bluuebunny/crossref_metadata_2025 huggingface dataset:
Petrology of an Irregular-Nodule Bed, Lower Carboniferous, Anglesey, North Wales
Authors: Nichols R. A. H.
Published: May 2009

Some of the nodules described are similar to trace-fossils described by Donaldson and Simpson and some ichnofossils described by Seilacher, but many appear to be structures produced by sedimentary boudinage. These do not seem to be a result of organic or concretionary action. It is suggested that currents deposited thin bioclastic calcarenites with interbeds of calcite silt, and that crinoids and coral patches developed only sporadically during deposition. A few scavengers reworked the bioclastic calcarenites and calcite silt layers thus forming the trace-fossils; many of the irregular-nodules, however, were probably formed by differential compaction and segregation in the calcite silt beds, and may represent sedimentary boudins, which are relicts of former layers.
Upper Palaeozoic and Lower Mesozoic stratigraphy of south-western Nordaustlandet, Spitsbergen
Authors: Lowell James D.
Published: May 2009

Upper Palaeozoic (Permian and possibly Carboniferous) basal sandstones and carbonate rocks rest with angular unconformity on Hecla Hoek rocks in the south-western part of the island of Nordaustlandet, Spitsbergen. Upper Palaeozoic rocks are in turn disconformably overlain by Lower Mesozoic (Triassic and possibly lowermost Jurassic) shales, siltstones, and minor sandstones. The Upper Palaeozoic-Lower Mesozoic sequence thins by sedimentary convergence north-eastward from more basinal areas in Vest-spitsbergen to a stable shelf in Nordaustlandet.
Five Viséan conodont horizons in the north of England
Authors: Austin Ronald L.
Published: May 2009

Five faunal lists of conodonts recovered from isolated Viséan outcrops in the north of England are presented. The fauna of the Bowland Shale at Burnsall, Yorkshire, and that of theOrionastraeaBed at Bordley, Yorkshire, are representative of theGnathodus mononodosusAssemblage Zone. The fauna of theBollandoceras hodderenseBed (B1), and that of a limestone near the top of the Worston Shale Group (B2) at Little Mearley, Lancashire, represent theMestognathus beckmanni-Gnathodus bilineatusAssemblage Zone. The presence of conodonts in the reef limestone of Swinden, Yorkshire, is also noted.
The term farsundite
Authors: Middlemost Eric
Published: May 2009

Farsundite from the type locality in southern Norway is described. The use and abuse of the term is discussed. It is recommended that the term should be restricted to use as a local specific name for the granitic rocks of the Farsund area.
A large temporary exposure in the Lower Silurian of Shropshire
Authors: Cocks L. R. M. , Walton G.
Published: May 2009

Fresh information on the ecology, sedimentology and structure of the Lower Silurian (Llandovery) Purple Shale of Shropshire has emerged as a result of large-scale excavations. The griestoniensis Zone is proved, and correlated by shelly fossils with the C5 substage of the type Llandovery area. Current directions indicate a source area up-slope to the south-east. Most of the fauna constitutes a Clorinda community, but towards the top of the sequence a Clorinda/Stricklandia mixture is developed.
The Evolution of the Earliest Llandovery monograptids
Authors: Hutt Jana , Rickards R. B.
Published: May 2009

The incommodus, atavus and cyphus monograptid groups appear more or less simultaneously in the atavus Zone. The atavus and cyphus groups are related, one of these probably giving rise to the later tenuis group of monograptids, Possible roots of these groups and relationships with later monograptids are discussed. Monograptus strachani sp. nov. is proposed to replace the name M. incommodus sensu Elles & Wood.
Stage Names within the Llandovery Series
Authors: Cocks L. R. M. , Toghill P. , Ziegler A. M.
Published: May 2009

Four stage names are erected within the southern part of the type area of the Llandovery Series, south-east of Llandovery, Carmarthenshire, Wales. They are Rhuddanian, to incorporate the existing Lower Llandovery; Idwian for the Middle Llandovery, and Fronian and Telychian for the Lower and Upper parts of the Upper Llandovery. Correlation with the sequence of graptolite zones is suggested.

The base of the Llandovery at Llandovery is poorly exposed and unfossiliferous, and detailed correlation with other areas may always remain uncertain. Thus the base of the Llandovery Series, and hence the base of the Silurian System, is defined in Lapworth's classic locality at Dobb's Linn, Moffat, Scotland, at the base of the zone of Glyptograptus persculptus.
Petrology of acid xenoliths from Surtsey
Authors: Sigurdsson Haraldur
Published: May 2009

A number of acid plutonic xenoliths from the volcano Surtsey are described, along with fine-grained rock fragments, consisting chiefly of anorthitic plagioclase and tridymite. The chemistry of the xenoliths indicates a compositional pattern from tonalitic to pyrometamorphic types. A hypothesis is put forward that the tonalitic xenoliths have undergone partial fusion during transport to the surface in the basaltic magma, and the removal of a salic liquid from granitic xenolith into the magma has resulted in the formation of a residue of anorthitic plagioclase and tridymite. Granitic xenoliths from other parts of Iceland, and their fusion products, are also described.
Coleoptera from the “Arctic Bed ” at Barnwell Station, Cambridge
Authors: Coope G. R.
Published: May 2009

Remains of coleoptera collected by Miss Chandler from the Barnwell Station beds (Cambridge) are described. Twenty-one recognizable taxa are recorded, all of which represent living genera or species. Five species are no longer found living in Britain and are confined today to arctic or sub-arctic environments. This interpretation of the fauna is in marked contrast to the identifications of P. Lesne, whose manuscript determinations are attached to the slides. He had attributed many of the specimens to new genera and species.

