Comparison of the spatial location of deep-sea polymetallic sulphide ore objects and deep mantle structure based on geophysical fields in the northern near-equatorial segment of the Mid-Atlantic Ridge

Abstract

A comparison of geophysical data along the segment of the Mid-Atlantic Ridge (MAR) between 10° N and 25° N and seafloor massive sulfides (SMS) ore objects revealed a number of regularities and relationships in their spatial distribution. SMS are grouped in areas with the following features: near subvertical «microplumes», into which the single axial anomaly of the MAR, determined by the seismotomographic model UU-P07, splits; maximums of Bouguer anomalies between the Vema and Kane transform faults, corresponding to dense mantle volumes and minimal magmatic debit; a pronounced alternation of spatiotemporal «voids» and «bands» of seismicity with a step of ~1.5°, comparable to the near-surface δVp minima; inversion of spreading rates asymmetry from east of the MAR to the west within 20° N and 24° N south of the Kane fault with nontransform south-oriented offsets; areas with positive correlation of the Bouguer anomalies and topography between 19° N and 22° N. The relation of SMS with the specified features of geophysical data forms a predictive basis for this type of objects.

Keywords

• seafloor sulfides
• seismotomography
• spreading
• bouguer anomalies
• nontransform displacements