Chemical composition of minerals and rocks from the Sierra Leone segment of the Mid-Atlantic Ridge and from the Markov depression, Central Atlantic

DOI

Silicic Fe-Ti-oxide magmatic series was the first recognized in the Sierra Leone axial segment of the Mid-Atlantic Ridge near 6°N. The series consists of intrusive rocks (harzburgites, lherzolites, bronzitites, norites, gabbronorites, hornblende Fe-Ti-oxide gabbronorites and gabbronorite-diorites, quartz diorites, and trondhjemites) and their subvolcanic (ilmenite-hornblende dolerites) and, possibly, volcanic analogues (ilmenite-bearing basalts). Deficit of most incompatible elements in the rocks of the series suggests that parental melts derived from a source that had already been melted. Correspondingly, these melts could not be MORB derivatives. Origin of the series is thought to be related to melting of the hydrated oceanic lithosphere during emplacement of an asthenospheric plume (protuberance on the surface of large asthenospheric lens beneath MAR). Genesis of different melts was supposedly controlled by ascent of a chamber of hot mantle magmas thought this lithosphere in compliance with the zone melting mechanism. Melt acquired fluid components from heated rocks at peripheries of the plume and became enriched in Fe, Ti, Pb, Cu, Zn, and other components mobile in fluids.

Supplement to: Sharkov, E V; Bortnikov, Nikolay S; Zinger, T F; Chistyakov, A V (2005): 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°N. Russian Journal of Earth Sciences, 7(4), 1-30

Identifier
DOI https://doi.org/10.1594/PANGAEA.745121
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.745121
Provenance
Creator Sharkov, E V; Bortnikov, Nikolay S; Zinger, T F; Chistyakov, A V
Publisher PANGAEA
Publication Year 2005
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Language English
Resource Type Supplementary Publication Series of Datasets; Collection
Format application/zip
Size 9 datasets
Discipline Earth System Research
Spatial Coverage (-33.822W, 5.811S, -33.057E, 6.677N); Mid-Atlantic Ridge; Atlantic Ocean