bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stratabound mineralisation in Dalradian rocks near Tyndrum, Perthshire
Authors: Fortey N. J. , Smith C. G. 
Published: January 2010

Synopsis
Two horizons of low-grade stratabound sulphide mineralisation occur east of Tyndrum in the Ben Challum Quartzite, a newly recognised formation in the Argyll Group (Middle Dalradian). The lower horizon exceeds 9 km along strike and averages 1250 ppm Zn and 340 ppm Cu over an 80 m intersection. The upper extends for 4 km and locally contains up to 3.6% Zn over 1 m. Both comprise stratiform pyrite with minor pyrrhotite, sphalerite and chalcopyrite, in quartzite with possible meta-chert and subordinate schists, and contain manganese-enriched garnet. Sphalerite and galena in the upper horizon are associated with microcrystalline quartz and siliceous breccia interpreted as relict hydrothermal rocks. The Ben Challum Quartzite is in part highly albitic and includes bands of hornblende-schist with tholeiitic composition, some of which probably formed as basic tuff or volcanic sediment. The basal part of the overlying Ben Lui Schist includes sediment carrying talc, magnesite, chromite and Ni-sulphides which probably derived from altered ultramafic rocks. The Zn–Cu–Pb mineralisation is considered to be of the sedimentary-exhalative type, deposition occurring during a regime of fault-bounded subsidence prior to the turbiditic sedimentation of the Ben Lui Schist.
On the origin and stability of remanence and the magnetic fabric of the Torridonian Red Beds, NW Scotland
Authors: Torsvik T. H. , Sturt B. A. 
Published: January 2010

Synopsis
Primary (compactional) magnetic fabrics and multicomponent remanences are recognized in the Stoer and Torridon Groups. Low temperature (LT) blocking remanences are randomized around 400–600°C and relate to a post-Torridonian magnetic overprint, possibly of early Mesozoic age. In the Stoer Group (and some Stoer boulders in the basal Torridon Group) LT remanences are partly or fully carried by magnetite (titanomagnetite). High temperature (HT) remanences are characterized by discrete unblocking above 600°C, having a specular haematite remanence carrier. Results of a conglomerate test of some Stoer boulders provides a positive stability test for HT remanences in the Torridon Group, and a convergence of evidence suggests that remanence acquisition of both the Stoer and Torridon Groups was facilitated by both detrital and early diagenetic processes. A fold test of the Stoer boulders (inclination data) indicates that the boulders have preserved a primary HT remanence. Secondary fabric is readily observed in the boulders, hence, HT remanences most likely reside in different grain- or mineral fractions than the bulk susceptibility.

The overall palaeomagnetic data (HT remanences), indicates that the angular unconformity, separating the Stoer and Torridon Groups, represents a considerable period of time. Palaeomagnetic results from the underlying Lewisian basement have traditionally been interpreted in terms of post-orogenic uplift associated with the Laxfordian event (
c.
1800–1400 Ma). Due to an apparent polar fit between Lewisian and Stoer Group data, we address the question as to the significance of post-Laxfordian magnetic overprinting in the Lewisian Complex.
The metamorphic rocks of the Scaraben area, East Sutherland and Caithness
Authors: Strachan Robin A. 
Published: January 2010

Synopsis
The Scaraben area contains a continuous sequence of metasediments which include psammites and semi-pelites, of undoubted Moine affinities, and the Scaraben Quartzite which several workers have assigned to the Dalradian. These metasediments have undergone a common tectono-metamorphic history, involving four phases of deformation (D1–D4) and associated amphibolite-facies metamorphism. Four different phases of granite intrusion have been identified. The Scaraben Quartzite is assigned to the ‘old Moine’ of the Northern Highlands: there is no evidence that it is an outlier of the Dalradian NW of the Great Glen Fault.
The concealed coalfield at Canonbie: an interpretation based on boreholes and seismic surveys
Authors: Picken G. S. 
Published: January 2010

Synopsis
A concealed coalfield at Canonbie has long been considered likely. Recent work, in conjunction with provings made in the 1950s, has shown the coalfield to exist and to be larger than most early workers envisaged. The structure of the coal bearing Carboniferous rocks is complicated, but concealed by the relatively undisturbed beds of the unconformably overlying New Red Sandstone. Although the limits to the coalfield have not yet been established, the work to date has shown there to be sufficient coal to consider the possibility of a major mining operation at some time in the future.
Magmatic and metasomatic differentiation in the petrogenesis of Archaean metabasites from Tigharry, North Uist
Authors: Williams Patrick J. 
Published: January 2010

