Comparison between the magnetic and petrological characteristics of the peridotites from the gorringe ridge and the peridotites from the mid-ocean ridges

• Published in: Oceanology (Washington. 1965) Vol. 51; no. 1; pp. 157 - 169
• Main Authors: Popov, K. V., Bazylev, B. A., Shcherbakov, V. P., Gapeev, A. K.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01-02-2011; Springer Nature B.V
• Subjects: Comparative studies; Continental margins; Earth and Environmental Science; Earth Sciences; Lithosphere; Magnetic fields; Magnetic properties; Magnetism; Marine; Marine Geology; Metamorphism; Oceanography; Oceans; Petrology; ANE, Spain, Galicia; ANE, Atlantic, Gorringe Ridge; A, Atlantic; Oceanic Crust; Natural Remanent Magnetization; Magnetite; Spinel Peridotite; Rift Valley
• ISSN: 0001-4370; 1531-8508
• DOI: 10.1134/S0001437011010140

The purpose of our work was to obtain the most possible detailed information about the composition, concentration, and structural features of the magnetic minerals contained in the rock to reveal the differences in the magnetic properties of the peridotites under various circumstances of the mantle magmatism and different conditions of metamorphism. To do this, we examined and analyzed the magnetic and petrographic characteristics of four collections of oceanic and alpinotype spinel peridotites. The main object for comparing the magnetic characteristics was the Gorringe ridge, which lies in the eastern part of the Atlantic Ocean. The peridotite samples from the Gorringe ridge differ from the other collections in many magnetic parameters:
I
n
, χ,
Q
,
I
rs
/
I
s
,
H
c
,
H
cr
, and
H
m
. The principal question of our work was to clarify the nature of the Earth’s crust where the Gorringe ridge formed. This subject was studied many times in the literature, but the researchers did not reach a common opinion. In accordance with our data, the spinel peridotites from the Gorringe ridge represent a subcontinental lithosphere mantle of the Iberian continental margin. During the metamorphism, the formation of magnetite occurred in the peridotites of the Gorringe ridge in several stages and had a regressive character. Our investigations explain the results of the analysis of the anomalous magnetic field over the Gorringe ridge, which is characterized by sharp roughness and high intensity of the local signchanging anomalies.