Maria Sgavetti's research while affiliated with Università degli Studi di Palermo and other places
What is this page?
This page lists the scientific contributions of an author, who either does not have a ResearchGate profile, or has not yet added these contributions to their profile.
It was automatically created by ResearchGate to create a record of this author's body of work. We create such pages to advance our goal of creating and maintaining the most comprehensive scientific repository possible. In doing so, we process publicly available (personal) data relating to the author as a member of the scientific community.
If you're a ResearchGate member, you can follow this page to keep up with this author's work.
If you are this author, and you don't want us to display this page anymore, please let us know.
It was automatically created by ResearchGate to create a record of this author's body of work. We create such pages to advance our goal of creating and maintaining the most comprehensive scientific repository possible. In doing so, we process publicly available (personal) data relating to the author as a member of the scientific community.
If you're a ResearchGate member, you can follow this page to keep up with this author's work.
If you are this author, and you don't want us to display this page anymore, please let us know.
Publications (83)
Mercury’s peculiar orbit around the Sun (3:2 spin–orbit resonance) and lack of atmosphere result in one the widest temperature ranges experienced at the surface of a planetary body in the solar system. Temperature variations affect the physical and, therefore, spectral properties of minerals to varying degrees; thus, it is crucial to study them in...
Mars has a relatively tenuous atmosphere, the remote-sensed spectral data of the surface are affected by the presence of the atmosphere. In particular the water and CO2 absorption of the atmosphere are in the same spectral region as water, OH⁻ and (CO3)²⁻ in minerals. An accurate correction of the gaseous contamination is thus mandatory for applyin...
The SIMBIO-SYS (Spectrometer and Imaging for MPO BepiColombo Integrated Observatory SYStem) is a complex instrument suite part of the scientific payload of the Mercury Planetary Orbiter for the BepiColombo mission, the last of the cornerstone missions of the European Space Agency (ESA) Horizon + science program.The SIMBIO-SYS instrument will provid...
The spectral characterization of planetary surfaces needs sets of laboratory's experiments to better characterize and model the properties on analogues or extraterrestrial material. Despite the differences in composition, the environmental condition, e.g. temperature and pressure, is also an important variable to consider on those laboratory experi...
Despite the growing employment of Remote Sensing (RS) techniques in paleoenvironmental studies, the stratigraphic interpretation of RS-derived paleodrainage traces is still an open issue, as their relation to subsurface is largely unexplored. Here we applied a multi-data analysis approach, including publicly available optical images from different...
Anorthositic rocks are widespread on the lunar surface and have probably been formed by flotation of PL over a magma ocean. A large portion of pristine rocks are characterized by a low Mg/(Mg+Fe) ratio, and have been classified as ferroan anorthosite, and recently, after observation from SELENE Spectral Profiler,pure anorthosites regions with more...
Among the techniques to detect planet’s mineralogical composition remote sensing, visible and near-infrared (VNIR) reflectance spectroscopy is a powerful tool, because crystal field absorption bands are related to particular transitional metals in well-defined crystal structures, e.g., Fe2+ in M1 and M2 sites of olivine (OL) or pyroxene (PX). Altho...
The aim of this work is to extract the surface contribution in the martian visible/near-infrared spectra removing the atmospheric components by means of Principal Component Analysis (PCA) and target transformation (TT). The developed technique is suitable for separating spectral components in a data set large enough to enable an effective usage of...
Lunar highlands are plagioclase-rich terrains produced by crystal floating in a Magma Ocean system. Lunar samples revealed the presence of anorthositic (plagioclase >90%) samples from the Highlands, associated to more mafic rocks. Recently, remote sensing data permit mapping those terrains with high spatial and spectral resolution allowing detectio...
Remote sensing data reveal the presence of several igneous-rock forming silicates on the surfaces of various Solar System bodies. Mafic (Mg–Fe silicates) materials were clearly recognized in the past on Mars, Moon, Vesta, and recently the weak absorption of plagioclase has been detected on the lunar highland. The advance in the detection of these i...
In this abstract, we analyze mixtures composed of plagioclase and mafic minerals at very fine particle sizes, comparable to those found on the lunar regolith.
Visible and Near-Infrared (VNIR) reflectance spectroscopy is an important technique with which to map mineralogy and mineralogical variations across planetary surfaces using remotely sensed data. Absorption bands in this spectral range are due to electronic or molecular processes directly related to mineral families or specific compositions. Effusi...
