Search

Your search keyword '"Lustrino, Michele"' showing total 327 results
Start Over Author "Lustrino, Michele"
327 results on '"Lustrino, Michele"'

2. Luminescence in the Mineral Realm to Teach Basic Physics Concepts

Author

Lustrino, Michele

Abstract

Every substance is associated to emission of electromagnetic radiation whose peaks are essentially influenced by temperature. Hot bodies (i.e., at T >700 °C) emit electromagnetic radiation in the field of visible light (incandescent light). The radiation emitted by cold bodies (i.e., at normal ambient conditions) in the visible light range is defined as luminescence. Luminescent light is emitted by exciting substances by means of electron fluxes (e.g., those generated in a cathode ray tube), using photon fluxes associated to electromagnetic radiations with wavelengths lower than ~390 nm (fluorescence), by mechanical stress (triboluminescence), by small temperature increase (thermoluminescence) or by biological processes (bioluminescence). The value of luminescence demonstrations in teaching is unique. Indeed, by illuminating specific minerals and other substances (such as chicken eggs, seashells, fossils, wood, scorpions, soda drinks) with non expensive ultraviolet (UV) lights, it is possible to introduce the audience to several scientific arguments. Among these, the most important are: a) the concept of radiation and electromagnetic spectrum, including the ?- and x-ray as well as the radio wave extremes; b) the discovery and the essence of natural radioactivity; c) the concept itself of visible light and the nature of the colours; d) the adaptability of the human eyes to the environment; e) the principles of the atomic structure as well as the basic concepts of energy quantization, including the photoelectric effect; f) the basic aspects of black-body radiation.

Published
2021

10. Large-volume and swift magmatic response to Late Cenozoic segmentation of the subducted Neotethyan oceanic slab: evidence from the Galatian Volcanic Province, northwestern Turkey.

Author

Karaoğlu, Özgür, Varol, Elif, Lustrino, Michele, Chiaradia, Massimo, Toygar Sağın, Özlem, Hemming, Sidney R., and Uysal, İbrahim

Subjects
SLABS (Structural geology), CONTINENTAL crust, STRESS concentration, METASOMATISM, VOLCANISM
Abstract

The Miocene Galatian Volcanic Province (GVP) is one of the largest volcanic provinces in central-western Anatolia, with an extent of ~ 8,900 km2. The volcanic activity is extended from 22.5 to 7.5 Ma. The volcanic compositions straddle the alkaline-subalkaline fields, from basic to acid compositions and mostly transitional to sodic affinity. Major oxides show good correlation with SiO2 indicating prolonged effects of fractional crystallization. Primitive mantle-normalized multi-element patterns indicate overall similarities among the different samples of the three geographic sectors, sharing strong negative anomalies in Nb–Ta–Ti, strong positive peaks at Cs and K, coupled with a common, albeit not always present, positive anomaly at Pb. Mineral-melt geothermobarometric estimates indicates ~1070–1235°C and ~7–19 kbar for melting conditions of basaltic compositions and ~1000–1150°C and ~3–12 kbar for andesitic-dacitic rocks. The absence of correlation between radiogenic isotopes and SiO2 and MgO is here interpreted as consequence of assimilation-fractional-crystalization processes involving lower continental crust as contaminant. The GVP parental magmas are generated from ~2% to 10% partial melting of a lherzolitic mantle with high spinel/garnet ratio based on intra-REE fractionation constraints. The subduction-related metasomatism inferred for the GVP mantle sources based on their chemistry is interpreted to be linked to the northward subduction of the northern branch of the Neo-Tethys slab. Successive slab retreat resulted in extension for the critical stress distribution through the Cyprus slab, favouring magma propagation for the GVP volcanic region. The eventual break-off of the slab after the continent-continent collision of Arabian and Eurasian plates could have caused a toroidal mantle flow, favouring the widely distributed 15–16 Ma alkaline magmatism in the eastern GVP, associated with passive hot asthenospheric upwelling imaged by teleseismic P-wave tomography. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

45. Experimental evidence on the origin of Ca-rich carbonated melts formed by interaction between sedimentary limestones and mantle-derived ultrabasic magmas

Author

Lustrino, Michele, Luciani, Natascia, Stagno, Vincenzo, Narzisi, Silvia, Masotta, Matteo, Scarlato, Piergiorgio, Lustrino, Michele, Luciani, Natascia, Stagno, Vincenzo, Narzisi, Silvia, Masotta, Matteo, and Scarlato, Piergiorgio

Abstract

In this experimental study, we documented the formation of strongly ultrabasic and ultracalcic melts through the interaction of melilititic and basanitic melts with calcite. Three strongly to moderately SiO2-undersaturated volcanic rocks from the Bohemian Massif (central Europe) were mixed with 10, 30, and 50 wt% CaCO3 and melted at 1100, 1200, and 1300 °C at 2 kbar to evaluate the maximum amount of carbonate that can be assimilated by natural ultrabasic melts at shallow depths. Experiments revealed a surprisingly complete dissolution of the CaCO3, only rarely reaching carbonate saturation, with typical liquidus phases represented by olivine, spinel, melilite, and clinopyroxene. Only in the runs with the most SiO2-undersaturated compositions did abundant monticellite form instead of clinopyroxene. For all starting mixtures, strongly ultrabasic (SiO2 down to 15.6 wt%), lime-rich (CaO up to 43.6 wt%), ultracalcic (CaO/Al2O3 up to ~27) melt compositions were produced at 1200 and 1300 °C, with up to ~25 wt% dissolved CO2. When present, quenched olivine showed much higher forsterite content (Fo95–97) than olivine in the natural samples (Fo79–85). The two major results of this study are (1) silicate-carbonatite melt compositions do not necessarily imply the existence of carbonatitic components in the mantle, because they are also produced during limestone assimilation, and (2) Fo-rich olivines cannot be used to infer any primitive character of the melt nor high potential temperature (Tp)

Published
2022
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results