Monte Amiata Research Articles

Comment on “Recurrence of volcanic activity along the Roman Comagmatic Province (Tyrrhenian margin of Italy) and its tectonic significance” by F. Marra, J. Taddeucci, C. Freda, W. Marzocchi, and P. Scarlato

Comment on “Recurrence of volcanic activity along the Roman Comagmatic Province (Tyrrhenian margin of Italy) and its tectonic significance” by F. Marra, J. Taddeucci, C. Freda, W. Marzocchi, and P. Scarlato

Dissolved potassium in the shallow groundwaters circulating in the volcanic rocks of central-southern Italy

The water–rock interaction processes occurring in the low-temperature, shallow volcanic aquifers of central-southern Italy were simulated by means of the EQ3/6 Software Package in reaction progress mode. In the investigation both the Roman Magmatic Province and Monte Amiata, which belongs to the Tuscan Magmatic Province, were included. The average K 2O content of the volcanic rocks from the two areas is similar but the main K-bearing phases are leucite, in the Roman Magmatic Province, and sanidine, at Monte Amiata. Computed concentrations of major dissolved components and SiO 2 are consistent with analytical data, suggesting that the results of the EQ3/6 runs are reliable simulations of the natural water–rock interaction processes. Hence, EQ3/6 results can be used to investigate the transfer of K from rocks to water. It turns out that the attainment of saturation with sanidine, during early stages of rock dissolution, limits K concentration in the Monte Amiata groundwaters to around an average of 2.9 ± 1.3 mg L −1 (1SD). In the silica undersaturated Roman Magmatic Province, saturation with leucite is not attained during the evolution of groundwaters and, consequently, K concentration reaches comparatively high levels, with an average of 24.6 ± 27.1 mg L −1 (1SD). Most of these unusually high K concentrations are due to natural weathering of silicates without any anthropogenic influence.

Essential oils of Galeopsis pubescens and G. tetrahit from Tuscany (Italy)

AbstractThe essential oils obtained from the flowering aerial parts of Galeopsis pubescens and G. tetrahit growing on Monte Amiata (Italy) have been studied. Sesquiterpenes were the main constituents of both essential oils (88.9% and 90.4%, respectively); the major compounds were germacrene D and bicyclogermacrene (about 60% and 6%, respectively). The differences between the two essential oils were mostly quantitative and were referred mainly to β‐caryophyllene (5.7% and 2.1%, respectively) and (E)‐β‐farnesene (1.1% and 5.6%). This is the first report about the composition of essential oils from this genus. Copyright © 2004 John Wiley & Sons, Ltd.

Chromosome numbers and distribution of the genusPulmonaria(Boraginaceae) in Tuscany and neighbouring areas

Abstract The investigation on the distribution of the genus Pulmonaria in Tuscany and neighbouring areas, has revealed that the cytotype with 2n = 16 (cfr. P. officinalis L.) occurs over a rather large area. This area in part overlaps that of the other two cytotypes with 2n = 22 and 2n = 28. While the former cytotype is distributed all along either side of the watershed of the Tosco-Emilian Apennines, the latter cytotype, besides overlapping the 2n = 16 and the 2n = 22 distribution areas to the north, extends its range southwards on the western side of the Apennines with populations scattered over the hills as far south as Monte Amiata and the hills north of Perugia in Umbria. Two somewhat aberrant chromosome numbers (2n = 25 and 2n = 26) have been found, albeit rarely, within 2n = 22 populations. Some hypotheses are offered regarding the origin of the various cytotypes through a change in basic chromosome number from x=7 to x=8, with subsequent hybridizations, leading to the establishment of the present ...

Archeologia dell’edilizia storica e costruzione del documento archeologico. Problemi di popolamento mediterraneo. II. Organizzazione del cantiere di una fortezza rurale di XIII secolo: il cassero di Montelaterone (Monte Amiata - Toscana)

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Mercury removal from geothermal exhaust gas by sulfur-impregnated and virgin activated carbons

Sulfur-impregnated and virgin activated carbons have been used in a laboratory scaled fixed-bed reactor to investigate their capability of removing mercury vapours from a gas mixture containing H 2S, O 2 and moisture that is representative of the exhaust gas emissions of the geothermal power plants of the Monte Amiata field in Italy. The observed deposition of sulfur from H 2S oxidation on the carbonaceous matrix increases the mercury scavenging capacity of the commercial sulfur-impregnated activated carbon and makes virgin activated carbon capable of adsorbing mercury vapours by the formation of HgS contextually to the deposition of sulfur, achieving a mercury adsorption capacity comparable to the commercial sulfur-impregnated activated carbon. This result suggests that the extremely economic virgin activated carbon can be used in this specific application, provided that a suitable carbonaceous matrix is selected to achieve a sulfur deposition rate that can guarantee a high mercury adsorption capacity.

