Martina Zucchi | University of Bari Italy (original) (raw)
Papers by Martina Zucchi
Tectonophysics, Dec 31, 2023
Advances in Science, Technology & Innovation/Advances in science, technology & innovation, 2024
Geochemistry, Geophysics, Geosystems
High‐temperature geothermal areas are often characterized by widespread surficial manifestations,... more High‐temperature geothermal areas are often characterized by widespread surficial manifestations, whose location is strictly controlled by sets of faults of regional relevance. The geochemical and isotopic signature of the discharged fluids can reveal key information on the geothermal fluids pathway, shedding light on the sources and fluid‐rock interaction within the geothermal reservoirs. In this paper, a geochemical and structural data set from the Larderello geothermal area and surroundings is presented and discussed. We constrain the role of transfer and normal faults in controlling the geothermal circulation enhanced by a cooling magmatic intrusion underneath the Lago area (SW of Larderello). The structural control on the fluids circulation is highlighted by both the location of the CO2 emissions along the fault segments, where permeability is enhanced, and their degassing rates, which increase moving away from the core of the Larderello geothermal system. The main results unra...
International Geology Review
Geosciences
The Pre-Mesozoic units exposed in the inner Northern Apennines mostly consist of Pennsylvanian-Pe... more 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 a...
Energies
Comparison between fossil and analogue active geothermal systems permit to obtain key-parameters ... more Comparison between fossil and analogue active geothermal systems permit to obtain key-parameters to define a conceptual model of the area under exploration. The approach is based on structural, kinematic, and fluid inclusions analyses. The fossil system is investigated to describe the distribution of the hydrothermal mineralization as witness of the fluid flow through geological structures and bodies, at depth. Structural and kinematic data (to define the preferential direction of fluid flow) are collected in structural stations and by scan lines and scan boxes on key outcrops. Distribution, length, width of fractures, and hydrothermal veins bring to evaluate permeability in the fossil system and, by analogy, in the deep roots of the active system. Fluid inclusions analysis shed light on density, viscosity, and temperature of the paleo-fluids. Data integration provides the hydraulic conductivity. In active geothermal systems, fieldwork is addressed to paleo-stress analysis with data...
We review and refine the geological setting of an area located nearby the Tyrrhenian seacoast, in... more We review and refine the geological setting of an area 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, known as the Gavorrano pluton, 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. The tectonic setting which favoured the emplacement and exhumation of the Gavorrano pluton is strongly debated with fallouts on the comprehension of the Neogene evolution of this sector of the inner Northern Apennines. Data from a new fieldwork dataset, integrated with information from the mining activity, have been integrated to refine the geological setting of th...
Geofluids
Banded Ca-carbonate veins in travertine deposits are efficient recorders of the compositional flu... more Banded Ca-carbonate veins in travertine deposits are efficient recorders of the compositional fluctuations of geothermal fluids flowing (or flowed) from deep reservoirs up to the surface, within fault zones. In this view, these veins represent key tools for decoding those factors that influenced the geochemical variations. We have analyzed veins developed in fractures channeling geothermal fluids forming travertine deposits. The studied veins cut a fossil travertine fissure ridge, near the Larderello geothermal area (Iano area, southern Tuscany) where geothermal fluid circulation is favored by NE-trending strike-to-oblique-slip faults and their intersections with NW-trending normal ones. U-Th dating indicates that fluid circulation occurred from (at least) 172 ka to 21 ka. In this time span, the geothermal fluid changed in composition, and the banded Ca-carbonate veins recorded these variations in terms of mineralogical and stable isotope composition and temperature ( T ) of deposit...
