Overview
We now recognize that mid-ocean ridges are not simple, two-dimensional features, but are instead partitioned into morphologically distinct segments on a variety of scales. Variations in axial morphology reflect differences in the structure of the magma reservoirs and in the nature of mantle upwelling beneath the ridge. Segment ends may be starved of magma, and spreading accommodated by tectonic stretching as well as by magmatic accretion. The location of the magmatic heat source and the distribution of permeability within the segment strongly control the geometry of seawater circulation in the crust and locus of hydrothermal discharge. In turn, the mechanisms of faunal colonization of vent sites and the evolutionary history of vent organisms depend strongly upon the spatial distribution of black smoker vents and the hydrodynamics of dispersal of the vent fluids. Segmentation, therefore, plays a vital role in the inter-relationship between all tectonic, magmatic, hydrothermal and biological processes at mid-ocean ridges. The recent research presented in this book, much of it carried out under the aegis of the British mid-ocean ridge 'BRIDGE' programme, examines this inter-relationship with the aim of furthering our understanding of the causes and consequences of ridge axial segmentation.Synopsis
We now recognize that mid-ocean ridges are not simple, two-dimensional features, but are instead partitioned into morphologically distinct segments on a variety of scales. Variations in axial morphology reflect differences in the structure of the magma reservoirs and in the nature of mantle upwelling beneath the ridge. Segment ends may be starved of magma, and spreading accommodated by tectonic stretching as well as by magmatic accretion. The location of the magmatic heat source and the distribution of permeability within the segment strongly control the geometry of seawater circulation in the crust and locus of hydrothermal discharge. In turn, the mechanisms of faunal colonization of vent sites and the evolutionary history of vent organisms depend strongly upon the spatial distribution of black smoker vents and the hydrodynamics of dispersal of the vent fluids. Segmentation, therefore, plays a vital role in the inter-relationship between all tectonic, magmatic, hydrothermal and biological processes at mid-ocean ridges. The recent research presented in this book, much of it carried out under the aegis of the British mid-ocean ridge 'BRIDGE' programme, examines this inter-relationship with the aim of furthering our understanding of the causes and consequences of ridge axial segmentation.