U-Pb zircon (ID-TIMS and SHRIMP) evidence for the early ordovician intrusion of metagranites in the late Proterozoic Canaveilles Group of the Pyrenees and the Montagne Noire (France)

2005 ◽  
Vol 176 (3) ◽  
pp. 269-282 ◽  
Author(s):  
Alain Cocherie ◽  
Thierry Baudin ◽  
Albert Autran ◽  
Catherine Guerrot ◽  
C. Mark Fanning ◽  
...  
Keyword(s):  
Late Proterozoic ◽  
The North ◽  
Continental Plate ◽  
Wide Range ◽  
Gondwana Margin ◽  
Group A ◽  
Montagne Noire ◽  
Representative Samples

Abstract Depending on the quality of the zircon grains available for analysis, two methods may be used to date igneous rock emplacement, namely U-Pb TIMS with isotope dilution or in situ U-Pb SIMS (SHRIMP). Both methods have been used to determine, in a precise and accurate manner, the emplacement age of the granitic protolith of the various orthogneisses in the Pyrenean Axial Zone. More specifically, four representative samples of G1, G2 and a “transition gneiss” yielded reliable datings with an average age of 473 ± 4 Ma for each sample. The surrounding sediments of the Canaveilles Group were constrained by zircon grains from interlayered metarhyodacite and dated at 581 ± 10 Ma using the SHRIMP method, clearly giving this group a late Proterozoic (Vendian) age. Finally, the Somail orthogneiss of the Montagne Noire, equivalent to that of the Canigou, yielded an age of 471 ± 4 Ma with the in situ U-Pb method, which is identical to the dating of the Pyrenean samples. In addition, most of the studied orthogneisses recorded a wide range of significant concordant inherited ages spanning from early Archaean (3.5 Ga) to Pan-African/Cadomian (600–800 Ma). Bearing in mind the calc-alkaline affinity of the studied rocks, this work demonstrates the huge contrast between the active Gondwana margin in the north (“South European terrane”) and the remarkably homogeneous continental plate that existed from Arabia to Morocco during the Ordovician.

Kean Miltos: The Well-Known Iron Oxides of Antiquity

1997 ◽  
Vol 92 ◽  
pp. 359-371 ◽  
Author(s):  
E. Photos-Jones ◽  
A. Cottier ◽  
A. J. Hall ◽  
L. G. Mendoni
Keyword(s):  
Iron Oxides ◽  
Analytical Techniques ◽  
Field Work ◽  
Archaeological Record ◽  
The North ◽  
Naturally Occurring ◽  
Physico Chemical ◽  
Wide Range ◽  
Industrial Mineral

The island of Kea in the North Cyclades was well known in antiquity for its miltos, a naturally occurring red iron oxide valued for its colour and wide range of applications. By combining geological field work, physico-chemical analytical techniques, simulation (heating) experiments as well as simple laboratory tests, this paper describes the study of Kean iron oxides in an attempt to characterize this material which is still largely elusive in the archaeological record. The present work corroborates previous observations about the superior quality of some Kean iron oxides. Furthermore, it puts forward the hypothesis that miltos may have been considered an industrial mineral, and as such may have been used as an umbrella term for a variety of materials including mineralogically distinct purple as well as red iron oxides.

The Geological Sources and Transport of the Bluestones of Stonehenge, Wiltshire, UK

1991 ◽  
Vol 57 (2) ◽  
pp. 103-157 ◽  
Author(s):  
Richard S. Thorpe ◽  
Olwen Williams-Thorpe ◽  
D. Graham Jenkins ◽  
J. S. Watson ◽  
R. A. Ixer ◽  
...  
Keyword(s):  
18Th Century ◽  
Archaeological Sites ◽  
Stone Monuments ◽  
The North ◽  
Rock Types ◽  
South West ◽  
South Wales ◽  
Wide Range ◽  
Contemporary Practice

