Daniele Brunelli

• PhD
• Researcher at University of Modena and Reggio Emilia

At mid‐ocean ridges, the mantle temperature and composition, and the lithosphere thickness control the melting conditions, which influence the feeding and structure of the neo‐volcanic areas. We present a study of the eastern intersection between the Romanche transform fault (TF) and the adjacent southward segments of the Mid‐Atlantic Ridge (MAR)....

Mantle processes control plate tectonics and exert an influence on biogeochemical cycles. However, the proportion of mantle sampled in-situ is minimal, as it is buried beneath igneous crust and sediments. Here we report the lithological characteristics of two mantle sections from an embryonic ocean drilled by the International Ocean Discovery Progr...

Volatiles (CO2, H2O) play a fundamental role in mantle melting beneath ocean spreading centers, but what role they play during the melt migration remains unknown. Using seismological data recorded by ocean-bottom seismometers, here we report the presence of deep earthquakes at 10–20 km depth in the mantle along the Mid-Atlantic Ridge axis, much bel...

Seafloor anomalies along mid-ocean ridges with exceptionally thick and compositionally distinct basaltic crust, for example, at Iceland, suggest that the underlying mantle is hotter and chemically different from the adjacent subridge mantle. Here we present hafnium and neodymium isotope ratios of peridotites from the Charlie Gibbs Transform Zone, w...

Most of the geologic CO 2 entering Earth’s atmosphere and oceans is emitted along plate margins. While C-cycling at mid-ocean ridges and subduction zones has been studied for decades, little attention has been paid to degassing of magmatic CO 2 and mineral carbonation of mantle rocks in oceanic transform faults. We studied the formation of soapston...

The mapping of radioactive heat production (RHP) and the respective radioactive heat flow (RHF) of Saint Peter and Saint Paul Archipelago (SPSPA), based on radioactive heat-producing elements (RPE) data from whole-rock chemical analysis and in situ Gamma radiation spectrometry. The SPSPA show a radioactive heat production that ranging from 0.08 to...

Oceanic Transform Faults are major plate boundaries representing the most seismogenic part of the mid ocean ridge system. Nonetheless, their structure and deformation mechanisms at depth are largely unknown due to rare exposures of deep sections. Here we study the mineral fabric of deformed mantle peridotites - ultramafic mylonites - collected from...

We present chemical and mineralogical data on a megacryst of a unique carbonate-bearing fluorapatite from altered Tertiary volcanics of the Veneto Volcanic Province (VVP) in the western Lessini Mountain range (Veneto, northern Italy). The cm-sized specimen was identified and characterized by scanning electron microscope (SEM), X-ray powder diffract...

Accretionary processes at mid‐ocean ridge segments with low magma input have seldom been investigated over the long term. The evolution of such magma‐starved segments over time is still largely unknown. We present a study on the structure and evolution of the southernmost intra‐transform ridge segment of the St. Paul Transform Fault System in the E...

This work presents the first mapping of the radiogenic heat production (RHP) and the respective radiogenic heat flow (RHF) of the Saint Peter and Saint Paul Archipelago (SPSPA) located at 1°N in the Equatorial Atlantic Ocean. Using radiogenic heat producing elements (RPE) we inferred a radiogenic heat production ranging 0.08–0.68 μW/m³ (Median: 0.2...

Oceanic crust is formed by melt derived from the mantle at oceanic spreading centers. A small amount of melting initiates at about 150-300 km depths in the presence of volatiles (CO2, H2O)1–3, but the extensive dry melting commences at 60-70 km depths due to the upwelling of the mantle as two diverging plates move apart4,5. However, how these melts...

The St. Peter and St. Paul archipelago (SPSPA) is composed of abyssal mantle rocks. It consists of a small group of islets (five) and rocks (five), located near the axis of the Mid-Atlantic Ridge, in an inside corner position on the southern edge of the northern transform limit of the St. Paul Transform Fault System. The archipelago forms the summi...

The large range of H 2 O contents recorded in minerals from exhumed mantle rocks has been challenging to interpret, as it often records a combination of melting, metasomatism, and diffusional processes in spatially isolated samples. Here, we determine the temporal variations of H 2 O contents in pyroxenes from a 24-Ma time series of abyssal peridot...

This paper discusses the tectonics of the St. Peter and St. Paul Archipelago (SPSPA) in the Equato-rial Atlantic Ocean, based on the joint-system geometry which show a North-South shorten-ing/transpressional uplift tectonism, is active leading to exhumation of the sub-oceanic mantle. These islets are the summits of a sigmoidal submarine ridge forme...

