bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new high-resolution aeromagnetic dataset over central Ayrshire: insights into the concealed geology
Authors: Busby J. P. , Akhurst M. C. , Walker A. S. D. 
Published: January 2010

Synopsis
High-resolution aeromagnetic data have been acquired over central Ayrshire as part of a multi-component environmental and resource survey. The data were recorded along easterly orientated flight lines at 200 m separation and show a very marked improvement in resolution over the pre-existing aeromagnetic data for the region. The distribution of the extensive volcanic and intrusive igneous rocks in the near sub-surface is defined more accurately, many new features are recognized and features distinguished in the pre-existing aeromagnetic data are now seen to be laterally continuous. Northwesterly trending lineaments are clearly defined and most can be attributed to Palaeogene dykes, the majority of which are reversely magnetized. Depth to source solutions and modelling suggest that even though the dykes have a limited width at outcrop, their widths increase with depth. Permo-Carboniferous easterly trending dykes are not well resolved in the new aeromagnetic data. This is most likely due to a low amplitude resultant magnetic vector that, combined with the easterly-orientated flight lines, results in few large anomalies. One significant northwesterly trending lineament is interpreted as the trace of the Cleveland Dyke across the Midland Valley. These new data should be of value to the extractive and water industries and assist in the planning and sustainable management of these resources.
The Cluanie granodiorite, NW Highlands of Scotland: a late Caledonian pluton of trondhjemitic affinity
Authors: Neill I. , Stephens W. E. 
Published: January 2010

SynopsisThe Cluanie Pluton is a late Caledonian granitoid emplaced into the Glenfinnan Division of the Moine Supergroup in the NW Scottish Highlands. A field investigation of the pluton and its internal facies is presented along with new major- and trace-element whole-rock XRF analyses, and geobarometric and geothermometric studies. Cluanie is predominantly composed of hornblende granodiorite characterized by varying concentrations of distinctive alkali feldspar megacrysts, with minor amounts of biotite granodiorite and rare mingled porphyritic microgranodiorite. The alkali feldspar megacrysts appear to be magmatic in origin. Rare spectacular pegmatitic concentrations most likely represent physical accumulation of the megacrysts. The pluton is geochemically a high Na/K trondhjemite, the only such pluton known among the Newer Granites of Scotland. On the basis of geochemical evidence and a comparison with partial melting experiments, we propose that the magmas were derived by fluid-rich melting of an amphibolitic source leading to relatively low temperature magmas which were significantly contaminated by Moine metasediments. The pluton was emplaced in the mid crust at about 4.3 kbar during an episode of dextral shear on the Glen Glass Fault related to regional strike-slip faulting on the Great Glen Fault system atc. 425 Ma.
The Highland Border Ophiolite of Scotland: observations from the Highland Workshop field excursion of April 2008
Authors: Henderson W. G. , Tanner P. W. G. , Strachan R. A. 
Published: January 2010

Synopsis
In April 2008, 23 attendees of the Highland Workshop visited critical localities of the Scottish Highland Border Complex between Aberfoyle and the Isle of Bute. Widespread existence of fragmental ophicarbonates was confirmed, with the possibility that at least some may have formed as fault gouges in an ocean–continent transition environment similar to those reported from serpentinites in Ligurian-type extensional continent–ocean margins. The consensus view was that amphibolites at Loch Ard and on Bute appear to have been at no higher metamorphic grade than epidote-amphibolite facies. Also that, narrow zones of ‘granitoid rocks’ and spotting in Dalradian rocks in contact with ophicarbonate rocks could represent relatively low Barrovian regional metamorphic temperature effects rather than evidence for contact metamorphism in the sole of an obducted ophiolite. Finally, the Highland Border Ophiolite appears to have originally overlain the Southern Highland and Trossachs groups and was rotated with them by the D4 Downbend Antiform. No evidence was seen at these localities to support the hypothesis that the Highland Border Complex youngs to the NW or did not undergo Grampian deformational events.
Digital surface models and the landscape: interaction between bedrock and glacial geology in the Ullapool area
Authors: Goodenough K. M. , Krabbendam M. , Bradwell T. , Finlayson A. , Leslie A. G. 
Published: January 2010

