, Manoj Kumar Pandit, Jorge Spangenberg, Juan Carlos Silva-Tamayo, Luis Drude de Lacerda, et al. "Globally enhanced Hg concentration and Hg and C isotopes in Permian–Triassic boundary successions: Possible linkage to volcanism." In Carbon Isotope Stratigraphy, 567–628. Elsevier, 2020. http://dx.doi.org/10.1016/bs.sats.2020.08.011.
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Gooley, Jared T., Marty Grove, and Stephan A. Graham. "Tectonic evolution of the central California margin as reflected by detrital zircon composition in the Mount Diablo region." In Regional Geology of Mount Diablo, California: Its Tectonic Evolution on the North America Plate Boundary. Geological Society of America, 2021. http://dx.doi.org/10.1130/2021.1217(14).
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ABSTRACT The Mount Diablo region has been located within a hypothesized persistent corridor for clastic sediment delivery to the central California continental margin over the past ~100 m.y. In this paper, we present new detrital zircon U-Pb geochronology and integrate it with previously established geologic and sedimentologic relationships to document how Late Cretaceous through Cenozoic trends in sandstone composition varied through time in response to changing tectonic environments and paleogeography. Petrographic composition and detrital zircon age distributions of Great Valley forearc stratigraphy demonstrate a transition from axial drainage of the Klamath Mountains to a dominantly transverse Sierra Nevada plutonic source throughout Late Cretaceous–early Paleogene time. The abrupt presence of significant pre-Permian and Late Cretaceous–early Paleogene zircon age components suggests an addition of extraregional sediment derived from the Idaho batholith region and Challis volcanic field into the northern forearc basin by early–middle Eocene time as a result of continental extension and unroofing. New data from the Upper Cenozoic strata in the East Bay region show a punctuated voluminous influx (>30%) of middle Eocene–Miocene detrital zircon age populations that corresponds with westward migration and cessation of silicic ignimbrite eruptions in the Nevada caldera belt (ca. 43–40, 26–23 Ma). Delivery of extraregional sediment to central California diminished by early Miocene time as renewed erosion of the Sierra Nevada batholith and recycling of forearc strata were increasingly replaced by middle–late Miocene andesitic arc–derived sediment that was sourced from Ancestral Cascade volcanism (ca. 15–10 Ma) in the northern Sierra Nevada. Conversely, Cenozoic detrital zircon age distributions representative of the Mesozoic Sierra Nevada batholith and radiolarian chert and blueschist-facies lithics reflect sediment eroded from locally exhumed Mesozoic subduction complex and forearc basin strata. Intermingling of eastern- and western-derived provenance sources is consistent with uplift of the Coast Ranges and reversal of sediment transport associated with the late Miocene transpressive deformation along the Hayward and Calaveras faults. These provenance trends demonstrate a reorganization and expansion of the western continental drainage catchment in the California forearc during the late transition to flat-slab subduction of the Farallon plate, subsequent volcanism, and southwestward migration of the paleodrainage divide during slab rollback, and ultimately the cessation of convergent margin tectonics and initiation of the continental transform margin in north-central California.
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"Permian volcanic series." In Dictionary Geotechnical Engineering/Wörterbuch GeoTechnik, 981. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-41714-6_160971.
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Graham, Alan. "Late Cretaceous through Early Eocene North American Vegetational History: 70-50 Ma." In Late Cretaceous and Cenozoic History of North American Vegetation (North of Mexico). Oxford University Press, 1999. http://dx.doi.org/10.1093/oso/9780195113426.003.0008.