The fauna as here interpreted indicates a truly tundra environment and qualitatively and quantitatively resembles very closely other British coleopteran assemblages from the latter part of the Upton Warren (Mid-Weichselian) interstadial, i.e. about 30,000 years B.P.
A Columnar Crystallization of Olivine and Plagioclase
Authors: Preston J.
Published: May 2009

A thin vein of dolerite at Slemish, Co. Antrim, shows an unusual plane and smooth contact against the dolerite of a Tertiary plug. A columnar growth at the contact indicates special conditions for crystallization. The selvedge is described and an attempt made to explain the growth and orientation of the olivine.
Some Investigations of the Roraima Formation Intrusives in British Guiana
Authors: Rust B. R.
Published: May 2009

A traverse of a noritic gabbro sill (c. 1,000 feet thick) intruding the Roraima Formation showed no cryptic layering, but small-scale fractionation throughout the sill is indicated by the strongly-zoned plagioclase (An80→40), and orthopyroxene (En79→54) with outer rims of inverted pigeonite. Olivine (Fo80) is only present in the chilled margin.

New evidence on the age of the granites underlying the Roraima Formation is given by the discovery of post-Roraima felsite dykes, with high-quartz phenocrysts.
An Occurrence of Regionally Metamorphosed Pre-Cambrian Schists in South-West Pembrokeshire
Authors: Claxton C. W.
Published: May 2009

Recent research work has revealed an area of regionally metamorphosed Pre-Cambrian schists (previously undescribed) in south-west Pembrokeshire. The name “Dutch Gin Schists” is proposed for this newly described group of rocks. The Johnston Plutonic Series (Dimetian) are seen to be intruded into these schists, and the nature of the intrusive contact is described. The structure and petrology of the schists, and the nature of diorites adjacent to the contact and that seen elsewhere in the igneous mass is compared, and a suggestion made regarding the age of the foliation. A comparison is made with the Pre-Cambrian metamorphosed rocks of Malvern, Shropshire, and Anglesey.
Paradoxides from colombia
Authors: Rushton A. W. A.
Published: May 2009

Paradoxides sp. is recorded from South America for the first time, together with an associated faunule which includes Ehmania cf. akanthophora Harrington and Kay, 1951.
The palaeogeographical significance of lateral variations in the ratio of sandstone to shale and other features of the Aberystwyth Grits
Authors: Lovell J. P. B.
Published: May 2009

Statistical sampling of the Aberystwyth Grits, using a method previously employed in an analogous study of Tyee Formation, Oregon, shows an overall decrease in the ratio of sandstone to shale from south-west to north-east, away from the supposed source of depositing currents. Comparison with other methods of proximality evaluation in turbidite sequences indicates that at least in this case the ratio of sandstone to shale is the most sensitive indicator of palaeogeography.
The structural characteristics of the Strathspey Complex, Inverness-shire
Authors: Smith T. E.
Published: May 2009

A detailed account is given of the structural features of the Strathspey Granite and Pegmatite Complex together with information about the metamorphic and tectonic environment of the surrounding metasediments. The evidence indicates that the granite core of the complex was intruded shortly after the latest phase of folding recorded in the area had taken place. The country rocks were still at relatively high temperatures at the time of intrusion and were deformed by the granite. The granite emplacement is also shown to be a separate event not directly connected with the formation of the regional migmatite complex, which extends for 48 km to the north-east.
Transcurrent faulting in the Sarawak-Kiri region, Sarawak, East Malaysia
Authors: Tjia H. D.
Published: May 2009

Geological discontinuities, lineaments, field observations, and interpreted π-girdles demonstrate a left lateral, NNW trending transcurrent fault in the Sarawak-kiri valley of West Sarawak. Topography and geology also suggest that the fault belongs to an important fracture zone that extends well into Indonesian Kalimantan, and continues in a northerly direction along the edge of the Sunda Shelf beneath the South China Sea.

Comparison with transcurrent faulting occuring in the Malay Peninsula and a probable wrench fault between Palawan island and Sabah (North Borneo) reveals the continental part of southeast Asia to have rotated counter-clockwise up to Lower Palaeogene time, probably as a response to spreading of the Pacific ocean floor.
The Correlation of the Ballachulish and Perthshire (Iltay) Dalradian Successions
Authors: Rast N. , Litherland M.
Published: May 2009

The historical background of correlations between various Dalradian successions is examined, and on the basis of recent mapping and observations it is suggested that the Ballachulish succession is the downward extension of the standard Perthshire sequence.
Pebble surface textures
Authors: Krinsley David , Donahue Jack
Published: May 2009

An electron microscope examination of beach and glacial pebbles suggests that these two environments do not impress distinctively different textures on pebble surfaces. A detailed study of surface textures of beach pebbles indicates that size reduction is predominantly an abrasional rather than solutional process. The three textural features noted, flat planar surfaces, pits and arc-shaped fractures, were characterized by an abundance of mechanical breakage blocks slightly modified by solution. All three textural types were experimentally duplicated.
A note on the relationship of sillimanite to biotite
Authors: Shelley David
Published: May 2009

A description is given of potassium feldspar which was produced during the fibrolitization of biotite.
Spongolites from the Arnsbergian of County Limerick, Ireland
Authors: Lewarne Gillian C.
Published: May 2009