Synopsis
The front cover image for this volume is a hill-shaded digital surface model (DSM) of the Ullapool area, created using NEXTMap Britain elevation data from Intermap Technologies. This is a classic area for bedrock geology, transected by the Moine Thrust Zone, and in recent years it has also been studied in detail for its glacial history. Perhaps equally important, this is one of Scotland's most iconic landscapes. The geology of the area comprises a number of distinct sequences, each of which has a characteristic landscape expression as illustrated by the DSM. This paper considers the influence of the bedrock geology on the glacial geomorphology, and shows that the interplay of the two has led to the development of the different landscape elements of this spectacular area. Surprisingly, it is not always the major geological features – such as the Moine Thrust – that have the strongest topographic expression.
The layered ultrabasic rocks of Sgurr Dubh, Isle of Skye
Authors: Weedon Douglas S. 
Published: January 2010

Synopsis
The Sgurr Dubh ultrabasic rocks show many features indicative of bottom accumulation of cumulus crystals from a basaltic or picritic magma.
Dunites are common towards the base of the layered sequence, intercumulus feldspar and clinopyroxene becoming more plentiful as the sequence is ascended. Chromite bands are common within the dunitic rocks. In the higher structural levels, cumulus feldspar crystals appear with the olivines, and layered structures, comprising alternating feldspar-rich and olivine-rich bands, here become common.

Optical studies of the component minerals, together with four analyses of selected rocks, indicate a small, albeit significant, cryptic variation throughout the mass—olivine from Fa
13
to Fa
16.5
, feldspar from An
85
to An
80.

Diffusion within intercumulus material is considered the most probable explanation for the local formation of dunites. Comparison with the layered ultrabasic rocks of Rhum indicates that the Skye ultrabasic rocks crystallized at somewhat higher temperature, and that a longer temperature interval ensued between the crystallization of the olivines and the feldspars, a factor considered important in explaining the formation of dunites within the Skye rocks.
Auto-brecciation and segregation-veins are common in parts of the mass, and there is evidence that marginal movements have occurred. The ultrabasic rocks are considered to have formed by crystal accumulation affected by various physical processes; they appear also to represent a magmatic disconformity within the sequence of basic igneous intrusions of the Cuillin.
Some structural features of the Caledonian granitic complex at Strontian, Argyllshire
Authors: Munro M. 
Published: January 2010

Synopsis
This complex consists of two main units—a mass of granodioritic rock, which has a non-porphyritic, tonalitic margin grading into a porphyritic core, and contains planar, and locally linear, flow structures, and a mass of virtually structureless biotite granite, which is bordered by a zone of vein-like apophyses. It is surrounded by a zone approximately three-quarters of a mile wide within which the country rock structures have been deflected and deformed. Fractures exploited by the biotite granite, and at various times by aplites and pegmatites, show similarities in orientation. Joints show a different orientation pattern and appear to be largely unrelated in origin to the complex. It is suggested that, firstly the granodioritic, and then the biotite granite magmas ascended within the crust to form stock-like bodies, and that in the former case a tongue-like extension to the north occurred, possibly under tectonic control.
White trap in some Ayrshire Coals
Authors: Mykura W. 
Published: January 2010

Synopsis
Small intrusions of basic igneous rock in certain coals in the West Ayrshire coalfield occur as discrete bodies of white trap. In the Sillyhole Coal near Dalmellington these bodies are either horizontally elongated varying in shape from lenticular to nearly spherical, or small, vertically elongated and of more irregular shape.
The coal is altered to vesicular natural coke with polygonal jointing, the axes of the coke polygons being curved so as to be normal both to the margins of the seam and to the junction with the white trap. The combined thickness of the seam of coal and white trap is always greater than the thickness of the same seam in an unaltered state, the total thickness being directly proportional to the amount of white trap present in the seam.
Coals containing white trap bodies of this type passed through a plastic phase when magma was being intruded. During this period the horizontally elongated white trap bodies were formed, their mode of formation being analogous to that of pillow lavas. With rising temperature the coal re-solidified and shrank to form coke polygons, the magma filling joints between polygons and locally expanding to form the vertically elongated white trap bodies.
The Bearreraig Sandstone Series (Middle Jurassic) of Skye and Raasay
Authors: Morton Nicol 
Published: January 2010

