Publication Date:
2017-04-04
Description:
The complex magnetic and gravity anomaly fields of the Southern Tyrrhenian Sea provide a record of the
complicated properties and evolution of the underlying crust. Geologic interpretation of these anomalies
is hindered by the effects of anomaly superposition and source ambiguity inherent to potential field analysis.
A common approach to minimizing interpretational ambiguities is to consider analyses of anomaly
correlations. Spectral correlation filters are used to separate positively and negatively correlated anomaly
features based on the correlation coefficient given by the cosine of the phase difference between common
wavenumber components. This procedure is applied to reduced-to-pole magnetic and first vertical
derivative gravity anomalies for mapping correlative crustal magnetization and density contrasts. Adding
and subtracting the standardized outputs of the filters yield summed (SLFI) and differenced (DLFI) local
favorability indices that, respectively highlight positive and negative feature correlations in the anomaly
data sets. Correlative maxima mainly reflect volcanic structures, and secondarily intrusive bodies and pre-
Tortonian carbonates of the Maghrebian chain and the basement rocks of the Sardinia eastern margin.
Correlative minima mostly mark sediment-filled peri-Tyrrhenian structural basins related to the Pliocene
extensional tectonics, and intra-slope marine depressions related to post-Pliocene and still-active compressional
tectonics off Northern Sicily. Prominent inverse anomaly correlations mainly reflect crustal
features around the southern margin of the Tyrrhenian Sea that include higher density, lower magnetization
pelagic-to-terrigenous and flysch-type nappes of the Sicilian-Maghrebian chain, as well as
lower density, higher magnetization sediments filling depressions of the chain, and syn-rift sediments
of Southeastern Sardinia.
Description:
Published
Description:
27-41
Description:
3.2. Tettonica attiva
Description:
3.4. Geomagnetismo
Description:
5.7. Consulenze in favore di istituzioni nazionali e attività nell'ambito di trattati internazionali
Description:
JCR Journal
Description:
restricted
Keywords:
Magnetism
;
Gravity
;
Modelling
;
Back-arc basin
;
Volcanism
;
Tectonics
;
Tyrrhenian Sea
;
04. Solid Earth::04.02. Exploration geophysics::04.02.99. General or miscellaneous
;
04. Solid Earth::04.05. Geomagnetism::04.05.04. Magnetic anomalies
;
04. Solid Earth::04.07. Tectonophysics::04.07.08. Volcanic arcs
;
04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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