Synopsis
The polymetamorphic supracrustal sequence at Tigharry, North Uist is associated with amphibolites, garnet–amphibolites, biotite–amphibolites, cummingtonite–garnet amphibolites, actinolitic hornblende–chlorite rocks and dolomite–actinolite–anthophyllite–chlorite rocks. These are a cogenetic group of tholeiitic basic and ultrabasic rocks belonging to the Archaean “banded basic” suite of the Lewisian complex in the Outer Hebrides. Diverse metabasite assemblages and cryptic variations of mineral composition are controlled by strong, predominantly magmatic chemical differentiation and the geochemistry is very similar to that of layered ultramafic/gabbro bodies of the mainland Lewisian complex. Volumetrically less important anthophyllite/gedrite–andesine–kyanite–phlogopite–quartz rocks and hornblende–anthophyllite–garnet–labradorite–staurolite–quartz rocks which have been described previously as metasediments are texturally and compositionally members of the basic/ultrabasic suite. The chemistry of these orthoamphibole-bearing rocks is not purely magmatic and reflects metasomatism (essentially Ca-depletion) of basic material either before or during metamorphism. Chlorite and biotite-rich assemblages including some with large garnets may also be of partially metasomatic derivation. The prograde assemblages of the basic rocks equilibrated during Proterozoic (Laxfordian) metamorphism under P–T conditions of 600–650°C and 6–9 kb. The associated metapelitic rocks contain kyanite and compositionally heterogeneous garnets whose complex zoning and inclusion fabrics may reflect growth during both the Laxfordian and Scourian metamorphic cycles.
Pleistocene ice-proximal glaciomarine sediments in boreholes from the Hebrides Shelf and Wyville-Thomson Ridge, NW UK Continental Shelf
Authors: Stoker M. S. 
Published: January 2010

Synopsis
Pleistocene sediments recovered in boreholes from the Hebrides Shelf and Wyville–Thomson Ridge indicate ice-proximal glaciomarine deposition in an outer shelf setting. The sediments are predominantly diamicts and in vertical profile display a general upward-fining trend. The lower part of the succession is characterised by a coarse, crudely stratified-to-massive, clast and matrix-supported diamict assemblage which is interpreted as an amalgamated sequence of debris flows. The upper part consists of finer, massive, matrix-supported diamicts deposited mainly from suspension but with a subsidiary input of ice-rafted material. Thin interbedded lag gravels and sandy sediment gravity flows form a minor component of the succession. This kind of succession is usually associated with a stationary or slowly retreating tidewater ice margin. The morphology of the outer shelf is characterised by a relict glaciated terrain; the sedimentary succession suggests that this is of submarine origin. These data indicate that at some time during the Pleistocene an ice-sheet extended out to the edge of the northern Hebrides Shelf and partly onto the Wyville-Thomson Ridge. The age of this glaciation is unknown but probably pre-dates the last Scottish ice-sheet (Late Devensian/Late Weichselian)
Sedimentological evidence for a major subsurface fracture system linking the eastern Campsie and the eastern Ochil faults
Authors: Read W. A. 
Published: January 2010

Synopsis
Evidence for intra-Carboniferous and end-Carboniferous right-lateral strike slip within the Midland Valley is concentrated along lineaments which reflect major subsurface fracture systems. One such lineament runs ENE below the Kincardine Basin and joins the eastern Campsie Fault to the eastern Ochil Fault. This moved right-laterally during the deposition of the Passage Group, as proved by contemporaneous movements of its associated oblique folds.
The hinge line between the Tulliallan Trough ‘low’ and the Bogside Saddle ‘high’ follows this lineament. The ‘low’ controlled the locus of the major Saline Channel Belt throughout most of the Namurian, whereas unusually thick peats commonly accumulated over the ‘high’. Reversals of apparent downthrow along this hinge reflected movements, probably right-lateral strike slip, along the underlying lineament. Low-angle detachments may explain the absence of any major ENE–WSW trending surface fracture above the lineament in the Kincardine Basin.
The lineament, which probably extends WSW below the eastern part of the Milngavie–Kilsyth Fault to underlie the Paisley Ruck, may have been initiated as a Riedel Shear by right-lateral strike-slip along the Highland Boundary Fault, or it may reflect a reactivated Late–Caledonian left-lateral strike-slip fault system.
The petroleum potential of the Old Red Sandstone of northern Scotland
Authors: Trewin N. H. 
Published: January 2010