Synopsis
The Bearreraig Sandstone Series crops out in north-east Skye, Raasay and Strathaird. In Strathaird the extremely rapid variations in thickness and lithology suggest near-shore deposition. In Raasay the northward increase in the proportion of bioclastic material suggests derivation of terrigenous material from a main source to the south. In north-east Skye, however, the dominant features of sedimentation can be traced over a wider area, suggesting that the area was less influenced by strictly local factors.
There were two main basins, one in north Skye, and the other in Raasay and Strathaird, separated by an area of relatively slow subsidence in the area between Raasay and north-east Skye.
In north-east Skye most of the ammonite zones have been located, but in Raasay and Strathaird, where much of the series is cross-bedded, only some zones can be identified. The base of the cross-bedded rocks is diachronous.
There are three sedimentary cycles, with a sharp change to shale at the base, followed by a gradation to sandstone. The bases of the cycles coincide with changes in the ammonite faunas, and can be correlated with transgressions in other areas.
The sedimentology and diagenesis of Silurian turbidites in South-east Wigtownshire, Scotland
Authors: Rust B. R. 
Published: January 2010

Synopsis
Sedimentary features of a marine Silurian sequence in south-west Scotland indicate transport and deposition by turbidity currents. Directional sedimentary structures at the base and top of graded greywackes show respectively that early erosive phases of the currents travelled from the north-east, whereas later depositional phases came from the north-west. Structures discussed in relation to their possible origin include sand volcanoes and current crescents.
The effects of widespread carbonate replacement and local hematite enrichment are described. There is little evidence in the greywackes for a diagenetic matrix, which is concluded to be largely detrital in origin.
Peat bogs in a Post-glacial sea and a buried raised beach in the western part of the Carse of Stirling
Authors: Sissons J. B. , Smith D. E. 
Published: January 2010

Synopsis
Borehole evidence shows that in the western part of the Carse of Stirling there occurs a buried raised beach whose surface is between about 30 and 36 ft O.D. The beach appears to have been formed after about 10 300 B.P. and before about 9500 B.P., more probably around the latter date. The buried raised beach is normally overlain by peat and this in turn by carse clay. Over part of the area the carse clay is covered by surface peat. In two areas the carse clay is absent and thick peat occurs instead. Part of this thick peat accumulated as the carse clay was being deposited around it.
The structural evolution of the Tarskavaig and Moine nappes in Skye
Authors: Cheeney R. F. , Matthews D. W. 
Published: January 2010

Synopsis
The structural complex comprising the Tarskavaig and Moine nappes of Skye has been re-mapped and analysed in detail. Large scale folds belong to only two generations and these can be correlated with generations of large folds in adjacent mainland areas. Small folds belong to at least four more generations in addition to the two generations already mentioned. Some of these small folds are, however, of little regional importance and are found only in zones of highly deformed rocks. These zones have developed at two separate times in the structural evolution; and, like thrust planes, belong to two other separate periods. General considerations indicate that the displacements on the thrust planes could be very much less than assumed, and there is the possibility that the Loch Alsh fold may well be a late stage structure, in contrast to earlier views.
A note on the age relationships between the Sgurr Dubh Ultrabasic Laccolite and the Cuillin Gabbros
Authors: Gibb Fergus G. F. 
Published: January 2010

Synopsis
The age relationship between the Sgurr Dubh ultrabasic laccolite and part of the surrounding gabbro that was established by Harker has recently been re-examined by Weedon. Weedon does not take into account, however, part of the evidence on which Harker’s original interpretation of the intrusive sequence was based, namely, that sizeable veins of gabbro extend into the peridotite. One such vein is described and Harker’s interpretation of its relationship with the peridotite shown to be wrong.
The limits of the Late-glacial Highland, or Loch Lomond, Readvance along the West Highland seaboard from Oban to Mallaig
Authors: McCann S. B. 
Published: January 2010

