scholarly journals Insights on the Origin of Vitrified Rocks from Serravuda, Acri (Italy): Rock Fulgurite or Anthropogenic Activity?

Geosciences ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 493
Author(s):  
Chiara Elmi ◽  
Anna Cipriani ◽  
Federico Lugli ◽  
Giampaolo Sighinolfi
Keyword(s):  
Mineralogical Composition ◽  
Anthropogenic Activity ◽  
Rock Composition ◽  
North West ◽  
Rock Fragments ◽  
Parent Rocks ◽  
Continuous Mass ◽  
Granitoid Rocks ◽  
Alteration Processes ◽  
The Hill

In this study, twenty five partially vitrified rocks and four samples of vitrified rocks collected on the top hill called Serravuda (Acri, Calabria, Italy) are analyzed. The goal is to shed light on the origin of these enigmatic vitrified materials. The analyzed vitrified rocks are a breccia of cemented rock fragments (gneiss, granitoid, and amphibolite fragments) which extends for more than 10 m, forming a continuous mass along the northern and north-west border of the flat top hill. Surrounded by the vitrified accumulation, exposed Paleozoic granitoid substrate rocks show limited melting or heat-alteration processes. By mapping minerals embedded in the glass matrix via X-ray powder diffraction (XRPD) and scanning electron microscopy (SEM), an interpretation of source rock material, reactions, and thermometric indications to form vitrified materials on the top hill of Serravuda, Acri (Italy), is provided. The mineralogical composition of heated or partially vitrified samples is heterogeneous owing to the effects of heating events, but it mostly recalls the parent rock composition (gneiss, granitoid, and amphibolite). The presence of quartz, cristobalite, tridymite, mullite, plagioclase, hercynite, cordierite, and olivine in Serravuda partially vitrified rocks and glasses suggests that samples were subjected to pyrometamorphism and the temperature range at which the glass formed was about 1000–1100 °C in the presence of hydrous gas, burning organic material (e.g., wood), and assuming thermodynamic equilibrium. Lithologies of the heated or partially vitrified rock fragments are a mixture of parent rocks not outcropping on the top of the hill such as gneiss and amphibolite. Data suggest that Serravuda vitrified rocks are most likely the result of anthropic activities and could represent remnants of vitrified fort walls. The mineral assemblage of partially vitrified rocks and glasses suggests that the fort walls were made of slabs derived from the local metamorphic rocks with the addition of Serravuda substrate Paleozoic granitoid rocks to improve the strength and insulation of the fort walls.

Geochemistry of the Namurian Lismore Formation, northern mainland Nova Scotia: sedimentation and tectonic activity along the southern flank of the Maritimes Basin

1999 ◽  
Vol 36 (10) ◽  
pp. 1655-1669 ◽  
Author(s):  
Jacquelyn E Stevens ◽  
J Brendan Murphy ◽  
Fred W Chandler
Keyword(s):  
Nova Scotia ◽  
Tectonic Activity ◽  
Isotopic Data ◽  
Rock Fragments ◽  
Metasedimentary Rocks ◽  
Clastic Rocks ◽  
Granitoid Rocks ◽  
Maritimes Basin ◽  
Group B ◽  
Southern Flank

Geochemical and isotopic data from the clastic rocks of the Namurian Lismore Formation in mainland Nova Scotia identify key episodes of tectonic activity during the development of the Maritimes Basin in Atlantic Canada. The Lismore Formation forms part of the Mabou Group and is an upward-coarsening 2500 m thick fluvial sequence deposited in the Merigomish sub-basin along the southern flank of the Maritimes Basin. Based on stratigraphic evidence, the Lismore Formation can be divided into upper and lower members which reflect variations in depositional environment and paleoclimate. The geochemical and isotopic data may also be subdivided into two groupings that primarily reflect varying contributions from accessory phases, clay minerals, or rock fragments. This subdivision occurs 115 m above the base of the upper member. The data from the lower grouping (group A) show an important contribution from underlying Silurian rocks, with a relatively minor contribution from Late Devonian granitoid rocks from the adjacent Cobequid Highlands and possibly metasedimentary rocks from the Meguma Terrane to the south. The data from the upper grouping (group B) reveal a more important contribution from the Cobequid Highlands granitoid rocks. This variation in geochemistry is thought to constrain the age of renewed motion and uplift along the faults along the southern flank of the Maritimes Basin and, more generally, suggests that geochemical and isotopic data of continental clastic rocks may help constrain the age of tectonic events that influence deposition of basin-fill rocks.