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At the end of the Cretaceous the Appalachian Mountains had undergone 180 m.y. of erosion since their principal uplift in the Middle Pennsylvanian through the Late Permian (300-250 Ma), but they were higher and more rugged than at present and provided a somewhat more diverse vertically zoned array of habitats. In contrast, the Rocky Mountains were only ~1 km above sea level at 65 Ma; the Coast Ranges, Sierra Nevada, and Cascade Mountains would not attain substantial heights until late in the Tertiary. Computer models in the NM mode, which simulate conditions in western North America in the Late Cretaceous, show a nearly continuous westerly jet stream with relatively small amplitude between the troughs (lowpressure systems) and ridges (high-pressure systems). The present north-south seasonal meandering of the jet stream was also less. Thus, in the models precipitation and temperatures were more uniform throughout the year and there was less regional differentiation in climate. CO2 concentrations during the Cretaceous are estimated to have been 4-8 times to 10-12 times higher than at present. With a 2-5°C warming for each doubling of CO2, this provides part of the explanation for the higher MAT documented for the Late Cretaceous and Early Tertiary. High CO2 concentrations near the end of the Cretaceous may have been a holdover from earlier intense volcanism in the South Pacific that began to subside at ~ 100 Ma. The term epeirogeny refers to vertical motions of the Earth’s crust, and these movements affect the ocean floor, as well as the continents. There was a 50% increase in the production of ocean crust in the Middle Cretaceous compared to earlier times, as represented by the early Aptian Ontong Java Plateau, the Earth’s largest oceanic plateau, now submerged over 2 km off the Solomon Islands. A sense of the magnitude of this structure can be gained by comparing its volume with that of the surface-exposed Deccan Traps of India (66 Ma). The latter are ~1 km thick and have a volume of 1.5 x 106 km3. The Ontong Java Plateau is ~36 km thick and has a volume of 50 x 106 km3.
Conference papers on the topic "Permian volcanism"
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Sial, Alcides N., JiuBin Chen, Christoph Korte, Manoj Pandit, Jorge Spangenberg, Juan Carlos Tamayo, Luiz Lacerda, et al. "Permian–Triassic boundary volcanism: Hg isotope and elemental Hg proxies in the Meishan and Guryul Ravine successions." In Goldschmidt2021. France: European Association of Geochemistry, 2021. http://dx.doi.org/10.7185/gold2021.5404.
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Apolinar Morales, Blanca, Juan Ramirez Fernandez, Uwe Jenchen, and Yolanda Pichardo-Barrón. "PERMIAN BASIC VOLCANISM ON THE NW MARGIN OF GONDWANA IN THE GUACAMAYA FORMATION, CIUDAD VICTORIA BLOCK, TAMAULIPAS, MEXICO." In South-Central Section - 56th Annual Meeting - 2022. Geological Society of America, 2022. http://dx.doi.org/10.1130/abs/2022sc-373982.
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Machen, Eldridge G., Shane D. Schoepfer, and Lei Xiang. "LINKS BETWEEN VOLCANISM AND THE END-PERMIAN MASS EXTINCTION IN SHALLOW MARINE ENVIRONMENTS OF THE NANPANJIANG BASIN, SOUTH CHINA." In 68th Annual GSA Southeastern Section Meeting - 2019. Geological Society of America, 2019. http://dx.doi.org/10.1130/abs/2019se-325878.
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Zhao, Shuo, Jin Zhang, Jianfeng Liu, and Jinyi Li. "Latest Carboniferous-earliest Permian subduction-related volcanism in the northwestern Lesser Xing’an Range: Implications for the tectonic evolution of Northeast China." In Goldschmidt2021. France: European Association of Geochemistry, 2021. http://dx.doi.org/10.7185/gold2021.4060.
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Shen, Jun, Thomas J. Algeo, Noah J. Planavsky, Qinglai Feng, Zhong Qiang Chen, Jianxin Yu, Jiubin Chen, Shengliu Yuan, and Lian Zhou. "MERCURY ENRICHMENT PROVIDES EVIDENCE OF GLOBAL VOLCANIC EFFECTS DURING THE PERMIAN-TRIASSIC BOUNDARY CRISIS." In GSA Annual Meeting in Seattle, Washington, USA - 2017. Geological Society of America, 2017. http://dx.doi.org/10.1130/abs/2017am-302655.
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Huang, Yuangeng, Zhong Qiang Chen, Paul B. Wignall, Stephen E. Grasby, Laishi Zhao, Xiangdong Wang, and Kunio Kaiho. "REEF ECOSYSTEM COLLAPSE AND BIOTIC EXTINCTION COINCIDE WITH VOLATILE VOLCANISMS AND ANOXIA OVER GUADALUPIAN-LOPINGIAN (PERMIAN) TRANSITION." In GSA Annual Meeting in Seattle, Washington, USA - 2017. Geological Society of America, 2017. http://dx.doi.org/10.1130/abs/2017am-301918.
