Luigi Folco

University of Pisa | UNIPI · Department of Earth Sciences

Extraterrestrial material collected during space missions is highly exposed to contamination issues during on-Earth analysis. Although high-protection-level protocols were developed, to minimize the contamination due to sample manipulation and the substrate contribution an optimal strategy is to perform in situ analysis with contactless techniques....

Reckling Peak (RKP) 17085 is a newly classified Antarctic CM chondrite that preserves a complex alteration history characterized by mild aqueous alteration (CM2.7), overprinted by a short-lived thermal metamorphic event (heating stage III [<750°C]), and affected by low-grade terrestrial weathering. This meteorite contains abundant Fe-rich bands wit...

C-type asteroids are planetary bodies with primitive composition that are thought to represent the parent-bodies of carbonaceous chondrites, which in turn are the probable source of the volatile species delivered to the Earth during its accretion history. The C-type asteroid (162173) Ryugu has been recently sampled by the JAXA/Hayabusa2 mission, pr...

Volatile-rich C-type asteroids are planetary bodies with primitive composition that are thought to represent the parent-bodies of carbonaceous chondrites, which in turn are the probable source of the volatile species delivered to the Earth during its accretion history. The C-type asteroid (162173) Ryugu has been recently sampled by the JAXA/Hayabus...

The Mighei-type CM carbonaceous chondrite Reckling Peak (RKP) 17085 is an Antarctic meteorite find collected in 2017 by a PNRA team. RKP 17085 is unusual for the occurrence of homogenously spread Fe-rich bands in the matrix. These features have been documented in only five other carbonaceous chondrites [1-5], where they are interpreted as reaction/...

A new type of silica-rich glass has been discovered associated with the known impact glass strewn field of the Atacama Desert. Based on petrography, chemical composition and indistinguishable 40 Ar/ 39 Ar formation ages at circa 6.6 Ma, we infer that these two glasses were produced by the same impact event, which gave rise to two successive composi...

We performed scanning electron microscopy and electron microprobe analysis on the eucritic meteorites Errachidia 002 and Northwest Africa 11911, with a focus on the metallic iron disseminated in them, in order to constrain the processes involved in its formation, and discuss its implication for their parent body collisional history. Errachidia 002...

TiO 2 II, a high‐pressure polymorph of titanium dioxide, is a diagnostic indicator of shock metamorphism in impact rocks. Due to its typical micro‐to‐nanometer scale, there are no ab initio structure solutions of natural TiO 2 II, thereby generating uncertainty about its crystal structure and its known similarity with srilankite (Ti 0.67, Zr 0.33 )...

In this work, we investigate macroscopic characteristics, magnetic susceptibility, mineralogy, and mineral composition of Al Haggounia 001. The samples were collected during eight field missions in the period between 2015 and 2019. In the strewn field of about 65 km in length, the specimens are found either on the surface or shallowly buried in loo...

Eucrites, diogenites and howardites (HEDs) form the most abundant clan of achondrites on Earth. They represent samples of a differentiated body, widely believed to be the asteroid (4) Vesta [1]. Telescopic observations and Dawn mission data showed that the surface of Vesta is heavily cratered, which is consistent with the brec-ciated nature of most...

We use optical and Raman Tweezers to manipulate micro and nano-plastics and individual cosmic dust particles. We identify their compositions and shapes studying their response to optical forces, enabling a better understanding of the plastics fragmentation processes in sea environment and the effects of light on single grains of cosmic dust.

Cosmic dust plays a dominant role in the universe, especially in the formation of stars and planetary systems. Furthermore, the surface of cosmic dust grains is the benchwork where molecular hydrogen and simple organic compounds are formed. We manipulate individual dust particles in a water solution by contactless and noninvasive techniques such as...

The mechanisms responsible for the formation of Fe-rich, metasomatic features in eucrites and their debris in howardites are yet controversial. In this study, secondary phases found in polymict eucrite NWA (Northwest Africa) 11911, howardite NWA 1664, monomict eucrite NWA 8675 and unbrecciated basaltic eucrite NWA 13269 were investigated to elucida...

Cosmic dust plays a dominant role in the universe, especially in the formation of stars and planetary systems. Furthermore, the surface of cosmic dust grains is the bench-work where molecular hydrogen and simple organic compounds are formed. We manipulate individual dust particles in water solution by contactless and non-invasive techniques such as...

Cosmic dust grains sample a diverse range of solar system small bodies. This includes asteroids that are not otherwise represented in our meteorite collections. In this work we obtained 3D images of micrometeorite interiors using tomography before collecting destructive high‐precision oxygen isotope measurements. These data allow us to link texture...