During the 2011–2012 hemispheric voyage of the M/V Italica from Italy to the Atlantic Ocean, southern Indian Ocean, New Zealand and Antarctica, atmospheric CO2 concentrations were continuously recorded and 52 air samples collected in 4-L Pyrex flasks for the measurement of the δ13C of atmospheric CO2. In the case of CO2 concentrations, new data inc...
Remote sensing from lunar highland and from Hermean surface showed reflectance spectra with no detectable absorption bands in the visible and near infrared, and recently M3 data from the lunar surface (e.g., Orientale Basin) have shown spectra with a weak absorption band centered at 1250 nm. Those terrains were generally interpreted as plagioclase...
The present work is focused on the distribution of landslides in Foglia
river basin area (northern Marche-Romagna), using a heuristic approach
supported by GIS tools for the construction of statistical analysis and
spatial data. The study area is located in the Adriatic side of the
northern Apennine in the boundary that marks the transition between...
In the western TC ILDs displaying dome morphology rise from the floor.
Analysis of the HiRISE images shows forms that we interpreted as
karst-like landforms.
In this abstract we describe plagioclase behavior when mixed with low
mafic mineral contents, in order to understand lunar highland
mineralogical composition.
From 1998 to 2010, during eight cruises of the M/V Italica between New Zealand and Antarctica, sets of flask air samples were collected and atmospheric CO2 concentrations were recorded. The δ13C of CO2 from the 1998 to 2003 air samples have already been published and show large interannual variability and an increasing frequency of 13C-depleted sam...
Fulgurites are glassy crusts or hollow glassy tubes formed by the impact of a lightning strike on a target material on the Earth's surface. The oxygen isotopic composition of fulgurites has never been measured and, consequently, it is unknown whether or not isotopic fractionations take place between the target material and the fulgurite glass durin...
A dome-shaped ILD in northern Coprates Chasma (CC) displays surface
signatures of sulphates minerals. The dome has surface features on its
summit, flanks, and at its base that were apparently formed by liquid
water probably released from melting ice in a periglacial environment,
or permafrost rich soil. These features include a variety of karst
lan...
Various ice-related features recognize on the floor of Danielson crater
suggest that this area located in the southeastern region of Arabia
Terra experienced in the recent past one or more periods of glacial
activity. Geomorphological observation highlight some landforms that on
the Earth are associated with fluvio-glacial and periglacial
environme...
The great variety of morphologies observed in the Daedalia Planum lava
flows (Mars) encouraged a detailed study of their spectral
characteristics, in order to obtain information about lava composition
and detect possible differences in the spectra of the flows. The OMEGA
spectral data collected from the lava field appear rather similar, with
absorp...
Moon Mineralogy Mapper data have revealed different portion of magmatic
chambers or separate plutons. We analysed Stillwater Complex (SWC) rock
suite. Spectral signatures and spectral parameters could help to
interpret the new spectral lunar data.
Spectra obtained on Lunar highland and on Mercury show low contrast
features. We suggest the interference of adjacent absorptions bands due
to different minerals as a possible cause of low contrast spectra. While
the combined effects of Fe2+ absorptions in various clinopyroxene,
orthopyroxene and olivine mixtures have been widely studied, the
spect...
The first orbit data of the MESSENGER (NASA) mission revealed several
volcanic features, confirming that volcanism was important in shaping
the surface of Mercury. Some northern plains show characteristics
typical of a flood-basalt style (Head et al.,2011), also consistent with
x-ray spectrometer data that suggest possibly surface compositions
betw...
In the Terra Meridiani- Arabia Terra region of Mars, layered rock units
with a range of stratal patterns have been widely reported in the
literature, and the record of the spectral signatures indicative of
hydrate minerals suggests the existence of aqueous activity in at least
some of the stratigraphic units. . In this work we investigated the
area...
Sinus Meridiani is part of the large area known as Terra Meridiani,
located near the southwestern margin of Arabia Terra, in the equatorial
region of Mars. In this area several studies showed the evidence for
past aqueous activity preserved in several distinct units that were
identified and classified as layered deposits with monohydrated and
polyh...