An Iron Age A site on the Chilterns

1951 ◽  
Vol 31 (3-4) ◽  
pp. 132-148 ◽  
Author(s):  
K. M. Richardson ◽  
Alison Young
Keyword(s):  
Water Supply ◽  
Iron Age ◽  
The West ◽  
North West ◽  
The North ◽  
Roman Villa ◽  
Adjoining Area ◽  
Cursory Examination ◽  
A Site ◽  
The Hill

In 1946 a visit to the barrow, which lies on the edge of the western scarp of Chinnor Common, and a cursory examination of the adjoining area, cultivated during the war, resulted in finds of pottery and other objects indicating Iron Age occupation. The site lies on the saddleback of a Chiltern headland, at a height of about 800 ft. O.D. Two hollow ways traverse the western scarp, giving access to the area from the Upper Icknield Way, which contours the foot of the hill, then drops to cross the valley, passing some 600 yards to the north of the Iron Age site of Lodge Hill, Bledlow, and rising again continues northwards under Pulpit Hill camp and the Ellesborough Iron Age pits below Coombe Hill. The outlook across the Oxford plain to the west is extensive, embracing the hill-fort of Sinodun, clearly visible some fourteen miles distant on the farther bank of the Thames. The hollow way at the north-west end of the site leads down to a group of ‘rises’ hard by the remains of a Roman villa, and these springs are, at the present day, the nearest water-supply to the site.

scholarly journals VZTAH MEZI PŘIROZENOU RADIOAKTIVITOU HORNIN A PŮD NA NICH VYTVOŘENÝCH – ZÁKLADNÍ PROBLÉM INTERPRETACE DAT ZÍSKANÝCH LETECKOU A TERÉNNÍ GAMASPEKTROMETRIÍ

2016 ◽  
Vol 22 (1-2) ◽  
Author(s):  
Jiří Zimák
Keyword(s):  
Natural Radioactivity ◽  
Gamma Ray ◽  
Natural Radionuclides ◽  
Size Fraction ◽  
Mineralogical Composition ◽  
Gamma Ray Spectrometry ◽  
Spectrometric Analysis ◽  
Radiation Dose Rate ◽  
Parent Rocks ◽  
Mass Activity

The objective of this study was to assess the amount of natural radionuclides in fresh parent rocks and their effect on natural radioactivity of soils developed from them. Forty-five fresh rocks consisting mainly of granitoids, syenitoids, acid to basic metavolcanites, mica schists, gneisses, quartzites, serpentinites, sandstones, graywackes, and limestones and their corresponding overlying soils were sampled for laboratory gamma-ray spectrometric analysis. Contents of potassium, uranium and thorium were converted to mass activity of 226Ra equivalent (am) and terrestrial gamma radiation dose rate (D). Data are tabled and discussed. The highest am values occured in syenitoids (386–441 Bq·kg-1) followed by granitoids, mica schists, greywackes and gneisses, whereas the lowest am values were found in quartzose sandstones (15–36 Bq·kg-1) followed by limestones (less than 15 Bq·kg-1) and serpentinites (less than 6 Bq·kg-1). The natural radioactivity of soils is usually slightly lower than that of parent rocks due to the lower content of potassium, uranium and thorium in soils. This is typical for granitoids, syenitoids and rocks of similar mineralogical composition. In soils developed on granitoids and syenitoids were found increased concentrations of all three elements in the grain size fraction below 0.063 mm. Soils developed on rocks with low natural radioactivity (such as limestones and serpentinites) tend to have significantly higher natural radioactivity than their parent rocks. This may complicate the interpretation of data obtained by airborne gamma-ray spectrometry.

