The plume and spreading associations of basalt and their reflection in the petrological and geophysical parameters of the northern Mid-Atlantic Ridge

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

“…It is also confirmed by the results of geochemical studies of basalts throughout the MAR length (Fig. 15) (Dmitriev et al, 1999;Silantyev, Sokolov, 2010).…”

“…Asthenospheric plastic material, in contrast to the melt, is mixed substantially worse, which are evidence from variations of isotopic and geochemical characteristics of the fresh basalts (see Section 2.1). (Dmitriev et al, 1999).…”

Hydrothermal fields in the Mid-Atlantic Ridge: Setting and prospects for further discoveries

“…This profile shows clearly three minima ( Figure 5C), corresponding (from north to south) to the Iceland, Azores, and South Atlantic plumes. Above these plumes, basaltic magmatism is especially extensive [Dmitriev et al, 1999b]. In combination with slow spreading, this gives rise to conspicuous positive anomalies of seafloor topography along the ridge axis, because in these MAR zones basaltic products are accumulated appreciably more vigorously than in zones of "background type" magmatism [Dmitriev et al, 2001c].…”

“…On Figure 5, correlation of seismicity with the other geophysical parameters shows that in plume regions, seismic events are more frequent and have lower magnitudes than those in the "cool" mantle region near the equator and in certain fragments to the north. Correlation of seismicity to geophysical and petrologic parameters is detailed in [Dmitriev et al, 1999b]. The above does not apply to the reduced frequency of seismic events in the South Atlantic, which is an artifact of the sparser network of recording stations in this part of the world.…”

Silicic Fe-Ti-oxide series of slow-spreading ridges: petrology, geochemistry, and genesis with reference to the Sierra Leone segment of the Mid-Atlantic Ridge axial zone at 6\deg N

“…Spreading versus plume association. According to REE ratios, many researchers classify MAR basalts with two types of associations: related to spreading (normal) or plume (anomalous) [Dmitriev et al, 1999;Douglass et al, 1999;Schilling et al, 1983;Silantyev et al, 2002]. Following Schilling et al [1983], the distinction is commonly drawn using the (La/Sm)N and (Ce/Yb)N ratios.…”