Publication Date:
2017-04-04
Description:
The silicate parageneses of variably retrogressed eclogites
are extensively used by metamorphic petrologists to
reconstruct the tectonometamorphic evolution of ophiolitesbearing
units and high-pressure continental tectonic slices
in orogenic belts from initial burial to exhumation. On the
other hand, the opaque mineralogy of these rocks is
generally not studied in detail although the characterization
of Fe-Ti oxides and sulphides in metabasites has a great
potential [Clark, 1997; Dunlop and O¨ zdemir, 1997; Frost,
1991b] to better understand the processes controlling the
formation and stability of magnetic minerals (mainly magnetite
and pyrrhotite) in subduction zones and collisional
orogens and to improve geological interpretation of magnetic
survey data.
[3] The Hercynian basement of northern Sardinia provides
a case study to define the relationships between
metamorphic evolution and magnetic properties of eclogite
and amphibolite facies metabasites in a number of structurally
and petrologically well-studied outcrops within a
representative crustal section of the southern European
Variscan belt.
[4] To characterize the magnetic properties of these rocks,
we conducted a series of minero-petrographical analyses
and mineral magnetic measurements on a suite of samples
representative of all the main mafic/ultramafic lenses of the
region. In this study, we report on new data and interpretations
which are essential (1) to characterize and to verify
primary and secondary oxide contributions to the overall
magnetization, (2) to link the stability/instability of magnetic
assemblages to specific metamorphic stages, and (3) to
provide a preliminary regional-scale perspective on the level
of magnetization in all the main metamorphic mafic rock
units of the Hercynian orogenic belt in northern Sardinia.
Description:
Published
Description:
B12S26
Description:
reserved
Keywords:
Magnetic
;
Sardinia
;
04. Solid Earth::04.01. Earth Interior::04.01.04. Mineral physics and properties of rocks
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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