bluuebunny/crossref_metadata_2025_split huggingface dataset:
Potassium-argon age determinations on rocks from St Kilda and Rockall
Authors: Miller J. A. , Mohr P. A. 
Published: January 2010

Synopsis
St Kilda intrusive rocks have yielded the following ages:

Post-granophyre dykes and sheets
35 m.y. (approx.)

Granophyres and associated sheets
56 m.y.

Dolerites and basic sheets
60 m.y.

Eucrite
?60 m.y. +

A sample of aegerine-granite from Rockall has provided an age of 60±10 m.y.
The stratigraphy and structure of the Whithorn area of Wigtownshire, Scotland
Authors: Rust B. R. 
Published: January 2010

Synopsis
The rocks of the Whithorn area comprise two groups of Silurian strata: the Riccarton Beds, of Wenlock age, and the Hawick Rocks. The boundary between these groups is reinterpreted as a strike fault with major southward downthrow.
Five fold movements have been recognised in the area. The first two comprise N.E.-S.W. folds and are responsible for the major monoclinal structure of the area. Folds of the third movement have E-W axial planes and steep plunges, and are considered contemporaneous with members of the Caledonian dyke suite. Fourth generation folds have low-angle axial planes, and are associated with late thrusts and mineralisation (probably Hercynian). The latest folds, dextral kink bands with N-S modal trend, are believed to post-date a Tertiary dyke series.
Early thrusts are associated with the first folds, and a conjugate set of wrench faults with the second folds. It is suggested that strike faults originated as dip-slip fractures before or during the second fold movement, and were later reactivated by strike- and oblique-slip movement.
The structural history of the area is found to be comparable with those of other parts of the southern Caledonian fold belt, especially the Silurian areas.
The buried channel of the River Nith and its marked change in level across the Southern Upland Fault
Authors: Lumsden G. I. , Davies A. 
Published: January 2010

Synopsis
The base of the buried channel of the River Nith falls eastwards (in the same direction as the flow of the present river) from 650 ft above Ordnance Datum to 400 ft O.D. as it approaches the outcrop of the Southern Upland Fault. Across the fault the base of the channel is proved again at 520 ft O.D. and falls eastwards to 400 ft O.D. at Sanquhar. Ice-gouging is an unlikely explanation of the anomalous levels across the Southern Upland Fault. The possibility of late movement along the Southern Upland Fault, with a resultant downthrow to the north of a little under 200 ft is supported by the details of the buried channel of the neighbouring River Doon. Such probable late fault movement can be dated no more closely than at some time after the Upper Cretaceous (but probably much later) and before the end of the Glacial period.
Geomorphic evolution in Hebridean Scotland
Authors: George T. Neville 
Published: January 2010

Synopsis
The view is challenged that the Highland plateau in Scotland originated during later Palaeozoic times and evolved as a complex ‘peneplain’.
The view is also challenged that the Highland plateau originated as an emergent Cretaceous sea-floor. Although Cretaceous rocks were repeatedly deformed by Palaeogene earth-movement and igneous action, there is no sign of a ‘Hebridean rift’ to which the complexities of Hebridean geology may be relegated. Arran, of Hebridean igneous facies in an alien structural context, confirms other evidence in demonstrating that the evolution of regional relief is not to be separated into one mode in a conjectural rift, another in a mainland massif.
The primary Hebridean landform appears to be the product of the pulsed emergence of little-warped wave-cut benches. The benches continue uninterruptedly from the Hebridean province into the Highlands, and prove an original geomorphic unity of the whole country. Since the benches bevel the Palaeogene igneous masses and are later than the mid-Tertiary folds and faults, the regional landscape is essentially Neogene in origin. So also appears to be the landscape of other parts of Britain.
The stratigraphy and structure of north-eastern Morar, Inverness-shire
Authors: Poole A. B. 
Published: January 2010

Synopsis
North-eastern Morar is composed of a complex of high grade Moine and Lewisian rocks. The succession is closely comparable to that of western Knoydart though reduced in total thickness. Four phases of folding are recognised, early isoclinal folding of Moine and Lewisian, followed by the development of an antiform in the west, and later a complex synform further east. A fourth phase of folding about east-west axes has produced a series of folds in the east of the area and given a steep southerly plunge to the earlier north-south trending folds and their associated minor structures.
Recent evidence for the age of the Hagshaw Hills Silurian Inlier, Lanarkshire
Authors: Ian Rolfe W. D. , Fritz Madeleine A. 
Published: January 2010

