Sara Callegaro - Academia.edu (original) (raw)

Papers by Sara Callegaro

Research paper thumbnail of The Central Atlantic Magmatic Province (CAMP) in Morocco

Journal of Petrology, 2019

The Central Atlantic Magmatic Province (CAMP) is a large igneous province (LIP) composed of basic... more The Central Atlantic Magmatic Province (CAMP) is a large igneous province (LIP) composed of basic dykes, sills, layered intrusions and lava flows emplaced before Pangea break-up and currently distributed on the four continents surrounding the Atlantic Ocean. One of the oldest, best preserved and most complete sub-provinces of the CAMP is located in Morocco. Geochemical, geochronologic, petrographic and magnetostratigraphic data obtained in previous studies allowed identification of four strato-chemical magmatic units, i.e. the Lower, Intermediate, Upper and Recurrent units. For this study, we completed a detailed sampling of the CAMP in Morocco, from the Anti Atlas in the south to the Meseta in the north. We provide a complete mineralogical, petrologic (major and trace elements on whole-rocks and minerals), geochronologic (40Ar/39Ar and U–Pb ages) and geochemical set of data (including Sr–Nd–Pb–Os isotope systematics) for basaltic and basaltic–andesitic lava flow piles and for their...

Research paper thumbnail of Time-related variation of volatile contents of Western Ghats volcanic formations, Deccan, India

Research paper thumbnail of Origin and environmental impact of the Central Atlantic Magmatic Province

The Central Atlantic Magmatic Province (CAMP), associated with the breakup of Pangea and straddli... more The Central Atlantic Magmatic Province (CAMP), associated with the breakup of Pangea and straddling the Triassic-Jurassic boundary, has been recognized as one of the largest Phaneorozoic igneous provinces. Its volcanogenic gas outpurs possibly led to global climatic perturbations that in turn have been suggested to have had a trigger role on the end-Triassic biotic crisis. To further test this causal link, several aspects need to be investigated, through a multidisciplinary approach. In particular, eruptive style and rate as well as chemistry of the outpurred volcanics may influence the quantity and modality of the outgassing, thus determining either a severe or weak environmental impact of a Large Igneous Province. Additionally, precise (isotopic and biochronostratigraphic) geochronological investigations are required to unravel the time relationship between CAMP onset and other events documented in the global stratigraphic record, such as the end-Triassic biological turnover. In t...

Research paper thumbnail of Sulfur partitioning applied to LIP magmatism-A new approach for quantifying sulfur concentration in basaltic melts

Research paper thumbnail of Assessing the causes of the end-Triassic biotic crisis: a review

The end-Triassic biotic crisis marks one of the major mass extinction events in the history of li... more The end-Triassic biotic crisis marks one of the major mass extinction events in the history of life. Several explanations for this event have been suggested, but all present unanswered challenges: (i) sea-level fluctuations during the Late Triassic, does not explain the suddenness of the extinctions in the marine realm; (ii) no impact crater has been dated to coincide with the Triassic–Jurassic boundary (the impact responsible for the annular Manicouagan Reservoir occurred about 12 million years before the extinction event and the Rochechouart impact predates the Tr-J boundary by 1-2 Ma); (iii) massive volcanic eruptions, specifically the flood basalts of the Central Atlantic Magmatic Province (CAMP), would have released carbon dioxide or sulfur dioxide and aerosols, which would cause either intense global warming (from the former) or cooling (from the latter). In this work we will discuss the possibility of causal link between the CAMP, the bolide impact(s) and the end-Triassic mas...

