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| Leroux, Estelle; Counts, J.; Jorry, Stephan; Jouet, Gwenael; Révillon, Sidonie; Boudagher-fadel, M.k.; Courgeon, S.; Berthod, C.; Ruffet, G.; Bachèlery, P.; Grenard-grand, E.. |
| Little is known about the geological history of the Glorieuses seamount including basic information about its age and origin related to the regional evolution of the southern tip of the Somali Basin. This study focused on describing and reconstructing the long-term stratigraphic evolution of the Glorieuses seamount (SW Indian Ocean) to identify the mechanisms that have occurred through time to finally shape the emerged modern islands. Distinct terrace levels, currently submerged along the flanks of the seamount and surrounding seamounts, have already been interpreted as resulting from successive carbonate development and back-stepping episodes over the last 62 Myr. New isotopic and biostratigraphic dating on the flanks of the seamount, coupled with... |
| Tipo: Text |
Palavras-chave: Glorieuses seamount; Somali Basin; Seismic stratigraphy; Tectonics; Vertical movement (uplift and subsidence); Volcanism; Shallow-water carbonate platform; Ar-40/Ar-39. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00628/73965/73324.pdf |
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| Courgeon, Simon; Jorry, Stephan; Jouet, Gwenael; Camoin, G.; Boudagher-fadel, M. K.; Bachelery, P.; Caline, B.; Boichard, R.; Revillon, Sidonie; Thomas, Yannick; Thereau, Estelle; Guerin, Charline. |
| Understanding the impact of tectonic activity and volcanism on long-term (i.e. millions years) evolution of shallow-water carbonate platforms represents a major issue for both industrial and academic perspectives. The southern central Mozambique Channel is characterized by a 100 km-long volcanic ridge hosting two guyots (the Hall and Jaguar banks) and a modern atoll (Bassas da India) fringed by a large terrace. Dredge sampling, geophysical acquisitions and submarines videos carried out during recent oceanographic cruises revealed that submarine flat-top seamounts correspond to karstified and drowned shallow-water carbonate platforms largely covered by volcanic material and structured by a dense network of normal faults. Microfacies and well-constrained... |
| Tipo: Text |
Palavras-chave: Carbonate platform; Drowning; Volcanism; Tectonic; Mozambique Channel. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00384/49554/50048.pdf |
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| Chaneton,Enrique J; Mazía,Noemí; Garibaldi,Lucas A; Chaij,Jaquelina; Kitzberger,Thomas. |
| Volcanism has been a major force shaping the dynamics of Andean landscapes during the Holocene. Yet we still know little about the consequences of modern volcanic events on forest functioning. Ash fall may elicit multiple direct and indirect effects on key ecosystem attributes, with disturbance severity likely varying with distance to the crater. We examined the impact of ash deposition on foliage productivity and insect herbivory after the 2011 eruption of the Volcán Puyehue-Cordón Caulle system, in Nothofagus pumilio forests of northern Patagonia, Argentina. Tree leaf litterfall, a surrogate for annual foliar production, was measured before and after the event in wet and dry forest sites, which were located 22 km and 80 km east from the crater and were... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Canopy insects; Disturbance; Herbivory; Long-term study; Nothofagus pumilio; Productivity; Volcanism. |
| Ano: 2014 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2014000100007 |
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| Moreira, M. A.; Geoffroy, Laurent; Pozzi, J. P.. |
| The localization of magma melting areas at the lithosphere bottom in extensional volcanic domains is poorly understood. Large polygenetic volcanoes of long duration and their associated magma chambers suggest that melting at depth may be focused at specific points within the mantle. To validate the hypothesis that the magma feeding a mafic crust, comes from permanent localized crustal reservoirs, it is necessary to map the fossilized magma flow within the crustal planar intrusions. Using the AMS, we obtain magmatic flow vectors from 34 alkaline basaltic dykes from SAo Jorge, SAo Miguel and Santa Maria islands in the Azores Archipelago, a hot-spot related triple junction. The dykes contain titanomagnetite showing a wide spectrum of solid solution ranging... |
| Tipo: Text |
Palavras-chave: AMS; Azores; Dykes; Lithosphere; Magma flow; Volcanism. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00639/75144/75499.pdf |
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| Hekinian, Roger; Cheminee, J; Dubois, J; Stoffers, P; Scott, S; Guivel, C; Garbe Schonberg, D; Devey, C; Bourdon, B; Lackschewitz, K; Mcmmurtry, G; Le Drezen, Eliane. |
| Multibeam bathymetry and bottom imaging (Simrad EM12D) studies on an area of about 9500 km(2) were conducted over the Pitcairn hotspot near 25degrees10'S, 129degrees 20'W In addition, 15 dives with the Nautile submersible enabled us to obtain ground-true observations and to sample volcanic structures on the ancient ocean crust of the Farallon Plate at 3500-4300 in depths. More than 100 submarine volcanoes overprint the ancient crust and are divided according to their size into large ( > 2000 in in height), intermediate (500-2000 in high) and small ( < 500 in high) edifices. The interpretation of seafloor backscatter imagery accompanied by submersible observations and sampling enabled us to infer that the total volume of submarine lava erupted during... |
| Tipo: Text |
Palavras-chave: Petrology; Volcanic sequences; Morphology; Volcanism; Hotspot. |
| Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/2003/publication-784.pdf |
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| CITRONI,SERGIO B.; BASEI,MIGUEL A. S.; SIGA JR.,OSWALDO; REIS NETO,JOSÉ M. DOS. |
| The depositional succession of the Campo Alegre Basin (Santa Catarina - southern Brazil) was investigated having the evolution of the volcanic activity as background. The different stratigraphic units are interpreted as belonging to different volcanic stages: Bateias Formation, conglomerates and sandstones, related with a pre-volcanic stage; Campo Alegre Group, at the main volcanic stage, with each different formation corresponding to different episodes of volcanism - Rio Negrinho Formation, corresponding to the basic volcanism, Avenca Grande Formation to ignimbritic event, Serra de São Miguel Formation to the acid volcanism and Fazenda Uirapuru Formation, related to an explosive event; Rio Turvo and Arroio Água Fria formations correspond respectively to... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Neoproterozoic Basin; Volcanism; Caldera deposits; Paleogeographic evolution. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652001000400012 |
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