Synopsis
The major Late-glacial gravel deposits of Loch Linnhe and the mainland coast of the Firth of Lome, and at the western ends of Loch Morar and Loch Shiel, are described; and it is suggested that they represent the contemporaneous outwash material of the last major Late-glacial readvance of the area. This suggestion of a similar mode of origin for all the deposits involves a modification of earlier views that much of the material is raised beach gravel, and reinforces criticisms, already made, of the methods of correlation used by J. K. Charlesworth to define important Late-glacial stages throughout the Highlands. Nonetheless, the limits suggested by Charlesworth for Stage M (the Loch Lomond or Highland Readvance) which is the major Late-glacial readvance of this part of the western Highlands, is substantiated with only minor modifications.
Dumbarton Rock
Authors: Whyte F. 
Published: January 2010

Synopsis
A study of the attitude of columnar joints in the Dumbarton Rock basalt suggests that the plug is narrowing downwards and could represent an infilled crater.
At a late stage in the volcano’s history, before the emplacement of the plug, subsidence took place along fractures developed around the crater. The narrow strip of pyroclastic rocks and sediments exposed along the north-west shore represents part of this subsided mass.

Chemical analyses of the contact basalt show increasing MgO and H
2
O and decreasing CaO towards the contact. It is thought that the albitised and chloritised contact basalt is due to migration of volatiles towards these contacts.
Nature and origin of Lewisian basic rocks of Gairloch, Ross-shire
Authors: Park R. Graham 
Published: January 2010

Synopsis
A series of basic sheets in the Lewisian complex of the Gairloch area was emplaced prior to the main tectonic phase (1400+m.y.) and metamorphosed in epidote-amphibolite facies. Several different modes of origin have previously been proposed for the various members of this suite, but most of the thinner bodies had been assumed to represent metamorphosed Scourie dolerite dykes although there was no evidence that they were of igneous origin.
The suite is divided into eight types based mainly on macroscopic differences in texture and on the presence or absence of metasediment interlayers, but it is concluded that the marked textural variation is due largely to structural and metamorphic differences rather than to original heterogeneity.
Petrographic data are given, and major and trace-element analyses, with modes and catanorms, presented for nineteen representative samples. It is suggested that in certain cases small changes in composition may have occurred through alkali metasomatism.
A comparison of chemical variation trends with the igneous trends of the Karroo dolerites points to an igneous origin for the Gairloch basites which appear to represent tholeiites and olivine-tholeiites. The thicker bodies are either sills or lavas and the thinner bodies dykes or sills.
On the possible occurrence of Dalradian rocks in the Southern Uplands of Scotland
Authors: Shiells K. A. G. , Dearman W. R. 
Published: January 2010

Synopsis
A structural profile has been constructed across the eastern end of the Southern Uplands. Three areas of distinct structural style are recognised. Two of these areas illustrate structures which can be identified with the end-Silurian orogeny; the third area, comprising the Coldingham nappe, shows evidence of two periods of orogenic deformation, one of which pre-dates the end-Silurian orogeny. The stratigraphical implications of this early deformation are considered, bearing in mind the importance of the position of the Southern Upland region between the Highlands to the north and the remainder of the Caledonide fold-belt to the south.
An ice-wedge and associated phenomena in the Lower Limestone Series of Fife
Authors: McManus John 
Published: January 2010

Synopsis
A previously unrecorded ice-wedge structure in the carbonaceous shales above the Charlestown Main Limestone at Cults, Fife, is described. Associated fracturing and distortion of the bedding are ascribed to an origin during Pleistocene periglacial conditions. Intense fracturing of the uppermost 5 metres of the shales suggests that the active layer penetrated to this depth for some time, its base being marked by sub-horizontal breaks.
Hugh Miller’s Reptile Bed and the Mytilus Shales, Middle Jurassic, Isle of Eigg, Scotland
Authors: Hudson J. D. 
Published: January 2010