Kamil crater (Egypt) is a natural laboratory for the study of processes and products associated with the impacts of small iron projectiles on the Earth’s crust. In particular, because of the distinctive composition of the impactor (an ungrouped Ni-rich ataxite) and the target (Cretaceous sandstones and minor wackes) it offers a unique opportunity t...

During the systematic magnetic susceptibility survey of the Paris Museum Australasian tektite collection, we identified three previously overlooked occurrences of volcanic glass that resembles tektites, based on anomalous magnetic properties, high water content, the presence of microcrystals, and anomalous chemical composition. These occurrences ar...

The cosmochemistry of meteorites provides unique clues on asteroids accretion, differentiation, collisional break-up and reassembly, processes of critical importance for understanding planet formation in the early solar system. Mesosiderites are a complex group of achondrites whose nearly 50:50 metal-silicate composition is interpreted in the liter...

We present a scheme for non-destructive provenancing of granite shafts dating from the Roman to the medieval period using a combination of visual, magnetic, and chemical determinations. Our results on two monumental medieval complexes in Europe, in Pisa and Lyon, shows both oriental provenance, most likely spolia, and shaft from the quarries within...

EURO—CARES (European Curation of Astromaterials Returned from the Exploration of Space) was a European Commission funded project under the Horizon 2020 Research and Innovation program and ran between January 2015 and December 2017. The core project team was made up of academic and industry experts from 14 different organisations from the United Kin...

Since its discovery, the Kamil crater (Egypt) has been considered a natural laboratory for studying small-scale impact cratering. We report on a previously unknown shock-related phenomenon observed in impact melt masses from Kamil; that is, the shock-triggered formation of skeletal quartz aggregates from silica-rich fluids. These aggregates are uns...

Optical tweezers are powerful tools based on focused laser beams. They are able to trap, manipulate and investigate a wide range of microscopic and nanoscopic particles in different media, such as liquids, air, and vacuum. Key applications of this contactless technique have been developed in many fields. Despite this progress, optical trapping appl...

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Fractionation effects related to evaporation and condensation had a major impact on the current elemental and isotopic composition of the Solar System. Although isotopic fractio-nation of moderately volatile elements has been observed in tektites due to impact heating, the exact nature of the processes taking place during hypervelocity impacts rema...

Coesite in impact rocks is traditionally considered a retrograde product formed during pressure release by the crystallisation of an amorphous phase (either silica melt or diaplectic glass). Recently, the detailed microscopic and crystallographic study of impact ejecta from Kamil crater and the Australasian tektite strewn field pointed in turn to a...

This volume represents the proceedings of the homonymous international conference on all aspects of impact cratering and planetary science, which was held in October 2019 in Brasília, Brazil. This volume contains a sizable suite of contributions dealing with regional impact records (Australia, Sweden), impact craters and impactites, early Archean i...

Sample return missions are among the most exciting space missions, providing both scientifically unique information and an unparalleled mechanism for the inspiring the public. Returned samples allow us to make critical ground truth measurements that can calibrate remote sensing measurements from spacecraft. Some scientific studies can only be done...

We report on the geochemical analyses of glassy spherules from sediments at three Transantarctic Mountain locations and the discovery of Australasian microtektites at two of these sites. Australasian microtektites are present at Mt. Raymond (RY) in the Grosvenor Mountains and Meteorite Moraine (MM) at Walcott Névé, in the Beardmore Glacier region o...

Remnants of shooting stars are preserved in form of cosmic spherules in ice and sediments. The extraterrestrial material is heated and melted upon atmospheric entry and is collected at the Earth's surface as cosmic spherules. A fraction of cosmic spherules (I‐type cosmic spherules) sources from extraterrestrial Fe,Ni metal. These metal particles me...

Optical tweezers are powerful tools based on focused laser beams. They are able to trap, manipulate, and investigate a wide range of microscopic and nanoscopic particles in different media, such as liquids, air, and vacuum. Key applications of this contactless technique have been developed in many fields. Despite this progress, optical trapping app...

Microtektites represent high-velocity/distal meteorite impact ejecta. Demonstrating that microtektites found at several locations throughout East-Antarctica consist of a homogeneous class of geological objects belonging to the Australasian tektite/microtektite strewn field is fundamental to define the actual extent of the largest and youngest known...

We analysed the heterogenous fine-grained (sub-μm) matrix of a small (58 × 93 μm), unmelted and minimally heated (<350 °C) micrometeorite (CP94-050-052) recovered from Antarctic blue ice. This particle contains some unaltered highly primitive phases, including refractory anhydrous high-Mg silicates and submicron crystalline needle-shaped acicular g...

