scholarly journals Cyclic Development of Axial Parts of Slow-Spreading Ridges: Evidence from Sierra Leone Area, the Mid-Atlantic Ridge, 5-7°N

10.5772/39372 ◽  
2012 ◽  
Author(s):  
E.V. Sharkov
Keyword(s):  
Sierra Leone ◽  
Spreading Ridges ◽  
Mid Atlantic Ridge ◽  
Slow Spreading

scholarly journals Magmatic processes at slow spreading ridges: implications of the RAMESSES experiment at 57° 45′N on the Mid-Atlantic Ridge

1998 ◽  
Vol 135 (3) ◽  
pp. 731-745 ◽  
Author(s):  
M. C. Sinha ◽  
S. C. Constable ◽  
C. Peirce ◽  
A. White ◽  
G. Heinson ◽  
...  
Keyword(s):  
Spreading Ridges ◽  
Magmatic Processes ◽  
Mid Atlantic Ridge ◽  
Slow Spreading

scholarly journals Prospectivity Mapping for Magmatic-Related Seafloor Massive Sulfide on the Mid-Atlantic Ridge Applying Weights-of-Evidence Method Based on GIS

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 83
Author(s):  
Lushi Liu ◽  
Jilong Lu ◽  
Chunhui Tao ◽  
Shili Liao
Keyword(s):  
Massive Sulfide ◽  
Spreading Rate ◽  
Mineral Prospectivity Mapping ◽  
Spreading Ridges ◽  
Mid Atlantic Ridge ◽  
Slow Spreading ◽  
Mineral Prospectivity ◽  
Seafloor Massive Sulfide ◽  
Crust Thickness ◽  
Prospectivity Mapping

The Mid-Atlantic Ridge belongs to slow-spreading ridges. Hannington predicted that there were a large number of mineral resources on slow-spreading ridges; however, seafloor massive sulfide deposits usually develop thousands of meters below the seafloor, which make them extremely difficult to explore. Therefore, it is necessary to use mineral prospectivity mapping to narrow the exploration scope and improve exploration efficiency. Recently, Fang and Shao conducted mineral prospectivity mapping of seafloor massive sulfide on the northern Mid-Atlantic Ridge, but the mineral prospectivity mapping of magmatic-related seafloor massive sulfide on the whole Mid-Atlantic Ridge scale has not yet been carried out. In this study, 11 types of data on magmatic-related seafloor massive sulfide mineralization were collected on the Mid-Atlantic Ridge, namely water depth, slope, oceanic crust thickness, large faults, small faults, ridge, bedrock age, spreading rate, Bouguer gravity, and magnetic and seismic point density. Then, the favorable information was extracted from these data to establish 11 predictive maps and to create a mineral potential model. Finally, the weights-of-evidence method was applied to conduct mineral prospectivity mapping. Weight values indicate that oceanic crust thickness, large faults, and spreading rate are the most important prospecting criteria in the study area, which correspond with important ore-controlling factors of magmatic-related seafloor massive sulfide on slow-spreading ridges. This illustrates that the Mid-Atlantic Ridge is a typical slow-spreading ridge, and the mineral potential model presented in this study can also be used on other typical slow-spreading ridges. Seven zones with high posterior probabilities but without known hydrothermal fields were delineated as prospecting targets. The results are helpful for narrowing the exploration scope on the Mid-Atlantic Ridge and can guide the investigation of seafloor massive sulfide resources efficiently.

scholarly journals Pervasive detachment faults within the slow spreading oceanic crust at the poorly coupled Antilles subduction zone

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Boris Marcaillou ◽  
Frauke Klingelhoefer ◽  
Muriel Laurencin ◽  
Jean-Frédéric Lebrun ◽  
Mireille Laigle ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Oceanic Crust ◽  
Bathymetric Data ◽  
Detachment Faults ◽  
Spreading Ridges ◽  
Basement Rocks ◽  
Mid Atlantic Ridge ◽  
Slow Spreading ◽  
Deep Fluid ◽  
Shear Planes

AbstractOceanic crust formed at slow-spreading ridges is currently subducted in only a few places on Earth and the tectonic and seismogenic imprint of the slow-spreading process is poorly understood. Here we present seismic and bathymetric data from the Northeastern Lesser Antilles Subduction Zone where thick sediments enable seismic imaging to greater depths than in the ocean basins. This dataset highlights a pervasive tectonic fabric characterized by closely spaced sequences of convex-up Ridgeward-Dipping Reflectors, which extend down to about 15 km depth with a 15-to-40° angle. We interpret these reflectors as discrete shear planes formed during the early stages of exhumation of magma-poor mantle rocks at an inside corner of a Mid-Atlantic Ridge fracture zone. Closer to the trench, plate bending could have reactivated this tectonic fabric and enabled deep fluid circulation and serpentinization of the basement rocks. This weak serpentinized basement likely explains the very low interplate seismic activity associated with the Barbuda-Anegada margin segment above.

scholarly journals Fast and slow spreading ridges: Structure and hydrothermal activity, ultramafic topographic highs, and CH4output

1993 ◽  
Vol 98 (B6) ◽  
pp. 9643 ◽  
Author(s):  
Henri Bougault ◽  
Jean-Luc Charlou ◽  
Yves Fouquet ◽  
Hubert D. Needham ◽  
Nathalie Vaslet ◽  
...  
Keyword(s):  
Hydrothermal Activity ◽  
Spreading Ridges ◽  
Slow Spreading
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