Spongolite beds are common in the basal Namurian shales of Co. Clare and Co. Limerick, and are especially well developed north of Ardagh, Co. Limerick. Spongolites from this locality are described and are considered to represent a local deposit of siliceous monactinellid spicules. They are compared with the “phtanites” of the Assise de Chokier of Belgium, which are of the same age and similarly preserved. Stylolite seams developed within the rocks are briefly described.
Origin of ash deposits in the Santiago area, Central Chile
Authors: Guest J. E. , Jones G. P.
Published: May 2009

Non-stratified, poorly-sorted rhyolitic ash deposits previously described as morainic and mudflow deposits are reinterpreted as ignimbrites emplaced in the topographically lower parts of the Santiago basin by pyroclastic flows. These flows probably originated from sources high in the Andes, and swept down the deep Maipo valley to spread out over the sediments filling the basin. An ignimbrite with a zone of dense welding but otherwise of similar character to the non-welded ashes of the basin occurs in one of the Andean valleys; and peculiar ‘pipe’ structures in the ashes of the basin support a pyroclastic flow origin.

Further study of the nature and origin of these rocks may lead to a better understanding of the structural evolution of the area.
Callocystites brevis, a new Silurian rhombiferan cystoid from Indiana
Authors: Frest T. , Paul C. R. C.
Published: May 2009

A new rhombiferan cystoid, Callocystites brevis, is described from the top 45 cm of the Laurel Limestone at Sandusky, Decatur County, Indiana. The species is known from a single crushed theca and many isolated plates. C. brevis is characterized by short, unbranched ambulacra. The subfamily Callocystitinae and the genus Callocystites are redefined.
Initiation of the Northumberland basin
Authors: Leeder M. R.
Published: May 2009

A north-easterly palaeoslope is demonstrated for the south-eastern Scottish Borders during the Upper Devonian. Alkali basalt extrusion in the (?basal) Tournaisian was followed by initiation of the Northumberland basin as a structural feature. Basin subsidence gave rise to a south-easterly palaeoslope in the Southern Uplands and was coincident with the mid-Tournaisian marine transgression.
Some relations between common acid–basic associations
Authors: Roobol M. J.
Published: May 2009

Net veined complexes and basic dykes with lobate or planar margins are commonly contained in granophyre and felsite. A study of three Tertiary centres reveals that the associations do not occur as distinct types but show gradational relations. Examples are used to illustrate a gradational morphological series. The interpretation of this series is best accounted for in terms of a basic magma invading an acid host. The factors considered capable of producing the described variations are (a) the volume of basic magma (and therefore amount of heat introduced), and (b) the degree of consolidation (ratio of crystals to melt) of the acid host.
Rate of uptake of calcium carbonate in underground karst water
Authors: Pitty A. F.
Published: May 2009

A method of estimating the rate of flow-through time of water moving in an outcrop of massive limestone is reviewed. Mean values of calcium carbonate dissolved are shown to be proportional to flow-through times. The rate of uptake is very similar in both Derbyshire and Yorkshire. The pattern demonstrated resembled the relationship between salinity and increased depth noted for deep sub-surface brines.
Fossil Coccospheres from a Tertiary Outcrop on the Continental Slope
Authors: Black Maurice
Published: May 2009

A soft chalky limestone or coccolith-marl, believed to form a submarine outcrop in the upper part of the continental slope off Brittany, consists largely of coccoliths, with subordinate quantities of foraminifera and sponge-spicules. Of the twenty or more species of Coccolithophoridae found in this deposit, two are preserved as complete coccospheres more frequently than as separate placoliths; these are described and named. The age of the rock is probably late Tertiary.
Biotite- and Sphene-rich rocks in the Moine Series of Ardnamurchan, Argyllshire
Authors: Butler B. C. M.
Published: May 2009

Schists composed essentially of biotite and sphene have been found in many localities in the psammitic groups of the Moine Series in Ardnamurchan. From petrographic and chemical evidence it is concluded that they were heavy mineral bands, composed of sphene and iron oxides with a matrix which was partly pelitic and partly quartzo-feldspathic. This postulated original composition may have been produced by sedimentary slumping, for which field evidence is available. The unusual chemical composition was probably accentuated at higher grades of metamorphism by metamorphic metamorphic segregation, particularly a loss of soda or of segregation, particularly a loss of soda or of albite into the surrounding arkoses.
A trace fossil from the Lower Dalradian, Co. Donegal, Eire
Authors: Wolfe M. J.
Published: May 2009

A new interpretation of a polygonal pattern of ridges in the Marble Hill Dolomitic Limestone, at Ballymore, suggests that it was formed by a soft-bodied, worm-like organism.
The origin of eclogite and ariégite nodules in basalt
Authors: O'Hara M. J.
Published: May 2009

The origin of eclogite nodules in basalt is reviewed in the light of experimental studies and the conclusion reached that many of them precipitated from basic magma as garnet-pyroxene accumulates at high pressure, although some may represent exsolved clinopyroxenite accumulates.
Sponges and the Chalk Rock
Authors: Reid R. E. H.
Published: May 2009

Chalk Rock lithology suggests shallow-water conditions, but the fauna has been said (Woods, 1897; Jukes-Brown, 1904) to imply a depth between about 100–500 fm. A study of the sponges which are numerous in the Oxfordshire–Hertfordshire area shows that these form a fauna of the sort which is typical of the Chalk as a whole, with Hexactinellida predominant as was pointed out by Woods; this is a fauna of deep-water type by both modern and Cretaceous standards. The depth which these sponges imply need, however, not be much more than 100 fm., and their presence need have no direct bearing on the depth at which erosional features were formed.
Tholeiite from the Simien alkali basalt centre, Ethiopia
Authors: LeBas M. J. , Mohr P. A.
Published: May 2009