Research paper thumbnail of Sulfur Partitioning Between Clinopyroxene and Melt: Tackling Gas Loads from Lip Magmas

Research paper thumbnail of Circum-Atlantic CAMP volcanism at the Triassic-Jurassic boundary

Combined bio-, magneto-and chemostratigraphic data show that eruption of the 200 Ma Central Atlan... more Combined bio-, magneto-and chemostratigraphic data show that eruption of the 200 Ma Central Atlantic magmatic province (CAMP) lava flows from the High Atlas of Morocco straddled the Triassic-Jurassic (T-J) boundary and originated from het-erogenous lithospheric and then from asthenospheric mantle sources (Marzoli et al., 2004). Similar timing and systematic geochemical evolution are now defined for several CAMP flow sections from the Middle Atlas and NorthEastern Morocco. According to new palynological data, the oldest lava flows from at least two Middle Atlas localities (Maaziz, Midelt) are emplaced on alternating gray and black siltstone layers which yield, up to the contact with the basalts a late Triassic sporomorph assemblage similar to that of the sediments in direct, normal contact with the oldest High Atlas basalts. This assemblage includes Triassic sporomorphs such as P. densus and A. parvus along with specimens of the circumpolles group (e.g. G. meyeriana, C. toro-sus, C. murphyae) and suggest thus synchronous onset of CAMP volcanism throughout Morocco. Despite a generally reduced thickness of the lava pile compared to the High Atlas, three, relatively complete Middle Atlas basalt piles (Maaziz, Oum R-bia, Midelt) show the same progressive up-section depletion of TiO 2 (ca. 1.4-1.5 to 1.1-1.0 wt%), Zr (ca. 120 to ca. 80 ppm) and light Rare Earth elements observed for the Lower to Upper lava flows of the High Atlas. Thus, synchronous eruption straddling the T-J boundary and similar time-related geochemical evolution of CAMP basalts is suggested for the entire area now corresponding to central-northern Morocco (about 0.3 million square km) and is consistent with preliminary magnetostratigraphic data for the Middle Atlas CAMP. Correlation with eastern North American (ENA) CAMP basalts is based on palynological data from the sedimentary successions of three continental basins (Hartford, Deerfield, Fundy) and on geochemical data for the basalts. In the more complete sedimentary successions of ENA Hartford basin, the palynological association occurring just below the oldest (Talcott basalt) up to the youngest CAMP lava flow (Hampden basalt) are similar and of likely latest Triassic age. However, these sporomorph associations are distinct (e.g., scattered presence of P. densus) and thus probably slightly younger than those at the base of the oldest Moroccan CAMP basalts. A slightly younger age for the onset of ENA compared to the Moroccan CAMP can not be resolved through Ar/Ar geochronology, but is consistent with magnetostratigraphic and new geochemical data, which suggest synchrony between the Moroccan Intermediate and the Hartford Talcott basalts. In summary, widespread CAMP volcanism seems to occur before the T-J boundary and likely contributed to the end-Triassic extinction event.

Research paper thumbnail of Revision 1 of manuscript # 7868 1 2 Fluorine partitioning between quadrilateral clinopyroxenes and melt 3 4 5

°C, at hydrous and anhydrous conditions. Additionally, we determined the crystal-melt partitionin... more °C, at hydrous and anhydrous conditions. Additionally, we determined the crystal-melt partitioning of F 27 This is the peer-reviewed, final accepted version for American Mineralogist, published by the Mineralogical Society of America. The published version is subject to change. Cite as Authors (Year) Title. American Mineralogist, in press. DOI: https://doi.org/10.2138/am-2021-7868. http://www.minsocam.org/

Research paper thumbnail of A crystal/melt partitioning study for sulfur and halogens: pyroxenes as probes for assessing gas loads in LIP magmas

Research paper thumbnail of The High-Ti Camp Freetown Layered Complex (Sierra Leone) - Lithospheric Imprinting Revealed by Isotope Systematics

Research paper thumbnail of Tracing volcanic emissions from the CAMP volcanism in the sedimentary and biotic record

Research paper thumbnail of Volatile-Free Minerals and Silicate Melts

15 Magmatic systems are dominated by five volatiles, namely H2O, CO2, F, Cl, and S (the igneous 1... more 15 Magmatic systems are dominated by five volatiles, namely H2O, CO2, F, Cl, and S (the igneous 16 quintet). Multiple studies have measured partitioning of 4 out of these 5 volatiles (H2O, CO2, F, and 17 Cl) between nominally volatile-free minerals and melts, whereas the partitioning of sulfur is poorly 18 known. To better constrain the behavior of sulfur in igneous systems we measured the partitioning of 19 sulfur between clinopyroxene and silicate melts over a range of pressure, temperature, and melt 20 composition from 0.8 to 1.2 GPa, 1000 to 1240 °C, and 49 to 66 wt% SiO2 (13 measurements). 21 Additionally, we determined the crystal-melt partitioning of sulfur for plagioclase (6 measurements), 22 orthopyroxene (2 measurements), amphibole (2 measurements) and olivine (1 measurement) in some of 23

