Publication Date:
2017-10-18
Description:
We report on results from anisotropy of magnetic susceptibility (AMS) analyses carried out on
weakly deformed fine-grained sediments from the Northern Apennine orogenic system (Italy). We sampled
63 sites from preorogenic, synorogenic, and postorogenic sequences, which differ in age, composition,
depositional environment, degrees of deformation, and tectonic regimes. The magnetic fabric is typical of
weakly deformed sediments, with a magnetic foliation subparallel to the bedding plane and a magnetic
lineation well defined in this plane. Northern Apennine chain deposits are characterized by strongly oblate
magnetic susceptibility ellipsoids, indicating that the magnetic fabric is the result of both compaction process
and tectonic load experienced by the sediments during diagenesis and orogenic events. The orientation
of magnetic lineation is significantly different depending whether the studied sites underwent extensional
or compressional tectonic regimes. In the Northern Apennine chain, the magnetic lineation is mostly oriented
NNW-SSE, parallel to the main compressional structures. It suggests a tectonic origin of the magnetic
lineation with an acquisition related to the Apennines compressional phases. In the extensional Tuscan
Tyrrhenian margin, magnetic lineation is oriented ENE-WSW, almost perpendicular to the main extensional
faults, which represent the main deformation elements of the area. Our results demonstrate a close
relationship between the shape and orientation of magnetic fabric and the tectonic history of rocks,
confirming that AMS represents a valuable tool to investigate the tectonic history of weakly deformed
sedimentary rocks.
Description:
Published
Description:
238–256
Description:
1A. Geomagnetismo e Paleomagnetismo
Description:
JCR Journal
Description:
restricted
Keywords:
Magnetic Anisotropy Apennines rock fabric sediments
;
04. Solid Earth::04.05. Geomagnetism::04.05.07. Rock magnetism
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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