Manuscript books at Monte Amiata in the eleventh century [To the memory of Wilhelm Kurze (1933-2002)

Manuscript books at Monte Amiata in the eleventh century [To the memory of Wilhelm Kurze (1933-2002)

Mercury deposits in metamorphic settings: the example of Levigliani and Ripa mines, Apuane Alps (Tuscany, Italy)

In addition to the world-class epithermal deposits in the Monte Amiata area (Southern Tuscany), mercury production in Tuscany is recorded from the Levigliani and Ripa deposits in Apuane Alps. Both deposits are hosted by sedimentary and subordinate volcanic rock sequences, belonging to the Apuane Metamorphic Complex (AMC), metamorphosed in the greenschist facies during the Apenninic orogeny (ca. 27–8 Ma). At Ripa, mineralization is very simple, consisting of cinnabar with minor pyrite in quartz gangue. Its emplacement is obviously controlled by shear structures produced during the second Apenninic deformation event (D 2). At Levigliani, both the setting and the mineral assemblage are more complex. Mineralization is confined to a lithologic horizon comprised of carbonatic chloritic phyllites and calc-alkaline metabasites. The mineralizing process spanned the entire tectono-metamorphic Apenninic event. A first mineral assemblage (cinnabar I+zincian metacinnabar+pyrite) was formed under conditions presumably not far from the metamorphic thermal peak, whereas a second assemblage (cinnabar II+mercurian sphalerite+pyrite±native mercury±chalcopyrite±galena±pyrrhotite±grumiplucite) was formed in a retrograde stage. In both deposits, the overall P– T– X features of fluid inclusions in quartz are similar to those previously established for syn-metamorphic hydrothermal circulation in AMC. At Ripa, the syn-D 2 shear structures provided a hydrologic trap for mercury mobilized from an unknown source. At Levigliani, the strict lithological control, the protracted nature of the mineralizing process, and the similarities to the setting of Palaeozoic peri-Mediterranean mercury deposits, suggest a small scale remobilization from a pre-existing anomaly.

Impact of silvicultural system on Cryphonectria parasitica incidence and on genetic variability in a chestnut coppice in Central Italy

This study was carried out in order to analyze the effect of silvicultural treatment on the structure and productivity of the chestnut stands, on the disease evolution and on the genetic structure of the species. The study considered a coppice stand aged 35 years (1994), growing on Monte Amiata (Tuscany, Italy). In the winter of 1994–1995, a low thinning of moderate intensity was applied; all suppressed shoots were removed, the intermediate class was partially reduced while the dominant storey was lightly thinned. Before, and after thinning, a description of stand structure, evaluation of number and typology of cankers caused by Cryphonectria parasitica on each tree and characterization of genotypical profile of all stumps was carried out. The structural and pathological surveys were repeated in February 1997 in order to analyze the growth trend of the stand and to verify the incidence and the evolution of disease two years after thinning. The results show that the applied silvicultural system neither reduced the genetic variability nor influenced the genotypic distribution of the stand. The removal of virulent cankers and the reduction of the individual susceptibility by the selection of the most vigorous trees has a positive effect on pathogen evolution.

Biomass, litterfall and productivity in chestnut coppices of various age at Monte Amiata (Central Italy)

The effects of longer rotation periods and thinning practice on bio-ecological processes and indexes such as biomass, litterfall, leaf area index (LAI) and productivity have been analysed in thinned and unthinned permanent plots in a chestnut (Castanea sativa Mill.) coppices under traditional system (11 yrs.) and under long rotation (35 yrs.). Plots were established in a large chestnut vegetation area (Monte Amiata -Tuscany) in order to evaluate the sustainability of management options alternative to the traditional intensive exploitation. Both traditional and long rotation coppices showed high productivity (aboveground biomass 108.4 Mg ha'1 and 239.5 Mg ha'1 respectively), high LAI (6.5 nr m"2 and 5.1 m2 m'2) and annual litterfall values (6.28 Mg ha'1 and 5.60 Mg ha'1). The applied thinning (one third of basal area removal) affected stocking, stand growth and efficiency. Chestnut coppices, namely those under traditional rotation, showed however a good aptitude to re-build an homogeneous canopy cover a few years after thinning occurrence. Results concur to positively evaluate, not only from an economic point of view but also from a bio-ecological one, the adoption of management systems based upon long rotation period and on a less intensive exploitation of chestnut coppice.