Research paper thumbnail of Deep CO2 from the Central Atlantic Magmatic Province during the end-Triassic mass extinction

Research paper thumbnail of Possible climate effects of the CAMP intrusive and extrusive activity and its influence on the end-Triassic mass extinction

Research paper thumbnail of Synchrotron light X-ray microtomography reveals a crystalline mush within the deep plumbing system of Large Igneous Provinces

Goldschmidt2021 abstracts

Research paper thumbnail of Geochemistry of low-Ti Siberian Traps sills from the Tunguska Basin bears evidence of magma-crust interaction

Goldschmidt2021 abstracts

Research paper thumbnail of Constraining the enigmatic source of Vesteris Seamount volcanism

Goldschmidt2021 abstracts

Research paper thumbnail of The quintet completed: the partitioning of sulfur between nominally volatile-free minerals and silicate melts

American Mineralogist

Magmatic systems are dominated by five volatiles, namely H2O, CO2, F, Cl, and S (the igneous quin... more Magmatic systems are dominated by five volatiles, namely H2O, CO2, F, Cl, and S (the igneous quintet). Multiple studies have measured partitioning of four out of these five volatiles (H2O, CO2, F, and Cl) between nominally volatile-free minerals and melts, whereas the partitioning of sulfur is poorly known. To better constrain the behavior of sulfur in igneous systems we measured the partitioning of sulfur between clinopyroxene and silicate melts over a range of pressure, temperature, and melt composition from 0.8 to 1.2 GPa, 1000 to 1240 °C, and 49 to 66 wt% SiO2 (13 measurements). Additionally, we determined the crystal-melt partitioning of sulfur for plagioclase (6 measurements), orthopyroxene (2 measurements), amphibole (2 measurements), and olivine (1 measurement) in some of these same run products. Experiments were performed at high and low oxygen fugacities, where sulfur in the melt is expected to be dominantly present as an S6+ or an S2– species, respectively. When the parti...

Research paper thumbnail of Sr, Nd, Pb and Os Isotope Systematics of CAMP Tholeiites from Eastern North America (ENA): Evidence of a Subduction-enriched Mantle Source

Journal of Petrology, 2014

The Central Atlantic Magmatic Province (CAMP) is one of the largest igneous provinces on Earth, w... more The Central Atlantic Magmatic Province (CAMP) is one of the largest igneous provinces on Earth, with an areal extent exceeding 10 7 km 2. Here we document the geochemical characteristics of CAMP basalts fromTriassic^Jurassic basins in northeastern USA and Nova Scotia (Canada). The CAMP rocks occur as lava flows, sills and dykes. All of our analysed samples show chemical characteristics typical of CAMP basalts with low titanium content, which include enrichment in the most incompatible elements and negative Nb anomalies. All the basalts also show enriched Sr^Nd^Pb initial (t ¼ 201 Ma) isotopic compositions (206 Pb/ 204 Pb ini. ¼ 18•1551 8•691, 207 Pb/ 204 Pb ini. ¼ 15•616^15•668, 208 Pb/ 204 Pb ini. ¼ 38•160^38•616, 143 Nd/ 144 Nd ini. ¼ 0•512169^0•512499). On the basis of stratigraphy, rare earth element (REE) chemistry and SrN d^Pb isotope composition, three chemical groups are defined. The Hook Mountain group, with the lowest La/Yb ratios, initial 206 Pb/ 204 Pb ini. 418•5 and 143 Nd/ 144 Nd ini. 40•51238, comprises all the lastest and upper stratigraphic units. The Preakness group, with intermediate La/Yb ratios, 206 Pb/ 204 Pb ini. 418•5 and

Research paper thumbnail of Don’t blame it on Fluorine: Low F concentrations in Deccan Traps magmas straddling the extinction interval estimated from in situ analyses on clinopyroxene