Stonehenge on Salisbury Plain is one of the most impressive British prehistoric(c.3000–1500 BC) monuments. It is dominated by large upright sarsen stones, some of which are joined by lintels. While these stones are of relatively local derivation, some of the stone settings, termed bluestones, are composed of igneous and minor sedimentary rocks which are foreign to the solid geology of Salisbury Plain and must have been transported to their present location. Following the proposal of an origin in south-west Wales, debate has focused on hypotheses of natural transport by glacial processes, or transport by human agency. This paper reports the results of a programme of sampling and chemical analysis of Stonehenge bluestones and proposed source outcrops in Wales.Analysis by X-ray-fluorescence of fifteen monolith samples and twenty-two excavated fragments from Stonehenge indicate that the dolerites originated at three sources in a small area in the eastern Preseli Hills, and that the rhyolite monoliths derive from four sources including northern Preseli and other (unidentified) locations in Pembrokeshire, perhaps on the north Pembrokeshire coast. Rhyolite fragments derive from four outcrops (including only one of the monolith sources) over a distance of at least 10 km within Preseli. The Altar Stone and a sandstone fragment (excavated at Stonehenge) are from two sources within the Palaeozoic of south-west Wales. This variety of source suggests that the monoliths were taken from a glacially-mixed deposit, not carefully selected from anin situsource. We then consider whether prehistoric man collected the bluestones from such a deposit in south Wales or whether glacial action could have transported bluestone boulders onto Salisbury Plain. Glacial erratics deposited in south Dyfed (dolerites chemically identical to Stonehenge dolerite monoliths), near Cardiff, on Flatholm and near Bristol indicate glacial action at least as far as the Avon area. There is an apparent absence of erratics east of here, with the possible exception of the Boles Barrow boulder, which may predate the Stonehenge bluestones by as much as 1000 years, and which derived from the same Preseli source as two of the Stonehenge monoliths. However, 18th-century geological accounts describe intensive agricultural clearance of glacial boulders, including igneous rocks, on Salisbury Plain, and contemporary practice was of burial of such boulders in pits. Such erratics could have been transported as ‘free boulders’ from ‘nunataks’ on the top of an extensive, perhaps Anglian or earlier, glacier some 400,000 years ago or more, leaving no trace of fine glacial material in present river gravels. Erratics may be deposited at the margins of ice-sheets in small groups at irregular intervals and with gaps of several kilometres between individual boulders.‘Bluestone’ fragments are frequently reported on and near Salisbury Plain in archaeological literature, and include a wide range of rock types from monuments of widely differing types and dates, and pieces not directly associated with archaeological structures. Examination of prehistoric stone monuments in south Wales shows no preference for bluestones in this area. The monoliths at Stonehenge include some structurally poor rock types, now completely eroded above ground. We conclude that the builders of the bluestone structures at Stonehenge utilized a heterogeneous deposit of glacial boulders readily available on Salisbury Plain. Remaining erratics are now seen as small fragments sometimes incorporated in a variety of archaeological sites, while others were destroyed and removed in the 18th century. The bluestones were transported to Salisbury Plain from varied sources in south Wales by a glacier rather than human activity.

scholarly journals Caledonian and pre-Caledonian geology of the region between Grandjean Fjord and Bessel Fjord (75°–76°N), North-East Greenland

1989 ◽  
Vol 145 ◽  
pp. 90-97
Author(s):  
N Henriksen ◽  
J.D Friderichsen ◽  
R.A Strachan ◽  
N.J Soper ◽  
A.K Higgins
Keyword(s):  
Amphibolite Facies ◽  
Sedimentary Sequence ◽  
East Greenland ◽  
Early Proterozoic ◽  
Late Proterozoic ◽  
North East ◽  
The North ◽  
Group A ◽  
Metasedimentary Sequence

The area between Grandjean Fjord and Bessel Fjord was the focus in 1988 of regional geological investigations and 1:500000 mapping during the North-East Greenland project (Henriksen, 1989). The greater part of the area forms part of the East Greenland Caledonides and can be divided into three distinct rock groups: infracrustal gneisses and granites of possibie Archaean or early Proterozoic origin; a metasedimentary sequence which has probably suffered both mid-Proterozoic and Caledonian migmatisation and metamorphism; and the late Proterozoic Eleonore Bay Group, a thick sedimentary sequence which has undergone amphibolite facies Caledonian metamorphism in its lower parts and is intruded by Caledonian granites. Aspects of the stratigraphy and sedimentology of the Eleonore Bay Group are described by Sønderholm et al. (1989); only the structures affecting the sequence are described here.

scholarly journals Mediaeval Gravestones from the Crimean Steppe

2021 ◽  
pp. 362-373
Author(s):  
Elena A. Aibabina
Keyword(s):  
Asia Minor ◽  
Crimean Peninsula ◽  
The North ◽  
Wide Range ◽  
The Crimea ◽  
Rough Form ◽  
Stone Carving ◽  
High Base ◽  
The Town

