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Landslides are a major threat for population and urban areas. Persistent Scatterer Interferometry (PSI) is a powerful tool for identifying landslides and monitoring their evolution over long periods and has proven to be very useful especially in urban areas, where a sufficient number of PS can be generated. In this study, we applied PS interferometry to investigate the landslide affecting Santo Stefano d’Aveto (Liguria, NW Italy) by integrating classic interferometric techniques with cross-correlation analysis of PS time-series and with geological and geotechnical field information. We used open-source software and packages to process Synthetic Aperture Radar (SAR) images from the Copernicus Sentinel-1A satellite for both ascending and descending orbits over the period 2015–2021 and calculate both the vertical motion and the E-W horizontal displacement. By computing the cross-correlation of the PS time-series, we identified three families of PS with a similarity greater than 0.70. The cross-correlation analysis allowed subdividing the landslide in different sectors, each of which is characterized by a specific type of movement. The geological meaning of this subdivision is still a matter of discussion but it is presumably driven by the geomorphological setting of the area and by the regional tectonics.
Evandro Balbi; Martino Terrone; Francesco Faccini; Davide Scafidi; Simone Barani; Silvano Tosi; Laura Crispini; Paola Cianfarra; Flavio Poggi; Gabriele Ferretti. Persistent Scatterer Interferometry and Statistical Analysis of Time-Series for Landslide Monitoring: Application to Santo Stefano d’Aveto (Liguria, NW Italy). Remote Sensing 2021, 13, 3348 .
AMA StyleEvandro Balbi, Martino Terrone, Francesco Faccini, Davide Scafidi, Simone Barani, Silvano Tosi, Laura Crispini, Paola Cianfarra, Flavio Poggi, Gabriele Ferretti. Persistent Scatterer Interferometry and Statistical Analysis of Time-Series for Landslide Monitoring: Application to Santo Stefano d’Aveto (Liguria, NW Italy). Remote Sensing. 2021; 13 (17):3348.
Chicago/Turabian StyleEvandro Balbi; Martino Terrone; Francesco Faccini; Davide Scafidi; Simone Barani; Silvano Tosi; Laura Crispini; Paola Cianfarra; Flavio Poggi; Gabriele Ferretti. 2021. "Persistent Scatterer Interferometry and Statistical Analysis of Time-Series for Landslide Monitoring: Application to Santo Stefano d’Aveto (Liguria, NW Italy)." Remote Sensing 13, no. 17: 3348.
For more than half a century, exploring a complete sequence of the oceanic crust from the seafloor through the Mohorovičić discontinuity (Moho) and into the uppermost mantle has been one of the most challenging missions of scientific ocean drilling. Such a scientific and technological achievement would provide humankind with profound insights into the largest realm of our planet and expand our fundamental understanding of Earth's deep interior and its geodynamic behavior. The formation of new oceanic crust at mid-ocean ridges and its subsequent aging over millions of years, leading to subduction, arc volcanism, and recycling of some components into the mantle, comprise the dominant geological cycle of matter and energy on Earth. Although previous scientific ocean drilling has cored some drill holes into old (> 110 Ma) and young (< 20 Ma) ocean crust, our sampling remains relatively shallow (< 2 km into intact crust) and unrepresentative of average oceanic crust. To date, no hole penetrates more than 100 m into intact average-aged oceanic crust that records the long-term history of seawater–basalt exchange (60 to 90 Myr). In addition, the nature, extent, and evolution of the deep subseafloor biosphere within oceanic crust remains poorly unknown. To address these fundamentally significant scientific issues, an international workshop “Exploring Deep Oceanic Crust off Hawai`i” brought together 106 scientists and engineers from 16 countries that represented the entire spectrum of disciplines, including petrologists, geophysicists, geochemists, microbiologists, geodynamic modelers, and drilling/logging engineers. The aim of the workshop was to develop a full International Ocean Discovery Program (IODP) proposal to drill a 2.5 km deep hole into oceanic crust on the North Arch off Hawai`i with the drilling research vessel Chikyu. This drill hole would provide samples down to cumulate gabbros of mature (∼ 80 Ma) oceanic crust formed at a half spreading rate of ∼ 3.5 cm a−1. A Moho reflection has been observed at ∼ 5.5 km below the seafloor at this site, and the workshop concluded that the proposed 2.5 km deep scientific drilling on the North Arch off Hawai`i would provide an essential “pilot hole” to inform the design of future mantle drilling.
Susumu Umino; Gregory F. Moore; Brian Boston; Rosalind Coggon; Laura Crispini; Steven D'Hondt; Michael O. Garcia; Takeshi Hanyu; Frieder Klein; Nobukazu Seama; Damon A. H. Teagle; Masako Tominaga; Mikiya Yamashita; Michelle Harris; Benoit Ildefonse; Ikuo Katayama; Yuki Kusano; Yohey Suzuki; Elizabeth Trembath-Reichert; Yasuhiro Yamada; Natsue Abe; Nan Xiao; Fumio Inagaki. Workshop report: Exploring deep oceanic crust off Hawai`i. Scientific Drilling 2021, 29, 69 -82.
AMA StyleSusumu Umino, Gregory F. Moore, Brian Boston, Rosalind Coggon, Laura Crispini, Steven D'Hondt, Michael O. Garcia, Takeshi Hanyu, Frieder Klein, Nobukazu Seama, Damon A. H. Teagle, Masako Tominaga, Mikiya Yamashita, Michelle Harris, Benoit Ildefonse, Ikuo Katayama, Yuki Kusano, Yohey Suzuki, Elizabeth Trembath-Reichert, Yasuhiro Yamada, Natsue Abe, Nan Xiao, Fumio Inagaki. Workshop report: Exploring deep oceanic crust off Hawai`i. Scientific Drilling. 2021; 29 ():69-82.
Chicago/Turabian StyleSusumu Umino; Gregory F. Moore; Brian Boston; Rosalind Coggon; Laura Crispini; Steven D'Hondt; Michael O. Garcia; Takeshi Hanyu; Frieder Klein; Nobukazu Seama; Damon A. H. Teagle; Masako Tominaga; Mikiya Yamashita; Michelle Harris; Benoit Ildefonse; Ikuo Katayama; Yuki Kusano; Yohey Suzuki; Elizabeth Trembath-Reichert; Yasuhiro Yamada; Natsue Abe; Nan Xiao; Fumio Inagaki. 2021. "Workshop report: Exploring deep oceanic crust off Hawai`i." Scientific Drilling 29, no. : 69-82.
Exhumed faults in granitoids along the Lanterman Fault-Rennick Graben Fault system (northern Victoria Land, Antarctica) show superposed ductile to brittle deformation and pervasive hydrothermal fluid-rock interaction. These processes triggered multiple brittle slip events producing crosscutting epidote and prehnite-rich fault veins, ultracataclasites and pseudotachylytes of crushing origin. Combined microstructural and minerochemical investigations on fault damage zones show three types of alteration: (i) albitization of K-feldspar and Ca-plagioclase; (ii) crystallization of prehnite and calcite in veins; (iii) alteration of magmatic phases by secondary hydrous minerals (e.g. chlorite, white mica, epidote and prehnite). The fault experienced various episodes of strain weakening and hardening, due to alteration of minerals and precipitation of epidote and prehnite within ultracataclastic intervals, at decreasing temperature conditions (200 < T°C < 450) and varying CO2 fugacity of the fluids. Cyclic crystallization of epidote/prehnite within the fault cores caused cementation and locking of faults, concentration of deformation at weaker horizons and a progressive broadening of the fault zone. Our results indicate that multiple co-seismic slip and syntectonic fluid flow very likely occurred prior to the Cenozoic brittle reactivation of inherited anisotropies in the northern Victoria Land crust along the Lanterman Fault-Rennick Graben Fault system and underlines its high potential for polyphasicity.