The abstract shows the results of geomorphologic study in great detail
of the northern part of Sinus Meridiani. Here karst-like landforms are
observed. Based on the kind and degree, three morpho-units are
identified.
In this abstract we show plagioclase effects on three different Fe,Mg
mixtures. The spectra of these mixtures were analyzed via decomposition
with an EGO algorithm in order to determine band spectral parameters,
particularly in the 1.2-μm region.
This paper describes karst landforms observed in the northern Sinus Meridiani region of Mars, located between 1°20′–2°20′ N and 2°50′ W–1°E and covering an area of about 20,000 km2.The karst is characterised by spectral signatures of mono- and poly-hydrated sulphates. A morphologic and morphometric survey of the study area was performed through an...
In this paper we applied Hapke's radiative transfer model (Hapke, 1993,
1998, 2002, 2008) to laboratory reflectance spectra of four pyroxenes
powders of known composition and grain size. We measured spectra in the
350 - 2500 nm range under different viewing conditions: this enabled us
to study both spectral and photometric properties of these miner...
Remote-sensing studies have revealed that most of the inner planets
surfaces are composed of silicate bearing rocks with variable relative
mineral abundances and compositions that could be indicative of
genetically related rocks. Quantifying and modeling those phases in
mineral mixtures is an important task to characterize the surface
compositions...
Laboratory spectra of four pyroxenes have been investigated applying the
Hapke model. The aim of this work is to test the Hapke model on minerals
that can be found as analogs of planetary surfaces, focusing on the
spectral effects induced by observing geometry, powder grains size and
mixing of different end-members. Here we present preliminary resu...
In this paper we present preliminary results of the determination of the
optical constants of complex silicates mixture obtained applying the
Hapke radiative transfer model to visible-near infrared reflectance
spectra. The selected silicates mixtures are representative of possibly
igneous co-genetic rocks. We first calculated optical constants of t...
In spectroscopic remote sensing for the exploration of the surface compositions of Earth and terrestrial planets, reflectance spectra with very low spectral contrast and even devoid of diagnostic absorption bands can be observed, which make the interpretation of the component minerals ambiguous. Using selected examples of terrestrial rock samples f...
Remote-sensing studies have revealed that most of the inner planets surfaces are composed by magmatic effusive rocks as lava flows or pyroclastic deposits, that are the natural products of magma-rock dynamic systems controlled by T, P, oxygen fugacity and time. These materials generally contain a fair amount of volcanic glass, due to the magma rapi...
Daedalia Planum is a large lava plain, consisting of more than 1500 km lava flows emplaced over an almost flat terrain in the south-east area of Arsia Mons. The morphology of this region has been studied by Giacomini et al. (Planet.SpaceSci., 2009) and revealed the presence of various features indicative of inflation mechanisms. Thirteen morphologi...
Daedalia Planum is one of the Tharsis volcanic plains and is located
southwest of the Arsia Mons. MOLA, THEMIS, MOC and OMEGA data have been
analysed, providing a multi-scale characterisation of this Martian lava
field. According to Mars Global Surveyor's MOLA data, the flanks of
Arsia have an average slope <5°, while the surrounding regions,
inclu...
Our study has been focused on the Daedalia Planum geological mapping. THEMIS, MOC, HiRISE images were analyzed to perform a stratigraphic and morphological analysis. OMEGA data revealed spectral differences that permitted to improve our mapping.
The limited knowledge about the majority of the Mercury surface leaves many open questions regarding its geological evolution, the anomalously high metal/silicate ratio, the magnetic field generation and exosphere evolution. An integrated suite of instruments, Spectrometer and Imagers for MPO BepiColombo-Integrated Observatory SYStem (SIMBIO-SYS),...
The stereo camera (STC) is one of the channels of SIMBIOSYS, the remote sensing instrument that will be on board the BepiColombo, and it will provide the global mapping of Mercury and Digital Terrain Model of the entire surface. The maximum spatial resolution will be of 50 m per pixel at the periherm (400 km from the surface) and the vertical accur...
Exponential Gaussian approach for spectral modeling: the EGO algorithm, I. Band saturation, Icarus (2009), doi: 10.1016/j.icarus.2009.01.022 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting...