There are late eighteenth-century maps of the town of Eski-Krym (Solkhat, Krym, Staryi Krym) which Muslim commune shaped by the last third of the thirteenth century showing a number of significant architectural objects and gravestones with stone-carved decorations. The system of Muslim gravestones developed by O.-N. A. Akchokrakly and A. S. Bashkirov is based on the study of forms and the location of ornamental and epigraphic parts of monuments from the cemeteries of Staryi Krym. Carved decorations of medieval grave monuments of Solkhat show by the high artistic level of carving, the quality of technical execution, and original ornamentation. Their connection of stone carving of the Crimea in the Golden Horde Period with the Asia Minor appeared simultaneously with the development of Muslim architecture. Photographs and drawings made by an academic expedition in 1925 that surveyed ancient Tatar settlements and cemeteries in the Crimean steppe (its western areas close to Yevpatoria, as well as the north of the Crimean Peninsula and its east close to the town of Staryi Krym) show a wide range of gravestones, mostly of geometrical forms like pillars topped with turbans. There is a small group of grave monuments, or the so-called two-horned gravestones, representing a rough form of similar tombstones originating from the Muslim cemeteries of Solkhat as the capital of the Crimea in the Golden Horde Period and other large settlements, such as Eski-Iurt. The two-horned gravestones from the cemeteries of large settlements present elaborate forms and inscriptions; they are covered with ornaments featuring the Seljuk style of the Asia Minor. The two-horned gravestones from the cemeteries in the steppe have a high base, with their pillars following the shape of vertical

Meta-igneous rocks of the West-Carpathian basement, Slovakia: indicators of Early Paleozoic extension and shortening events

2009 ◽  
Vol 180 (6) ◽  
pp. 461-471 ◽  
Author(s):  
Marián Putiš ◽  
Peter Ivan ◽  
Milan Kohút ◽  
Ján Spišiak ◽  
Pavol Siman ◽  
...  
Keyword(s):  
Early Paleozoic ◽  
The South ◽  
Ophiolite Complex ◽  
The North ◽  
Late Cambrian ◽  
Collision Zone ◽  
Gondwana Margin ◽  
Group A ◽  
Arc Setting ◽  
Back Arc

Abstract The paper reviews the main West-Carpathian Early Paleozoic metamorphosed originally sedimentary-magmatic complexes, dated by SHRIMP on zircons, as indicators of crustal extension and shortening events. Igneous precursors of a Layered Amphibolite Complex (LAC) – fractionated upper mantle gabbros to diorites, dated at 503 ± 4 and 492 ± 4 Ma from the North-Veporic, or 480 ± 5 and 450 ± 6 Ma from the Tatric basement are contemporaneous with subaluminous to metaluminous I-type (507 ± 4 Ma, the South-Veporic basement), peraluminous S-type (497 ± 4 Ma, the South-Veporic basement; 516 ± 7, 485 ± 6 and 462 ± 6 Ma, the North-Veporic basement; 497 ± 6, 472 ± 6 and 450 ± 6 Ma, the Tatric basement), alkaline A-type (511 ± 6 Ma, South-Veporic basement) granitic orthogneisses and calcalkaline rhyolitic (482 ± 6 Ma) and dacitic (476 ± 7 Ma) metavolcanics (Gemeric basement), indicating a magmatic immature back arc setting. The ages point to Middle/Late Cambrian, Early and Late Ordovician magmatic phases, coeval with the extension in the northern Gondwana margin. Separation of an inferred Avalonian and/or Galatian terranes distal continental ribbon corresponds with the opening of a Medio-European Basin. A 430-390 Ma dated MP/HP metamorphic event, recorded in the LAC and associated orthogneisses, occurred in the area of thinned immature back arc basin crust due to closure of the Medio-European Basin. Thus a distal Gondwana continental ribbon north of this basin could be an eastward lateral pendant of Armorica, derived from Galatian terrane. Metaophiolites of the Pernek Group (a metagabbrodolerite dated at 371 ± 4 Ma) in the Tatric basement, analogous to island-arc tholeiites and back-arc basin basalts, indicate a back-arc basin setting north of a 430-390 Ma old northward dipping subduction/collision zone, dividing the northward drifting western Galatian terrane microplate from the Gondwana margin. Some metabasites of the Gemeric basement might indicate Late Devonian to Mississippian opening of a peri-Gondwanan Paleotethyan oceanic basin: a 383 ± 3 Ma old remelted metagabbro (482 ± 9 Ma) from the Klátov gneiss-amphibolite complex, ca. 385 Ma old porphyritic metabasite of the Zlatník ophiolite complex, as well as a 350 ± 5 Ma old HP metabasite as tectonic fragment within the Rakovec Group. The closure of Devonian-Mississippian basins, accompanied by medium-pressure (the Pernek Group) to high-pressure (blueschist to eclogitic tectonic fragments in greenschist facies rocks of the Rakovec Group) metamorphism, occurred in late Carboniferous to early Permian, when Paleotethyan realm complexes accreted to a Galatian terrane microplate, the latter represented by the older and the higher-grade Tatric and Veporic basement complexes.