Cristina Malatesta; Laura Crispini; Benoit Ildefonse; Laura Federico; Frank Lisker; Andreas Läufer. Microstructures of epidote-prehnite bearing damaged granitoids (northern Victoria Land, Antarctica): clues for the interaction between faulting and hydrothermal fluids. Journal of Structural Geology 2021, 147, 104350 .
AMA StyleCristina Malatesta, Laura Crispini, Benoit Ildefonse, Laura Federico, Frank Lisker, Andreas Läufer. Microstructures of epidote-prehnite bearing damaged granitoids (northern Victoria Land, Antarctica): clues for the interaction between faulting and hydrothermal fluids. Journal of Structural Geology. 2021; 147 ():104350.
Chicago/Turabian StyleCristina Malatesta; Laura Crispini; Benoit Ildefonse; Laura Federico; Frank Lisker; Andreas Läufer. 2021. "Microstructures of epidote-prehnite bearing damaged granitoids (northern Victoria Land, Antarctica): clues for the interaction between faulting and hydrothermal fluids." Journal of Structural Geology 147, no. : 104350.
The Mt. Melbourne Volcanic Complex (MMVC) is located in Northern Victoria Land (Antarctica) along the western flank of the West Antarctic Rift System, at the boundary with the Transantarctic Mountains. It is constituted by two main volcanic areas, i.e. the Mt. Melbourne Edifice (MME) and the Cape Washington Shield (CWS), and some other minor centres.
To date, the inner structure of this volcanic complex is still poorly known, being the direct geological information on site confined to either glacial erratics or a few rock outcrops not hidden by the ice sheet. Consequently, even the temporal building up and evolution of the MMVC as well as its primary magmatic source are still under investigation (debated).
Recently, we attempted to define the geological structure of the MMVC by means of digital enhancement and forward modeling performed on a high-resolution aeromagnetic dataset (Ghirotto et al. 2020, EGU). Coupling both information derived from past geological/geophysical studies and unpublished magnetic susceptibility measurements from rock samples collected in the field, we proposed two models to explain the chronological evolution of the MME and CWS. These models involve either i) major magmatic events occurred in periods of both normal and reverse magnetic polarity or ii) only magmatic flows with normal polarity.
To gain further insights into the geological structure and the geodynamic evolution of the MMVC in relation to the two proposed models, we develop here a Hamiltonian Monte Carlo (HMC) algorithm (Fichtner et al. 2018) based on the probabilistic approach to inverse problems. To date, this methodology has never been applied to aeromagnetic data for geological studies. In detail, the above proposed models provide some soft a priori information from which to start exploring potential solutions. The parameterization of the volcanic area is defined in terms of 2-D polygonal bodies, representing e.g. magmatic lava flows, where the unknown parameters are represented by both the position of the vertices and/or the magnetization (induced and/or remnant), resulting in a non-linear forward model. The HMC algorithm requires the computation of gradients of the posterior probability density (PPD), i.e., derivatives of the objective functional with respect to the position of vertices of the bodies and magnetization, in order to better move the inversion process toward high-probability areas in the model space manifold. We implement such calculations using automatic differentiation, a tool which is very accurate and fast compared to other approaches such as finite difference. The result of the inversion is then a collection of models representing the PPD, from which statistical analysis can provide measures of uncertainty and plausible geological scenarios.
In this study we present some preliminary results of applying the above-mentioned methodology, which finally could help unravel the framework of the MMVC.
Alessandro Ghirotto; Andrea Zunino; Egidio Armadillo; Laura Crispini; Fausto Ferraccioli. Imaging the Mt. Melbourne Volcanic Field (Northern Victoria Land, Antarctica): a Hamiltonian Monte Carlo approach applied to high-resolution aeromagnetic data. 2021, 1 .
AMA StyleAlessandro Ghirotto, Andrea Zunino, Egidio Armadillo, Laura Crispini, Fausto Ferraccioli. Imaging the Mt. Melbourne Volcanic Field (Northern Victoria Land, Antarctica): a Hamiltonian Monte Carlo approach applied to high-resolution aeromagnetic data. . 2021; ():1.
Chicago/Turabian StyleAlessandro Ghirotto; Andrea Zunino; Egidio Armadillo; Laura Crispini; Fausto Ferraccioli. 2021. "Imaging the Mt. Melbourne Volcanic Field (Northern Victoria Land, Antarctica): a Hamiltonian Monte Carlo approach applied to high-resolution aeromagnetic data." , no. : 1.
Northern Victoria Land constitutes the Pacific terminus of the Transantarctic Mountains (TAM) on the western shoulder of the Cenozoic West Antarctic Rift System. It is characterised by a distinct morphological transition from an elevated peneplain that dominates throughout most of the TAM to a strongly undulating relief with prominent narrow crests and alpine peaks. This contrast is associated with a lithological change from high-grade metamorphics and granitoids to low-grade metasedimentary rocks that contain only few scattered igneous bodies.
New high-resolution thermochronological data (fission-track and (U-Th-Sm)/He) from more than 60 locations in the Southern Cross Mountains and Mountaineer Range of northern Victoria Land provide the basis for studying regional exhumation and uplift with particular focus on the establishment of landscape contrasts. In an integrated approach, differences in topography are examined with respect to regional and local controls including tectonics, lithology and climate to identify differential trends and quantify the morphological evolution of the TAM and West Antarctic Rift System.
Two coastal profiles covering 2 to 3 km in elevation reveal apatite fission track ages from 23 to 45 Ma with mean track lengths of 13.3 – 14.7 μm. Corresponding (U-Th-Sm)/He apatite and zircon data range between 19 – 32 Ma and 24 – 27 Ma, respectively. The dates show distinctive spatial trends of increasing ages from north to south and at greater distance to the coast whereby younger cooling ages correlate with stronger terrain segmentation and higher topographic relief.
Thermal history modelling of the combined data indicates that accelerated cooling commencing at 35 Ma proceeded at progressively higher rates reaching >25°C/Ma in late stages. This cooling episode continued until at least 20 Ma and refers to exhumation from burial depths of more than 5 km, clearly exceeding the calculated overburden on adjacent crustal blocks to the south. Although rapid upper lithospheric cooling is a generic feature of northern Victoria Land, the current data demonstrates that Cenozoic exhumation dynamics were highly differential. Understanding these patterns requires thorough balancing of structural against isostatic factors, lithological against climate parameters and focussed local incision against large-scale denudation and levelling processes.
Daniela Roehnert; Frank Lisker; Maria Laura Balestrieri; Luca Grewe; Evandro Balbi; Andreas Läufer; Laura Crispini; Cornelia Spiegel. Thermochronology as a key to deciphering controls on landscape evolution in northern Victoria Land (Transantarctic Mountains) . 2021, 1 .
AMA StyleDaniela Roehnert, Frank Lisker, Maria Laura Balestrieri, Luca Grewe, Evandro Balbi, Andreas Läufer, Laura Crispini, Cornelia Spiegel. Thermochronology as a key to deciphering controls on landscape evolution in northern Victoria Land (Transantarctic Mountains) . . 2021; ():1.