Oceanic transform faults, a key element of plate tectonics, represent the first-order discontinuities along mid-ocean ridges, host large earthquakes, and induce extreme thermal gradients in lithosphere. However, the thermal structure along transform faults and its effects on earthquake generation are poorly understood. Here we report the presence o...

Tremolite is one of the most common amphibole species and, in the fibrous form (i.e., characterized by crystals/particles consisting of fibres with length > 5 µm, width < 3 µm and aspect ratio > 3), one of the six asbestos minerals. Until now the attention of crystallographers has focused only on samples from continental environment. Here we report...

The Eocene basaltic extrusions in the Paso de Indios region (Chubut-Argentina) are one manifestation of the extensional tectonism of the active margin of South America during the Cenozoic. Ultramafic xenoliths embedded in these volcanics are mainly harzburgites and lherzolites with subordinate pyroxenites, estimated equilibrium temperatures ranging...

Oxide gabbros are a minor but diffuse component of the lower oceanic crust. Their presence poses questions on lower crust exhumation processes and magma differentiation at mid ocean ridges because they are systematically associated with shear zones and are hardly explained by classical fractionation and melt migration models. Here, we report on a s...

Mineralogical and chemical investigations were carried out on intra-craterial bedrocks (Lower Devonian sandstone) and regolithic residual soil deposits present around the Amguid structure, to discuss the hypothesis of its formation through a relatively recent (about 0.1 Ma) impact event. Observations with an optical microscope on intra-craterial ro...

Global correlations of mid-ocean-ridges basalt chemistry, axial depth and crustal thickness have been ascribed to mantle temperature variations affecting degree of melting. However, mantle H2O content and elemental composition may also play a role. How H2O is distributed in the oceanic upper mantle remains poorly constrained. We tackled this proble...

Lipari, the largest island in the Aeolian archipelago, commands a strategic position in the Central Mediterranean, and its pre and proto history extends over 5000 years of continuous habitation. This paper aims to discuss the Lipari cultural sequence in a new interdisciplinary perspective juxtaposing the different spheres of innovation, connectivit...

The end of prehistory in the Maltese archipelago is characterized by the production of a problematic class of pottery, until now attested just at the site of Baħrija, on the western coast of Malta. Such a production represents a break with the tradition in terms of repertoire of shapes, style and technology and it has been interpreted as the result...

Large-scale landslides at volcanic islands are one of the most dangerous geological phenomena, able to generate tsunamis whose effects can propagate far from the source. However, related deposits are scarcely preserved on-land in the geologic records, and are often difficult to be interpreted. Here we show the discovery of three unprecedented well-...

Thermodynamic modeling has recently suggested that condensed carbonaceous matter should be the dominant product of abiotic organic synthesis during serpentinization, although it has not yet been described in natural serpentinites. Here we report evidence for three distinct types of abiotic condensed carbonaceous matter in paragenetic equilibrium wi...

After travelling in Earth’s interior for up to billions of years, recycled material once injected at subduction zones can reach a subridge melting region as pyroxenite dispersed in the host peridotitic mantle. Here we study genetically related crustal basalts and mantle peridotites sampled along an uplifted lithospheric section created at a segment...

Serpentinization is known to provide substantial amounts of energy in the form of molecular hydrogen along with a suite of abiotic organic compounds of low molecular weight (mainly as short chain alkanes and carboxylic acids), all sustaining the development of microbial ecosystems in the mantle-derived crust. The latter have a cryptoendolithic life...

Mantle-derived peridotites sampled at three dredge sites between the Discovery and Indomed fracture zones on the Southwest Indian Ridge axis are analyzed for petrography and major and trace element mineral compositions. While textures and microstructures are those typical of normal residual peridotites these rocks display a large compositional vari...

This exploratory study focuses on the elemental analysis by p-XRF (portable X-Ray Fluorescence Analyser) of 62 samples of coarse wares, consisting of Bronze Age handmade burnished ware, so-called Impasto, and of Cooking ware (dated from the Roman period to Modern times). All wares originate from the site of San Vincenzo, Stromboli, and Aeolian Isla...

Mid-ocean ridges are the Earth's most extensive and active volcanic chains. They are also, particularly at slow spreading rates, rift zones, where plate divergence is in part accommodated by faults. Large offset normal faults, also called detachments, are characteristic of slow-spreading ridges, where they account for the widespread emplacement of...