Safe Quality of Service Aware Management of Heterogeneous Sensor Networks

2006 ◽  
Vol 07 (01) ◽  
pp. 179-193 ◽  
Author(s):  
Mohamed Younis ◽  
Waleed Youssef ◽  
Mohamed Eltoweissy ◽  
Stephan Olariu
Keyword(s):  
Quality Of Service ◽  
Network Performance ◽  
Vital Role ◽  
Heterogeneous Sensor Networks ◽  
Evolutionary Neural Network ◽  
Wide Range ◽  
Pervasive Service ◽  
Potential Damage

Wireless networked sensors are envisioned to play a vital role in the emerging pervasive service platforms that will instrument a wide range of next generation civil and military applications. Recently, we have proposed ANSWER: AutoNomouS Wireless sEnsor netwoRk as a service platform whose mission is to provide dependable information services to in-situ mobile users while satisfying their quality-of-service (QoS) requirements. Alongside with the stationary tiny sensors, the network employs more powerful mobile devices referred to as aggregation and forwarding nodes (AFNs). ANSWER exploits AFN mobility to support QoS requirements. However, as an AFN moves closer to an event (for example, a hazardous spill), it may be at risk (for example, due to potential damage). In this paper, we present a quantitative analysis of the interplay and balance between QoS support and asset safety. We propose a new scheme, called SAFER (for SAFEty-aware Relocation), which pursues relocation of the AFN in order to boost network performance without unnecessarily compromising AFN safety. For the relocation process to take place, SAFER uses historical data on detected events and employs an evolutionary neural network to assess the risk involved and predict good quality new position(s). Experimental results demonstrate the effectiveness of SAFER.

scholarly journals The analysis on the correlation parameters of the embankment compaction under in situ conditions

2013 ◽  
Vol 12 (3) ◽  
pp. 097-104
Author(s):  
Maciej Kumor ◽  
Łukasz Kumor ◽  
Joanna Farmas
Keyword(s):  
Particle Size ◽  
In Situ Tests ◽  
Geotechnical Assessment ◽  
In Situ Conditions ◽  
Wide Range ◽  
Correlation Parameters ◽  
And Control

Geotechnical assessment of the implementation correctness of a road embankment wide range of issues, among which important selection and control of the quality of the earthworks are extremely significant. The article presents results of in situ tests determining correlations between the depending parameters defined by a static plate – VSS test – E1 and E2, and obtained from the study LFG Dynamic Load Plate. Studies indicate that the determination of the correlation between the parameters characterizing the particle size distribution (Cc, Cu, D10, D20, D30, D60), and the compaction parameters obtained by examining the compaction of sand embankment (Evd, E1, E2, I0) is physically complex and hence extremely difficult. 

scholarly journals Creation and Validation of a Comprehensive 1° by 1° Daily Gridded North American Dataset for 1900–2009: Snowfall

2016 ◽  
Vol 33 (5) ◽  
pp. 857-871 ◽  
Author(s):  
Daria Kluver ◽  
Tom Mote ◽  
Daniel Leathers ◽  
Gina R. Henderson ◽  
Weihan Chan ◽  
...  
Keyword(s):  
North America ◽  
North American ◽  
Independent Set ◽  
Measurement Sensitivity ◽  
The North ◽  
In Situ Observations ◽  
Point Data ◽  
Fold Cross Validation

AbstractThis study details the creation of a gridded snowfall dataset for North America, with focus on the quality of the interpolated product. Daily snowfall amounts from National Weather Service Cooperative Observer Program stations and Meteorological Service of Canada surface stations are interpolated to 1° by 1° grids from 1900 to 2009 and examined for data record length and quality. The interpolation is validated spatially and temporally through the use of stratified sampling and k-fold cross-validation analyses. Interpolation errors average around 0.5 cm and range from less than 0.01 to greater than 2.5 cm. For most locations, this is within the measurement sensitivity. Grid cells with large variations in elevation experience higher errors and should be used with caution. A new gridded snowfall climatology is presented based on in situ observations that capture seasonal and interannual variability in monthly snowfall over most of the North American land area from 1949 to 2009. The Community Collaborative Rain, Hail and Snow Network is used as an independent set of point data that is compared to the gridded product. Errors are mainly in the form of the gridded data underestimating snowfall compared to the point data. The spatial extent, temporal length, and resolution of the dataset are unprecedented with regard to observational snowfall products and will present new opportunities for examining snowfall across North America.