Chicago/Turabian StyleDaniela Roehnert; Frank Lisker; Maria Laura Balestrieri; Luca Grewe; Evandro Balbi; Andreas Läufer; Laura Crispini; Cornelia Spiegel. 2021. "Thermochronology as a key to deciphering controls on landscape evolution in northern Victoria Land (Transantarctic Mountains) ." , no. : 1.
The Rennick Geodynamic Belt (RGB, East Antarctica) is a regionally sized, ca N-S trending, deformation zone (length > 100 km) where a dense fault network separates tectonic units of northern the Victoria Land, to the W from the East Antarctic Craton, to the E.
The RGB is long known to have been active since Cambrian-Ordovician times up to recent, but its framework and geodynamic evolution is still debated and partially investigated. The long-lived tectonic activity led to a great structural complexity, due to the superposition and polyphasic reactivation of regional faults. Such complexity is reflected by the numerous (in some cases contrasting) tectonic reconstructions of the RGB area.
In this contribution we explore the present-day tectonic framework of the RGB, investigating the stress field that possibly characterised the last geodynamic events in the area. We base on selected datasets of fault-slip data and fractures density (collected by the Authors in various PNRA Italian Antarctic expeditions) and combine fault-slip data inversion with the azimuthal orientation of faults and the spatial distribution of fractures intensity across the RGB.
To obtain a more robust portrait of the RGB geodynamic evolution, two different software based on different fault-inversion methods were used in this study: DAISY (Windows, version 3.5) and FSA (MAC, version 36.5x7i). The software DAISY implements the multiple Monte Carlo convergent method and provides the best orientation of the principal paleostresses with an estimate of the error quantified by the factor MAD (Mean Angular Deviation, corresponding to the average angular deviation between the measured pitch of the kinematic vector on the fault plane and the predicted one by applying to the fault the computed paleostress). At each step, faults are uniquely associated to the stress tensor that provides the lowest MAD. Differently, the FSA software combines a random grid search of the stress tensors following a Monte Carlo approach, under the univocal condition of fulfilment of the frictional constraint (i.e. the fault plane must form with an orientation that satisfies the Mohr-Coulomb yield criterion, i.e. t/sn = tgf with t = shear stress, sn = normal stress and f = angle of internal friction). Additionally, this software allows a direct examination of the reduced Mohr circle of the calculated stress tensors, so that we can select the one with the largest number of faults showing a high t/sn ratio.
The paleostress tensors were computed from 373 fault-slip data collected in 34 structural stations on site. Results from this multi methodological approach revealed:
(i) the existence of two, N-S oriented geotectonic provinces (namely the Bowers Mts province to the W and Usarp Mts to the E) characterized by the different spatial distribution of brittle deformation, more intense in the Bower Mts domain.
(ii) The superposition of two recent (Meso-Cenozoic) major tectonic events, with prevalent strike-slip kinematics and characterized by faults reactivation with right-lateral movement overprinting a previous left-lateral one.
Michele Locatelli; Paola Cianfarra; Laura Crispini; Laura Federico. Multiple reactivation of the Rennick Geodynamic Belt (northern Victoria Land, Antarctica): insights from inversion of fault slip data . 2021, 1 .
AMA StyleMichele Locatelli, Paola Cianfarra, Laura Crispini, Laura Federico. Multiple reactivation of the Rennick Geodynamic Belt (northern Victoria Land, Antarctica): insights from inversion of fault slip data . . 2021; ():1.
Chicago/Turabian StyleMichele Locatelli; Paola Cianfarra; Laura Crispini; Laura Federico. 2021. "Multiple reactivation of the Rennick Geodynamic Belt (northern Victoria Land, Antarctica): insights from inversion of fault slip data ." , no. : 1.
In Antarctica, spectral mapping of altered minerals is very challenging due to the remoteness and inaccessibility of poorly exposed outcrops. This investigation evaluates the capability of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite remote sensing imagery for mapping and discrimination of phyllosilicate mineral groups in the Antarctic environment of northern Victoria Land. The Mixture-Tuned Matched-Filtering (MTMF) and Constrained Energy Minimization (CEM) algorithms were used to detect the sub-pixel abundance of Al-rich, Fe3+-rich, Fe2+-rich and Mg-rich phyllosilicates using the visible and near-infrared (VNIR), short-wave infrared (SWIR) and thermal-infrared (TIR) bands of ASTER. Results indicate that Al-rich phyllosilicates are strongly detected in the exposed outcrops of the Granite Harbour granitoids, Wilson Metamorphic Complex and the Beacon Supergroup. The presence of the smectite mineral group derived from the Jurassic basaltic rocks (Ferrar Dolerite and Kirkpatrick Basalts) by weathering and decomposition processes implicates Fe3+-rich and Fe2+-rich phyllosilicates. Biotite (Fe2+-rich phyllosilicate) is detected associated with the Granite Harbour granitoids, Wilson Metamorphic Complex and Melbourne Volcanics. Mg-rich phyllosilicates are mostly mapped in the scree, glacial drift, moraine and crevasse fields derived from weathering and decomposition of the Kirkpatrick Basalt and Ferrar Dolerite. Chlorite (Mg-rich phyllosilicate) was generally mapped in the exposures of Granite Harbour granodiorite and granite and partially identified in the Ferrar Dolerite, the Kirkpatrick Basalt, the Priestley Formation and Priestley Schist and the scree, glacial drift and moraine. Statistical results indicate that Al-rich phyllosilicates class pixels are strongly discriminated, while the pixels attributed to Fe3+-rich class, Fe2+-rich and Mg-rich phyllosilicates classes contain some spectral mixing due to their subtle spectral differences in the VNIR+SWIR bands of ASTER. Results derived from TIR bands of ASTER show that a high level of confusion is associated with mafic phyllosilicates pixels (Fe3+-rich, Fe2+-rich and Mg-rich classes), whereas felsic phyllosilicates (Al-rich class) pixels are well mapped. Ground truth with detailed geological data, petrographic study and X-ray diffraction (XRD) analysis verified the remote sensing results. Consequently, ASTER image-map of phyllosilicate minerals is generated for the Mesa Range, Campbell and Priestley Glaciers, northern Victoria Land of Antarctica.
Amin Pour; Milad Sekandari; Omeid Rahmani; Laura Crispini; Andreas Läufer; Yongcheol Park; Jong Hong; Biswajeet Pradhan; Mazlan Hashim; Mohammad Hossain; Aidy M. Muslim; Kamyar Mehranzamir. Identification of Phyllosilicates in the Antarctic Environment Using ASTER Satellite Data: Case Study from the Mesa Range, Campbell and Priestley Glaciers, Northern Victoria Land. Remote Sensing 2020, 13, 38 .
AMA StyleAmin Pour, Milad Sekandari, Omeid Rahmani, Laura Crispini, Andreas Läufer, Yongcheol Park, Jong Hong, Biswajeet Pradhan, Mazlan Hashim, Mohammad Hossain, Aidy M. Muslim, Kamyar Mehranzamir. Identification of Phyllosilicates in the Antarctic Environment Using ASTER Satellite Data: Case Study from the Mesa Range, Campbell and Priestley Glaciers, Northern Victoria Land. Remote Sensing. 2020; 13 (1):38.