The Ethiopian Cainozoic volcanics associated with the African rift system comprise one of the world's most voluminous alkaline igneous provinces. The Simien Mountains are the remnants of a Miocene alkali olivine-basalt volcanic centre in the north-western part of this province. The end-phase activity at Simien featured intrusion of dyke-swarms of two trends, one parallel to the rift system, the other almost perpendicular to it. Dykes of the rift trend are typically alkaline, but a dyke sampled from the other trend proves to be an olivine-tholeiite. Its presence is interpreted, along with similar rocks from the Harar region in eastern Ethiopia, in terms of upper mantle rifting extending from the Gulf of Aden and Red Sea under the continental blocks of the Ethiopian swell.
The Crush Zone of the Iranian Zagros Mountains, and its implications
Authors: Wells Alan J.
Published: May 2009

An early study of part of the Zagros mountains of south-western Iran put forward evidence for extensive overthrusting and nappe formation. A simplified interpretation of the stratigraphy now obviates the necessity for such tectonic complications.

The north-eastern limit of Zagros folding is marked by a long narrow belt of structural deformity and stratigraphic discontinuity known as the Crush Zone, which includes basic intrusive rocks contemporaneous with the late Tertiary foldings.

It is suggested that the Crush Zone is closely related to the Zagros orogeny, and geophysical evidence is used to speculate on a possible explanation. The general concept of the Crush Zone could prove to be of more widespread application.
The reptile Fauna Of The ‘Lower Keuper’ Sandstone
Authors: Walker A. D.
Published: May 2009

Previous records are revised, and new identifications of reptiles are presented, based on a study of specimensin older collections. Amphibious marine forms of Alpine Trias and Muschelkalk affinities are recognized from the Midlands, albeit on tantalizingly incomplete material. Such evidence as the reptiles provide indicates an early to mid-Ladinian age for the upper part of the Building Stones, the boundary between Anisian and Ladinian here being taken to lie within the Middle Muschelkalk.
Post-burial sideritisation of calcite in Eocene beds from the Maracaibo Basin, Venezuela
Authors: Phipps C. B.
Published: May 2009

Core material from carbonate cemented sandstones of Eocene age from the Maracaibo Basin, Venezuela, exhibits evidence of post-burial sideritisation of calcite. the process being identical in its essentials with dolomitisation. and resulting in a marked increase in porosity and permeability of the cemented sandstones. As a result of this increase, sub-surface waters have been able to leach out much of the sideritc cement, and subsequent mechanical compaction of the sandstones has produced a characteristic “bead”-like arrangement of remnant sideritc granules around the sand grains. The whole process can be reconstructed from thin-sections, and these are used to illustrate the text.
The Geology of the Snøfjella and Dovrefjella in Vestspitsbergen
Authors: Preston John
Published: May 2009

The area yields marbles, schists, and quartzites, probably of Hecla Hoek age, a series similar in lithology to those in the Kongsfjorden region. Their structure and metamorphic condition fit in with the general picture of Caledonian trend and of increasing orogenic activity westwards. Later faulting along the western edge of a graben has broken this ground up into independent blocks as witnessed by the disposition of the Devonian conglomerates. The youngest rocks are a southerly outlier of the plateau basalts best seen around Woodfjorden, remnants of at least two flows are preserved, both of olivine basalt rich in olivine phenocrysts and carrying inclusions of a more alkaline rock type.
The Intrusion-Breccia of Dunmore, Co. Donegal
Authors: French W. J. , Pitcher W. S.
Published: May 2009

A small plug-like body is made up of an intrusive breccia contained within a ring of felsite. The felsitic matrix of the breccia is of composite origin and certain textures may indicate contemporaneous breaking of crystals. Attention is drawn to the association of this diatreme with the suite of felsite, hornblende lamprophyre, and hornblendite intrusions clustered around the diapiric pluton of Ardara.
Partial silicification of chalk fossils from the Chilterns
Authors: Brown G. , Catt J. A. , Hollyer S. E. , Ollier C. D.
Published: May 2009

The calcite of brachiopod, lamellibranch and echinoid shells from the Upper and Middle Chalk of Hertfordshire and Bedfordshire is partly replaced by chalcedonic silica. The crystallographic forms of the silica are described, and its diagenetic emplacement inferred from thin section studies.
The Revised Ludlovian Stratigraphy of the Type Area—A Discussion
Authors: Phipps C. B.
Published: May 2009

A recent revision of the type Ludlovian succession at Ludlow (Holland et al., 1959) has raised a number of problems concerning the classification and nomenclatureof the proposed divisions. It is here suggested that these can be resolved by adopting adual systemof classification, in which both rock-stratigraphic and biostratigraphic units are recognized. The impropriety of discarding the names Aymestry and Mocktree is established, and a plea is made for the erection of stages to aid in local and regional correlation.
Metamorphic Grade and Iron-Magnesium Distribution between Co-Existing Garnet-Biotite and Garnet-Hornblende
Authors: Frost M. J.
Published: May 2009

It is shown that in the two mineral pairs discussed the metamorphic grade can be estimated from the atomic ratios (Xa = Mg/Mg + Fe + 0·175 Mn + 0·360 Ca) in garnet and Xb = Mg/(Mg + Fe) in the other mineral. The standard error of the estimation is about one-third of the temperature range of the amphibolite facies.