The practical limitations inherent to human and robotic planetary exploration necessitate the development of specific protocols and methods. This non-standard approach requires testing and validation phases in order to optimize instrumental setups and improve data interpretation; this can occur prior to, during, or even after a mission. Flight inst...

The Atlas of Meteorites in Thin Section is an on-line educational resource of the Dipartimento di Scienze della Terra of the Università di Pisa, Italy. It is a collection of optical microscopic images of 45 polished thin sections from 45 meteorites representative of a variety of different types of stony meteorites, belonging to the Museo Nazionale...

Goldschmidt 2021 Abstract https://doi.org/10.7185/gold2021.5445 Isotope fractionation of Fe by hypervelocity impacts evidenced by Australasian microtektites STEPAN M. CHERNONOZHKIN1, CLAUDIA GONZÁLEZ DE VEGA1, NATALIA ARTEMIEVA2, BASTIEN SOENS3, JOKE BELZA1, EDUARDO BOLEA FERNANDEZ1, MATTHIAS VAN GINNEKEN4, BILLY P. GLASS5, LUIGI FOLCO6, MATTHEW J...

We trap individual cosmic dust particles by Raman Tweezers to identify their compositions and to characterize their response to optical forces without any substrate effects, documenting the high potential of this novel technique for space exploration.

Muong Nong-type (MN) tektites are a layered type of tektite associated to the Australasian strewn field, the youngest (790 kyr) and largest on Earth. In some MN tektites, coesite is observed in association with relict quartz and silica glass within inclusions surrounded by a froth layer. The formation of coesite-bearing frothy inclusions is here in...

Bulk oxygen isotope data has the potential to match extraterrestrial samples to parent body sources based on distinctive δ18O and Δ17O ratios. We analysed 10 giant (>500 μm) micrometeorites using combined micro-Computer Tomography (μCT) and O-isotope analysis to pair internal textures to inferred parent body groups. We identify three ordinary chond...

Comets are typically considered to be pristine remnants of the early solar system. However, by definition they evolve significantly over their lifetimes through evaporation, sublimation, degassing and dust release. This occurs once they enter the inner solar system and are heated by the Sun. Some comets (e.g. 1P/Halley, 9P/Tempel and Hale-Bopp) as...

Giant micrometeorites (MMs; 400–2000 µm) are exceedingly rare and scientifically valuable. Three‐dimensional nondestructive characterization by X‐ray computed tomography (X‐CT) provides information on the petrography and thus petrogenesis of MMs and serves as a guide to maximize subsequent multi‐analytical studies on such precious planetary materia...

51st Lunar and Planetary Science Conference (2020)

This study explores the long‐duration (0.8–2.3 Ma), time‐averaged micrometeorite flux (mass and size distribution) reaching Earth, as recorded by the Transantarctic Mountains (TAM) micrometeorite collection. We investigate a single sediment trap (TAM65), performing an exhaustive recovery and characterization effort and identifying 1,643 micrometeor...

We examined 16 white opaque inclusions exposed on two polished slices of a Muong Nong‐type Australasian tektite from Muong Phin, Laos. The inclusions usually consist of a core, surrounded by a froth layer, and a quartz neoblast layer. The cores are composed primarily of a mixture of silica glass, coesite, and quartz in varying proportions. A thin (...

This chapter provides an account of the present Egyptian impact cratering record as well as an overview of the Egyptian meteorite collection. The 45-m-diameter Kamil crater in the East Uweinat District in southwestern Egypt is so far the only confirmed impact crater in Egypt. Due to its exceptional state of preservation Kamil can be considered a ty...

TAM5.29 is an extraterrestrial dust grain, collected on the Transantarctic Mountains (TAM). Its mineralogy is dominated by an Fe‐rich matrix composed of platy fayalitic olivines and clasts of andradite surrounded by diopside‐jarosite mantles; chondrules are absent. TAM5.29 records a complex geological history with evidence of extensive thermal meta...

We describe the geological, geomorphological, and paleoclimatic setting of the Sahara of North Africa in particular, focused on the main meteorite dense collection areas (DCA; Morocco, Algeria, Tunisia, and Libya). We report on the outcome of several meteorite recovery field expeditions in Morocco and Tunisia since 2008, by car and by foot, that ap...

We report the discovery of a unique micrometeorite, containing an exotic Al-Cu-Fe alloy composed of two intermixed phases: khatyrkite (CuAl2) and stolperite (CuAl) and both containing minor Fe (<1.4 wt%). These phases are dendritic and rapidly co-crystallized at the binary system’s peritectic (~550 °C). The host micrometeorite is an otherwise typic...

Kamil can be considered a type-structure for small-impact craters on Earth and as such, as a natural laboratory to investigate the processes and products associated with the impact of small projectiles. Kamil Crater is a 45-m-diameter impact crater with a pristine ejecta ray structure in the the rocky Sahara desert of southwestern Egypt (East Uwein...