Chicago/Turabian StyleAmin Pour; Milad Sekandari; Omeid Rahmani; Laura Crispini; Andreas Läufer; Yongcheol Park; Jong Hong; Biswajeet Pradhan; Mazlan Hashim; Mohammad Hossain; Aidy M. Muslim; Kamyar Mehranzamir. 2020. "Identification of Phyllosilicates in the Antarctic Environment Using ASTER Satellite Data: Case Study from the Mesa Range, Campbell and Priestley Glaciers, Northern Victoria Land." Remote Sensing 13, no. 1: 38.
Deep-seated gravitational slope deformation (DsGSD) represents a relevant geological-geomorphological feature of the landscape and has drawn scientific attention for the past several decades. During a detailed fieldwork in the Ligurian Alps, we identified areas (larger than ca 5 km2), characterized by very low percentage of outcrops, with rock blocks on the watershed and many morpho-tectonic evidences. Through the integration of geological-geomorphological mapping, structural data, photo interpretation, GIS-based analyses, we identified a number of typical DsGSDs. The example here described is one major complex-sagging-type DsGSD that is not present in national land planning and/or management databases but that is likely at the origin of the large-scale landslides which affected the villages of the area. This DsGSD is also located within the Beigua UNESCO Global Geopark, in an area of unique natural and historical value. This study once again highlights the importance of ground truth observations as the basis for further investigations.
F. Faccini; L. Federico; S. Torchio; A. Roccati; G. Capponi; L. Crispini. A mountain slope deformation in an alpine metaophiolitic massif (Ligurian Alps, Italy). Journal of Maps 2020, 1 -13.
AMA StyleF. Faccini, L. Federico, S. Torchio, A. Roccati, G. Capponi, L. Crispini. A mountain slope deformation in an alpine metaophiolitic massif (Ligurian Alps, Italy). Journal of Maps. 2020; ():1-13.
Chicago/Turabian StyleF. Faccini; L. Federico; S. Torchio; A. Roccati; G. Capponi; L. Crispini. 2020. "A mountain slope deformation in an alpine metaophiolitic massif (Ligurian Alps, Italy)." Journal of Maps , no. : 1-13.
The importance of magnesite for the EU economy and industry is very high, making the understanding of their genesis for the exploration for new deposits a priority for the raw materials scientific community. In this direction, the study of the magnesite-hosting ultramafic rocks can be proved very useful. For the present study, ultramafic rock samples were collected from the magnesite ore-hosting ophiolite of the Gerakini mining area (Chalkidiki, Greece) to investigate the consecutive alteration events of the rocks which led to the metallogenesis of the significant magnesite ores of the area. All samples were subjected to a series of analytical methods for the determination of their mineralogical and geochemical characteristics: optical microscopy, XRD, SEM, EMPA, ICP–MS/OES and CIPW normalization. The results of these analyses revealed that the ultramafic rocks of the area have not only all been subjected to serpentinization, but these rocks have also undergone carbonation, silification and clay alteration. The latter events are attributed to the circulation of CO2-rich fluids responsible for the formation of the magnesite ores and locally, the further alteration of the serpentinites into listvenites. The current mineralogy of these rocks was found to be linked to one or more alteration event that took place, thus a significant contribution to the metallo- and petrogenetic history of the Gerakini ophiolite has been made. Furthermore, for the first time in literature, Fe inclusions in olivines from Greece were reported.
Evangelos Tzamos; Micol Bussolesi; Giovanni Grieco; Pietro Marescotti; Laura Crispini; Andreas Kasinos; Niccolò Storni; Konstantinos Simeonidis; Anastasios Zouboulis. Mineralogy and Geochemistry of Ultramafic Rocks from Rachoni Magnesite Mine, Gerakini (Chalkidiki, Northern Greece). Minerals 2020, 10, 934 .
AMA StyleEvangelos Tzamos, Micol Bussolesi, Giovanni Grieco, Pietro Marescotti, Laura Crispini, Andreas Kasinos, Niccolò Storni, Konstantinos Simeonidis, Anastasios Zouboulis. Mineralogy and Geochemistry of Ultramafic Rocks from Rachoni Magnesite Mine, Gerakini (Chalkidiki, Northern Greece). Minerals. 2020; 10 (11):934.
Chicago/Turabian StyleEvangelos Tzamos; Micol Bussolesi; Giovanni Grieco; Pietro Marescotti; Laura Crispini; Andreas Kasinos; Niccolò Storni; Konstantinos Simeonidis; Anastasios Zouboulis. 2020. "Mineralogy and Geochemistry of Ultramafic Rocks from Rachoni Magnesite Mine, Gerakini (Chalkidiki, Northern Greece)." Minerals 10, no. 11: 934.
The remote lower reaches of the Rennick Glacier in the far north of Victoria Land hold some of the least-explored outcrop areas of the Transantarctic basin system. Following recent international field-work efforts in the Helliwell Hills, we here provide a comprehensive emendation to the regional stratigraphy. Results of geological and palaeontological reconnaissance and of petrographic, geochemical and palynostratigraphic analyses reveal a stack of three previously unknown sedimentary units in the study area: the Lower Triassic Van der Hoeven Formation (new unit, 115+ m thick) consists mainly of quartzose sandstone and non-carbonaceous mudstone rich in continental trace fossils. The Middle to Upper Triassic Helliwell Formation (new unit, 235 m thick) consists of coal-bearing overbank deposits and volcaniclastic sandstone and yielded typical plant fossils of the Gondwanan Dicroidium flora together with plant-bearing silicified peat. The succession is capped by c. 14 m of the sandstone-dominated Section Peak Formation (uppermost Triassic–Lower Jurassic). Our results enable more detailed correlation of the Palaeozoic–Mesozoic successions throughout East Antarctica and into Tasmania. Of particular interest is one section that spans the end-Permian mass extinction interval, which promises to allow detailed reconstructions of high-latitude vegetation dynamics across this critical interval in Earth history.Supplementary material: A Supplementary Data File containing supplementary information, figures S1–S7, and additional references is available at https://doi.org/10.6084/m9.figshare.c.5118431
Benjamin Bomfleur; Thomas Mörs; Jan Unverfärth; Feng Liu; Andreas Läufer; Paula Castillo; Changhwan Oh; Tae-Yoon S. Park; Jusun Woo; Laura Crispini. Uncharted Permian to Jurassic continental deposits in the far north of Victoria Land, East Antarctica. Journal of the Geological Society 2020, 178, 1 .
AMA StyleBenjamin Bomfleur, Thomas Mörs, Jan Unverfärth, Feng Liu, Andreas Läufer, Paula Castillo, Changhwan Oh, Tae-Yoon S. Park, Jusun Woo, Laura Crispini. Uncharted Permian to Jurassic continental deposits in the far north of Victoria Land, East Antarctica. Journal of the Geological Society. 2020; 178 (1):1.
Chicago/Turabian StyleBenjamin Bomfleur; Thomas Mörs; Jan Unverfärth; Feng Liu; Andreas Läufer; Paula Castillo; Changhwan Oh; Tae-Yoon S. Park; Jusun Woo; Laura Crispini. 2020. "Uncharted Permian to Jurassic continental deposits in the far north of Victoria Land, East Antarctica." Journal of the Geological Society 178, no. 1: 1.
