Magmatic and tectonic extension at mid-ocean ridges: 2. Origin of axial morphology

Tectonic, Magmatic, Hydrothermal and Biological Segmentation of Mid-Ocean Ridges

Magma Flow at Mid-Ocean Ridges

Liquid water is not stable under current martian surface conditions, but the presence of small gullies on the polewardfacing slopes of midto highlatitude martian surfaces suggests that erosion by liquid water might have occurred. Costard et al. (p. 110) developed a global climate model for Mars when it had a higher obliquity (about 300,000 years ago). Their model shows that more melting of the ...

Causes for axial high topography at mid-ocean ridges and the role of crustal thermal structure

Mid-ocean ridge topography is modeled as the flexural response to loads using a thin plate approximation and setting thermal structure of the lithosphere to allow, but not require, a region of rapid cooling near the axis. Loads on the lithosphere arise from the presence of lowdensity melt, densification due to cooling with distance from the ridge axis, and thermal contraction stresses. We find ...

On origin of near-axis volcanism and faulting at fast spreading mid-ocean ridges

At fast and superfast spreading mid-ocean ridges, such as the East Pacific Rise, a plate boundary is defined by a narrow (tens to hundreds of meters wide) neovolcanic zone within which the bulk of the upper oceanic crust is created. However, detailed near-bottom observations indicate that the volcanic construction may occasionally persist several kilometers off of the ridge axis. It has been pr...

Magmatic filtering of mantle compositions at mid-ocean-ridge volcanoes

Earth’s dominant form of magmatism occurs at mid-ocean ridges (MORs), producing the igneous crust for two-thirds of the planet’s surface and conveying significant heat and material fluxes from the mantle to the world’s oceans. Mid-ocean-ridge basalt (MORB) magmas form from upwelling compositionally heterogeneous mantle1 by aggregation of near-fractional melts beneath spreading centres2. Multipl...