Goldschmidt2021 abstracts

Research paper thumbnail of The Central Atlantic Magmatic Province (CAMP) in Morocco

Journal of Petrology, 2019

The Central Atlantic Magmatic Province (CAMP) is a large igneous province (LIP) composed of basic... more The Central Atlantic Magmatic Province (CAMP) is a large igneous province (LIP) composed of basic dykes, sills, layered intrusions and lava flows emplaced before Pangea break-up and currently distributed on the four continents surrounding the Atlantic Ocean. One of the oldest, best preserved and most complete sub-provinces of the CAMP is located in Morocco. Geochemical, geochronologic, petrographic and magnetostratigraphic data obtained in previous studies allowed identification of four strato-chemical magmatic units, i.e. the Lower, Intermediate, Upper and Recurrent units. For this study, we completed a detailed sampling of the CAMP in Morocco, from the Anti Atlas in the south to the Meseta in the north. We provide a complete mineralogical, petrologic (major and trace elements on whole-rocks and minerals), geochronologic (40Ar/39Ar and U–Pb ages) and geochemical set of data (including Sr–Nd–Pb–Os isotope systematics) for basaltic and basaltic–andesitic lava flow piles and for their...

Research paper thumbnail of Time-related variation of volatile contents of Western Ghats volcanic formations, Deccan, India

Research paper thumbnail of Origin and environmental impact of the Central Atlantic Magmatic Province

The Central Atlantic Magmatic Province (CAMP), associated with the breakup of Pangea and straddli... more The Central Atlantic Magmatic Province (CAMP), associated with the breakup of Pangea and straddling the Triassic-Jurassic boundary, has been recognized as one of the largest Phaneorozoic igneous provinces. Its volcanogenic gas outpurs possibly led to global climatic perturbations that in turn have been suggested to have had a trigger role on the end-Triassic biotic crisis. To further test this causal link, several aspects need to be investigated, through a multidisciplinary approach. In particular, eruptive style and rate as well as chemistry of the outpurred volcanics may influence the quantity and modality of the outgassing, thus determining either a severe or weak environmental impact of a Large Igneous Province. Additionally, precise (isotopic and biochronostratigraphic) geochronological investigations are required to unravel the time relationship between CAMP onset and other events documented in the global stratigraphic record, such as the end-Triassic biological turnover. In t...

Research paper thumbnail of Sulfur partitioning applied to LIP magmatism-A new approach for quantifying sulfur concentration in basaltic melts

Research paper thumbnail of Assessing the causes of the end-Triassic biotic crisis: a review

The end-Triassic biotic crisis marks one of the major mass extinction events in the history of li... more The end-Triassic biotic crisis marks one of the major mass extinction events in the history of life. Several explanations for this event have been suggested, but all present unanswered challenges: (i) sea-level fluctuations during the Late Triassic, does not explain the suddenness of the extinctions in the marine realm; (ii) no impact crater has been dated to coincide with the Triassic–Jurassic boundary (the impact responsible for the annular Manicouagan Reservoir occurred about 12 million years before the extinction event and the Rochechouart impact predates the Tr-J boundary by 1-2 Ma); (iii) massive volcanic eruptions, specifically the flood basalts of the Central Atlantic Magmatic Province (CAMP), would have released carbon dioxide or sulfur dioxide and aerosols, which would cause either intense global warming (from the former) or cooling (from the latter). In this work we will discuss the possibility of causal link between the CAMP, the bolide impact(s) and the end-Triassic mas...

Research paper thumbnail of Sulfur Partitioning Between Clinopyroxene and Melt: Tackling Gas Loads from Lip Magmas

Research paper thumbnail of Circum-Atlantic CAMP volcanism at the Triassic-Jurassic boundary