scholarly journals The Caratacus Stone on Exmoor

1919 ◽  
Vol 9 ◽  
pp. 208-210
Author(s):  
F. A. Bruton
Keyword(s):  
The Other ◽  
Southern Limit ◽  
North West ◽  
The Hill

On the very top of Winsford Hill, the southern limit of Exmoor, more than twelve hundred feet above the sea, two roads meet at right angles, at a point called Spire Cross. One connects the ancient (some say prehistoric) bridge known as Tarr Steps, on one side of the hill, with the picturesque village of Winsford, lying deep down in the valley of the Exe, on the other. The second road runs north-west from Dulverton to Exford, and so to Porlock and Lynmouth, passing on the left Hawkcombe Head, the favourite meeting-place of the Somerset and Devon Staghounds, and the Lorna Doone country.

The minerals in the clay fractions of a black cotton soil and a red earth from Hyderabad, Deccan State, India

1940 ◽  
Vol 30 (4) ◽  
pp. 639-653 ◽  
Author(s):  
G. Nagelschmidt ◽  
A. D. Desai ◽  
Alex. Muir
Keyword(s):  
Grain Size ◽  
Mineralogical Composition ◽  
Principal Factor ◽  
Black Cotton Soil ◽  
Red Clay ◽  
Black Clay ◽  
Close Proximity ◽  
Parent Rocks ◽  
Red Earth ◽  
Mineral Compositions

The mineral compositions of the clays from a red earth and a black cotton soil from Hyderabad, Deccan State, India, occurring in close proximity in the field are determined. Both soils are derived from the same or from very similar parent rocks, a coarsely crystalline granite or gneiss.For both soils there is practically no variation in the mineralogical composition of the clay throughout the profile, but for any given clay there is some variation with grain size. The main contrast between the two is that the red clay contains predominantly kaolinite or halloysite, whereas the black clay contains mainly beidellite, a member of the montmorillonite group. The topography appears to be the principal factor associated with this difference in minerals, and the processes of weathering believed to have produced the contrasted clays are discussed with reference to experiments on the leaching of felspar in the laboratory and on hydrothermal synthesis.

scholarly journals “Trachytes” from Sardinia: Geoheritage and Current Use

2019 ◽  
Vol 11 (13) ◽  
pp. 3706 ◽  
Author(s):  
Nicola Careddu ◽  
Silvana Maria Grillo
Keyword(s):  
Volcanic Rocks ◽  
Mineralogical Composition ◽  
Building Stone ◽  
Step Method ◽  
Public And Private ◽  
Current State ◽  
Igneous Activity ◽  
Mineral Components ◽  
Granitoid Rocks ◽  
The Aesthetic

Sardinia was affected by an intense igneous activity which generated calc-alkaline products during the Oligo-Miocene period. The volcanic substance shows large variations, ranging from pyroclastic flow deposits, lava flows and domes. By composition, the deposits are all primarily dacites and rhyolites, with subordinate andesites and very scarce basalts. The rhyolite lavas show porphyritic and ash-flow tuffs. Ignimbrite structures are found in the dacitic domes and rhyolitic lavas. These rocks—commercially known as “Trachytes of Sardinia”—used to be quarried in all historical provinces, mainly in the central part of the island to be used as ornamental and building stone. They continue to be commonly used nowadays, but their use dates back to the prehistoric age. They are easily found in many nuraghi, “domus de janas”, holy wells, Roman works (mosaics, paving, roads, bridges), many churches built in Sardinia and practically in all kinds of structural elements in public and private buildings, such as walls, houses, and bridges. Contrary to the granitoid rocks, whose appearance is largely influenced by the mineralogical composition, the aesthetic feature of volcanic rocks is rather affected by the widest range of colors, structure and texture, i.e., shape, size and distribution of mineral components, porphyric index, etc. “Trachyte” is quarried opencast with the “single low step” method, with descending development, with prevalent use of double-disc sawing machines. Whenever the stone deposit allows higher steps, the chain cutting machine, in combination with diamond wire, becomes the preferred extraction solution. This study aims to at look Sardinian “trachytes” from a geoheritage perspective. After a geological-petrographic framework, the paper discusses the historical uses of “trachyte” in Sardinia. The current state of the art of “trachyte” quarrying, processing and usage in the Island is also described. An analysis of the “trachyte” production has been carried out. Finally, a consideration about how to enhance geotourism in the area is suggested.