This is an overview of the results of our ongoing research aiming at better understanding of the formation and survival of impact coesite - a debated issue in impact cratering and shock metamorphism studies.

Coesite, a high-pressure silica polymorph, is a diagnostic indicator of impact cratering in quartz-bearing target rocks. The formation mechanism of coesite during hypervelocity impacts has been debated since its discovery in impact rocks in the 1960s. Electron diffraction analysis coupled with scanning electron microscopy and Raman spectroscopy of...

Introduction: Hydrated fine-grained micrometeorites are the most abundant subtype of cosmic dust across the entire size range of the flux (50-3000μm) [1,2,3]. They are chondritic particles dominated by Fe-Mg phyllosilicates and may contain as minor components: partially replaced anhydrous silicates (forsterite, enstatite and augite), magnetite, Fe-...

Introduction: We provide a comprehensive overview of micrometeorite statistics from a single sediment trap within the TAM (Transantarctic Mountain) micrometeorite collection[1]. Trap No.65 was recovered from the glacially eroded, flat-toped nunatak: Mille Bute, within Victoria Land, Antarctica. The analysis of large numbers of micrometeorites is es...

We report the discovery of a partially altered microchondrule within a fine-grained micrometeorite. This object is circular, <10μm in diameter, and has a cryptocrystalline texture, internal zonation, and a thin S-bearing rim. These features imply a period of postaccretion parent body aqueous alteration, in which the former glassy igneous texture wa...

EURO-CARES (European Curation of Astromaterials Returned from the Exploration of Space) was a three-year multinational project (2015-2017) funded by the European Commission's Horizon 2020 research programme. The objective of EURO-CARES was to create a roadmap for the implementation of a European Extra-terrestrial Sample Curation Facility (ESCF). Th...

This study explores the petrology of five giant (>400μm) hydrated fine-grained micrometeorites from the Transantarctic Mountain (TAM) micrometeorite collection. For the first time, the extent and mechanisms of aqueous alteration in unmelted cosmic dust are evaluated and quantified. We use a range of criteria, previously defined for use on hydrated...

__________________________________________________________________________________ The separation of unoxidized Fe-Ni metal beads from molten cosmic spherules during atmospheric entry is a well-documented process that has been extensively investigated within the Fe-dominated [I-type] micrometeorites (Bi et al., 1993; Yada et al., 1996; Genge et al....

The early stages of atmospheric entry are investigated in four large (250–950 μm) unmelted micrometeorites (three fine‐grained and one composite), derived from the Transantarctic Mountain micrometeorite collection. These particles have abundant, interconnected, secondary pore spaces which form branching channels and show evidence of enhanced heatin...

The degree of aqueous alteration affecting the fine-grained micrometeorite population is investigated using criteria originally developed for CM chondrites. We analyse >50 micrometeorites derived from the Transantarctic Mountain (TAM) and Cap Prud'homme collections, revealing that most unmelted fine-grained particles are intensely altered, with pet...

Scanning and transmission electron microscopy observations on shocked silica mineral grains from the Australasian tektite/microtektite strewn field suggest that coesite crystals form directly in contact with quartz grains through a subsolidus reconstructive transformation. This finding is in contrast with the current mainstream view, which consider...

We analyse primitive heterogeneous fine-grained matrix within a small (58 x 93 µm), unmelted Antarctic micrometeorite (CP94-050-052). This study uses a multi-element approach, combining wavelength-dispersive electron probe microanalysis (WD-EPMA) and standard-based energy-dispersive X-ray spectrometry (EDS) with high spatial resolution, low voltage...

High ¹⁰Be contents in tektites reported in literature are taken as evidence of a source material, melted at the impact site, enriched in atmospheric ¹⁰Be; i.e., a soil or sediment. In 0.8 Ma Australasian tektites, ¹⁰Be content increases with distance from the putative impact location in Indochina, with geographic averages from 69 × 10⁶ atoms/g (Ind...

The bulk of extraterrestrial matter currently accreted by the Earth is in the form of micrometeorites (MMs) and interplanetary dust particles (IDPs), thus they may have collectively made a substantial contribution to the volatile inventory of the Earth and the other terrestrial planets. We have performed a complete noble gas study, accompanied by a...

Coesite, a high-pressure silica polymorph (pressure 3–10 GPa, temperature <3000 K), is a diagnostic feature of shock metamorphism associated with impact cratering on quartz-bearing target rocks. It is preserved as a metastable phase in sedimentary target rocks that experienced peak pressures in excess of ~10 GPa, where it typically occurs as interg...