International Journal of Earth Sciences
Journal of Volcanology and Geothermal Research
Geothermics, 2020
Geothermal fluid circulation and storage within rock volumes are essential conditions for an effe... more Geothermal fluid circulation and storage within rock volumes are essential conditions for an effective geothermal system. Although several studies examine fluid migration through permeable rock volumes, few papers deal with fluid flow and fluid-rock interaction within the cap rocks of magma-driven geothermal systems. In this paper, I present the results of an integrated study focused on the circulation of geothermal uids and fluid-rock interaction with clayey-carbonate sedimentary rocks and interbedded tectonic slices of serpentinite, representing the cap of an exhumed geothermal system located in the south-eastern Elba Island (Acquarilli-Norsi area, Tuscan Archipelago). Structural and kinematic data highlight that the prevalent geothermal uid pathways correspond to NE- trending normal to oblique-slip faults. A Fe-amphibole + quartz + calcite ± chlorite ± epidote ± titanite mineral assemblage filled the fracture networks associated with two different fault generations. Fluid-rock interaction gave rise to skarnoids having three distinct mineralised zones, locally, crossed by the faults. Fluid inclusions data on quartz and calcite coexisting with the amphibole in the first fault generation and calcite of the second fault generation suggest that at least two paleo-geothermal uids permeated through the fault zones, at a maximum P of about 0.8 kbar. The sequence was (i) first an H2O-rich uid enriched by a volatile phase mainly made up of CO2 derived from the decarbonation and dehydration reactions of the hosting metacarbonate and metapelitic rocks. This fluid characterised by temperature up to 495 °C and salinity between 1.0 and 6.4 wt.% NaClequiv, records the residual intra-formational uid (derived from dehydration of phyllosilicate and serpentinite bodies) already present within the host rocks. This fluid was successively mobilised during the development of the fault zones and progressively cooled and CO2-depleted with time; (ii) a second fluid likely of meteoric origin, devoid of CO2 and characterised by relatively low-temperature from 146.5 to 254 °C and salinity between 1.9 and 2.9 wt.% NaClequiv related to the last uid circulation event. The main conclusions are that: (i) geothermal fluid circulation occurred within the cap rocks of the paleo-geothermal system, along fault zones; (ii) fluid circulation occurred within restricted fault-damaged volumes, developed in an extensional setting; iii) faults dissected rocks that were affected by high-temperature metamorphism induced by the cooling of a magmatic intrusion. The super-hot fluid was produced by metamorphic reactions and only in the latest stage, meteoric water infiltrated in the geothermal system due to the progressive faulting and exhumation.
Tectonophysics, Dec 31, 2023
Advances in Science, Technology & Innovation/Advances in science, technology & innovation, 2024
Geochemistry, Geophysics, Geosystems
High‐temperature geothermal areas are often characterized by widespread surficial manifestations,... more High‐temperature geothermal areas are often characterized by widespread surficial manifestations, whose location is strictly controlled by sets of faults of regional relevance. The geochemical and isotopic signature of the discharged fluids can reveal key information on the geothermal fluids pathway, shedding light on the sources and fluid‐rock interaction within the geothermal reservoirs. In this paper, a geochemical and structural data set from the Larderello geothermal area and surroundings is presented and discussed. We constrain the role of transfer and normal faults in controlling the geothermal circulation enhanced by a cooling magmatic intrusion underneath the Lago area (SW of Larderello). The structural control on the fluids circulation is highlighted by both the location of the CO2 emissions along the fault segments, where permeability is enhanced, and their degassing rates, which increase moving away from the core of the Larderello geothermal system. The main results unra...
International Geology Review
Geosciences
The Pre-Mesozoic units exposed in the inner Northern Apennines mostly consist of Pennsylvanian-Pe... more 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 a...
Energies
Comparison between fossil and analogue active geothermal systems permit to obtain key-parameters ... more Comparison between fossil and analogue active geothermal systems permit to obtain key-parameters to define a conceptual model of the area under exploration. The approach is based on structural, kinematic, and fluid inclusions analyses. The fossil system is investigated to describe the distribution of the hydrothermal mineralization as witness of the fluid flow through geological structures and bodies, at depth. Structural and kinematic data (to define the preferential direction of fluid flow) are collected in structural stations and by scan lines and scan boxes on key outcrops. Distribution, length, width of fractures, and hydrothermal veins bring to evaluate permeability in the fossil system and, by analogy, in the deep roots of the active system. Fluid inclusions analysis shed light on density, viscosity, and temperature of the paleo-fluids. Data integration provides the hydraulic conductivity. In active geothermal systems, fieldwork is addressed to paleo-stress analysis with data...