The Excavation of an Iron Age Souterrain and Settlement at Carn Euny, Sancreed, Cornwall

1978 ◽  
Vol 44 ◽  
pp. 309-433 ◽  
Author(s):  
Patricia M. L. Christie ◽  
S. M. Elsdon ◽  
G. W. Dimbleby ◽  
A. Saville ◽  
S. Rees ◽  
...  
Keyword(s):  
Iron Age ◽  
Word Meaning ◽  
The West ◽  
North West ◽  
The North ◽  
South West ◽  
Dry Valley ◽  
The 19Th Century ◽  
The Hill ◽  
The Village

The ancient village of Carn Euny, formerly known as Chapel Euny, lies on a south-west slope just above the 500 foot contour in the parish of Sancreed in West Cornwall (fig. 1). The granite uplands of the region are rich in antiquities, as a glance at a recent survey shows (Russell 1971), not least those of the prehistoric period. The hill on which the site is situated is crowned by the circular Iron Age Fort of Caer Brane (pl. 27). Across the dry valley to the north-west rises the mass of Bartinny Down, with its barrows, while in the valley below the site near the hamlet of Brane is a small, well preserved entrance grave and other evidence of prehistoric activity. To the south-east about one mile away is the recently excavated village of Goldherring dating from the first few centuries of our era (Guthrie 1969). From later times, the holy well of St Uny and the former chapel which gave its name to the site, lie nearby to the west. The village contains a fine souterrain, locally known as a fogou, after a Cornish word meaning a cave (Thomas 1966, 79).Nothing appears to have been known of the settlement or Fogou before the first half of the 19th century when the existence of an unexplored fogou at Chapel Uny is first mentioned by the Reverend John Buller (1842), shortly followed by Edmonds (1849) who described to the Penzance Natural History and Antiquarian Society an ‘Ancient Cave’ which had been discovered by miners prospecting for tin.

scholarly journals Dust from the dark region in the western ablation zone of the Greenland ice sheet

2011 ◽  
Vol 5 (3) ◽  
pp. 589-601 ◽  
Author(s):  
I. G. M. Wientjes ◽  
R. S. W. Van de Wal ◽  
G. J. Reichart ◽  
A. Sluijs ◽  
J. Oerlemans
Keyword(s):  
Organic Material ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Ice Cores ◽  
Mineralogical Composition ◽  
Anthropogenic Activity ◽  
Ablation Zone ◽  
Elemental Ratios ◽  
Dark Region ◽  
Volcanic Material

Abstract. A dark region tens of kilometres wide is located in the western ablation zone of the Greenland ice sheet. The dark appearance is caused by higher amounts of dust relative to the brighter surroundings. This dust has either been deposited recently or was brought to the surface by melting of outcropping ice. Because the resulting lower albedos may have a significant effect on melt rates, we analysed surface dust on the ice, also called cryoconite, from locations in the dark region as well as locations from the brighter surrounding reference ice with microscopic and geochemical techniques to unravel its composition and origin. We find that (part of) the material is derived from the outcropping ice, and that there is little difference between dust from the dark region and from the reference ice. The dust from the dark region seems enriched in trace and minor elements that are mainly present in the current atmosphere because of anthropogenic activity. This enrichment is probably caused by higher precipitation and lower melt rates in the dark region relative to the ice marginal zone. The rare earth elemental ratios of the investigated material are approximately the same for all sites and resemble Earth's average crust composition. Therefore, the cryoconite probably does not contain volcanic material. The mineralogical composition of the dust excludes Asian deserts, which are often found as provenance for glacial dust in ice cores, as source regions. Consequently, the outcropping dust likely has a more local origin. Finally, we find cyanobacteria and algae in the cryoconite. Total Organic Carbon accounts for up to 5 weight per cent of the cryoconite from the dark region, whereas dust samples from the reference ice contain only 1 % or less. This organic material is likely formed in situ. Because of their high light absorbency, cyanobacteria and the organic material they produce contribute significantly to the low albedo of the dark region.

