scholarly journals Neogene deformation and granite emplacement in the metamorphic units of northern Apennines (Italy): Insights from mylonitic marbles in the Porto Azzurro pluton contact aureole (Elba Island)

Geosphere ◽  
2012 ◽  
Vol 8 (2) ◽  
pp. 470-490 ◽  
Author(s):  
Giovanni Musumeci ◽  
Luca Vaselli
Keyword(s):  
Northern Apennines ◽  
Contact Aureole ◽  
Granite Emplacement ◽  
Elba Island

The cooling, deformation and exhumation history of the late Miocene syn-tectonic Porto Azzurro pluton in a regional transfer zone (Elba Island, Italy)

2020 ◽  
Author(s):  
Andrea Brogi ◽  
Richard Spiess ◽  
Alfredo Caggianelli ◽  
Antonio Langone ◽  
Fin Stuart ◽  
...  
Keyword(s):  
Tectonic Setting ◽  
Northern Apennines ◽  
Contact Metamorphism ◽  
Pluton Emplacement ◽  
Vertical Permeability ◽  
Extensional Tectonic ◽  
History Of ◽  
Elba Island ◽  
Exhumation History ◽  
Transfer Zone

<p>In extensional tectonic settings, stretched terrains are often associated to lithosphere partial melting and widespread magmatism with plutons emplaced in the thinned crust. Emplacement of felsic magmas, at upper crustal levels, represents the final stage of the magma transfer from profound to shallow depth. In this framework, a mostly vertical permeability controls the magma uprising migration, as induced by dominant transcurrent crustal structures. Nevertheless, the interplay between extension and prolonged heat transfer favors uplift and progressive exhumation of the magmatic bodies, during their cooling.</p><p>In this presentation, we show an example of a felsic magmatic intrusion, the Porto Azzurro pluton (inner northern Apennines), emplaced in an extensional tectonic setting and mainly controlled by a regional transfer zone related to the opening of the Tyrrhenian Basin. This is exposed in the eastern Elba Island (Tuscan Archipelago). The hosting rocks of the Porto Azzurro pluton are mainly represented by micaschist, paragneiss and quartzite, affected by contact metamorphism and intense fluid circulation. We have analysed the structures that assisted the pluton emplacement and the ones that deformed the pluton itself during its cooling, from melt-present to brittle conditions, based on the integration among fieldwork, micro-structural, petrological and EBSD analyses. Furthermore, new U/Pb geochronological data on zircons and (U-Th)/He on apatite fission track refined the age of the pluton emplacement and its cooling, adding new data about the pluton history. Existing petrological analyses of the hosting rocks allowed us to better constrain the time-evolution of the thermal perturbation, permitting to frame the deformation and exhumation history of the Porto Azzurro monzogranite in the context of the Neogene extensional tectonics affecting the inner Northern Apennines.</p>

Multiple hydro-fracturing by boron-rich fluids in the Late Miocene contact aureole of eastern Elba Island (Tuscany, Italy)

Terra Nova ◽  
2008 ◽  
Vol 20 (4) ◽  
pp. 318-326 ◽  
Author(s):  
A. Dini ◽  
F. Mazzarini ◽  
G. Musumeci ◽  
S. Rocchi
Keyword(s):  
Late Miocene ◽  
Contact Aureole ◽  
Elba Island

HP-LT metamorphism in Elba Island: Implications for the geodynamic evolution of the inner Northern Apennines (Italy)

2015 ◽  
Vol 91 ◽  
pp. 13-25 ◽  
Author(s):  
Caterina Bianco ◽  
Andrea Brogi ◽  
Alfredo Caggianelli ◽  
Giovanna Giorgetti ◽  
Domenico Liotta ◽  
...  
Keyword(s):  
Northern Apennines ◽  
Geodynamic Evolution ◽  
Elba Island

Reconsidering the Variscan basement of southern Tuscany (inner Northern Apennines)

2021 ◽  
Author(s):  
Enrico Capezzuoli ◽  
Amalia Spina ◽  
Andrea Brogi ◽  
Domenico Liotta ◽  
Gabriella Bagnoli ◽  
...  
Keyword(s):  
Continental Crust ◽  
Early Carboniferous ◽  
Northern Apennines ◽  
Time Interval ◽  
Structural Studies ◽  
Structural Setting ◽  
Elba Island ◽  
Orogenic Cycle ◽  
Existing Data ◽  
Variscan Basement