We present the Messinian evaporite suite (Mediterranean region) and the Solfatara hydrothermal system (Phlegraean Fields volcanic province, Italy), discuss their implications for understanding the origin of sulfates on Mars and show preliminary sets of VNIR laboratory and in situ reflectance spectra of rocks from these geologic systems. The choice...
Here we present demonstrative results of the multi-resolution approach to the interpretation of the spectral variability of a multispectral survey for a terrestrial area, through multispectral Landsat TM5 data.
The stereo camera (STC) is one of three channels of the spectrometer and imagers for Mercury Planet Orbiter BepiColombo Integrated Observatory SYStem (SIMBIOSYS), which will be on board the Mercury Planetary Orbiter of the ESA mission BepiColombo. SIMBIOSYS includes also an high resolution imaging channel (HRIC), providing images at spatial resolut...
Rocks from two terrestrial intrusions are proposed. Linear relationships are observed between pyroxene band I centers vs. mineral chemistry and pyroxene band I depths vs. modal composition. Lunar rocks match the terrestrial sample regression curves.
We present the preliminary results of testing a new fitting technique for modeling VNIR spectra (Exponential Gaussian Optimization), including band saturation effects, overlapping absorptions and effects due to sample impurities and neutral phases.
The field measurements campaign made
in July 2003 on Etna, Vulcano Island and Campi
Flegrei was dedicated to the calibration and validation
of airborne and spaceborne data.
The campaign activities were relevant part of two
ASI funded projects:
1) FASA, dedicated to airborne system and data
validation/calibration
2) HypSEO, dedicated to multispectr...
The field measurements campaign made in July 2003 on Etna, Vulcano Island and Campi Flegrei was dedicated to the calibration and validation of airborne and spaceborne data. The campaign activities were relevant part of two ASI funded projects: 1) FASA, dedicated to airborne system and data validation/calibration 2) HypSEO, dedicated to multispectra...
We describe the contributions that we expect by the Visual and Infrared
Hyper-spectral Imager channel (VIHI) to make towards increased knowledge
and understanding of Mercury's surface and composition. Due to the
difficulties of observing Mercury from ground, relatively little is
known about its surface composition, and Mercury spectra are vulnerabl...
Mount Etna volcano is the tallest and most active of European volcanoes. It is characterised by four craters (Northeast Crater, Voragine, Bocca Nuova, Southeast Crater) with a highest point at 3315m elevation. Eruptions are frequently observed on Etna, and are typical of basaltic volcanism, consisting of voluminous lava flows and ash-generating exp...
From 16 to 26 July 2003 an extensive field campaign was carried out around Mt Etna, Sicily, Italy. During the campaign a new airborne system, Fire Airborne Spectral Analyzer (FASA), was tested. The main instrument of the payload is a high resolution Michelson Interferometer with Rotating Retroreflector (MIROR), which operates in the nominal infrare...
A stereo camera (STC) with panchromatic and 4 visible-near infrared (NIR) filters and a visible-near infrared hyperspectral imager (VIHI) with 400–2000 nm spectral range, integrated into the spectrometers and imagers for BepiColombo integrated observatory-system (SIMBIO-SYS) selected for BepiColombo, are dedicated to the geologic exploration of Mer...
Laboratory visible and near-infrared reflectance spectra of solid rock slabs, mineral separates and systematic mixtures were simultaneously investigated. We apply an empirical approach to evaluate spectra, in order to achieve qualitative and quantitative information. We use cumulates (mostly norites, leuconorites, melanorites and anorthosites) belo...
Our knowledge about the crustal composition of the Moon, Mars and Mercury are summarized, with particular regard to the models of crust structure, compositional profiles, and evolution, as a basis for the selection of suitable terrestrial analogues for the interpretation of reflectance spectra from orbit. The examples of analogues shown here are fr...
This paper describes CIRILLO, a new software for the correction of spaceborne images acquired in the VIS-SWIR spectral range. Moreover the capability to retrieve minerals composing the Solfatara di Pozzuoli surface using ASTER multispectral data is shown. In order to identify the mineralogical composition of the collected sample, mineralogy analysi...
Knowledge regarding the surface composition of Mars and other bodies of the inner solar system is fundamental to have an understanding of their origin, evolution, and internal structures. Approaches to qualitative and quantitative analysis of remotely-acquired spectra have been successfully used to infer the presence and abundance of minerals and t...