Synopsis
The type locality of the Mytilus Shales, the lowest division of the Great Estuarine Series on the Isle of Eigg, is described. A map of the exposures is presented, and the detailed stratigraphy of the beds, which include a bed rich in reptilian bones discovered by Hugh Miller, is expounded for the first time. The outcrop is disturbed by small faults and intrusions and partially obscured, so that the succession has to be constructed from five partial sections. The invertebrate faunas, mainly of brackish-water mollusca, are listed. The Reptile Bed itself, a sideritic shelly limestone, is described in detail. Recent work by others on the reptiles, mainly plesiosaurs, is referred to. The conditions of deposition of the Mytilus Shales and especially of the Reptile Bed are considered and analogies are drawn with the bays of the Florida Everglades.
The Lewisian geology of the area between Loch Shieldaig and Loch Bràigh Horrisdale, Gairloch, Ross-shire
Authors: Ghaly Tharwat S. 
Published: January 2010

Synopsis
The Lewisian rocks between Loch Shieldaig and Loch Bràigh Horrisdale consist mainly of acid gneisses, hornblende schists, metadolerites and pegmatites together with quartzo-felspathic and hornblendic segregation veins, lenses and pods. The structural deformation is shown to have occurred in three phases. The dominant foliation and lineation are the result of deformation during the main phase, the N.W.-S.E. trend of the lithological banding and the present lineation pattern are the result of mid phase deformation, while the open folds, which affect both banding and foliation, are the products of late phase deformation.
The acid gneiss/hornblende schist banded sequence is considered to have been derived from a concordant sequence of sediments and basic masses during main phase metamorphism and felspathisation. Emplacement of basic dykes took place after the mid phase deformation, and the pegmatites were developed by an extension of the felspathisation processes.
Variations within a Scottish Lower Carboniferous lava flow
Authors: MacDonald J. G. 
Published: January 2010

Synopsis
Systematic vertical gradational variations within a ‘hawaiite’ lava flow of Calciferous Sandstone age are investigated. The variations include an increase in the amount of augite, and in the size and anorthite content of plagioclase microphenocrysts upwards through the flow. There are corresponding variations in the chemical composition, particularly in CaO and systematic variations in the oxidation state. It is concluded that the major variations could not have resulted from post-eruptive processes and hence the flow must have been erupted in a differentiated condition. It is thought that the differentiation is most probably the result of selective fusion rather than crystal fractionation and that this mechanism could also explain the variations in the suite to which the differentiated flow belongs.
Torridonian sediments at Enard Bay, Ross-shire
Authors: Gracie A. J. , Stewart A. D. 
Published: January 2010

Synopsis
Two cycles of sedimentation are present in these Precambrian strata. First cycle sediments were lithified and tilted 25–30 degrees to the west before those of the second cycle were deposited.
The first cycle begins with a thin mantle of massive, unsorted gneiss breccia (I) deposited on a hilly, unweathered surface of Lewisian gneiss. Then follow tabular-bedded breccias and red sandstones (IIa) grading upwards and laterally into red mudstone (IIc). A brown mudflow about 32 m thick, containing accretionary lapilli, is intercalated (IIb). These sediments probably margined a sea or lake. Fades IIc is erosively overlain by large-scale planar cross-bedded, medium to coarse-grained red sandstones (III), perhaps of fluvial origin.
Sediments of the second cycle rest on an irregular unconformity cutting both gneiss and first cycle sediments. Tabular-bedded, (locally massive) breccias, containing gneiss, sandstone and breccia clasts (IVa), pass upwards and laterally into red and grey flaggy sandstones and siltstones (IVb). Facies IV originated like facies II. It is erosively overlain by the fluvial trough cross-bedded pebbly red arkoses (V) of the Applecross Formation.
Facies I–IV probably belong to the Geological Survey’s Diabaig Formation. It follows that the ‘Diabaig’ (and the Torridonian) have not the stratigraphic unity implied by the existing nomenclature.