Manus Bedae: Bede's contribution to Ceolfrith's bibles

Bede entered Wearmouth–Jarrow at the age of seven and thereafter, he tells us at the conclusion of his Historia ecclesiastica, spent all his life ‘applying myself entirely to the study of the Scriptures’. He goes on, ‘From the time I became a priest until the fifty-ninth year of my life I have made it my business, for my own benefit and that of my brothers, to make brief extracts from the works of the venerable fathers on the holy scriptures, or to add notes of my own to clarify their sense and interpretation.’ Bede's modest remarks preface an impressive list of his own works, which includes commentaries on Genesis, I Samuel, Kings, Proverbs, the Prophets, Mark, Luke, Acts and Revelation, and many other exegetical, didactic and historical volumes. Installed at Jarrow from about 679 until his death in 735, he contributed more than anyone to the intellectual distinction of early-eighth-century Northumbria. At the same time, the twin house of Wearmouth–Jarrow was winning lasting renown for the products of its scriptorium (or scriptoria). Not least among these were the three great Vulgate bible pandects which Abbot Ceolfrith caused to be made, an achievement celebrated by the chroniclers of the house, who included Bede himself. One of these pandects, which we know today as the Codex Amiatinus, was dispatched to St Peter's in Rome in 716, then spent more than 900 years at Monte Amiata in the Appenines, and is now in Florence (Biblioteca Medicea Laurenziana, Amiatino 1). The other two were for use in the Wearmouth and Jarrow churches. One of these has been lost without trace, but the second survived in the cathedral priory of Worcester until the sixteenth century, when an entrepreneurial Nottinghamshire family made use of some of its torn-out leaves as document wrappers. Twelve of these, with some fragments of a thirteenth, are now in the British Library under three different shelfmarks (Loan 81, Add. 37777 and Add. 45025).

Historical exposure to inorganic mercury at the smelter works of Abbadia San Salvatore, Italy

Metallic mercury production from cinnabar ore may result in high exposures to inorganic mercury, that are difficult to assess separately from the exposures originating from underground extraction, and previously have only been scantily described. We retrieved and analysed the air and biological mercury determinations on workers involved in the smelting process of the Abbadia San Salvatore mine (Monte Amiata, Italy). Native mercury was not present in the ore, and the exposure in the underground extraction was low. The smelter operated from 1897 to 1983.Blood and urine (24/h urine collections and concentration samples) had been sampled in 1968 to 1982, and analysed for mercury by atomic absorption spectrophotometry, and relate to all subjects. Exposure to mercury in air had been determined in a small set of personal samples in 1982.The data relate to all jobs in the smelter process, and all jobs entailed substantial exposure to mercury. The overall distribution of breathing zone air, blood and urinary levels is right-skewed and similar to the log-normal distribution (air, median 48 μg/m3, n = 49; blood, arithmetic mean AM 49μg/L; geometric mean GM 26 μg/L, n = 192; urinary excretion, AM 140 μg/24h, GM 78 μg/24h, n = 839; and urinary concentration, AM 160 μg/L, GM 83 μg/L, n = 632). Air, blood and urinary values show a high ratio of the between- and within-job variance, indicating differences in exposure by job.Cinnabar pigment production, of which the exposure has not been characterised previously, was the job with the highest air (AM 160 μg/m3) and urinary levels (excretion AM 690 μg/24h; concentration AM 1100 μg/L). Other jobs with high urinary levels were soot purification, laboratory work, and bottling. Cleaning of condensers showed the highest blood level (AM 280 μg/L).There is a downwards time trend in mercury concentration in blood and in urine. The corresponding trend is not seen for urinary excretion levels, the reason for this being unclear. Roasters, which is the most frequently monitored group, show however a decreasing trend in all sets of data (e.g. the mean of urinary excretion decreased from 300 μg/24h in 1968/69 to 50 μg/24h in 1980/81).The mercury exposure experienced by the smelters of Abbadia San Salvatore is in line with the few available data on workers from other mercury mines and smelters, and our data confirm the high exposure levels in this occupational group, in particular at cinnabar pigment production, soot purification, and condenser cleaning.

