The composition and distribution of nodular monazite in the Lower Palaeozoic rocks of Great Britain

1987 ◽  
Vol 51 (360) ◽  
pp. 271-280 ◽  
Author(s):  
D. Read ◽  
D. C. Cooper ◽  
J. M. McArthur
Keyword(s):  
Great Britain ◽  
Host Rock ◽  
Sedimentary Rock ◽  
Sedimentary Rocks ◽  
Source Rocks ◽  
Low Grade ◽  
South West ◽  
Lower Palaeozoic ◽  
South West England

AbstractMillimetric, ellipsoidal monazite nodules found within Lower Palaeozoic sedimentary rocks in Wales, south-west England and Brittany are characterised by a pronounced zonation of light and heavy REE, an inclusion fabric of low-grade metamorphic minerals indistinguishable from the host rock and a low Th content. They are interpreted as the product of in situ recrystallization of detrital monazites derived from pegmatitic or granitic source rocks and are potentially useful as indicators of Lower Palaeozoic sedimentary rock provenance.

scholarly journals CASE HISTORIES OF TWO ESTUARIES

1968 ◽  
Vol 1 (11) ◽  
pp. 82
Author(s):  
C.H. Dobbie
Keyword(s):  
Great Britain ◽  
Case Histories ◽  
Littoral Drift ◽  
South West ◽  
Sand Spit ◽  
Tidal Estuaries ◽  
Moray Firth ◽  
South West England ◽  
Historical Detail

The coast of Great Britain has many interesting examples of the interaction between tidal estuaries of rivers and the littoral drift of the coast. These have been described with historical detail mainly by geographers (ref.l). Two cases coming to the author's firm for action have interest for coastal engineers. For the River Spey m the Moray Firth of Scotland, a famous and vigorous river, unusual works have been undertaken with success. For Dawlish Warren, a sand spit m the Exe Estuary of Devon m South West England, a scheme of works is being prepared which has novelty in regard to British practices.

scholarly journals Triassic Low Temperature Hydrothermal Activities(LTHA) From the Ordos Basin of Northern China

2021 ◽  
Author(s):  
Jiyuan You ◽  
Yiqun Liu ◽  
Dingwu Zhou ◽  
Yiyao Yang
Keyword(s):  
Hydrothermal Vents ◽  
Sedimentary Environment ◽  
Ordos Basin ◽  
Sedimentary Rocks ◽  
Northern China ◽  
Source Rocks ◽  
Three Samples ◽  
The Ordos Basin ◽  
Hydrothermal Activities

Abstract Because few well-preserved hydrothermal channels have been found in terrestrial sedimentary rocks, research on LTHA in geological history is relatively sparse. In this study, we present our original discovery of “hydrothermal channels” from the Chang 7 source rocks of the Triassic Yanchang Formation in the Ordos Basin, China, and provide the best evidence for deciphering LTHA preserved in the geological record (i.e., sedimentary rocks). Three possible LTHA samples (i.e., samples 1551.6, 1551.6-2 and 1574.4) were collected for this study; they were interbedded with mudstones and oil shales, indicative of a deep-lake sedimentary environment. All three samples consist mainly of anhydrite, pyrite, and dolomite with the formation of mineral zoning across the walls of these structures, suggesting a sulfate-dominated stage and a carbonate-sulfide replacement stage. Moreover, their in situ geochemistry is characterized by high Eu, U, Th, Sr, Mn and U/Th ratios, which are typical indicators of hydrothermal vents. In addition, their S isotopes range from 7.89% to 10.88%, the magmatic sulfur accounted for approximately 94.3%, implying a possible magmatic trigger for these hydrothermal channels. All this evidence shows that the Triassic sedimentary rocks of the Ordos Basin probably contain LTHA. Comparing ancient LTHA to modern hydrothermal chimneys, we should note the important implications of LTHA; their formation mechanism may have been related to oil production, and they are possible indicators for future oil investigations. Further, they have great significance for studying the hydrothermal properties of primary dolomite.

The Bionomics of the Lesser Bulb Flies, Eumerus strigatus, Flyn., and Eumerus tuberculatus, Rond., in South–west England

1927 ◽  
Vol 17 (4) ◽  
pp. 373-384 ◽  
Author(s):  
W. E. H. Hodson
Keyword(s):  
Great Britain ◽  
North America ◽  
Host Plants ◽  
Plant Pests ◽  
South West ◽  
The Family ◽  
Type Of Injury ◽  
South West England

The larvae of certain flies belonging to the family Syrphidae have long been recognised as plant pests. Merodon equestris, Fab., was recorded in Great Britain as far back as 1869, having probably been imported in narcissus bulbs from Holland (Verrall). This fly is now universally known as the “ Large Narcissus Fly,” the larvae causing serious losses in nearly every locality where the narcissus is grown commercially. More recently flies of the genus Eumerus have been associated with a type of injury very similar to that caused by the larger fly, and the larvae have been recorded on a variety of host-plants in Europe and America. Chief among these hosts may be included narcissus, onion, hyacinth, parsnip, iris, and potato. The flies are commonly referred to as “ Lesser Bulb Flies ” or alternatively in some parts of North America, where they were first recorded as European introductions in 1904, as “ Lunate Onion Flies.”