Where M is the metamorphic grade on an arbitrary scale, in which the lower boundary of the amphibolite facies is at 4·2 and the upper at 5·1, and K is the distribution coefficient (Xb—XaXb)/(Xa—XaXb), then the estimating equation is M = 5·6 — 1·5 log10 K.
On the Genus Amplexograptus Lapworth, Elles & Wood
Authors: Bulman O. M. B.
Published: May 2009

The type species of Amplexograptus is re-examined and is considered to include two distinct species. In neither of these is there any indication of a concavo-convex rhabdosome cross-section. A revised diagnosis of the genus is given and its relation to Climacograptus briefly discussed.
Steeply Plunging Recumbent Folds
Authors: Naha Kshitindramohan
Published: May 2009

The definition of a recumbent fold as one with subhorizontal axial surface is best with difficulties when recumbent folds plunge. Recumbent folds are redefined here as folds whose axial planes give subhorizontal trace in profile plane, with the fold-axis plunging at any angle up to 80°. A neutral to slightly antiformal recumbent fold half mile across and plunging 75° is described from the Pre-Cambrian metamorphic terrain in Eastern India.
The Upper Middle Hecla Hoek Rocks of Ny Friesland, Spitsbergen
Authors: Wilson C. B.
Published: May 2009

This paper gives a definitive description of the lithology and thicknesses of the Upper Middle Hecla Hoek rocks of Ny Friesland, Spitsbergen, arising out of Cambridge expeditions since 1951. The succession is the late Pre-Cambrian part of the Hecla Hoek Geosyncline, lying below the Tillite horizons and characterized essentially by limestones and dolomites.
A “Vein” of Trondhjemite aplite: Granitization of Quartzite forming the sole of a Fold-thrust, Malin Head, Co. Donegal
Authors: Reynolds Doris L.
Published: May 2009

A narrow layer of quartzite, emplaced within epidiorite by foldthrusting, is transformed to albite-trondhjemite aplite and contiguous zones of the epidiorite are enriched in biotite. By reference to six chemical analyses it is found that, with but small additions of potash these transformations can be accounted for by the combined processes of (a) mechanical mixing of the initial quartzite and epidiorite, and (b) metamorphic inter-diffusion between this mixture and the adjoining epidiorite.
On the species Orbignyella fibrosa (Lonsdale)
Authors: Owen David E.
Published: May 2009

The species Alveolites fibrosa Lonsdale, 1839, described also as Stenopora fibrosa var. β Regularis McCoy, 1851, and referred to as Stenopora fibrosa var. incrustans McCoy, was recognized originally by Lonsdale (1839) as different from Calamopora fibrosa Goldfuss, 1826. It is described here as Orbignyella fibrosa (Lonsdale) and shown to occur typically in beds of Leintwardine age.
On Deformation at Thrust Planes in Shetland and the Jotunheim area of Norway
Authors: Flinn Derek
Published: May 2009

In both north-east Shetland and the Jotunheim area of Norway two nappes of crystalline rocks occur lying one above the other and separated in time and space by orogenic sediments. These sediments were formed in part at least by erosion of the lower, and first emplaced, of the two nappes in both areas. Later emplacement of the upper nappes caused the deformation and metamorphism of these rocks. In both Norway and Shetland large quartzite conglomerates which occur immediately beneath the upper nappes have been deformed on patterns which have been determined from a study of the pebble shapes. From these patterns in both areas it is argued that the deformation was due to flow caused by pressure differences developed in the sole of the advancing nappe and possibly to extrusion from beneath the nappe.
The Occurrence of Hypersthene in Hawaiian Basalts
Authors: Tilley C. E.
Published: May 2009

The occurrence of hypersthene in Hawaiian basalts, related broadly to the lime-silica values in the bulk analyses, is now considered and graphically expressed in terms of the quantitative proportions of the normative constituents, diopside, hypersthene, olivine, and quartz in analyses of Kilauea and Mauna Loa lavas.
An Unusual Gabbroic Intrusion from Northern Rhodesia
Authors: Newton A. R.
Published: May 2009

Gabbro is intruded near the contact of gneiss and schist groups in the Southern Province of Northern Rhodesia. The petrography of normal and altered rocks is described. The rocks may have originated as an intrusion into an original reversed drag fold which it has emphasized and distorted. Intrusion took place at a late stage of regional metamorphism and folding.
A Note on Greisening in the Bodmin Moor Granite
Authors: Exley C. S.
Published: May 2009

Some differential weathering of tors on Bodmin Moor has been found to be due to narrow zones of greisen. These zones are not related to the joint system in the granite and appear to have arisen by the alteration of feldspars in the path of escaping late-magmatic fluids.
Structural Behaviour of Quartzite in a Migmatite Area, Tanganyika
Authors: Brown P. E.
Published: May 2009

Quartz-magnetite rocks occur as lenses in an area of migmatitic mica gneiss and have acted as resisters to deformation as well as migmatization. Due to plastic deformation in the enclosing gneisses a quartzite lens now strikes perpendicular to the trend of other resisters which are abruptly truncated.
The Distribution of Radioactivity in some Fine-grained Igneous Rocks
Authors: Hamilton E.
Published: May 2009

The quantitative distribution of the alpha particle activity in rocks and minerals by nuclear emulsion techniques is applied to some exceptionally fine-grained rocks. The distribution of radioactivity is comparable to that observed in the coarser-grained rock types more suitable to nuclear emulsion studies.
The Permian and Trias of the Oman Peninsula, Arabia
Authors: Hudson R. G. S.
Published: May 2009