Combined bio-, magneto-and chemostratigraphic data show that eruption of the 200 Ma Central Atlan... more Combined bio-, magneto-and chemostratigraphic data show that eruption of the 200 Ma Central Atlantic magmatic province (CAMP) lava flows from the High Atlas of Morocco straddled the Triassic-Jurassic (T-J) boundary and originated from het-erogenous lithospheric and then from asthenospheric mantle sources (Marzoli et al., 2004). Similar timing and systematic geochemical evolution are now defined for several CAMP flow sections from the Middle Atlas and NorthEastern Morocco. According to new palynological data, the oldest lava flows from at least two Middle Atlas localities (Maaziz, Midelt) are emplaced on alternating gray and black siltstone layers which yield, up to the contact with the basalts a late Triassic sporomorph assemblage similar to that of the sediments in direct, normal contact with the oldest High Atlas basalts. This assemblage includes Triassic sporomorphs such as P. densus and A. parvus along with specimens of the circumpolles group (e.g. G. meyeriana, C. toro-sus, C. murphyae) and suggest thus synchronous onset of CAMP volcanism throughout Morocco. Despite a generally reduced thickness of the lava pile compared to the High Atlas, three, relatively complete Middle Atlas basalt piles (Maaziz, Oum R-bia, Midelt) show the same progressive up-section depletion of TiO 2 (ca. 1.4-1.5 to 1.1-1.0 wt%), Zr (ca. 120 to ca. 80 ppm) and light Rare Earth elements observed for the Lower to Upper lava flows of the High Atlas. Thus, synchronous eruption straddling the T-J boundary and similar time-related geochemical evolution of CAMP basalts is suggested for the entire area now corresponding to central-northern Morocco (about 0.3 million square km) and is consistent with preliminary magnetostratigraphic data for the Middle Atlas CAMP. Correlation with eastern North American (ENA) CAMP basalts is based on palynological data from the sedimentary successions of three continental basins (Hartford, Deerfield, Fundy) and on geochemical data for the basalts. In the more complete sedimentary successions of ENA Hartford basin, the palynological association occurring just below the oldest (Talcott basalt) up to the youngest CAMP lava flow (Hampden basalt) are similar and of likely latest Triassic age. However, these sporomorph associations are distinct (e.g., scattered presence of P. densus) and thus probably slightly younger than those at the base of the oldest Moroccan CAMP basalts. A slightly younger age for the onset of ENA compared to the Moroccan CAMP can not be resolved through Ar/Ar geochronology, but is consistent with magnetostratigraphic and new geochemical data, which suggest synchrony between the Moroccan Intermediate and the Hartford Talcott basalts. In summary, widespread CAMP volcanism seems to occur before the T-J boundary and likely contributed to the end-Triassic extinction event.

Research paper thumbnail of Revision 1 of manuscript # 7868 1 2 Fluorine partitioning between quadrilateral clinopyroxenes and melt 3 4 5

°C, at hydrous and anhydrous conditions. Additionally, we determined the crystal-melt partitionin... more °C, at hydrous and anhydrous conditions. Additionally, we determined the crystal-melt partitioning of F 27 This is the peer-reviewed, final accepted version for American Mineralogist, published by the Mineralogical Society of America. The published version is subject to change. Cite as Authors (Year) Title. American Mineralogist, in press. DOI: https://doi.org/10.2138/am-2021-7868. http://www.minsocam.org/

Research paper thumbnail of A crystal/melt partitioning study for sulfur and halogens: pyroxenes as probes for assessing gas loads in LIP magmas

Research paper thumbnail of The High-Ti Camp Freetown Layered Complex (Sierra Leone) - Lithospheric Imprinting Revealed by Isotope Systematics

Research paper thumbnail of Tracing volcanic emissions from the CAMP volcanism in the sedimentary and biotic record

Research paper thumbnail of Volatile-Free Minerals and Silicate Melts

15 Magmatic systems are dominated by five volatiles, namely H2O, CO2, F, Cl, and S (the igneous 1... more 15 Magmatic systems are dominated by five volatiles, namely H2O, CO2, F, Cl, and S (the igneous 16 quintet). Multiple studies have measured partitioning of 4 out of these 5 volatiles (H2O, CO2, F, and 17 Cl) between nominally volatile-free minerals and melts, whereas the partitioning of sulfur is poorly 18 known. To better constrain the behavior of sulfur in igneous systems we measured the partitioning of 19 sulfur between clinopyroxene and silicate melts over a range of pressure, temperature, and melt 20 composition from 0.8 to 1.2 GPa, 1000 to 1240 °C, and 49 to 66 wt% SiO2 (13 measurements). 21 Additionally, we determined the crystal-melt partitioning of sulfur for plagioclase (6 measurements), 22 orthopyroxene (2 measurements), amphibole (2 measurements) and olivine (1 measurement) in some of 23