We discussed the possibilities and open questions concerning laboratory refl ectance spectroscopy, spectroscopic measurements in the fi eld, hyperspectral image data from spacecraft, and integration of multiscale data. Open questions included: (1) bulk-rock spectral complexity, which provides the geo- logic basis for every spectroscopic analysis; (...
Problems related to airborne hyperspectral image data are reviewed and the requirements for data analysis applied to mineralogical (rocks and soils) interpretation are discussed. The variability of mineral spectral features, including absorption position, shape and depth is considered and interpreted as due to chemical composition, grain size effec...
Knowledge regarding the surface composition of Mars and other bodies of the inner solar system is fundamental to understanding of their origin, evolution, and internal structures. Technological improvements of remote sensors and associated implications for planetary studies have encouraged increased laboratory and field spectroscopy research to mod...
BepiColombo is the cornerstone n.5 of ESA, and it will be launched on August 2013. It is composed by two modules: the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (MMO), and with a suite of instruments which shall allow to perform observations with a level of details considerably improved respect to the NASA's Messenger mi...
MEMORIS (MErcury Moderate Resolution Imaging System) is a wide angle camera (WAC) concept for the ESA mission BepiColombo. The main scientific objectives consist of observing the whole surface of Mercury in the spectral range of 400–1000 nm, with a spatial resolution of 50 m per pixel at peri-Herm (400 km) and 190 m at apo-Herm (1500 km). It will o...
This from 17 July until 26 July, 2003, a field campaign on Mount Etna and on the island of Vulcano, was carried out jointly to airborne campaign (FASA). FASA (Fire Airborne Spectral Analyze) is the airborne main instrument composed by an imager and a Fourier Transform Spectrometer in the 3.3-13 mum IR range. The field campaign was aimed to the vali...
Mineral interpretation of a planet surface using spectral libraries can be improved if the spectral variability, often characterizing the spectral data, can be explained as the result of well-defined geological processes. Reflectance spectra of metamorphic rocks are analyzed. Selected examples point out systematic and non-systematic relationships b...
Noisy spectra were simulated from laboratory 2000-2500 nm reflectance spectra of polymineralic sand samples and synthetic composite spectra, using MIVIS calibration parameters and measured solar irradiance both with and without diffuse atmospheric radiance at the sensor. Noise content variation in output data with varying sensor parameters and atmo...
Mineralogical and short wave infrared (SWIR) spectral characters of North-East Italian beach sands have been investigated in order to define interpretation rules for high spatial and spectral resolution remote sensed data. Beach sands are complex mineralogical mixtures, yielding spectral curves which are the result of non-linear interactions of the...
Laboratory reflectance (0.4-2.5 w m ) spectra of 41 samples of metamorphic rocks from the Precambrian basement of Madagascar were analysed on the basis of absorption band position and shape, and classified on the basis of recurrent associations of absorption bands. Petrographic analyses allowed us to interpret the absorption features in composition...
Visible short-wave infrared laboratory reflectance spectra of quartzites and micaschists from the Precambrian basement of central-western Madagascar are dominated by the muscovite spectrum. The spectra were measured from rock samples collected along an E–W traverse across a metamorphic sequence recording progressively higher metamorphic grades. The...
Using remote sensing data for geological applications requires specific spatial and spectral resolution combinations for the different geological problems. We evaluate the most adequate combinations for (1) lithological analysis and (2) delineation of depositional bodies. Responses of various hyperspectral and multispectral sensors were simulated u...
Reflectance (0.4 - 2.5 micrometer) and transmittance (2.5 - 25 micrometer) laboratory spectra of sedimentary and metamorphic rocks from different geologic settings were analyzed and classified, and used for the simulation of hyperspectral (MIVIS) response. The analysis regarded both freshly cut and exposed rock surfaces. Classification was based on...
Rock expression in a multi-spectral image is referred to as multi-spectral image facies. Thematic Mapper (TM) multi-spectral facies of sedimentary rock bodies outcropping in an overall arid area of northern Somalia were interpreted by: (1) comparison with laboratory reflectance spectra of weathered surfaces of rock samples from the study area; (2)...
Integrated analyses of aerial photographs and multispectral remote sensing images were used for stratigraphic correlation in mainly carbonate and evaporitic rocks. These rocks crop out in an area of northern Somalia characterized by an arid climate. By the aerial photo analysis, we recognized photostratigraphic logs and stratal patterns and establi...