Synopsis
A graptolite fauna discovered in the basal beds of the Hagshaw Hills Inlier suggests an Upper Valentian age. Fragments of stromatoporoid and bryozoan colonies found in the hitherto unfossiliferous Parishholm Conglomerate indicate derivation from a source rock of Wenlock age. Since the Parishholm Conglomerate is thus younger than some part of the Wenlock it supports the recent suggestion that this conglomerate is paraconformable. The new evidence implies that the upper ‘fish’ beds of the Midland Valley inliers are post-Wenlock and therefore Ludlow in age as maintained by Westoll, but that a greater time interval separates upper from lower ‘fish’ beds than was formerly allowed. An overlooked publication by Peach in 1902 records a shelly fauna from the base of the Lesmahagow succession which permits closer correlation between the Hagshaw Hills and Lesmahagow inliers.
Sedimentary affiliations and stratigraphic correlation of the Dalradian rocks in the South-west Highlands of Scotland
Authors: Roberts John L. 
Published: January 2010

Synopsis
The concept of sedimentary affiliations (cf. the sedimentary associations of Knill 1959) is introduced, and three such affiliations (the black slate, the graded quartzite, and the greywacke affiliations) are described from the Dalradian metasediments younger than the Easdale Slates. The stratigraphic distribution of these affiliations is the basis for the proposed stratigraphic correlations. The difficulties of correlation across the Cowal Antiform and along the Highland Border are discussed. Current directions and facies changes allow the palaeogeography to be outlined. The distinction between the graded quartzite and greywacke affiliations provides evidence on the ‘greywacke problem’.
The Oxford Clay of Skye, Scalpay and Eigg
Authors: Turner Judith 
Published: January 2010

Synopsis
Callovian and Oxfordian rocks outcrop on the Inner Hebridean Islands of Skye, Scalpay and Eigg. The Callovian and Lower Oxfordian argillaceous beds in Staffin Bay are described. The deposits are fossiliferous and include all zones from the Jason Zone of the Middle Callovian to the Plicatilis Zone of the Middle Oxfordian. In Strathaird the lowest proved zone is of Lamberti or possibly Upper Athleta Zone age. In Strathaird, on Scalpay and in Staffin Bay the succession reaches the Upper Oxfordian, while even higher beds occur in Staffin Bay and on Mull. The name Staffin Shales is proposed for the fine-grained sediments of North Skye.
Deposition of some Upper Old Red Sandstone conglomerates in the Clyde area: A study in the significance of bedding
Authors: Bluck Brian J. 
Published: January 2010

Synopsis
On the basis of structure and texture, the Upper Old Red Sandstone conglomerates and conglomeratic sandstones of the Clyde area of Western Scotland are divided into four types which represent the accumulations of alluvial fans (mudflow and stream), braided streams, and floodplains. The deposits of alluvial fans show a relationship between bed thickness and maximum particle size, but this relationship is not clear in the case of floodplain deposits. The relationship of the bed thickness to maximum particle size and the nature of the frequency distribution of both maximum particle size and bed thickness are shown to be of considerable importance in determining conglomerate genesis.
Stratigraphical sections show an upward reduction in grain size together with a change from fan mudflow to fan stream to braided stream to floodplain deposition. These features suggest the diminishing effects of the source areas through time at any one locality; probably due to erosion and planation of newly emergent fault-bounded mountains. The transition from essentially untrenched mudflow deposits to channel-filling stream deposits and possibly braided stream deposits is regarded as the inevitable change an alluvial fan suffered in the tectonic setting of the Clyde area during Upper Old Red Sandstone times.
Intra-bed palaeocurrent variations in a Silurian flysch sequence, Kirkcudbrightshire, Southern Uplands of Scotland
Authors: Scott Kevin M. 
Published: January 2010

Synopsis

Palaeocurrent indicators
within
individual sandstone beds in the Riccarton-Raeberry Castle flysch succession show the following upward differences between erosional, sole-marking currents and depositional currents:

Grain elongation-imbrication orientations in poorly laminated basal parts of beds show statistically significant and highly variable deflections from sole-markings.

Internal current lineations within laminated portions of beds indicate deflections averaging 25 degrees.