Research paper thumbnail of Deep CO2 from the Central Atlantic Magmatic Province during the end-Triassic mass extinction

Research paper thumbnail of Possible climate effects of the CAMP intrusive and extrusive activity and its influence on the end-Triassic mass extinction

Research paper thumbnail of Synchrotron light X-ray microtomography reveals a crystalline mush within the deep plumbing system of Large Igneous Provinces

Goldschmidt2021 abstracts

Research paper thumbnail of Geochemistry of low-Ti Siberian Traps sills from the Tunguska Basin bears evidence of magma-crust interaction

Goldschmidt2021 abstracts

Research paper thumbnail of Constraining the enigmatic source of Vesteris Seamount volcanism

Goldschmidt2021 abstracts

Research paper thumbnail of The quintet completed: the partitioning of sulfur between nominally volatile-free minerals and silicate melts

American Mineralogist

Magmatic systems are dominated by five volatiles, namely H2O, CO2, F, Cl, and S (the igneous quin... more Magmatic systems are dominated by five volatiles, namely H2O, CO2, F, Cl, and S (the igneous quintet). Multiple studies have measured partitioning of four out of these five volatiles (H2O, CO2, F, and Cl) between nominally volatile-free minerals and melts, whereas the partitioning of sulfur is poorly known. To better constrain the behavior of sulfur in igneous systems we measured the partitioning of sulfur between clinopyroxene and silicate melts over a range of pressure, temperature, and melt composition from 0.8 to 1.2 GPa, 1000 to 1240 °C, and 49 to 66 wt% SiO2 (13 measurements). Additionally, we determined the crystal-melt partitioning of sulfur for plagioclase (6 measurements), orthopyroxene (2 measurements), amphibole (2 measurements), and olivine (1 measurement) in some of these same run products. Experiments were performed at high and low oxygen fugacities, where sulfur in the melt is expected to be dominantly present as an S6+ or an S2– species, respectively. When the parti...

Research paper thumbnail of Sr, Nd, Pb and Os Isotope Systematics of CAMP Tholeiites from Eastern North America (ENA): Evidence of a Subduction-enriched Mantle Source

Journal of Petrology, 2014

The Central Atlantic Magmatic Province (CAMP) is one of the largest igneous provinces on Earth, w... more The Central Atlantic Magmatic Province (CAMP) is one of the largest igneous provinces on Earth, with an areal extent exceeding 10 7 km 2. Here we document the geochemical characteristics of CAMP basalts fromTriassic^Jurassic basins in northeastern USA and Nova Scotia (Canada). The CAMP rocks occur as lava flows, sills and dykes. All of our analysed samples show chemical characteristics typical of CAMP basalts with low titanium content, which include enrichment in the most incompatible elements and negative Nb anomalies. All the basalts also show enriched Sr^Nd^Pb initial (t ¼ 201 Ma) isotopic compositions (206 Pb/ 204 Pb ini. ¼ 18•1551 8•691, 207 Pb/ 204 Pb ini. ¼ 15•616^15•668, 208 Pb/ 204 Pb ini. ¼ 38•160^38•616, 143 Nd/ 144 Nd ini. ¼ 0•512169^0•512499). On the basis of stratigraphy, rare earth element (REE) chemistry and SrN d^Pb isotope composition, three chemical groups are defined. The Hook Mountain group, with the lowest La/Yb ratios, initial 206 Pb/ 204 Pb ini. 418•5 and 143 Nd/ 144 Nd ini. 40•51238, comprises all the lastest and upper stratigraphic units. The Preakness group, with intermediate La/Yb ratios, 206 Pb/ 204 Pb ini. 418•5 and

Research paper thumbnail of Don’t blame it on Fluorine: Low F concentrations in Deccan Traps magmas straddling the extinction interval estimated from in situ analyses on clinopyroxene

Goldschmidt2021 abstracts