In-Situ Techniques for Studying Epitaxially Grown Layers and Determining their Magnetic Properties

1989 ◽  
Vol 151 ◽  
Author(s):  
B. Heinrich ◽  
A. S. Arrott ◽  
J. F. Cochran ◽  
K. B. Urquhart ◽  
K. Myrtle ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Surface Science ◽  
Easy Axis ◽  
Film Surface ◽  
In Situ Techniques ◽  
Wide Range ◽  
Bcc Structure ◽  
Crystallographic Defects

ABSTRACTUltrathin films of bcc Fe (001) on Ag (001) and Fe/Ni (001) bilayers on Ag were grown by molecular beam epitaxy. A wide range of surface science tools (RHEED, REELFS, AES, and XPS) were employed to establish the quality of epitaxial growth. Ferromagnetic resonance and Brillouin light scattering were used to extract the magnetic properties. Emphasis was placed on the study of magnetic anisotropies. Large uniaxial anisotropies with the easy axis perpendicular to the film surface were observed in all ultrathin structures studied. In sufficiently thin samples the saturation magnetization was oriented perpendicular to the film surface in the absence of an applied field. It has been demonstrated that in bcc Fe films the uniaxial perpendicular anisotropy originates at the film interfaces. Fe/Ni bilayers were also investigated. Ni grows in the pure bcc structure for the first 3–6ML and then transforms to a new structure which exhibits unique magnetic properties. Transformed ultrathin bilayers possesses large in-plane 4th order anisotropies far surpassing those observed in bulk Fe and Ni. The large 4th order anisotropies originate in crystallographic defects formed during the Ni lattice transformation.

Overview of the 2019 Sentinel-5p TROpomi vaLIdation eXperiment (TROLIX)

2020 ◽  
Author(s):  
Arnoud Apituley ◽  
Karin Kreher ◽  
Ankie Piters ◽  
John Sullivan ◽  
Michel vanRoozendael ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Stratospheric Ozone ◽  
Aerosol Layer ◽  
Data Set ◽  
Local Networks ◽  
Validation Experiment ◽  
Wide Range ◽  
Data Products

<p>For the validation of Sentinel-5p/TROPOMI the TROpomi vaLIdation eXperiment (TROLIX) was held in the Netherlands based at the Cabauw Experimental Site for Atmospheric Research during September 2019. TROLIX consisted of active and passive remote sensing platforms in conjunction with several balloon-borne and surface measurements.</p><p>The intensive observations will serve to establish the quality of TROPOMI L2 main data products (UVAI, Aerosol Layer Height, NO<sub>2</sub>, O<sub>3</sub>, HCHO, Clouds) under realistic conditions with varying cloud cover and a wide range of atmospheric conditions.</p><p>Since TROPOMI is a hyperspectral imager with a very high spatial resolution of 3.6 x 5.6 km<sup>2</sup>, understanding local effects such as inhomogeneous sources of pollution, sub-pixel clouds and variations in ground albedo is important to interpret TROPOMI results. Therefore, the campaign included sub-pixel resolution local networks of sensors, involving MAXDOAS and Pandora instruments, around Cabauw (rural) and within the city of Rotterdam (urban). Utilising its comprehensive in-situ and remote sensing observation program in and around the 213 m meteorological tower, Cabauw was the main site of the campaign with focus on vertical profiling using lidar instruments for aerosols, clouds, water vapor, tropospheric and stratospheric ozone, as well as balloon-borne sensors for NO<sub>2</sub> and ozone.</p><p>The data set collected can be directly compared to the TROPOMI L2 data products, while measurements of parameters related to a-priori data and auxiliary parameters that infuence the quality of the L2 products such as aerosol and cloud profiles and in-situ aerosol and atmospheric chemistry were also collected.</p><p>This paper gives an overview of the campaign, and an overview of the participating main and ancillary instrumentation and preliminary results.</p><p>Future activities include the deployment in 2020 of an airborne hyperspectral imager.</p>

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