The lower part of the limestone succession of the Hagab Monocline in the Oman Peninsula, Arabia, is divided into the Bih Dolomite (Permian, 650 m.), Hagil Limestone (Permian, 260 m.), Ghail Limestone (Trias, 600 m.) and the Elphinstone Beds (Noric, 431 m.). The latter consists of five formations, two of which are very fossiliferous. The succession also occurs to the south in borings in the forelands of the Oman Mountains and is similar to that of the foreland of the Zagros Range of Iran.
The Late Palaeozoic Glaciation of Gondwanaland in Relation to West Africa and to Northern South America During Carboniferous Time
Authors: Anderson M. M.
Published: May 2009

Lower Carboniferous strata are shown to be absent from the Amazon basin and Ghana, the Bermejo series of Bolivia is Permo-Triassic, the Sekondi series of Ghana does not include glacial deposits and may prove to be Devonian, early Carboniferous glaciation is unknown in Africa and restricted to Argentina in South America. In the light of these interpretations the extent to which late Carboniferous glaciation affected northern South America and Africa is briefly reviewed and shown to conflict with the reconstructions by L. C. King (1958). The non-glaciation of Africa and South America north of at least latitude 25 degrees South during early Carboniferous times is regarded as proving that these areas did not pass through the south polar region at that time. The known distribution of early and late Carboniferous glacial deposits is considered in relation to continental drift and movement can only have been westwards during the Carboniferous period.
Intrusive Phenomena of the Whin Sill, East of the R. North Tyne
Authors: Randall B. A. O.
Published: May 2009

The Whin Sill of this district has the form of a series of sills at different stratigraphical levels. Minor scarps at right angles to the main trend of the sill are explained by intrusion of offshoots, from its upper surface, along low angled fractures in the superincumbent strata. An intrusion mechanism is suggested to account for the presence of the Oxford Limestone both above and below the Whin Sill.
The Structure of the Grantown Granite Complex, Morayshire
Authors: Mackenzie David H.
Published: May 2009

The field relations and petrography of the Grantown Newer Granite are described. The structure of the country rocks—Moine gneisses—is compared with that of the numerous blocks included in the granite, the results being synoptically presented. The blocks originally bore the same orientation as the country rocks and have been rotated in the granite during its emplacement. From east to west three zones of orientation, showing increasing rotation of blocks from their original position, are recognized in the granite. As the granite lacks an internal penetrative structure the kinematics of the blocks in the granite remains uncertain. All the evidence suggests that the granite did not form in situ, but was emplaced in a plastic state by dilation of the country rocks mainly along their foliation.
A note on new Namurian plant localities at the head of the Neath Valley, South Wales
Authors: Jones D. G.
Published: May 2009

The occurrence of low Namurian plants in the Neath Valley is noted. It is believed that they show the presence of the Eumorphoceras Stage. This revision of age in relation to the Namurian-Avonian junction is briefly discussed.
Pelagic Foraminifera in the Tertiary of Victoria
Authors: Carter Alan Norval
Published: May 2009

A sequence of eleven faunal units characterized by pelagic foraminifera and embodying thirteen significant events has been recognized in the Tertiary of Victoria. They form a continuous sequence from the Upper Eocene to the Middle Miocene. Some of these events have been recognized in the same order in New Zealand, Europe, North America, the Caribbean region, and Saipan.
On the Occurrence of Ankerite in a Band of Non-marine Lamellibranchs from the Lancashire Coal Measures
Authors: Broadhurst F. M. , Howie R. A.
Published: May 2009

The shell-substance of the non-marine lamellibranchs from a band in the Lower similis-pulchra Zone of Lancashire is shown to be ankerite. The same mineral also forms pockets inside certain of the shells, the pockets being developed most frequently in the stratigraphically uppermost part of the spaces between the valves. It is considered that the ankerite in the pockets has occupied spaces left by shrinkage of the original mud-filling of the shells. Chemical analyses, specific gravity, and optical properties of the ankerite are given; its composition closely approximates to (Mg2Fe)Ca3(CO3)6.
The Significance of Septa and Sutures in Jurassic Ammonite Systematics
Authors: Westermann G. E. G.
Published: May 2009

A study of Stephanocerataceae and Perisphinctaceae of the Middle Jurassic demonstrates that the structure of the septa comprises a complex vault and pillar system which is functionally adapted to the dimensions of the tube so as to give maximal stability to the shell. Only through a study of the septum can we interpret the different forms of the suture and discriminate between important and unimportant features. Different septa may have analogous sutures, especially in the external parts. These septal patterns are strikingly consistent within subfamilies or families even where other features suggest overlap between the groups. Some parts of the septum are not adapted, but either retained from earlier ontogeny or inherited, and constitute vestigial (genotypic) characters distributed through taxons.