Flora and phytogeography of the volcanic dome of Monte Amiata (Central Italy)

Summary The most peculiar features of Monte Amiata are its orographic isolation and its recent volcanic origin. Accordingly, the vascular flora was investigated in order to shed light on its main ecological, chorogenetic and historical components. The flora includes 624 entities over about 74 Km2 and is poorer than others of Apenninic areas with comparable altitude and latitude. The largest part of the nemoral component is restricted to mesic chestnut and beech forests of the lower belt, whereas in chestnut groves the elio-xerotolerant plants are prevalent. In the oceanic beech forests of the higher belt, the flora is still poorer and largely composed of hygro-sciaphilous species linked to a elevated atmospheric and edaphic moisture. Therophytes are on the whole less represented than in near Apenninic mountains, whereas geophytes are slightly more abundant; they tend to increase from the lower to the higher beech belt. The boreal component is largely dominant over the tethyan one, and it increases along with the altitude to reach its maximum in the ipsophilous beech forests. Taking into account the numerous European and orophytic species beside the Apenninic endemics, M. Amiata belongs to the Apenninic sector of the European subregion (orophytic dominion). Historical aspects of the flora are also discussed in the light of chorological components, paleobotanical and geochronological data.

Preliminary results on the role of rivers in total Hg concentrations in marine sediments and benthic organisms of a coastal area of Italy

The paper reports the results of mercury (Hg) concentrations in the <20 μm grain-size fraction of shallow sediments of the northern Tyrrhenian sea, collected near the mouths of rivers flowing down from the Monte Amiata area (central Italy), which is characterized by cinnabar mineralization which was developped as mercury mine in the past. A few species of benthic marine organisms collected in the sediment sampling area were also analyzed. From the results, it emerged that the rivers contribute to the Hg concentration in the marine sediments which already contain high natural Hg background levels. The benthic organisms, which reflect sediment contamination, showed high Hg concentrations as well.

Silica separation from reinjection brines at monte amiata geothermal plants, Italy

A process for the separation of silica from geothermal reinjection brines is reported, in which the phases of coagulation, sedimentation and filtration of silica are involved. The effectiveness of lime and calcium chloride as coagulating agents has been investigated and the separating operations have been set out. Attention has been focussed on Monte Amiata reinjection geothermal brines, whose scaling effect causes serious problems in the operation and maintenance of reinjection facilities. The study has been conducted using different amounts of added coagulants and at different temperatures, to determine optimal operating conditions. Though calcium chloride was revealed to be effective as a coagulant of the polymeric silica fraction, lime has also proved capable of removing monomeric dissolved silica at high dosages. Investigation on the behavior of coagulated brine has revealed the feasibility of separating the coagulated silica by sedimentation and filtration.

Chorological and caryological investigation on Viola etrusca Erben (Violaceae)

Abstract Viola etrusca Erben, an endemic species of mountains of Southern Tuscany, belonging to the ser. Calcaratae Becker, is investigated under chorological and caryological aspects. On the basis of our data, the distribution area results larger than previously thought, extending to Monte Labbro and Monte Amiata. The known chromosome number is confirmed, and the caryotipic formula is reported.

Mercury in abiotic and biotic compartments of an area affected by a geochemical anomaly (Mt. Amiata, Italy)

Data both from the literature and from our own research are reported on the Hg levels in the soil, waters, sediment , atmosphere and some plants of the mineralized Monte Amiata region (Italy) with the aim of evidencing the interactions between the different environmental compartments. The presence of cinnabar in the soil affects the whole area, particularly near the mines, roasted cinnabar deposits and at the steam jets used for the geothermal power plants. Soil degassing represents the main source of atmospheric Hg which shows a concentration range of 5 to 200 ng m−3. Vegetables display high Hg levels (0.06 to 9.80 µg g−1) especially in the leaves. The aqueous transport of dissolved mercury is of no importance; suspended particulate matter, however, is able to carry a significant load of Hg.

FUSULINIDI PERMIANI NELLA SUCCESSIONE METAMORFICA DEL SOTTOSUOLO DEL M. AMIATA, TOSCANA MERIDIONALE (ITALIA)