Estimating the paleo-depth of a fossil fault usually requires the application of complex and highly specialized techniques. We propose a new method, that is based mainly on field data and simplifies the process: - calculation of the reduced stress tensor (with four variables) through inversion of fault-slip data; - calculation of the complete stress tensor (i.e., the two remaining unknowns) using the friction and the rupture laws; - estimation of the paleo-depth. The friction law is defined by the lower boundary of the cloud of points in the Mohr space represented by inherited faults. This operation fixes the abscissa origin of the Mohr diagram. To calculate the rupture law, we estimate both intact rock and outcrop quality parameters and need pairs of conjugate faults. Their dihedral angle fixes a point on the Mohr circle, where the rupture law has to be tangent, thus defining the scale of the axes and the values of the principal stresses. To define the paleo-depth, we estimate the average density of overlying rocks and the hydraulic conditions (i.e. the pore pressure).Testing of this workflow in three well-constrained geological case studies proved its promising reliability, showing a good agreement with independent stratigraphic and structural evidence.
Laura Federico; Matteo Maino; Giovanni Capponi; Laura Crispini. Paleo-depth of fossil faults estimated from paleostress state: Applications from the Alps and the Apennines (Italy). Journal of Structural Geology 2020, 140, 104152 .
AMA StyleLaura Federico, Matteo Maino, Giovanni Capponi, Laura Crispini. Paleo-depth of fossil faults estimated from paleostress state: Applications from the Alps and the Apennines (Italy). Journal of Structural Geology. 2020; 140 ():104152.
Chicago/Turabian StyleLaura Federico; Matteo Maino; Giovanni Capponi; Laura Crispini. 2020. "Paleo-depth of fossil faults estimated from paleostress state: Applications from the Alps and the Apennines (Italy)." Journal of Structural Geology 140, no. : 104152.
The chemical and physical processes operating during subduction-zone metamorphism can profoundly influence the cycling of elements on Earth. Deep-Earth carbon (C) cycling and mobility in subduction zones has been of particular recent interest to the scientific community. Here, we present textural and geochemical data (CO, Sr isotopes and bulk and in-situ trace element concentrations) for a suite of ophicarbonate rocks (carbonate-bearing serpentinites) metamorphosed over a range of peak pressure-temperature (P-T) conditions together representing a prograde subduction zone P-T path. These rocks, in order of increasing peak P-T conditions, are the Internal Liguride ophicarbonates (from the Bracco unit, N. Apennines), pumpellyite- and blueschist-facies ophicarbonates from the Sestri-Voltaggio zone (W. Ligurian Alps) and the Queyras (W. Alps), respectively, and eclogite-facies ophicarbonates from the Voltri Massif. The Bracco oceanic ophicarbonates retain breccia-like textures associated with their seafloor hydrothermal and sedimentary origins. Their trace element concentrations and δ18OVSMOW (+15.6 to +18.2‰), δ13CVPDB (+1.1 to +2.5‰) and their 87Sr/86Sr (0.7058 to 0.7068), appear to reflect equilibration during Jurassic seawater-rock interactions. Intense shear deformation characterizes the more deeply subducted ophicarbonates, in which prominent calcite recrystallization and carbonation of serpentinite clasts occurred. The isotopic compositions of the pumpellyite-facies ophicarbonates overlap those of their oceanic equivalents whereas the most deformed blueschist-facies sample shows enrichments in radiogenic Sr (87Sr/86Sr = 0.7075) and depletion in 13C (with δ13C as low as −2.0‰). These differing textural and geochemical features for the two suites reflect interaction with fluids in closed and open systems, respectively. The higher-P-metamorphosed ophicarbonates show strong shear textures, with coexisting antigorite and dolomite, carbonate veins crosscutting prograde antigorite foliation and, in some cases, relics of magnesite-nodules enclosed in the foliation. These rocks are characterized by lower δ18O (+10.3 to 13.0‰), enrichment in radiogenic Sr (87Sr/86Sr up to 0.7096) and enrichment in incompatible and fluid-mobile element (FME; e.g., As, Sb, Pb). These data seemingly reflect interaction with externally-derived metamorphic fluids and the infiltrating fluids likely were derived from dehydrating serpentinites with hybrid serpentinite-sediment compositions. The interaction between these two lithologies could have occurred prior to or after dehydration of the serpentinites elsewhere. We suggest that decarbonation and dissolution/precipitation processes operating in ancient subduction zones, and resulting in the mobilization of C, are best traced by a combination of detailed field and petrographic observations, C, O and Sr isotope systematics (i.e., 3D isotopes), and FME inventories. Demonstration of such processes is key to advancing our understanding of the influence of subduction zone metamorphism on the mobilization of C in subducting reservoirs and the efficiency of delivery of this C to depths beneath volcanic arcs and into the deeper mantle.
E. Cannaò; M. Scambelluri; G.E. Bebout; S. Agostini; T. Pettke; M. Godard; Laura Crispini. Ophicarbonate evolution from seafloor to subduction and implications for deep-Earth C cycling. Chemical Geology 2020, 546, 119626 .
AMA StyleE. Cannaò, M. Scambelluri, G.E. Bebout, S. Agostini, T. Pettke, M. Godard, Laura Crispini. Ophicarbonate evolution from seafloor to subduction and implications for deep-Earth C cycling. Chemical Geology. 2020; 546 ():119626.
Chicago/Turabian StyleE. Cannaò; M. Scambelluri; G.E. Bebout; S. Agostini; T. Pettke; M. Godard; Laura Crispini. 2020. "Ophicarbonate evolution from seafloor to subduction and implications for deep-Earth C cycling." Chemical Geology 546, no. : 119626.
The Mt. Melbourne field is interpreted as a quiescent volcanic complex, located in Northern Victoria Land, Antarctica, at the boundary between the Transantarctic Mountains (TAM) and the West Antarctic Rift System (WARS). It is one of the handful Antarctic volcanoes with the potential for large–scale explosive eruptions [1], with resulting key effects on the local environment and potentially on climate.
The geological and geophysical structure of this volcanic field remains poorly known, despite its key relevance to better comprehend the Cenozoic tectonic and geodynamic processes responsible for the opening of the WARS and the uplift of the TAM rift flank.
Here we present results derived from a novel high–resolution aeromagnetic dataset, collected in the austral summer 2002/2003 during the XVIII Italian Expedition, with the aim of investigating the geophysical structure of the main volcanic centres of the field.
Aeromagnetic data were processed and Digital Enhancement and Depth to Magnetic Source analysis performed to reveal the distribution of the main fault systems affecting the Mt. Melbourne volcanic field, particularly beneath the ice–covered areas. The results highlight NNE–SSW, NW–SE and E–W trending structural systems, in agreement with the available tectonic information for the study area [2, 3]. Furthermore, similar NNW–SSE trending pervasive negative anomalies are detected beneath both the Mt. Melbourne edifice and Cape Washington, superimposed by positive ones forming radial patterns.
With the aid of laboratory magnetic susceptibility data from rock samples collected in the field [4], we carried out forward and inverse modeling across the volcanic centres in order to image their subglacial internal structure.
Based on our results, considering the ambiguity and narrowness of the available geochronological data [1, 5, 6], we propose two (non–mutually exclusive) interpretative models to explain the evolution steps of the Mt. Melbourne volcanic complex. In the former, a major volcanic phase responsible for building of the inner part of the main volcanic centres likely occurred prior to the last magnetic polarity reversal (i.e. before 0.78 Ma, Matuyama Chron), explaining the negative anomalies detected as due to remnant magnetisation. During the Pleistocene–Holocene period, a following second volcanic phase put in place at shallower levels, primarily with present–day magnetization. In the alternative model, magma pulses originated at the lithospheric step between the thick East Antarctic craton and the thinner Ross Sea crust [7] caused i) widespread volcanism at the surface of the volcanic complex, particularly with the building up of the Mt. Melbourne edifice, and ii) a regional upward of the Curie isotherm at depth, causing partial de–magnetisation of the underlying volcanic rocks.