<p>The Pre-Mesozoic units exposed in the inner Northern Apennines mostly consist of middle-late Carboniferous-Permian successions unconformably deposited on a continental crust consolidated at the end of the Variscan (i.e. Hercynian) orogenic cycle (Silurian-Carboniferous). In the inner Northern Apennines, exposures of this continental crust, Cambrian?-early Carboniferous in age, have been described in the Northern Tuscany, Elba Island (Tuscan Archipelago) and, partly, in scattered and isolated outcrops of southern Tuscany. In this contribution, we reappraise the most significative succession (i.e. Risanguigno Formation) exposed in southern Tuscany and considered by most authors as part of the Variscan Basement. New stratigraphic and structural studies, coupled with palynological analyses, allow us to refine the age of the Risanguigno Fm and its geological setting and evolution. Based on the microfloristic content, the structural setting and the fieldwork study, we attribute this formation to late Tournaisian-Visean (middle Mississipian) time interval and conclude it is not showing evidence of a pre-Alpine deformation. These results, together with the already existing data, allow us to presume that no exposures of rocks involved in the Variscan orogenesis occur in southern Tuscany.</p>

Neogene tectonics during granite emplacement in Northern Apennines: the case of the Gavorrano monzogranite (southern Tuscany, Italy)

2021 ◽  
Author(s):  
Domenico Liotta ◽  
Alfredo Caggianelli ◽  
Andrea Brogi ◽  
Martina Zucchi ◽  
Amalia Spina ◽  
...  
Keyword(s):  
Tectonic Evolution ◽  
Tectonic Setting ◽  
Structural Data ◽  
Northern Apennines ◽  
Past Century ◽  
Extensional Tectonics ◽  
The Past ◽  
Granite Emplacement ◽  
Geothermal Fluids ◽  
Magmatic Body

<p>The tectonic setting of Neogene is under debate, being interpreted as a contractional, pulsing or extensional framework. On the key-areas to unravel this issue is the Gavorrano monzogranite, located  nearby the Tyrrhenian seacoast, in the inner zone of the Northern Apennines (southern Tuscany), where a Neogene monzogranite body (estimated in about 3 km long, 1.5 km wide, and 0.7 km thick) emplaced during early Pliocene. This magmatic intrusion is partially exposed in a ridge bounded by regional faults delimiting broad structural depressions. A widespread circulation of geothermal fluids accompanied the cooling of the magmatic body and gave rise to an extensive Fe-ore deposit (mainly pyrite) exploited during the past century. Data from a new fieldwork dataset, integrated with information from the mining activity, have been integrated to refine the geological setting of the whole crustal sector where the Gavorrano monzogranite was emplaced and exhumed. Our review, implemented by new palynological, petrological and structural data pointed out that: i) the age of the Palaeozoic phyllite (hosting rocks) is middle-late Permian, thus resulting younger than previously described (i.e. pre-Carboniferous); ii) the P-T conditions at which the metamorphic aureole developed are estimated at about 660 °C and at a maximum depth of c. 5 km; iii) the tectonic evolution which determined the emplacement and exhumation of the monzogranite is constrained in a transfer zone, in the frame of the extensional tectonics affecting the area continuously since Miocene.</p>

scholarly journals Reconsidering the Variscan Basement of Southern Tuscany (Inner Northern Apennines)

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 84
Author(s):  
Enrico Capezzuoli ◽  
Amalia Spina ◽  
Andrea Brogi ◽  
Domenico Liotta ◽  
Gabriella Bagnoli ◽  
...  
Keyword(s):  
Continental Crust ◽  
Organic Matter Content ◽  
Matter Content ◽  
Northern Apennines ◽  
Structural Studies ◽  
Middle Mississippian ◽  
Elba Island ◽  
Orogenic Cycle ◽  
Existing Data ◽  
Variscan Basement

The Pre-Mesozoic units exposed in the inner Northern Apennines mostly consist of Pennsylvanian-Permian successions unconformably deposited on a continental crust consolidated at the end of the Variscan orogenic cycle (Silurian-Carboniferous). In the inner Northern Apennines, exposures of this continental crust, Cambrian?-Devonian in age, have been described in Northern Tuscany, Elba Island (Tuscan Archipelago) and, partly, in scattered and isolated outcrops of southern Tuscany. This paper reappraises the most significant succession (i.e., Risanguigno Formation) exposed in southern Tuscany and considered by most authors as part of the Variscan Basement. New stratigraphic and structural studies, coupled with analyses of the organic matter content, allow us to refine the age of the Risanguigno Fm and its geological setting and evolution. Based on the low diversification of palynoflora, the content of sporomorphs, the structural setting and the new field study, this formation is dated as late Tournaisian to Visean (Middle Mississippian) and is not affected by pre-Alpine deformation. This conclusion, together with the already existing data, clearly indicate that no exposures of rocks involved in the Variscan orogenesis occur in southern Tuscany.

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