The PC/33b well drilled by the ENEL Company in the Monte Amiata area near Piancastagnaio (Southern Tuscany, Italy) yielded some fossiliferous layers from 3024.40 to 3028.40 m. Thc cored interval is interpreted as belonging to the Paleozoic Basement of the Tuscan Series which includes some informai Units (A, Band C) indicated as Formations in this paper. Fm A consists of graphitic phyllites and metasandstones with rare intercalations of mudstone to wackestone-packstone; Fm B consists of chloritic phyllites and metasandstones with some intercalations of impure microcrystalline dolostones. Fm A seems to pass to the underlying Fm C, which gradually consists of thick mudstone to dolostone layers interbedded into the graphitic metasandstone-phyllitic lithotypes. The few crystalline fossiliferous layers occur in the transi­tion levels between Fm A and Fm C. The fossils identified in the cored interval belong to fragmented crinoids, gasteropods, gymnocodiacean and dasycladacean algae, and to foraminifers (mainly fusulinids). Despite the strong recrystallization and metamorphism affecting the rocks, some fusulinids could be identified. They are Praeparafusulina cf. lutugini (Schellwien) (possibly reworked), Polydiexodina (Eopolydiexodina ?) cf. shabalkini Leven, Yangkienia sp., Y. aff. compressa (Ozawa), Cancellina sp., Pseudodoliolina ex. gr. P. ozawai Yabe & Hanzawa,? Chusenella sp., ghosts of Misellina sp. and ?Neofusulinella sp. This fusulinid association is indicative of the Cancellina Zone of Kubergandian age (Late Permian), which is recorded in Italy for the first time. A brief review of the Permian fusulinid assemblages from the Apennine region is included in the conclusions.

Magnetic anomalies and magmatic events in and around the island of Elba (Northern Tyrrhenian Sea)

The island of Elba is located at the eastern margin of a N-S-trending high-intensity magnetic lineation. Measurements of magnetic susceptibility of the different lithologies that outcrop in the island indicate that only the peridotites (serpentinites), which are associated with other ophiolitic rocks such as gabbro, diabase and siliceous sediments, possess high magnetic susceptibility (4000−10,000 × 10 -5 SI units). We infer that the long intense N-S magnetic alignment in Northern Tyrrhenian sea is the expression of a segment of oceanic upper mantle and crust of the Jurassic Tethys. The oceanic rocks have been emplaced in the Alpine-Apenninic orogen (ophiolitic suture zone) that, subsequently, through rifting processes, evolved into the opening Tyrrhenian with subsequent basin formation. The island of Elba marks the site of a W-E zone of magnetic lineations related to magmatism of late Neogene age (7.5-5 Ma). The intrusive melts affected a suture site that probably represents an inherited Tethyan ridge-transform structure and have granodiorite-granite compositions and a calcalkaline affinity. Magmatic events in the Northern Tyrrhenian Sea and adjacent Tuscan areas are from Late Miocene (∼7.5–7 Ma) to late Quaternary (0.21 Ma) (Monte Amiata volcano) in age and are related to asthenospheric updoming and stretching, attenuation of the lithosphere, and possibly accompanying underplating beneath the continental crust. Some other main magnetic W-E lineations in the Tyrrhenian Sea and adjoining eastern margins are considered. They are also linked to extensive magmatic manifestations that migrated from west to east along deep sinistral strikeslip fault zones. These faults separate adjacent areas of the seafloor, the extent of opening to the east being different (greater in the south).

Geological model of a young volcano-plutonic system: The geothermal region of Monte Amiata (Tuscany, Italy)

Geological, geophysical and petrologic data point to the presence of a granitic body below the geothermal region of Mt Amiata (central Italy). A broad area of about 900–1300 km 2 centered on Amiata volcano shows a regional uplift of the Pliocene beds to 950 m a.s.l. The uplift began during the lower Pliocene, with a regression of the Pliocene sea from an uplifted area centered in the volcano zone. The temperature distribution below the Piancastagnaio field shows an updoming of the isotherms, forming a thermal high, probably present since the earliest stages of interaction between geothermal fluids and country rocks. A re-evaluation of the petrologic data from the xenoliths included in the lava flows allows an estimate of the P-T conditions of the magma body; a minimum temperature of 575°C and pressures of 1550–2200 bars can be estimated for the confining rocks around the magma body. Magmatologic data show a temperature of 800–900°C and a P load - 1000 bar. Therefore the roof of the magma body should be present at about 6 km depth. Seismic reflection data reveal the continuous and widespread occurrence of a reflecting horizon ( K) of all over the geothermal region. This horizon is present at a depth of 5–6 km. By analogy with Larderello, it is interpreted as a fracture interval filled with hot fluids, contact metamorphic minerals and hydrothermal minerals generated in the uppermost part of the granite and the basal levels of the wall rocks. By integrating geophysical and geological data, a two-dimensional gravimetric model of the volcano-plutonic system of Mt Amiata is proposed, with the following features: roof depth = 5–6 km, T = 820°C, d(magma) = 2.15 g cm −3, d(wall rock) = 2.8 g cm −3, shape of the intrusion is lens shaped or mushroom-like with possible thickening and roots just below Piancastagnaio. This model fits well with gravimetric data, which show a negative anomaly in correspondence with the uplifted area.