The ammonite succession in the Lower Oxford Clay and Kellaways beds at Kidlington, Oxfordshire, and the zones of the Callovian stage

1955 ◽  
Vol 239 (664) ◽  
pp. 215-264 ◽  
Keyword(s):  
Sensu Stricto ◽  
West Germany ◽  
North West ◽  
Additional Information ◽  
South West ◽  
The Mediterranean ◽  
Callovian Stage ◽  
Lower Callovian ◽  
South West England

The paper describes temporary sections through the Lower Oxford Clay, Kellaways Rock and Kellaways Clay down to the Cornbrash in a part of England in which these beds were previously little known. All the beds were fossiliferous, and more than 200 ammonites ascribed to twentyfive species were collected in situ , bed by bed throughout the succession. The ammonites of the genus Kosmoceras in the Lower Oxford Clay were sufficiently numerous to allow them to be studied statistically by the methods employed by Brinkmann in 1929 on similar ammonites of the same age from the Lower Oxford Clay at Peterborough. His results for the lower part of the sequence comprising the jason Zone were fully reproduced. In addition, ammonites of other genera were found, including several specimens of Reineckeia, among the first to be recorded from beds of this age in this country. The Kellaways Rock, consisting mainly of sands, was extremely fossiliferous and yielded, besides many lamellibranchs and gastropods, numerous, although poorly preserved, ammonites. These were the same as those of the Kellaways Rock of Wiltshire, with the addition of a specimen of Macrocephalites sensu stricto . The Kellaways Clay was poorly fossiliferous, but it produced six specimens of Macrocephalites (subgenera Kamptokephalites and Dolikephats ), an assemblage similar to that of the Upper Cornbrash of Yorkshire and quite different from that of the Kellaways Clay of Wiltshire. The position of this clay above typical Upper Cornbrash as developed in south-west England, and belonging to the siddingtonensis and in part lagenalis brachiopod Subzones, confirms previous suspicions that the Cornbrash of Yorkshire is later than that of the south-west. In the light of these results, the older evidence relating to the beds of this age in this country and abroad, including some of the old collections, is re-examined. Additional information from new or undescribed exposures at Calvert, Frome, Sutton Bingham near Yeovil, Weymouth, and Herznach in Switzerland, is included. In consequence, a much closer correlation of the beds of the Middle and Lower Callovian than was previously possible is now made between outcrops in Scotland, Yorkshire, north-west Germany, central and south-west England and the Argovian Jura. A revised zonal table of the Callovian has been constructed, designed to be generally applicable to the area outlined above and including as subzones finer divisions which are in practice recognizable more locally. The relation between these west European zones and some of those used in the Mediterranean province is briefly indicated.

Teloschistes Flavicans in Great Britain: Distribution and Ecology

1996 ◽  
Vol 28 (6) ◽  
pp. 493-506 ◽  
Author(s):  
O. L. Gilbert ◽  
O. W. Purvis
Keyword(s):  
Great Britain ◽  
The Other ◽  
England And Wales ◽  
South West ◽  
North Wales ◽  
Coastal Cliff ◽  
Southern Half ◽  
Distribution And Ecology ◽  
South West England

AbstractOver the last century, the distribution of Teloschistes flavicans has contracted from being widespread in the southern half of England and Wales to being limited to South-West England with outlying populations in Pembrokeshire and North Wales. Twelve core sites have been identified where the species is well established: ten of these are saxicolous/terricolous habitats on windy coastal cliff tops; the other two are lines of sycamore trees near the coast. At 39 further localities, some inland, the species is in very small amounts (often on one tree) and vulnerable to extinction. It is normally a member of the Parmelietum revolutae or Ramalinetum scopularis associations. The conservation of the species is discussed.

scholarly journals Triassic hydrothermal chimneys from the Ordos Basin of Northern China

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiyuan You ◽  
Yiqun Liu ◽  
Dingwu Zhou ◽  
Yiyao Yang
Keyword(s):  
Hydrothermal Vents ◽  
Sedimentary Environment ◽  
Ordos Basin ◽  
Sedimentary Rocks ◽  
Northern China ◽  
Hydrothermal Activity ◽  
Source Rocks ◽  
Three Samples ◽  
The Ordos Basin