Human osteological samples (n = 23) taken from different anatomical parts of 11 individuals from the post-medieval (16th to 18th century AD) site of Roccapelago (Modena, Italy) were systematically analysed for δ13C, δ15N and trace elements to investigate their diet. δ13C and δ15N correlate and show a high variability between individuals, attesting...

Bone and tooth tissues are important biological archives to study eating habits and provenance of ancient humans and animals. By taking advantage of the high spatial resolution offered by the Laser Ablation Multi Collector Inductively Coupled Plasma Mass Spectrometry (LA–MC–ICP–MS) technique, we investigated the ⁸⁷Sr/⁸⁶Sr intra-tooth variability of...

The easternmost part of the Southwest Indian Ridge (61°-67°E) is an end-member of the global ridge system in terms of very low magma supply. As such, it is a good laboratory to investigate the effect of melt/mantle interactions on the composition of erupted basalts: for a given volume of erupted basaltic melt, the volume of reacted mantle is potent...

Mantle exhumation at slow-spreading ridges is favoured by extensional tectonics through low-angle detachment faults, and, along transforms, by transtension due to changes in ridge/transform geometry. Less common, exhumation by compressive stresses has been proposed for the large-offset transforms of the equatorial Atlantic. Here we show, using high...

Strontium isotope ratios are a strong tool to study ancient hominin and animal migrations, hence the increasing need to have a simple, fast and micro-destructive analytical technique to obtain accurate and precise 87Sr/86Sr ratios of precious tooth enamel and bone tissue. The traditional analysis by the TIMS or MC-ICPMS tecniques requires sample di...

New samples of clay cores from the two Riace bronze statues have been analysed chemically, petrographically and by SEM to shed light on their origins. Sources in or around Corinth and Athens are excluded; the Argolid in the Peloponnese remains a possibility, and the Megarid should be considered further on geological grounds.

This paper focuses on the site of San Vincenzo, Stromboli, Italy, and the use of the portable X-Ray Fluorescence analyser (p-XRF) in the field, as a fast and efficient means of geochemical data collection and processing, without the need to remove a sample. The purpose of the exercise is to aid the archaeological enquiry and to attempt to tie archa...

Preliminary report of the COLMEIA cruise along the St. Paul Fracture Zone System, Equtorial Atlantic. FROM INTERRIDGE NEWS 2013/2014 - VOLUME 22 http://www.interridge.org/

Cannat, M. ; Brunelli, D. ; Paquet, M. ; Sforna, M. C. ; Seyler, M. Ultraslow spreading ridges are key regions to unravel mantle processes. Low potential temperatures and reduced melting allow decrypting early melting processes and shad lights on the source short-scale heterogeneities and their interactions with transient melts. Mantle-derived peri...

Cenozoic basalts carrying ultramafic mantle xenoliths occur in the Matilde, León and Chenque hills in the Paso de Indios region, Argentina. The mantle xenoliths from the Chenque and León hills mainly present porphyroclastic textures, whereas the Matilde hill xenoliths have coarse-grained to porphyroclastic textures. The equilibrium temperatures are...

Aims. After the advent of the laser ablation system (LA), the analysis of micro-samples of hard materials has spread to many scientific fields (i.e. geology, engineering, archaeometry, anthropology). The Laser Ablation Coupled with a Mass Spectrometer (as in the LA–ICP–MS) allows to investigate any hard material at the scale of a few µms, for examp...

We measured trace elements and stable isotopes (C and N on collagen) on 19 samples, taken from different anatomical area of 7 individuals from the medieval site of Roccapelago (Modena): our attempt is to reconstruct the diet of these individuals and discuss the role of trace elements in palaeodiet. The good preservation of these bodies represents a...

The use of LA–MC–ICPMS in anthropological research is an innovative approach for measuring strontium isotopic ratios of human enamel. This technique, due to its micro-destructivity, allows to exam 87Sr/86Sr on precious human remains, without the drawbacks of the dissolution method. Despite this advantage, the laser ablation technique (LA) is not wi...

Our study area is located at the ultra-slow Southwest Indian Ridge, east of the Melville Fracture Zone, between 61 and 67°E. The melt distribution in this area is very heterogeneous, with corridors of ultramafic seafloor where plate separation is accommodated by large offset normal faults [Sauter, Cannat et al., 2013]. These ultramafic corridors al...