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Bai, Libing. "The characteristics and tectonic significance of Permian volcanic rocks in habudala Mountain of alashan right banner, Inner Mongolia." In 2011 International Conference on Electrical and Control Engineering. IEEE, 2011. http://dx.doi.org/10.1109/iceceng.2011.6057441.
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Powolny, Tomasz, Aneta Anczkiewicz, and Dumańska-Słowik Magdalena. "Spilitzation of Early-Permian Volcanics from Głuszyca Górna (the Intra-Sudetic Basin, Poland) - Constraints from Chlorite Thermometry Coupled with Apatite Fission-Track Dating (AFT)." In The 2nd International Electronic Conference on Mineral Science. Basel, Switzerland: MDPI, 2021. http://dx.doi.org/10.3390/iecms2021-09342.
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Crowley, James. "Alternative Exploration in the Denison Trough." In PESA Symposium Qld 2022. PESA, 2022. http://dx.doi.org/10.36404/dxsq2922.
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State Gas was formed in 2017 to develop an historic shallow gas resource at PL-231 Reid’s Dome in the Denison Trough. The company used simultaneous inversion to define the extent of the gas and identify further exploration targets. Between 2018 – 2020, State Gas tested the coal-seam gas potential of the Reid’s Dome Beds in PL-231 and subsequently tested the Bandanna Coal measures in the newly awarded ATP-2062. In September 2021, State Gas entered into a Memorandum of Understanding with Rockminsolutions Pty Ltd to evaluate the Buckland Tableland Volcanics within EPM-27596 which partially overlies ATP-2062. The permits contain a significant area with potential for carbon mineralisation using the "CarbFix" process which can permanently store CO2 removed from produced gas or from the atmosphere.
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Granath, James, Rolf Rango, Pete Emmet, Colin Ford, Robert Lambert, and Michael Kasli. "New Viewpoint on the Geology and Hydrocarbon Prospectivity of the Seychelles Plateau." In SPE/AAPG Africa Energy and Technology Conference. SPE, 2016. http://dx.doi.org/10.2118/afrc-2556681-ms.
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ABSTRACT We have reprocessed, re-imaged, and interpreted 10000+ km of legacy 2D seismic data in the Seychelles, particularly in the western part of the Plateau. Seychelles data have been difficult to image, particularly for the Mesozoic section: volcanics are a major attenuator of low frequency signal, and a hard water bottom contributes to signal problems. Enhanced low frequency techniques were applied to improve the signal fidelity in the 4 to 20 Hz range, and to remove spectral notches of shallow geologic origin. These efforts have allowed a reasonable view of the structure of the Plateau to a depth equivalent to about 3.5 sec TWT, and permit a comparison of areas atop the Plateau to the south coast where the three 1980's Amoco wells were drilled. It is clear that the main Plateau area of the Seychelles (excluding the outlying territories) is comprised of several separate basins, each with similar Karoo, Cretaceous, and Cenozoic sections that relate to the East African and West Indian conjugate margins, but the basins each have nuanced tectono-stratigraphic histories. The previously recognized Correira Basin in the SE and the East and West South Coast Basins face the African conjugate margin; other unimaged ones complete the periphery of the Plateau. The interior of the Plateau is dominated by the Silhouette Basin to the west of the main islands and the Mahé Basin to the east. The co astal basins have harsh tectono-thermal histories comparable to other continental margins around the world; they are typically characterized by stretching, subsidence and breakaway from their respective conjugate margins. In contrast the interior basins are comparable to ‘failed’ rift systems such as the North Sea or the Gulf of Suez. The South Coastal Basins, for example, tend to be more extended which complicated interpretation of the Amoco wells, but they have significant upside, as exemplified by the Beau Vallon structure. The interior basins, on the other hand, have typically simpler structure: the Silhouette Basin contains a system of NW-trending linked normal faults that could easily harbor North Sea-sized hydrocarbon traps with a variety of rift-related reservoir possibilities. Bright, reflective, hard volcanic horizons are less common than usually presumed, but most of the basins may contain considerable pyroclastic material in parts of the section. All of the basins appear to be predominantly oil prone, with considerable upside prospectivity.