These empirical results have been applied to the taxonomy of some groups of hitherto doubtful systematic position (Cadomitinae, Normannitinae, Sphaeroceratinae, Parkinsoniidae, Spiroceratidae).
Pyroxenes from the Dawros Peridotite and some comments on their nature
Authors: Rothstein A. T. V.
Published: May 2009

The paper contains eight analyses of primary and recrystallized pyroxenes from the layered ultramafic peridotite at Dawros. The assemblages in which these pyroxenes occur are compared to those from other peridotites and some comments are made on the pyroxene sequence. Consideration is also given to the problems arising as the result of the metamorphism of the primary igneous accumulate at Dawros.
Pre-Cambrian Rocks in Co. Wexford
Authors: Baker J. Wellstood
Published: May 2009

An area of rocks in S.E. Co. Wexford, the age of which has not been previously established, is now shown to be a metamorphic assemblage, probably of Pre-Cambrian age. It is suggested that this formed the south-western extension of the L. Palaeozoic Irish Sea geanticline postulated by previous workers.
Alkali Metasomatism and the Petrology of Some Keratophyres
Authors: Battey M. H.
Published: May 2009

Petrographic and chemical study of New Zealand keratophyres, occurring in a typical spilite-keratophyre association, shows that they were originally partly glassy flow-rocks and breccias comparable with rhyolites of young volcanic areas. They are now composed of a low temperature mineral assemblage inconsistent with textural evidence of high temperature extrusive origin, and alkali metasomatism has enriched some rocks in soda and others in potash, so that their compositions are symmetrically disposed about that of a primary rhyolite magma with roughly equal amounts of the two alkalis.

Data from other occurrences suggest that this condition is common amongst described keratophyres.

Though the rocks do not originate from any special magma, the term keratophyre should be retained, with appropriate qualifiers, for old rhyolites with low-temperature mineralogy, which, incidentally, will often be found to have been affected by alkali metasomatism.
Metamorphism of the Manx Slates
Authors: Gillott J. E.
Published: May 2009

The chief metamorphic minerals are described and, in addition to those reported by Lamplugh, cordierite (at scattered localities along the structural axis) and staurolite (at Glion Darragh, Archal-lagan) are found to occur. The distribution of metamorphic minerals recorded by Lamplugh is confirmed. The age relation of the new minerals to the movements is deduced from microscopic evidence. This is: early folding and development of biotite; relaxation of stress and development of cordierite; shearing and recrystallization of biotite along planes of fracture-cleavage; high grade metamorphism at Archallagan which outlasted the fracture-cleavage movements.

It is concluded that the postulate of a buried granite beneath the axial belt most readily accounts for the distribution of the metamorphism.
The Stratigraphical Range of the Foraminiferal Genus Orbulina D'Orbigny 1839
Authors: Bowen R. N. C.
Published: May 2009

This genus is not present in pre-Oligocene rocks and probably does not occur below the basal Miocene. Stratigraphical and micropalaeontological evidence is produced to support this statement.
The Upper Carboniferous Rocks of the Stainmore Coalfield
Authors: Ford T. D.
Published: May 2009

The sequence of Upper Carboniferous rocks in the outlier at the western end of Stainmore Pass is described. The Upper Yoredale Series is shown to be separated by an unconformity from the overlying “Millstone Grit” series. The Coal Measures are about 800 feet thick and appear to be unconformable on the “Millstone Grit”. Hitherto unrecorded non-marine faunas and floras indicate horizons near the base and at the top of the Modiolaris zone. The sequence of Upper Carboniferous rocks at Stainmore is briefly compared with those of surrounding coalfields.
Some Devonian Fish Remains from North Central Vestspitsbergen
Authors: Dineley D. L.
Published: May 2009

Fish remains from the Wijde Bay Series of the Wijdefjorden area include (1) pteraspids, not previously recorded from so high an horizon, which appear to bear sensory canals upon the exterior surface of the ventral disc; (2) an Asterolepis, and (3) rhizodontid scales, resembling those of Holoptychius. A very large antiarch from an unknown horizon is also recorded.
Corundum from Ceylon
Authors: Wells A. J.
Published: May 2009

The origin of precious corundum found in the gem-bearing gravels of Ceylon has long been unknown. An occurrence of sapphire is described from a contact zone where syenite has been intruded into, and desilicated by, crystalline limestone. The process of desilication in such contact zones is considered capable of accounting for much of the gem-quality corundum of the island.
The Occurrence of Chloritoid in the Hecla Hoek Formation of Prince Charles Foreland, Spitsbergen
Authors: Atkinson D. J.
Published: May 2009

In the Hecla Hoek rocks of Prince Charles Foreland, field evidence indicates that chloritoid has developed only where conditions of extreme stress have affected pelitic rocks of a certain type. Microscopic examination confirms that many of the chloritoid-bearing rocks are extremely strained, and demonstrates that growth of the mineral was contemporaneous with movement. The distribution of chloritoid is in complete discordance with the pattern of regional metamorphism.
The Stratigraphy of Cuilcagh, Ireland
Authors: Padget Peter
Published: May 2009

Of the three main lithological units on Cuilcagh, namely, Millstone Grit, Yoredale Sandstone, and Yoredale Shale, particular attention is paid to the latter which attains a thickness of 700 feet. Numerous goniatites were collected from the lowermost 450 feet of it and these establish the existence of the P1b, P1c, P2, E1a zones and possibly the E1c zone also. Higher beds are very poorly fossiliferous and their age is uncertain. Brief comparisons are also made with Yoredale Beds in England and in other parts of Ireland.
A New Lower Carboniferous Echinoid from North America
Authors: Kier Porter M.
Published: May 2009

A new species ofPalaeechinus, and the first certain member of that genus from North America, is described and several unusual features of its test noted. The apical disc of the specimen is extremely well preserved.
New Evidence of Intra-Formational Piping at Two Separate Horizons in the Carboniferous Limestone (Dibunophyllum Zone) at South Cornelly, Glamorgan
Authors: Thomas Trevor M.
Published: May 2009