AbstractBecause few well-preserved hydrothermal chimneys have been found in terrestrial sedimentary rocks, research on paleo-thermal vents in geological history is relatively sparse. In this study, we present our original discovery of “hydrothermal chimneys” from the Chang 7 source rocks of the Triassic Yanchang Formation in the Ordos Basin, China, and provide the best evidence for deciphering hydrothermal activity preserved in the geological record (i.e., sedimentary rocks). Three possible chimney samples (i.e., samples 1551.6, 1551.6–2 and 1574.4) were collected for this study; they were interbedded with mudstones and oil shales, indicative of a deep-lake sedimentary environment. All three samples consist mainly of anhydrite, pyrite, and dolomite with the formation of mineral zoning across the walls of these structures, suggesting a sulfate-dominated stage and a carbonate-sulfide replacement stage. Moreover, their in situ geochemistry is characterized by high Eu, U, Th, Sr, Mn and U/Th ratios, which are typical indicators of hydrothermal vents. In addition, their S isotopes range from 7.89% to 10.88%, near the values of magma sulfur, implying a possible magmatic trigger for these hydrothermal vents. All this evidence shows that the Triassic sedimentary rocks of the Ordos Basin probably contain hydrothermal chimneys. Comparing ancient hydrothermal chimneys to modern hydrothermal chimneys, we should note the important implications of ancient chimneys; their formation mechanism may have been related to oil production, and they are possible indicators for future oil investigations. Further, they have great significance for studying the hydrothermal properties of primary dolomite.

An environmental study of the Upper Domerian and Lower Toarcian in Great Britain

1967 ◽  
Vol 252 (778) ◽  
pp. 393-445 ◽  
Keyword(s):  
Great Britain ◽  
Environmental Study ◽  
Invertebrate Fauna ◽  
South West ◽  
Facies Associations ◽  
Local Topography ◽  
Shelf Sea ◽  
Shallow Seas ◽  
South West England

An integrated petrological and palaeoecological study has been undertaken of the Spinatum, Tenuicostatum and Falciferum zones of the Lias in all the major British sections. After a brief stratigraphical review the deposits are described systematically in terms of four regions, Yorkshire, the Midlands, south-west England and the Inner Hebrides. The Spinatum Zone consists of a series of ironstones, bioclastic limestones and fine sandstones with a rich and diverse fauna dominated by brachiopods, bivalves and belemnites. The Tenuicostatum Zone , thin or absent in most areas, tends to be finer grained and more argillaceous, with a fauna related to that of the underlying beds. The Falciferum Zone is characterized especially by the extremely widespread development of laminated bituminous shales with an impoverished invertebrate fauna. A brief world stratigraphical review leads to the conclusion that there was a notable eustatic rise of sea level in the early part of the Toarcian. The British deposits are considered to have been laid down in a very shallow shelf sea in an area of great tectonic stability and very slight relief. Within this context, the facies was controlled primarily by rates of deposition and subsidence, local topography, liability to wave action and proximity of rivers. The early Toarcian transgression, following a late Domerian regression, had the effect of inducing widespread stagnation below wave base, until the sea had deepened sufficiently in mid Toarcian times to allow freer circulation. Four different facies associations in the fauna can be distinguished and related to environmental conditions. The development of faunal provinces among the later Domerian ammonites and brachiopods and some extinction is attributed to the existence of extremely shallow seas extensively broken up by newly emergent land. The widespread phase of bottom stagnation in the Falciferum Zone led to extinction of most of the benthos, so that the overlying beds contain a substantially new fauna, with Middle Jurassic affinities.

Direct Observation of Crystalline Ordering In Naturally Graphitized Carbon Produced by Low Grade Metamorphism

1977 ◽  
Vol 35 ◽  
pp. 162-163
Author(s):  
Thomas R. McKee ◽  
Peter R. Buseck
Keyword(s):  
Crystallite Size ◽  
Sedimentary Rocks ◽  
Carbonaceous Material ◽  
Low Grade ◽  
X Ray ◽  
Graphitized Carbon ◽  
Transmission Electron ◽  
Heat Treated ◽  
Commercial Carbon ◽  
Metamorphic Zone

Sediments commonly contain organic material which appears as refractory carbonaceous material in metamorphosed sedimentary rocks. Grew and others have shown that relative carbon content, crystallite size, X-ray crystallinity and development of well-ordered graphite crystal structure of the carbonaceous material increases with increasing metamorphic grade. The graphitization process is irreversible and appears to be continous from the amorphous to the completely graphitized stage. The most dramatic chemical and crystallographic changes take place within the chlorite metamorphic zone.The detailed X-ray investigation of crystallite size and crystalline ordering is complex and can best be investigated by other means such as high resolution transmission electron microscopy (HRTEM). The natural graphitization series is similar to that for heat-treated commercial carbon blacks, which have been successfully studied by HRTEM (Ban and others).

TBE in United Kingdom

2020 ◽  
Keyword(s):  
United Kingdom ◽  
Clinical Disease ◽  
England And Wales ◽  
Probable Case ◽  
The United Kingdom ◽  
South West ◽  
Louping Ill ◽  
The Uk ◽  
North And South ◽  
South West England

Until 2019, TBE was considered only to be an imported disease to the United Kingdom. In that year, evidence became available that the TBEV is likely circulating in the country1,2 and a first “probable case” of TBE originating in the UK was reported.3 In addition to TBEV, louping ill virus (LIV), a member of the TBEV-serocomplex, is also endemic in parts of the UK. Reports of clinical disease caused by LIV in livestock are mainly from Scotland, parts of North and South West England and Wales.4

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