More than seventy reflectance spectra measured on mainly carbonate and evaporitic rocks outcropping in an area of northern Somalia have been analysed and classified through the recognition of specifically defined spectrofacies. The spectrofacies are associations of absorption features produced by specific electronic and molecular processes or a com...
Citations
... While BepiColombo, and in particular the BepiColombo Laser Altimeter (Thomas et al. 2007) and the Spectrometer and Imaging for MPO BepiColombo Integrated Observatory SYStem (Cremonese et al. 2020) instruments, will in the future provide a first homogeneous mapping of both Mercury's hemisphere, the mission is still several years away from entering orbit and it is thus important to further exploit MESSENGER's extensive data sets to retrieve additional information about the planet, for both geophysical analysis, improving available a priori information, and supporting the preparation for the upcoming mission. Indeed, our work also has important implications for the planning of BepiColombo's observations, by allowing us to target the most interesting regions based on detailed and reliable simulations. ...
![[object Object]](https://i1.rgstatic.net/ii/profile.image/291006395240457-1446392739341_Q64/Gabriele-Cremonese.jpg)
![[object Object]](https://i1.rgstatic.net/ii/profile.image/272736937312261-1442036961419_Q64/Maria-Capria.jpg)
![[object Object]](https://i1.rgstatic.net/ii/profile.image/1136797128101888-1648044964093_Q64/Alain-Doressoundiram.jpg)
![[object Object]](https://i1.rgstatic.net/ii/profile.image/556613794791426-1509718478957_Q64/Diego-Turrini.jpg)
... Emissivity measurements are recorded using an external emissivity chamber (designed at DLR), attached to a Bruker Vertex80V FTIR spectrometer with a nitrogen-cooled MCT detector and a KBr beamsplitter. Several Mercury analogs have been measured in this configuration to determine their emissivity behavior under simulated daytime surface conditions of Mercury, including silicates Ferrari et al. , 2020, sulfides (Varatharajan et al. 2019a(Varatharajan et al. , 2019bHelbert et al. 2013b;Carli et al. 2019), and graphite . A unique spectral library is being created for the spectral range of 7-14 µm, at five temperatures (100, 200, 300, 400, 500°C) and in a low vacuum environment, to support MERTIS observations. ...
![[object Object]](https://i1.rgstatic.net/ii/profile.image/272384489947167-1441952931886_Q64/Cristian-Carli.jpg)
![[object Object]](https://i1.rgstatic.net/ii/profile.image/272435375243264-1441965063196_Q64/Alessandro-Maturilli.jpg)
![[object Object]](https://i1.rgstatic.net/ii/profile.image/272384624164872-1441952963589_Q64/Sabrina-Ferrari.jpg)
... The spatio-temporal mapping of deltaic landforms provides insights into delta dynamics and can reveal their main controlling parameters (Aiello et al., 2013;Tarragoni et al., 2011). It also evidences the long-term evolutionary trajectories of fluvial-coastal systems (Ainsworth et al., 2011;Rossetti et al., 2015;Giacomelli et al., 2018;Mathers & Zalasiewicz, 1999;Rao et al., 2015;Rossetti et al., 2015). So far, the main targets have been the major deltaic systems (Amorosi & Milli, 2001;Anthony et al., 2014;Caldwell et al., 2019;Ericson et al., 2006;Korus & Fielding, 2015;Stanley & Warne, 1994), because they echo to broader research interest and have global environmental significance, thus determining funding allocations. ...
![[object Object]](https://i1.rgstatic.net/ii/profile.image/345072559247361-1459283117069_Q64/Giacomelli-Serena.jpg)
![[object Object]](https://i1.rgstatic.net/ii/profile.image/278805248790543-1443483760037_Q64/Luigi-Bruno.jpg)
![[object Object]](https://i1.rgstatic.net/ii/profile.image/873550772719617-1585282142134_Q64/Carlos-Souza-Filho-3.jpg)
... On the other hand, a lot of progress has been made with the use of the Modified Gaussian Model (MGM) to address the non-linear deconvolution of visible-infrared spectra, including the cases of complex mineralogical assemblages (e.g., Noble et al., 2006;Pompilio et al., 2009;Clenet et al., 2011;Parente et al., 2011;Verpoorter