We review and refine the geological setting of an area located nearby the Tyrrhenian seacoast, in... more We review and refine the geological setting of an area 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, known as the Gavorrano pluton, 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. The tectonic setting which favoured the emplacement and exhumation of the Gavorrano pluton is strongly debated with fallouts on the comprehension of the Neogene evolution of this sector of the inner Northern Apennines. Data from a new fieldwork dataset, integrated with information from the mining activity, have been integrated to refine the geological setting of th...
Geofluids
Banded Ca-carbonate veins in travertine deposits are efficient recorders of the compositional flu... more Banded Ca-carbonate veins in travertine deposits are efficient recorders of the compositional fluctuations of geothermal fluids flowing (or flowed) from deep reservoirs up to the surface, within fault zones. In this view, these veins represent key tools for decoding those factors that influenced the geochemical variations. We have analyzed veins developed in fractures channeling geothermal fluids forming travertine deposits. The studied veins cut a fossil travertine fissure ridge, near the Larderello geothermal area (Iano area, southern Tuscany) where geothermal fluid circulation is favored by NE-trending strike-to-oblique-slip faults and their intersections with NW-trending normal ones. U-Th dating indicates that fluid circulation occurred from (at least) 172 ka to 21 ka. In this time span, the geothermal fluid changed in composition, and the banded Ca-carbonate veins recorded these variations in terms of mineralogical and stable isotope composition and temperature ( T ) of deposit...
International Journal of Earth Sciences
Journal of Volcanology and Geothermal Research
Geothermics, 2020
Geothermal fluid circulation and storage within rock volumes are essential conditions for an effe... more Geothermal fluid circulation and storage within rock volumes are essential conditions for an effective geothermal system. Although several studies examine fluid migration through permeable rock volumes, few papers deal with fluid flow and fluid-rock interaction within the cap rocks of magma-driven geothermal systems. In this paper, I present the results of an integrated study focused on the circulation of geothermal uids and fluid-rock interaction with clayey-carbonate sedimentary rocks and interbedded tectonic slices of serpentinite, representing the cap of an exhumed geothermal system located in the south-eastern Elba Island (Acquarilli-Norsi area, Tuscan Archipelago). Structural and kinematic data highlight that the prevalent geothermal uid pathways correspond to NE- trending normal to oblique-slip faults. A Fe-amphibole + quartz + calcite ± chlorite ± epidote ± titanite mineral assemblage filled the fracture networks associated with two different fault generations. Fluid-rock interaction gave rise to skarnoids having three distinct mineralised zones, locally, crossed by the faults. Fluid inclusions data on quartz and calcite coexisting with the amphibole in the first fault generation and calcite of the second fault generation suggest that at least two paleo-geothermal uids permeated through the fault zones, at a maximum P of about 0.8 kbar. The sequence was (i) first an H2O-rich uid enriched by a volatile phase mainly made up of CO2 derived from the decarbonation and dehydration reactions of the hosting metacarbonate and metapelitic rocks. This fluid characterised by temperature up to 495 °C and salinity between 1.0 and 6.4 wt.% NaClequiv, records the residual intra-formational uid (derived from dehydration of phyllosilicate and serpentinite bodies) already present within the host rocks. This fluid was successively mobilised during the development of the fault zones and progressively cooled and CO2-depleted with time; (ii) a second fluid likely of meteoric origin, devoid of CO2 and characterised by relatively low-temperature from 146.5 to 254 °C and salinity between 1.9 and 2.9 wt.% NaClequiv related to the last uid circulation event. The main conclusions are that: (i) geothermal fluid circulation occurred within the cap rocks of the paleo-geothermal system, along fault zones; (ii) fluid circulation occurred within restricted fault-damaged volumes, developed in an extensional setting; iii) faults dissected rocks that were affected by high-temperature metamorphism induced by the cooling of a magmatic intrusion. The super-hot fluid was produced by metamorphic reactions and only in the latest stage, meteoric water infiltrated in the geothermal system due to the progressive faulting and exhumation.