The intrusive complexof the Island of Giglio: geomagnetic characteristics of plutonic facies with low susceptibility contrast
Main Article Content
Abstract
Two main plutonic facies characterize the intrusive complex of the Island of Giglio, and the trend of their contact at depth has been modelled using a 2D½ analysis based on a detailed geomagnetic survey in order to verify the geological hypothesis of the subsurface geometry of this contact. The magnetic anomaly connected with the discontinuity is quite low, due to the small difference between the magnetic susceptibilities of the two granitic facies. Development of this model of inversion of the magnetic field, which is in good agreement with the geological interpretation, was made possible by: 1) accurate control of the geomagnetic time variations and consequent temporal reduction, 2) a very low level of the artificial magnetic noise, 3) high density of the magnetic survey, 4) detailed knowledge of the mapped geologic contact between facies and of their petrologic characteristics, and 5) direct local measurements of the magnetic susceptibilities of the key lithologies. The model shows the trends of the geological contact, as projected in three E-W sections, that dips eastward in the range between 210 and 540, supporting the geologic hypothesis that the Pietrabona facies represents an external shell of the shallowly emplaced Giglio monzogranite intrusion.
Article Details
How to Cite
Faggioni, O., Westerman, D., Innocenti, F., Beverini, N., Carmisciano, C., Cavallini, R. and Dini, A. (1998) “The intrusive complexof the Island of Giglio: geomagnetic characteristics of plutonic facies with low susceptibility contrast”, Annals of Geophysics, 41(3). doi: 10.4401/ag-4343.
Issue
Section
OLD
Open-Access License
No Permission Required
Istituto Nazionale di Geofisica e Vulcanologia applies the Creative Commons Attribution License (CCAL) to all works we publish.
Under the CCAL, authors retain ownership of the copyright for their article, but authors allow anyone to download, reuse, reprint, modify, distribute, so long as the original authors and source are cited. No permission is required from the authors or the publishers.
In most cases, appropriate attribution can be provided by simply citing the original article.
If the item you plan to reuse is not part of a published article (e.g., a featured issue image), then please indicate the originator of the work, and the volume, issue, and date of the journal in which the item appeared. For any reuse or redistribution of a work, you must also make clear the license terms under which the work was published.
This broad license was developed to facilitate open access to, and free use of, original works of all types. Applying this standard license to your own work will ensure your right to make your work freely and openly available. For queries about the license, please contact ann.geophys@ingv.it.