The Plio-Quaternary alkaline volcanics from Sardinia include abundant mantle xenoliths which mainly consist of four-phase anhydrous spinel harzburgite and Cpx-poor lherzolites representing the uppermost levels of the Sardinia lithospheric mantle. They are variably depleted rocks generally affected by cryptic enrichment which was ascribed to alkalin...

Abstract The effects of melting in an open-system scenario are here explored looking to the rare earth element (REE) distribution in mantle residues. We consider a peridotite matrix equilibrated in the spinel field accounting for melt inflow during partial melting. The fertility of the source, inflowing melt composition and melt addition rate as we...

The origin of light hydrocarbons discovered at serpentinite-hosted mid-ocean hydrothermal fields is generally attributed to the abiogenic reduction of carbon (di)oxide by molecular hydrogen released during the progressive hydration of mantle-derived peridotites. These serpentinization by-products represent a valuable source of carbon and energy and...

The seawater Mg/Ca ratio increased significantly from ~ 80 Ma to present, as suggested by studies of carbonate veins in oceanic basalts and of fluid inclusions in halite. We show here that reactions of mantle-derived peridotites with seawater along slow spreading mid-ocean ridges contributed to the post-Cretaceous Mg/Ca increase. These reactions ca...

Mantle peridotites from an exposed lithospheric section (Vema Lithospheric Section, VLS), generated during ~ 26 Ma at a ~ 80 km long Mid Atlantic Ridge segment (11° N), have been sampled and studied to understand the evolution of the serpentinization process. The VLS was uplifted due to a 10 Ma transtensional event along the Vema transform. Before...

An integrated microchemical–petrographic approach is here proposed to discriminate the provenance of archaeological pottery artefacts from distinct production centres. Our study focuses on a statistically significant sampling (n=186) of volcanic temper-bearing potteries representative of the manufacturing and dispersion among the islands of the Aeo...

The global mid-ocean ridge system, where tectonic plates diverge, is traditionally thought of as the largest single volcanic feature on the Earth. Yet, wide expanses of smooth sea floor in the easternmost part of the Southwest Indian Ridge in the Indian Ocean lacks the hummocky morphology that is typical for submarine volcanism. At other slow-sprea...

The carbonation of ultramafic rocks is, theoretically, the most efficient reaction to trap CO2 irreversibly in the form of solid carbonates, as predicted by equilibrium thermodynamic calculations. However, the success of industrial or natural carbonation in large ultramafic aquifers or oceanic ultramafic exposures does not only rely on the thermody...

The recesses of the oceanic crust harbour microbes that influence geochemical fluxes between the solid Earth and the hydrosphere1, 2. In the roots of the crust, mantle-derived rocks are progressively hydrated by hydrothermal circulation, a process known as serpentinization. The associated release of molecular hydrogen could provide metabolic energy...

Riassunto Questo lavoro si pone l'obiettivo di ricostruire la rete interinsulare di scambi ceramici nei contesti Capo Graziano [BA-BMII (2300-1430 a.C.)] dell'arcipelago eoliano. A tal fine sono stati esaminati 274 campioni ceramici provenienti da Lipari, Filicudi e Stromboli e 16 campioni di lave affioranti nelle vicinanze dell'insediamento di San...

Das Ziel der hier präsentierten Untersuchung ist eine möglichst umfassende Rekonstruktion des inter- und extrainsularen Keramikaustauschsystems im Äolischen Archipel (Messina, Sizilien, Italien) während der Capo Graziano Phasen [FBZ-MBZII (2200-1430 v. Chr.)]. Hierzu wurden 259 Proben von Fundplätzen der benachbarten Inseln Stromboli, Filicudi und...

Although detachment faulting is thought to be a fundamental, widespread style of accretion of oceanic lithosphere, the kinematic evolution of faulting and the link between deformation and magmatic emplacement are still poorly known. Here we use newly acquired geological and geophysical data from the eastern Southwest Indian Ridge (SWIR) to address...

The eastern Southwest Indian Ridge (SWIR) is among the deepest part of the oceanic ridge system, and it is thus inferred to represent a melt-poor end-member for this system. It displays the widest expanses known to date of seafloor with no evidence for a volcanic upper crustal layer. This nonvolcanic ocean floor has no equivalent at faster spreadin...

The REE compositional space provides a reliable means to recognize the degree of depletion and melt rock reactional events undergone by a parcel of mantle. We model residual clinopyroxene compositions from slow (MAR) and ultraslow (SWIR) sectors of the Mid Ocean Ridges. REE ratios (e.g. SmN/YbN vs. YbN) show compositional trends crosscutting the ex...