Small-scale cross-laminations within the upper part of many beds were formed by currents of which 36 per cent diverged more than 90 degrees from sole-markings.

Terminal currents, forming cross-laminated transverse ripples on bed tops, were commonly normal to initial currents but some had reversed directions.

Sense of deflection was not constant but two successions showed predominant counterclockwise current rotation. Magnitude of deflections in each section correlates crudely with sole-marking trend dispersion. An example of total lateral filling of sole-markings was observed.
Two of five beds in which vertical changes in grain orientation were studied showed increasing upward deflection corresponding with upward decrease in grain size.
During each sand influx, changing resolution of forces due to fluid energy, associated with decreasing competency in the case of deposition of a graded bed, and the downslope force of gravity probably caused the current variation.
The age of the Durine Member of the Durness Limestone Formation at Durness
Authors: Higgins A. C. 
Published: January 2010

Synopsis
Conodont faunas from the Durine Member of the Durness Limestone Formation have yielded sixteen species. These faunas bear a close resemblance to previously described ones from North America and Scandinavia and suggest an age for the upper part of the Durine Member near the Arenig-Llanvirn boundary. This is somewhat at variance with Poulsens’ suggestion that the whole of the Durine Member is of Llanvirn age.
Metamorphism of minor intrusions associated with the Newer Granites of the Western Highlands of Scotland
Authors: Dearnley R. 
Published: January 2010

Synopsis
A late Caledonian phase of regional metamorphism is outlined in the Western Highlands. Minor intrusions associated with the Newer Granites are found to exhibit varying degrees of regional metamorphism in which the zonal ‘isograds’ trend about north-east-south-west, approximately parallel to and increasing in grade towards the Great Glen. There is a major break in the zoning along the line of the Great Glen Fault.
The Caledonian history of the north-eastern Irish Sea region and its relation to surrounding areas
Authors: Simpson Alexander 
Published: January 2010

Synopsis
In the light of recent work in the Isle of Man and the Lake District, the Caledonian histories of these two areas are outlined and correlated. The tectonic history of this north-eastern quarter of the Irish Sea region consists of two evorogenic episodes of severe Caledonian deformation. The earlier tectogenesis took place during the Lower Ordovician after the infilling of a rapidly subsiding geosynclinal trough. The importance of this orogenic phase within the British Caledonides is considered by comparison with surrounding areas. The structures produced during the subsequent end-Silurian evorogenesis are examined and compared with those formed at this time elsewhere in the British Isles.
The origin of the basic and ultrabasic rocks of the Loch Ailsh alkaline intrusion, Assynt
Authors: Parsons Ian 
Published: January 2010

Synopsis
The field relationships and textural and mineralogical features of basic syenites, ultrabasic rocks and dolomites associated with leucocratic syenites in the Loch Ailsh intrusion demonstrate that both basic syenites and ultrabasic rocks are the products of reaction between dolomite and syenite.
Pyrope from Elie, Fife
Authors: Colvine R. J. L. 
Published: January 2010

Synopsis
The garnets from a vent at Elie, Fife, have been collected and analysed. This analysis is compared with recent analyses of pyrope from, a number of other environments. On the basis of this comparison and the occurrence of the pyrope as xenocrysts in the vent agglomerate of Elie Ness Neck, a primary precipitate origin from a magma in depth is postulated.
Palaeozoic and Tertiary transcurrent movements on the Great Glen fault
Authors: Holgate Norman 
Published: January 2010

Synopsis
Two periods of major transcurrent movement on the Great Glen fault are here recognised: (1) a sinistral shift (essentially that of Kennedy 1946) of about 83 miles, which occurred in late Lower or early Middle Old Red times; and (2) a dextral shift of 18 miles which was initiated at the close of the strictly regional phase of the Hebridean Tertiary vulcanicity. The north-westerly dyke-swarms of the latter are dislocated by the dextral movement at the Great Glen and Firth of Lorne faults, while the extension of the Great Glen fault across SE. Mull is deformed and locally transgressed by intrusives emplaced about the Mull Early Caldera. The crustal stress system causing dextral shift on the Great Glen fault terminated the period of intrusion of north-westerly dykes; a few later dykes in Mull show an east-north-easterly trend in conformity with the new direction of regional stress maximum. The maximum age of the dextral movement is therefore indicated by the minimum age value for the dykes of the north-westerly swarm; at about 52 m.y., this corresponds to early Eocene times. The same dextral movement has dislocated an ancient river system which formerly flowed eastwards across the Scottish Highlands.
Investigation and treatment of leakage through Carboniferous rocks at Clubbiedean Dam, Midlothian
Authors: Sivasubramaniam A. , Carter Anne V. F. 
Published: January 2010