Large-scale extractions from a limestone quarry immediately east of the village of South Cornelly have provided sections of the Dibunophyllum Zone (probably the top of D1 Subzone) showing deep piping at two separate horizons. On the lower sides and floors of some of the larger pipes, the limestones and pseudo-breccias have been metasomatically replaced by a thin layer or by irregular pockets of haematite up to a foot in thickness. All the evidence points to two periods of emergence and sub-aerial erosion followed by lagoonal conditions with a Keuper-like environment when the irregularities of the underlying rock surface were filled with marl.
Facies Changes versus Sliding: Loch Leven, Argyll
Authors: Bailey E. B.
Published: May 2009

As is well known the northern face of Garbh Bheinn, which rises from Loch Leven east of Caolasnacon farm, is occupied by a “very obvious asymmetric downfold” of inversion Eilde Quartzite (Hardie, 1952, p. 273; Bailey, 1934, p. 485). The inversion is established by current bedding and is unquestioned. The Eilde Quartzite here floats on Eilde Schist, younger than itself. The occurrence marks the western end of the Kinlochleven Inversion, one of the most remarkable geological structures known to science.
Progressive Replacement of Limestone Inclusions in Granite at Ballynacarrick, Co. Donegal
Authors: Gindy Amin R.
Published: May 2009

Limestone inclusions in granite show a skarn armour made up of definite mineral zones. From the limestone side these are in order: grossular zone (with or without idocrase), clinozoisite zone, plagio-clase-pyroxene zone, and finally a hornblendic or dioritic zone that passes into the biotite-granite or granodiorite of the district. These different zones were not static but moved into the limestone, each zone replacing the one preceding it and being replaced by the zone following it. A mechanism by which limestone inclusions disappear in granite is clearly exemplified.
Daviesiella destinezi (Vaughan), a Lower Carboniferous Index Fossil in North-West Ireland
Authors: Simpson I. M.
Published: May 2009

Daviesiella destinezi (Vaughan), a large concavo-convex brachiopod, is very common in some of the Lower Carboniferous limestones of North-West Ireland. It appears to be confined to the C2S1 subzone. Easily recognizable in the field, it is thus a useful index fossil of the subzone. As the previous descriptions of the species are far from complete, a detailed description of some unusually well-preserved specimens from Co. Fermanagh is given and an attempt is made to relate certain features of the morphology of the specimens to their environment.
The Kirkmabreck Granodiorite, near Creetown, South Galloway
Authors: Blyth F. G. H.
Published: May 2009

The structure and flow-layering of a granodiorite dyke, as seen in extensive quarry exposures, are described and related to quarrying directions and the regional tectonic pattern.
On the Affinities of the Cretaceous Lamellibranch Genera Trigonioides and Hoffetrigonia
Authors: Cox L. R.
Published: May 2009

The East Asian Cretaceous lamellibranch genera Trigonioides and Hoffetrigonia are discussed after examining new material of the former, and the conclusion is reached that both belong to the Unionidae and not to the Trigoniidae. A proposal to include them in a new family is withdrawn.
Echinotiara arabica sp. nov., A Regular Echinoid from the Toarcian of Central Arabia
Authors: Melville R. V.
Published: May 2009

The new species Echinotiara arabica is described and referred to the family Stomopneustidae Meissner, 1903. It is compared with other Liassic species of “Stomechinus” which are considered to be congeneric with it, and its relationships with the genera Stomechinus, Psephechinus and Jeannetia are discussed.
Supposedly Colpate Pollen Grains from the Jurassic
Authors: Couper R. A.
Published: May 2009

Some Mesozoic spores and pollen grains claimed in a recent publication to exhibit angiosperm-like features are discussed. It is suggested that Poroplanites Pflug, is actually a trilete fern spore. The “ germinal apparatus ” of the Poroplanites type is simply an optical section of the characteristic folding of a lobe of a trilete spore, flattened along the polar axis and seen in equatorial view. It is shown that Pflug's Poroplanites type can be reproduced almost exactly in the trilete spores of a living tree fern. Classopollis Pflug, Circumpollis Pflug, and Canalopollis Pflug are pollen grains with distinct annular thickening, similar to the pollen grains of the Jurassic araucarian, Pagiophyllum connivens Kendall.
Petrofabric Analyses of the Loch Tay Limestone from Strachur, Argyll
Authors: Gilmour Paul , Carman Max F.
Published: May 2009

The paper records the results of petrofabric analyses of four specimens of marble from the South-West Highlands of Scotland. The marble fabric has a high degree of homogeneity. Calcite grains are flattened in the foliation plane and are elongate in a direction normal to the fold axis. The c crystal axes lie in a distinct girdle about b, with a maximum near the pole of the foliation; the a crystal axes tend to occupy three maxima, one of which is close to b. Late twinning has occurred on {011¯12} apparently in response to a simple stress system, operating in the ac plane. The symmetry of the general calcite fabric, the twinning and the megascopic structures coincide.
An Arenig Volcanic Series near Charlestown, Co. Mayo
Authors: Cummins W. A.
Published: May 2009

A graptolite fauna, found in cherty shales interbedded with volcanic rocks south of Charlestown, Co. Mayo, indicates an Arenig age.
The Carboniferous Rocks of Foynes Island, County Limerick
Authors: Hodson Frank
Published: May 2009

The lithological and faunal successions of some 1,150 feet of Carboniferous beds exposed on Foynes Island, County Limerick, are described and shown to be of Namurian Age. The stratigraphical position of Reticuloceras subreticulatum (Foord) and Homoceratoides divaricatus (Hind) has been ascertained by collecting from the type localities on the island. The palaeogeographical implications of the succession are discussed.