Modelling of mantle residua cpx REE patterns allow recognizing short wavelenght vertical variability of the porosity regime of a melting region differing from that deriving after melt focusing processes ultimately leading to dunitic channelling of the mantle section. A trace element detailed study of residual clinopyroxenes from the ultraslow easte...

The Andrew Bain Fracture Zone (ABFZ) represents one of the largest transform faults in the ridge system spanning 750 km in length with a characteristic lens-shape structure. The southern Ridge-Transform Intersection represents the deepest sector of the whole South West Indian Ridge system. During the Italian-Russian expedition S23-AB06, the seafloo...

The lower oceanic crust largely consists of cumulates, representing crystallization products from melt that erupt on the ocean floor. Removal of interstitial melt from the cumulate minerals is believed to be efficient, driven by compaction. Reaction between percolating melts and cumulate minerals can result in micron-to-meter-scale variations in th...

The Southwest Indian Ridge is characterized by frequent outcrops of mantle rocks in a very slow spreading context. In situ measurements of trace element concentrations in pyroxenes of these rocks, and associated petrogenetic modeling, are reported. Overall, the measured compositions cover the whole range typically observed for abyssal peridotites....

Expeditions 304 and 305 of the Integrated Ocean Drilling Program cored and logged a 1.4 km section of the domal core of Atlantis Massif. Postdrilling research results summarized here constrain the structure and lithology of the Central Dome of this oceanic core complex. The dominantly gabbroic sequence recovered contrasts with predrilling predictio...

The presence in the Earth’s mantle of even small amounts of water and other volatiles has major effects: first, it lowers drastically mantle’s viscosity, thereby facilitating convection and plate tectonics; second, it lowers the melting temperature of the rising mantle affecting the formation of the oceanic crust. H2O concentration in oceanic basal...

Two peridotite suites collected by submersible in the equatorial Atlantic Ocean (Hekinian et al., 2000) were studied for textures, modes, and in situ major and trace element compositions in pyroxenes. Dive SP12 runs along the immersed flank of the St. Peter and Paul Rocks islets where amphibole-bearing, ultramafic mylonites enriched in alkalies and...

The location of the La Galite Archipelago on the Internal/External Zones of the Maghrebian Chain holds strong interest for the reconstruction of the geodynamic evolution of the Mesomediterranean Microplate-Africa Plate Boundary Zone.New stratigraphic and petrographic data on sedimentary successions intruded upon by plutonic rocks enabled a better d...

Studies of MORB and of MORP (Mid Ocean Ridge Peridotite) show that the oceanic upper mantle is heterogeneous. Long and short wavelength chemical variability has been reported from the Mid Atlantic Ridge. The subridge mantle degree of melting, estimated from MORP mineral chemistry of mantle equilibrated spinel, opx and cpx, as well as from MORB glas...

A 26 Ma-long mantle stretch has been sampled at the Vema Lithospheric Section (VLS) (11° N along the MAR), providing a unique opportunity to analyze inside the mantle heterogeneities and unravel their effect on the melting regime looking at correlations between rock geochemistry and the amount of melt produced (crustal thickness). The geochemistry...

A >300 km long lithospheric section (Vema Lithospheric Section or VLS) is exposed south of the Vema transform at 11 degrees N in the Atlantic. It is oriented along a seafloor spreading flow line and represents similar to 26 Ma of accretion at a single 80 km long segment (EMAR) of the Mid-Atlantic Ridge. The basal part of the VLS exposes a mantle un...

Temporal variations of temperature and composition of the mantle upwelling below a 80-km long segment of the Mid Atlantic Ridge were reconstructed from 20 to 4 Ma ago from peridotites sampled along a >300-km long section of oceanic lithosphere (Vema Lithospheric Section or VLS) exposed south of the Vema transform at 11 degrees N [Bonatti, E., Ligi,...

A 50 m thick and 150 m long dunite body occurs as a subconcordant, tabular structure in the Balmuccia Massif, an Alpine peridotite thought to represent part of the subcontinental mantle. The contacts with the host spinel-facies depleted lherzolite are sharp. The dunite body is composed of spinel-rich dunite containing centimetre-size lenses of reli...

In the Balmuccia Massif, an Alpine peridotite thought to represent part of the subcontinental mantle, a 50 m thick and 150 m long dunite body, which occurs as a subconcordant, tabular structure, has been recently recognised. The contacts with the host spinel-facies depleted lherzolite are sharp. The dunite body is composed of spinel-rich dunite con...