Synopsis
The Devonian of northern Scotland and the Moray Firth contains lacustrine oil source rocks in both the Lower and Middle divisions. In onshore areas the majority of the source rocks lie in the oil window with the least mature rocks situated both at the basin margin and at the top of the succession in the main basin area which contains thick Middle ORS. Hydrocarbons generated and reservoired in pre-Permian times were probably lost during faulting and erosion episodes at the end of the early Devonian, the end of the mid-Devonian and in Carboniferous-Permian times.
Devonian rocks preserved beneath Permian and Mesozoic basin fills in excess of 2 km in the Inner Moray Firth would have generated hydrocarbons from late Jurassic times onwards. These hydrocarbons could be preserved within fault blocks or have migrated to reservoirs in the Mesozoic as has been postulated in the case of the Beatrice Oilfield.
The most prospective exploration areas for Devonian-sourced oil are considered to be in the Great Glen and Wick Sub-Basins and the Smith Bank Graben.
The early Kimmeridgian ammonite succession at Staffin, Isle of Skye
Authors: Wright John K. 
Published: January 2010

Synopsis
Detailed mapping of the Staffin Shales in the vicinity of the Oxfordian/Kimmeridgian boundary has revealed a succession of ammonite faunas, one of which was only known previously from Greenland. Recognition of distinctive marker bands has enabled correlation of scattered outcrops along 3 km of coastline and has revealed details of the manner of operation of the Quirang landslip.
Barrier island to tidal shelf transition in the early Cambrian Eriboll Sandstone
Authors: McKie Thomas 
Published: January 2010

Synopsis
The Cambrian Eriboll Sandstone, 150–225 m of quartz arenites deposited on the western margin of the Iapetus Ocean, consists of a Lower Member (75–125 m thick) overlain by the Pipe Rock Member (75–100 m thick). The basal 10 m consists of tabular cross-bedded sands deposited within channels of a mesotidal barrier island system. These sands are truncated by an extensive ravinement surface overlain by thin cross-bedded and parallel-bedded shoreface sands with bimodal palaeocurrents. The ravinement surface reflects erosional retreat of the barrier foreshore and upper shoreface during transgression. Lower shoreface deposits were dominated by storm and tidal processes. Palaeocurrents in these were enhanced by superposition of northwards flowing geostrophic storm currents. Shoreface sands pass upwards into tidal shelf sands deposited as dunes and sandwaves. Sandwave cosets thicken upwards in the Lower Member indicating increased tidal current velocities. This may reflect resonant amplification of tides as the shelf became wider during sea level rise.

As the transgression proceeded the bioturbated Pipe Rock was deposited. Proximal deposition was by large compound sandwaves, similar to those below, and grading offshore into small, simple dunes and sandwaves. Distal fades were storm dominated. Both were populated by suspension feeding animals which produced abundant
Skolithos
burrows.
Late Devensian glaciation of southern Caithness
Authors: Hall A. M. , Whittington G. 
Published: January 2010

Synopsis
A formal stratigraphy is proposed for the Quaternary deposits of south-east Caithness. A shelly till from the Moray Firth, the Forse Till, overlies an early till from inland, the Balantrath Till, which demonstrates an expansion of inland ice on to the edge of the plain of Caithness. Along its south-eastern margin the Forse Till is found interbedded with the Balantrath Till in the Dunbeath Water valley and a second inland till, the Ladies’ Tent Till, in the Langwell Water valley. The stratigraphy indicates that Moray Firth ice was contiguous with inland ice at this stage and evidence from striations shows that inland ice was diverted to run northwards parallel to the margin of the inland ice. After retreat of Moray Firth ice there was a minor advance of inland ice in the Berriedale area and formation of hummocky moraine. There is no evidence of any subaerial exposure within till sequences and the tills are therefore related to a single, complex phase of glaciation. The Forse Till and the Ladies’ Tent Till are overlain by peats of Windermere Interstadial age and by gelifluctates of Loch Lomond Stadial age. A variety of relative age criteria indicate that almost all the Quaternary deposits of south-east Caithness are of Late Devensian age.
Pressures and temperatures of Dalradian metamorphism and the andalusite–kyanite transformation in the northeast Grampians
Authors: Beddoe-Stephens B. 
Published: January 2010