References:
[1] Giordano et al. (2012). Bull. Volcanol., 74, 1985-2005.
[2] Storti et al. (2006). J. Struct. Geol., 28, 50-63.
[3] Vignaroli et al. (2015). Tectonophysics, 656, 74-90.
[4] Pasquale et al. (2009). Ann. Geophys., 52(2), 197-207.
[5] Armstrong (1978). New Zeal. J. Geol. Geophys., 21(6), 685-698.
[6] Armienti et al. (1991). Mem. Soc. Geol. Ital., 46, 427-452.
[7] Park et al. (2015). Earth Planet. Sci. Lett., 432, 293-299.
Alessandro Ghirotto; Egidio Armadillo; Laura Crispini; Andrea Zunino; Fausto Ferraccioli. New insights into the evolution of the Mt. Melbourne volcanic field (Northern Victoria Land, Antarctica) from high–resolution aeromagnetic data. 2020, 1 .
AMA StyleAlessandro Ghirotto, Egidio Armadillo, Laura Crispini, Andrea Zunino, Fausto Ferraccioli. New insights into the evolution of the Mt. Melbourne volcanic field (Northern Victoria Land, Antarctica) from high–resolution aeromagnetic data. . 2020; ():1.
Chicago/Turabian StyleAlessandro Ghirotto; Egidio Armadillo; Laura Crispini; Andrea Zunino; Fausto Ferraccioli. 2020. "New insights into the evolution of the Mt. Melbourne volcanic field (Northern Victoria Land, Antarctica) from high–resolution aeromagnetic data." , no. : 1.
The polar layered deposits (PLD) of Mars constitute the water ice stratigraphy of polar spiral troughs up to several kilometers thick (Phillips et al., 2011; Smith et al. 2015). PLD cross section profiles from the Shallow Subsurface Radar (SHARAD) instrument on NASA’s Mars Reconnaissance Orbiter, show the presence of internal discontinuities within these layers (Foss et al., 2017; Putzig et al., 2017). The mechanisms responsible for these deformations are still an open issue (Guallini et al., 2017) and this work represents the contribution of stress-related deformations. Layered ice is simulated by a mesh of cells within a HCA grid build replicating the physical properties and preserving volumes following balanced cross-section principles. Three major types of link exist among adjacent cells: 1. intra-layer relations link cells belonging to the same layer; 2. inter-layer relations regulate the relationships among adjacent layers; 3. discontinuity relations correspond to the presence of ruptures such as faults (Salvini et al., 2001). The HCA method allows to replicate the natural material anisotropies, such as rocks and ice sheet internal layering, and to simulate complex tectonic evolutionary paths (Cianfarra and Salvini, 2016; Cianfarra and Maggi, 2017). The models allow simulating the kinematics of the internal architecture of the layered deposits from both the north and the south Martian ice caps. In particular the observed stratigraphy (geometries and thickness of the ice layers) is replicated as resulting from the relative, normal movement among blocks separated by listric shaped normal faults and minor inversions.
The used HCA numerical methodology revealed an effective tool to support planetary geological mapping and 3D subsurface geological reconstructions. Through the integration of a net of spatially distributed along- and across- strike (balanced) sections it is possible to simulate the 4D (3D plus time) geological evolution of buried and/or topographic structures. Results have a wide range of applications including the optimal selection of landing sites for scheduled and future planetary exploration missions, as well as unravelling the geological and structural setting of enigmatic features on the planetary surfaces affected, for example, by salt tectonism, volcano-tectonics, tectonically-related hydrothermal activity, fluid storage and release, and ice tectonics.
Paola Cianfarra; Costanza Rossi; Francesco Salvini; Laura Crispini. Faulting in Mars Polar Layered deposits modeled by HCA method. 2020, 1 .
AMA StylePaola Cianfarra, Costanza Rossi, Francesco Salvini, Laura Crispini. Faulting in Mars Polar Layered deposits modeled by HCA method. . 2020; ():1.
Chicago/Turabian StylePaola Cianfarra; Costanza Rossi; Francesco Salvini; Laura Crispini. 2020. "Faulting in Mars Polar Layered deposits modeled by HCA method." , no. : 1.
Estimation of subglacial Geothermal Heat Flux (GHF) is of paramount importance to better understand the dynamics of cryosphere and ice flow of the East Antarctica Ice Sheet (EAIS). Unfortunately, the GHF of East Antarctica is still poorly known and constrained, and direct measurements are still challenging. The EIAS is underlain by major subglacial mountain ranges and basins resulting from distinct geodynamic domains. These include Northern Victoria Land-Ross Sea, the Transantarctic Mountains, the Wilkes Subglacial Basin, the Gamburtsev Subglacial Mountains, the East Antarctic System and a major transpressional fault zone in between (e.g. Cianfarra & Maggi, 2017), which hosts clusters of subglacial lakes. The distribution of sedimentary basins and tectonic structures may affect the GHF in that it exhibits strong regional variations as testified by the presence of subglacial lakes at bedrock topographic elevation/depth with a range exceeding 1500 m, from deep subglacial basins to the flanking highlands. In the framework of the G-IDEA (Geo Ice Dynamics of East Antarctica) project, heat flow from the basement is quantified in key areas of East Antarctica between 60°E and 180°E, by an innovative application of the HCA (Hybrid Cellular Automata) method: the description of stationary conditions of the temperature field is used to replicate the observed distribution of wet vs dry ice-rock contacts in an ice-flowing environment. Evaluation of the geothermal flux is performed in key areas based on the numeric modeling of the ice-rock interaction, which can replicate the spatial distribution of wet contacts and subglacial lakes and is related to local dynamics of the ice sheet and its interaction with the atmosphere. The model takes into account the spatial distribution of the Curie temperature depth as derived from literature. The heat flux is estimated by modeling the stationary state of the ice-rock system with the HCA numerical method, and by its discretization into a large number of cells. Each cell is characterized by physical parameters such as density, enthalpy, thermal capacity and conductivity. By their interaction it is possible to compute their temperature evolution and to replicate the heat diffusion by conduction and convection (the ice movement) in the interfaces ice-rock and ice-atmosphere. The final resolution of the model is about 100 m. The presence of possible anomalous heath flow in the bedrock are identified by a stochastic approach that allow the estimation of the error in the computed heath flow values.
Francesco Salvini; Paola Cianfarra; Giovanni Capponi; Laura Crispini; Laura Federico; Costanza Rossi. Geothermal Heat Flux in East Antarctica from HCA numerical modeling between 60-180°E Longitude. 2020, 1 .
AMA StyleFrancesco Salvini, Paola Cianfarra, Giovanni Capponi, Laura Crispini, Laura Federico, Costanza Rossi. Geothermal Heat Flux in East Antarctica from HCA numerical modeling between 60-180°E Longitude. . 2020; ():1.
Chicago/Turabian StyleFrancesco Salvini; Paola Cianfarra; Giovanni Capponi; Laura Crispini; Laura Federico; Costanza Rossi. 2020. "Geothermal Heat Flux in East Antarctica from HCA numerical modeling between 60-180°E Longitude." , no. : 1.