Synopsis
Clubbiedean Reservoir is impounded by an earth dam founded on calcareous shales and sandstones through which leakage paths have developed as a result of solution of the calcareous matrix of the sandstones. There is a history of attempts to plug the leaks in the reservoir floor. Recently the foundations of the dam were investigated by a series of cored boreholes and a grout curtain was subsequently established below the embankment. This curtain has reduced the leakage to negligible proportions.
The foundation investigations are described and the local geology discussed. The construction and effectiveness of the grout curtain are considered in detail.
The last glaciation and deglaciation of central Lanarkshire
Authors: McLellan A. G. 
Published: January 2010

Synopsis
Directions of ice movement have been deduced from glacial evidence (breached cols, striae, till fabrics and drumlins) and from fluvioglacial evidence (eskers and meltwater channels). The last glaciation of central Lanarkshire was effected by ice from both the Highlands and the Southern Uplands. It is shown that the Perth Readvance may have extended less far east than formerly supposed, and the Carstairs esker system is considered to be related to the wastage of an earlier ice cover. Doubts are raised about the value of till fabrics in the interpretation of ice movements.
Isotopic ages of dykes and pegmatitic gneiss from the southern islands of the Outer Hebrides
Authors: Lambert R. St J. , Evans C. R. , Dearnley R. 
Published: January 2010

Synopsis
Potassium-argon ages of 1720, 1565, and 1500 m.y. from dykes from South Uist and Benbecula confirm the existence of Laxfordian activity in the southern part of the Outer Hebrides. The pegmatitic gneiss of Ardivachar, South Uist, yields a whole-rock rubidium-strontium isochron age of 2560±80 m.y., closely correlating with the post-Scourie Group pegmatites of the mainland.
The Loch Ryan Fault
Authors: Kelling G. , Welsh W. 
Published: January 2010

Synopsis
Geological evidence is presented for the presence of a major fault near the east coast of Loch Ryan, a fracture whose existence was previously suggested from geophysical studies of the region by Mansfield and Kennett (1963) and Bott (1964). The location and nature of this fault have been determined from the repetition of a distinctive stratigraphical horizon on both sides of the loch, despite the regional fold plunge, and from a shift in the line of expression of the Southern Uplands Fault. This inferred fracture, the Loch Ryan Fault, is estimated to have a west-wards downthrow of approximately 5000 ft (1525 m).
Eolian sediments in the basal New Red Sandstone of Arran
Authors: Piper D. J. W. 
Published: January 2010

Synopsis
In the basal New Red Sandstone of Arran (Brodick Beds), interbedded eolian and water deposited sediments are found. Sedimentological features known from comparable modern environments, but not hitherto described from any other ancient sediments, include granule ripples, gravel deflation pavements, pebbles rolled into eolian sands, and fulgurites. Much of the eolian sand was deposited in dunes indicating a wind direction predominantly to the south-west. It has not been possible to determine the detailed morphology of the dunes.
Metasediments in the Rhiconich group of the Lewisian between Loch Laxford and Durness, Sutherland
Authors: Chowdhary P. K. , Dash B. , Findlay D. 
Published: January 2010

Synopsis
Metasedimentary quartzite and calc-silicate rock are of widespread distribution in the Rhiconich group of the Lewisian between Loch Laxford and Durness. Field relations, mineralogy and chemical composition are used as criteria for recognition, the mineral assemblages being indicative of amphibolite facies metamorphism. The calc-silicate rock has a mineralogical and chemical composition consistent with metamorphosed marl.
Sedimentation in the meandering River Endrick
Authors: Bluck B. J. 
Published: January 2010

