Publication Date:
2017-04-04
Description:
An example of sheet-like intrusion emplacement at very shallow crustal levels on Elba Island, Italy, is described. The Eastern Elba Dyke Complex (EEDC) consists of decimetre- to metre-thick sheeted aplites emplaced within intensely folded low-grade metamorphic rocks. Field data indicate that sill and dyke emplacement was controlled by mechanical discontinuities, represented by fractures in the host rocks, and was strongly favoured by magma overpressure. The occurrence of angular fragments of host rocks in the dyke border zones and the branching of sills testify to hydraulic fracturing. Analysis of the spatial distribution and geometry of EEDC sills and dykes provides clues on fluid pressure conditions and the stress state at the time of magma emplacement, as well as on the depth of emplacement. The calculated stress ratio and driving pressure ratio were used to estimate a magma overpressure of 6–54 MPa at the time of emplacement of the EEDC at a depth of about 2 km.
Description:
Published
Description:
121-129
Description:
3.3. Geodinamica e struttura dell'interno della Terra
Description:
3.5. Geologia e storia dei sistemi vulcanici
Description:
N/A or not JCR
Description:
reserved
Keywords:
Hydrofractures
;
magma emplacement
;
upper crust
;
southern Tuscany
;
04. Solid Earth::04.01. Earth Interior::04.01.99. General or miscellaneous
;
04. Solid Earth::04.04. Geology::04.04.09. Structural geology
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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