The West Antarctic Rift System (WARS) is known to have experienced distributed/wide mode extension in the Cretaceous, followed by narrow mode and variably oblique extension/transtension in the Cenozoic, the latter potentially linked to the onset of oceanic seafloor spreading within the Adare Basin (Davey et al., 2016, GRL). However, onshore the extent and impact of Cenozoic extension and transtension within the Transantarctic Mountains sector of East Antarctica is currently much less well-constrained from a geophysical perspective.
Here we combine aeromagnetic, aerogravity, land-gravity and bedrock topography imaging to help constrain the extent, architecture and kinematics of the largest Cenozoic pull-apart basin recognised so far in East Antarctica, the Rennick Graben (RG).
Enhanced potential field imaging reveals the extent of a Jurassic tholeiitic Large Igneous Province preserved within the RG and the inherited structural architecture of its basement, including remnants of uplifted ca 530-500 Ma arc basement in the northern Wilson Terrane and a ca 490-460 Ma subglacial thrust fault belt separating the Cenozoic western flank of the RG from the eastern margin of Wilkes Subglacial Basin (WSB).
The architecture of the RG is best explained in terms of a major composite right-lateral pull-part basin that extends from the Oates Coast to the Southern Cross Mountains block. We propose that Cenozoic strike-slip deformation kinematically connected the RG with both the western edge of the WARS and the eastern margin of the WSB. An earlier phase of left-lateral strike slip deformation is also emerging from recent geological field work in the study region but only relatively subtle offsets in aeromagnetic anomaly patterns are visible in currently available regional datasets.
We conclude that the RG is part of a wider distributed region of the continental lithosphere in East Antarctica that was deformed in response to an evolving Cenozoic transtensional tectonic setting that may have also affected enigmatic sub-basins such as the Cook Basins in the adjacent WSB region.
Laura Crispini; Fausto Ferraccioli; Egidio Armadillo; Andreas Läufer; Antonia Ruppel. Crustal architecture of the largest pull-apart basin in East Antarctica unveiled. 2020, 1 .
AMA StyleLaura Crispini, Fausto Ferraccioli, Egidio Armadillo, Andreas Läufer, Antonia Ruppel. Crustal architecture of the largest pull-apart basin in East Antarctica unveiled. . 2020; ():1.
Chicago/Turabian StyleLaura Crispini; Fausto Ferraccioli; Egidio Armadillo; Andreas Läufer; Antonia Ruppel. 2020. "Crustal architecture of the largest pull-apart basin in East Antarctica unveiled." , no. : 1.
Holes BA1B and BA3A were drilled into the Wadi Tayin Massif, southern ophiolite complex of Oman, a fragment of the Tethyan oceanic lithosphere obducted onto the Arabian continent. Within the sequence, we have studied a portion of the shallow mantle, composed mainly of strongly serpentinised harzburgite that embeds dunitic levels, the biggest being over 150 m thick. The formation of thick dunitic channels, already approached via published structural and mathematical models, is here investigated with a mineral chemistry approach. We focused on Cr-spinel, the only widespread phase preserved during serpentinization, whose TiO2 content displays a wide variability from low in harzburgite, (TiO2 < 0.25 wt. %), typical of non-metasomatised ophiolite mantle, to moderately high in dunite (TiO2 < 1.10 wt. %) characterizing a rock/melt interactions. The high variability of TiO2, accompanied by similar patterns of Cr# and Mg# is observed, in a fractal pattern, at all scales of investigation, from the whole channel scale to the single thin section, where it affects even single grain zonings. Our results suggest that the over 150 m thick dunite channel here investigated was formed by coalescence of different scale melt channels and reaction zones with different sizes, confirming the published structural model.
Giuseppe Cocomazzi; Giovanni Grieco; Paola Tartarotti; Micol Bussolesi; Federica Zaccarini; Laura Crispini; Oman Drilling Project Science Team. The Formation of Dunite Channels within Harzburgite in the Wadi Tayin Massif, Oman Ophiolite: Insights from Compositional Variability of Cr-Spinel and Olivine in Holes BA1B and BA3A, Oman Drilling Project. Minerals 2020, 10, 167 .
AMA StyleGiuseppe Cocomazzi, Giovanni Grieco, Paola Tartarotti, Micol Bussolesi, Federica Zaccarini, Laura Crispini, Oman Drilling Project Science Team. The Formation of Dunite Channels within Harzburgite in the Wadi Tayin Massif, Oman Ophiolite: Insights from Compositional Variability of Cr-Spinel and Olivine in Holes BA1B and BA3A, Oman Drilling Project. Minerals. 2020; 10 (2):167.
Chicago/Turabian StyleGiuseppe Cocomazzi; Giovanni Grieco; Paola Tartarotti; Micol Bussolesi; Federica Zaccarini; Laura Crispini; Oman Drilling Project Science Team. 2020. "The Formation of Dunite Channels within Harzburgite in the Wadi Tayin Massif, Oman Ophiolite: Insights from Compositional Variability of Cr-Spinel and Olivine in Holes BA1B and BA3A, Oman Drilling Project." Minerals 10, no. 2: 167.
Several regions in the High Arctic still lingered poorly explored for a variety of mineralization types because of harsh climate environments and remoteness. Inglefield Land is an ice-free region in northwest Greenland that contains copper-gold mineralization associated with hydrothermal alteration mineral assemblages. In this study, Landsat-8, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), and WorldView-3 multispectral remote sensing data were used for hydrothermal alteration mapping and mineral prospecting in the Inglefield Land at regional, local, and district scales. Directed principal components analysis (DPCA) technique was applied to map iron oxide/hydroxide, Al/Fe-OH, Mg-Fe-OH minerals, silicification (Si-OH), and SiO2 mineral groups using specialized band ratios of the multispectral datasets. For extracting reference spectra directly from the Landsat-8, ASTER, and WorldView-3 (WV-3) images to generate fraction images of end-member minerals, the automated spectral hourglass (ASH) approach was implemented. Linear spectral unmixing (LSU) algorithm was thereafter used to produce a mineral map of fractional images. Furthermore, adaptive coherence estimator (ACE) algorithm was applied to visible and near-infrared and shortwave infrared (VINR + SWIR) bands of ASTER using laboratory reflectance spectra extracted from the USGS spectral library for verifying the presence of mineral spectral signatures. Results indicate that the boundaries between the Franklinian sedimentary successions and the Etah metamorphic and meta-igneous complex, the orthogneiss in the northeastern part of the Cu-Au mineralization belt adjacent to Dallas Bugt, and the southern part of the Cu-Au mineralization belt nearby Marshall Bugt show high content of iron oxides/hydroxides and Si-OH/SiO2 mineral groups, which warrant high potential for Cu-Au prospecting. A high spatial distribution of hematite/jarosite, chalcedony/opal, and chlorite/epidote/biotite were identified with the documented Cu-Au occurrences in central and southwestern sectors of the Cu-Au mineralization belt. The calculation of confusion matrix and Kappa Coefficient proved appropriate overall accuracy and good rate of agreement for alteration mineral mapping. This investigation accomplished the application of multispectral/multi-sensor satellite imagery as a valuable and economical tool for reconnaissance stages of systematic mineral exploration projects in remote and inaccessible metallogenic provinces around the world, particularly in the High Arctic regions.