Synopsis
The River Endrick carries gravel and finer sediment in a pool and riffle channel. Point bars and riffles, which alternate along most of the channel, are foci of active particle-size segregation within the general downstream size decline: they are therefore centres of facies change. This differentiation results in sediment of a particular size being systematically and repeatedly placed in similar parts of the channel: on point bars, for example, proportionately more gravel is found at the apex and more sand in the cross-over reaches of the meander. Cross-stratal dip direction in these sediments is roughly parallel to the local flow and is therefore different in sand and gravels. It also follows that sand has a higher standard deviation of cross-bed dip orientation than gravel. The bed forms of the river often have only a superficial thickness of related sediment: they were built by a lower stage of flow than most of the sediment enclosed by the form, and in this sense forms give an erroneous measure of structure.
The meanders move phase downstream so that at point bars crescents of differentiated sediment accrete on the inside, as older crescents are eroded from the outside or cut bank of the channel. In this way the river builds up a facies mosaic whose interface zig-zags downstream, and the cut bank exposes a section with a lateral size decline opposite to that of the facing point bar. Sedimentary successions show more variability within than between bars and the use of this fact, together with the variation in dip of cross-strata and other criteria, facilitates the independent reconstruction of the scale and sinuosity of the river.
Palaeontological evidence bearing on the age of Dalradian deformation and metamorphism in Ireland and Scotland
Authors: Skevington D. 
Published: January 2010

Synopsis
The occurrences of fossils, mainly graptolites, in sediments deposited prior and subsequent to metamorphism of rocks of the Dalradian Series are reviewed and discussed. The available evidence suggests that this event had terminated by early Arenig time, at the latest, in western Ireland and south-west Scotland, but occurred, or persisted, later in northern Scotland.
The Eastern Gneisses of South Uist
Authors: Coward M. P. 
Published: January 2010

Synopsis
The Eastern Gneisses of South Uist which overlie the Outer Isles Thrust consist of three units; the Corodale Gneiss mass which is interpreted as an igneous body; the Mashed Gneiss; a group of quartzo-feldspathic gneisses and an intervening zone of phyllonites, the Usinish Mylonites. The phyllonites appear to have been formed by intense deformation at the margin of the igneous body.
Three phases of deformation have affected the Corodale Gneiss and are tentatively correlated with Laxfordian deformation phases affecting the rocks below the thrust. The igneous body is cut by dykes and is considered to be a member of a widespread group of basic to intermediate intrusions which post-date the Scourian gneiss-forming events, but pre-date the emplacement of Scourie dykes.
There is evidence for an eastward increase in metamorphic grade during an early Laxfordian episode, prior to the main deformation, and an eastward decrease in metamorphic grade during the three main Laxfordian deformation-phases.
The last glaciers in the Lochnagar area, Aberdeenshire.
Authors: Sissons J. B. , Grant A. J. H. 
Published: January 2010

Synopsis
Moraines in Glen Callater, Glen Muick and the four corries of Lochnagar are used to delimit a glacial readvance. The freshness of the forms and their relation to large solifluction lobes imply that the readvance is the Loch Lomond or Zone III Readvance. The very different type of interpretation recently given by Sugden for the adjacent Cairngorm area is discussed and rejected.
Zinnwaldite granite from Glen Gairn, Aberdeenshire
Authors: Hall A. , Walsh J. N. 
Published: January 2010

Synopsis
Zinnwaldite granite occurs in Glen Gairn, Aberdeenshire. Chemical analyses of both the granite and the zinnwaldite are given, and it is suggested that there may be an affinity between this granite and the mineralisation observed in neighbouring areas.
The Late Precambrian/Lower Cambrian Bonahaven Dolomite of Islay and its stromatolites
Authors: Spencer Anthony M. , Spencer Margaret O. 
Published: January 2010

Synopsis
The Bonahaven Dolomite (?295 m thick) lies in the Dalradian sequence between the Port Askaig Tillite (beneath) and the Jura Quartzite (above) and is best developed on Islay (Inner Hebrides). The sequence in the formation at five coastal outcrops is figured and four members erected. Member 3 (?150 m thick) contains stromatolite structures at ten horizons. These are described in terms of their bed geometry (laterally continuous, discontinuous), lamination (0.5–2 mm thick) and growth structures (stratiform, laterally linked hemispheroids, columnar, irregular). Ptygmatic sandstone crack–structures are ubiquitous in thinly interbedded sandstone/siltstone beds; they are thought to be subaqueous contraction cracks. The apparent palaeoclimatological contradiction posed by a dolomite overlying a tillite is discussed, and it is suggested that late Precambrian dolomites may not have needed a warm climate to form.