scholarly journals The ceramic artifacts in archaeological black earth (terra preta) from lower Amazon region, Brazil: mineralogy

2004 ◽  
Vol 34 (2) ◽  
pp. 165-178 ◽  
Author(s):  
Marcondes Lima da Costa ◽  
Dirse Clara Kern ◽  
Alice Helena Eleotério Pinto ◽  
Jorge Raimundo da Trindade Souza
Keyword(s):  
Sedimentary Rocks ◽  
Mineralogical Composition ◽  
Chemical Study ◽  
Amazon Region ◽  
Equivalent Material ◽  
Fine Grained ◽  
Rock Fragments ◽  
Clayey Material ◽  
Terra Preta ◽  
Low Crystalline

Several archaeological black earth (ABE) sites occur in the Amazon region. They contain fragments of ceramic artifacts, which are very important for the archaeological purpose. In order to improve the archaeological study in the region we carried out a detailed mineralogical and chemical study of the fragments of ceramic artifacts found in the two ABE sites of Cachoeira-Porteira, in the Lower Amazon Region. Their ceramics comprise the following tempers: cauixi, cariapé, sand, sand +feldspars, crushed ceramic and so on and are composed of quartz, clay equivalent material (mainly burned kaolinite), feldspars, hematite, goethite, maghemite, phosphates, anatase, and minerals of Mn and Ba. Cauixi and cariapé, siliceous organic compounds, were found too. The mineralogical composition and the morphology of their grains indicate a saprolite (clayey material rich on quartz) derived from fine-grained felsic igneous rocks or sedimentary rocks as source material for ceramic artifacts, where silica-rich components such cauixi, cariapé and/or sand (feldspar and rock fragments) were intentionally added to them. The high content of (Al,Fe)-phosphates, amorphous to low crystalline, must be product of the contact between the clayey matrix of pottery wall and the hot aqueous solution formed during the daily cooking of animal foods (main source of phosphor). The phosphate crystallization took place during the discharge of the potteries put together with waste of organic material from animal and vegetal origin, and leaving to the formation of the ABE-soil profile.

scholarly journals I. Observations on the Antiquity and Use of Beacons, more particularly here in England. By Mr. Professor Ward, of Gresham College

Archaeologia ◽  
1779 ◽  
Vol 1 (2) ◽  
pp. 1-7
Author(s):  
Ward
Keyword(s):  
West Side ◽  
North West ◽  
The North ◽  
The Hill ◽  
The Church

In the year 1740, as I was viewing, with a friend, the church at Burton Dasset in Warwickshire, we happened to observe a painted board placed over the entrance into the chancel, but so covered with dust, that neither we, nor the sexton who attended us, knew what to make of it. But as it seemed to represent something uncommon, we desired we might inspect it somewhat more nearly: And when the sexton had taken it down, and washed it, we perceived it was the picture of a coat of arms, with a Beacon for the crest, (as represented in plate I.) and upon further enquiry we found that, by tradition, there had been formerly a Beacon upon the North-west side of the hill where the church stands, erected by one of the Belknap family, who was then lord of that manor. The board that contains this picture, is nineteen inches and a half in height, and fourteen in breadth. The draught here given of it is reduced to the size of one fourth of the original.

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