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| Cannat, Mathilde; Sauter, Daniel; Bezos, Antoine; Meyzen, Christine; Humler, Eric; Le Rigoleur, Marion. |
| We use bathymetry, gravimetry, and basalt composition to examine the relationship between spreading rate, spreading obliquity, and the melt supply at the ultraslow spreading Southwest Indian Ridge (SWIR). We find that at regional scales (more than 200 km), melt supply reflects variations in mantle melting that are primarily controlled by large-scale heterogeneities in mantle temperature and/or composition. Focusing on adjacent SWIR regions with contrasted obliquity, we find that the effect of obliquity on melt production is significant (about 1.5 km less melt produced for a decrease of 7 mm/a to 4 mm/a in effective spreading rates, ESR) but not enough to produce near-amagmatic spreading in the most oblique regions of the ridge, unless associated with an... |
| Tipo: Text |
Palavras-chave: Mid-ocean ridges; Melt supply; Mantle melting; Magmatic segmentation. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00237/34860/33204.pdf |
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| Sauter, Daniel; Cannat, Mathilde; Roumejon, Stephane; Andreani, Muriel; Birot, Dominique; Bronner, Adrien; Brunelli, Daniele; Carlut, Julie; Delacour, Adelie; Guyader, Vivien; Macleod, Christopher J.; Manatschal, Gianreto; Mendel, Veronique; Menez, Benedicte; Pasini, Valerio; Ruellan, Etienne; Searle, Roger. |
| The global mid-ocean ridge system, where tectonic plates diverge, is traditionally thought of as the largest single volcanic feature on the Earth. Yet, wide expanses of smooth sea floor in the easternmost part of the Southwest Indian Ridge in the Indian Ocean lacks the hummocky morphology that is typical for submarine volcanism. At other slow-spreading ridges, the sea floor can extend by faulting the existing lithosphere, along only one side of the ridge axis. However, the smooth sea floor in the easternmost Southwest Indian Ridge also lacks the corrugated texture created by such faulting. Instead, the sea floor is smooth on both sides of the ridge axis and is thought to be composed of altered mantle-derived rocks. Here we use side-scan sonar to image the... |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00136/24771/22950.pdf |
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| Sloan, Heather; Sauter, Daniel; Goff, John A.; Cannat, Mathilde. |
| The morphology of the flanks of the Southwest Indian Ridge holds a record of seafloor formation and abyssal hill generation at an ultraslow spreading rate. Statistical analysis of compiled bathymetry and gravity data from the flanks of the Southwest Indian Ridge from 54 degrees E to 67 degrees E provides estimates of abyssal hill morphologic character and inferred crustal thickness. The extent of the compiled data encompasses a spreading rate change from slow to ultraslow at similar to 24 Ma, a significant inferred variation in sub-axis mantle temperature, and a patchwork of volcanic and non-volcanic seafloor, making the Southwest Indian Ridge an ideal and unique location to characterize abyssal hills generated by ultraslow spreading and to examine the... |
| Tipo: Text |
Palavras-chave: Southwest Indian Ridge; Abyssal hills; Seafloor morphology. |
| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00266/37682/36757.pdf |
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| Murton, Bramley J.; Tindle, Andrew G.; Milton, J. Andrew; Sauter, Daniel. |
| Between the Rodrigues Triple Junction and the Marie Celeste fracture zone, basalts from the Central Indian Ridge (CIR) exhibit an enrichment in incompatible elements that increases in intensity northward. In addition, H2O/TiO2, Al[8], and Dy/Yb ratios increase, while Na[8] remains unchanged and Fe[8] decreases. Evolution of the enriched magma appears to be affected by elevated water contents, which lower the mantle solidus, thereby increasing the initial depth of melting, as well as delaying plagioclase crystallization. However, the enrichment affecting the northern samples is not a just function of hydrous mantle melting and crystallization. Instead of trending toward a small melt fraction from the mantle, as predicted by hydrous melting models, the CIR... |
| Tipo: Text |
Palavras-chave: Central Indian Ridge; Hot spot–ridge interaction; MORB geochemistry. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/00135/24609/22639.pdf |
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