Amin Beiranvand Pour; Tae-Yoon S. Park; Jong Kuk Hong; Aidy M Muslim; Andreas Läufer; Laura Crispini; Biswajeet Pradhan; Basem Zoheir; Omeid Rahmani; Mazlan Hashim; Mohammad Shawkat Hossain. Landsat-8, Advanced Spaceborne Thermal Emission and Reflection Radiometer, and WorldView-3 Multispectral Satellite Imagery for Prospecting Copper-Gold Mineralization in the Northeastern Inglefield Mobile Belt (IMB), Northwest Greenland. Remote Sensing 2019, 11, 2430 .
AMA StyleAmin Beiranvand Pour, Tae-Yoon S. Park, Jong Kuk Hong, Aidy M Muslim, Andreas Läufer, Laura Crispini, Biswajeet Pradhan, Basem Zoheir, Omeid Rahmani, Mazlan Hashim, Mohammad Shawkat Hossain. Landsat-8, Advanced Spaceborne Thermal Emission and Reflection Radiometer, and WorldView-3 Multispectral Satellite Imagery for Prospecting Copper-Gold Mineralization in the Northeastern Inglefield Mobile Belt (IMB), Northwest Greenland. Remote Sensing. 2019; 11 (20):2430.
Chicago/Turabian StyleAmin Beiranvand Pour; Tae-Yoon S. Park; Jong Kuk Hong; Aidy M Muslim; Andreas Läufer; Laura Crispini; Biswajeet Pradhan; Basem Zoheir; Omeid Rahmani; Mazlan Hashim; Mohammad Shawkat Hossain. 2019. "Landsat-8, Advanced Spaceborne Thermal Emission and Reflection Radiometer, and WorldView-3 Multispectral Satellite Imagery for Prospecting Copper-Gold Mineralization in the Northeastern Inglefield Mobile Belt (IMB), Northwest Greenland." Remote Sensing 11, no. 20: 2430.
Dike swarms are commonly linked with extensional structures in diverse geodynamic environments. Mafic dyke swarms are typically used to reconstruct the paleo-stress fields of a given region. These dikes are considered paleo-stress indicators and excellent time marker (if related geochronological data are available) of the local and regional stress fields. In the Middle-Late Jurassic, swarms of mafic dikes emplaced into the Neoproterozoic schists and amphibolites in the Kalateh Alaeddin Mountain area in south Shahrood, north Iran. These dikes with different thicknesses show a general east–west strike direction, with mostly a steep dip angle. In this paper, we present structural data of these dike swarms for the sake of assessing the paleo-stress state and the magma pressure ratio at the time of their emplacement. Field and structural data are integrated with ASTER Global Digital Elevation Model (GDEM) and Centre National d’Etudes Spatiales (CNES)/SPOT imagery data, to extract important parameters of the investigated dikes and controlling fault/joint sets. Orientation of the principal paleo-stress axes, quantification of the stress ratio, and the associated magma pressure ratio (driving stress ratio) were calculated using the stereographic projection and Mohr’s circle reconstruction techniques. The results reveal that the maximum paleo-stress component (σ1) was sub-vertical and the intermediate (σ2) and minimum (σ3) paleo-stresses components were sub-horizontal in N264° E and N173° E trends, respectively. Due to the low value of the driving stress ratio (R = 0.05), these dikes developed perpendicular to the minimum principal stress (in E–W direction). The stress ratio value (ø = 0.66) indicates a moderately oblate stress ellipsoid. The orientation of the principal paleo-stress axes and the oblate ellipsoid are indicative of the dike emplacement during a N–S-directed tectonic extension, in agreement with the Jurassic subsidence phase and N–S stretching described for the Kalateh Alaeddin Mountain area.
Amir Pirouz Kolahi Azar; Ghasem Askari; Laura Crispini; Amin Beiranvand Pour; Basem Zoheir; Biswajeet Pradhan. Field and spaceborne imagery data for evaluation of the paleo-stress regime during formation of the Jurassic dike swarms in the Kalateh Alaeddin Mountain area, Shahrood, north Iran. Arabian Journal of Geosciences 2019, 12, 552 .
AMA StyleAmir Pirouz Kolahi Azar, Ghasem Askari, Laura Crispini, Amin Beiranvand Pour, Basem Zoheir, Biswajeet Pradhan. Field and spaceborne imagery data for evaluation of the paleo-stress regime during formation of the Jurassic dike swarms in the Kalateh Alaeddin Mountain area, Shahrood, north Iran. Arabian Journal of Geosciences. 2019; 12 (17):552.
Chicago/Turabian StyleAmir Pirouz Kolahi Azar; Ghasem Askari; Laura Crispini; Amin Beiranvand Pour; Basem Zoheir; Biswajeet Pradhan. 2019. "Field and spaceborne imagery data for evaluation of the paleo-stress regime during formation of the Jurassic dike swarms in the Kalateh Alaeddin Mountain area, Shahrood, north Iran." Arabian Journal of Geosciences 12, no. 17: 552.
Ultramafic soils are characterized by severe edaphic conditions induced by a low content of essential nutrients, an adverse Ca/Mg ratio, a low water-holding capacity, and high contents of geogenic potentially toxic elements (PTEs), in particular Cr, Ni, and Co. These metals commonly exceed the content limits set by environmental agencies and governments, representing serious environmental risks for ecosystems and human health. In alpine environments, ultramafic soils are characterized by modest thickness and poor horizon differentiation. Several studies on ultramafic soils have shown that their properties may be directly related to the characteristics of the parent rocks, but most of these studies deal with soil chemistry, metal availability, isotopic composition, and pedological characterization. The aim of this research is to investigate how much the geotectonic characteristics of ultramafic bedrocks, such as the degree of serpentinization, metamorphic imprint, and deformation, may affect the mineralogical and chemical variations of ultramafic soils, including the occurrence and potential mobility of the PTEs. Using a multiscale and multi-analytical approach, we fully characterize the properties and mineralogical composition of soil profiles with different ultramafic parent rocks, i.e., partially serpentinized peridotite, massive serpentinites, and foliated serpentinites, sampled within the Voltri Massif High Pressure–Low Temperature (HP–LT) metaophiolite (Western Alps, Italy). Our results, related to soils located at comparable latitude, altitude, landscape position, and pedological environment, outline that the degree of serpentinization, the metamorphic imprint, and the deformation history of the ultramafic parent rocks are key factors influencing soil evolution, mineralogy, and chemistry, as well as PTEs distribution and mobility. Moreover, this study shows that the high content of Cr, Ni, and Co in the studied ultramafic soils has to be considered of geogenic origin and highlights the need for new approaches and methods to obtain indications on the potential contamination of natural or anthropogenic soils.
Pietro Marescotti; Paola Comodi; Laura Crispini; Lara Gigli; Azzurra Zucchini; Silvia Fornasaro. Potentially Toxic Elements in Ultramafic Soils: A Study from Metamorphic Ophiolites of the Voltri Massif (Western Alps, Italy). Minerals 2019, 9, 502 .
AMA StylePietro Marescotti, Paola Comodi, Laura Crispini, Lara Gigli, Azzurra Zucchini, Silvia Fornasaro. Potentially Toxic Elements in Ultramafic Soils: A Study from Metamorphic Ophiolites of the Voltri Massif (Western Alps, Italy). Minerals. 2019; 9 (8):502.
Chicago/Turabian StylePietro Marescotti; Paola Comodi; Laura Crispini; Lara Gigli; Azzurra Zucchini; Silvia Fornasaro. 2019. "Potentially Toxic Elements in Ultramafic Soils: A Study from Metamorphic Ophiolites of the Voltri Massif (Western Alps, Italy)." Minerals 9, no. 8: 502.