Synopsis
Pressures and temperatures have been derived from Dalradian pelitic schists within the area from Tomintoul to the Banffshire coast, predominantly in terrain west of the Portsoy–Duchray Hill lineament and straddling the andalusite–kyanite inversion isograd. These indicate that pressures up to 8–9 kb occur at the base of the Dalradian sequence compared to 4–5 kb immediately west and east of the lineament. There is also a sharp thermal break across the lineament. Replacement of andalusitc by kyanite at Portsoy and further south to the west of the lineament implies that rocks in this area underwent a significant pressure increase. P–T path calculation using garnet zoning confirms this and indicates the increase to have been about 2 kb.

Following
Baker (1987)
it is postulated that the Portsoy lineament represents a thrust plane and that low-P, high-T Dalradian rocks of the Buchan terrain were thrust westwards, deformation that can be related to the local D2 episode. This event postdated emplacement of the Newer Basic masses. Later D3 movements resulted in rapid differential exhumation of the Dalradian which was partly taken up by further shear movement on the Portsoy lineament steepening it to its present attitude.
Former ice movement in Assynt, Sutherland, as shown by the distribution of glacial erratics
Authors: Lawson T. J. 
Published: January 2010

Synopsis
The distribution of glacial erratics shows that at some time in the past the Assynt area has been glaciated by an ice sheet of considerable thickness which, at the glacial maximum, probably covered all but the highest mountains. Whether this was the Late Devensian ice sheet or some earlier glacial phase cannot be determined from the evidence of glacial erratics alone. A model for the development of an ice sheet in this part of Scotland is proposed, whereby initial ice development occurred predominantly on the eastern side of the mountains, with glacial build-up continuing until the ice was thick enough to flow westwards as well as eastwards. The ice divide thus established always lay to the east of the Assynt mountains. The dispersal of erratics appears to have been limited in the ice-shed zone.
Tidal sandbank evolution in the Lower Cambrian Salterella Grit
Authors: McKie Thomas 
Published: January 2010

Synopsis
The Lower Cambrian Salterella Grit is a 0–15 m thick sequence of quartzarenites, siltstones and mudstones and represents an inner shelf tidal sandbank and sandwave complex. The bank facies consists of a coarsening-upward unit up to 15m thick, containing metre-scale cross-bedded sets enclosed by bounding surfaces that dip gently in a direction perpendicular to the palaeocurrent direction. Bank apron sandstones are thinner bedded with a greater proportion of mud-stones, an increased faunal diversity and bimodal palaeocurrents. The Salterella Grit banks were initiated following an abrupt regressive phase, the sediment being derived from local erosion of the underlying Fucoid Beds. During the subsequent transgression the shelf deepened, mean tidal velocities were reduced and the banks became moribund. Moribund bank facies are characterised by thin, highly burrowed sandstones which were deposited on the flanks of banks and in troughs between the banks. Further reduction in tidal currents resulted in the deposition of a thin sandstone sequence of storm origin in the troughs between banks. Nearshore facies are represented by smaller cosets which also show a vertical increase in bioturbation and decrease in thickness.
Authigenic sphene cement in Permian sandstones from Arran
Authors: van Panhuys-Sigler Michéle , Trewin Nigel H. 
Published: January 2010

Synopsis
Permian sandstones from the Cock of Arran area contain small amounts of sphene cement. The sphene occurs as a minor phase (up to 2%) in small patches cementing several grains, and as individual crystals with well developed crystal faces grown into pore space from quartz, feldspar or lithic grain surfaces. The sphene postdates the growth of red grain pellicles and chlorite rosettes and probably formed at a time of calcite dissolution and creation of secondary porosity. Sphene is apparently absent from Permian sandstones at Corrie and Brodick. It is postulated that the sphene was deposited from convective fluids associated with the intrusion of the Arran Granite in Tertiary times. Ti was probably derived from the alteration of Ti-bearing oxides and volcanic rock fragments in the sandstones.
New pollen-stratigraphic evidence for the deglaciation and lake drainage chronology of the Glen Roy-Glen Spean area
Authors: Lowe J. John , Cairns Peter 
Published: January 2010

Synopsis
Pollen-stratigraphic evidence is presented from a number of sites in Glen Roy and lower Glen Treig. The new data do not support the chronology of the Glen Roy-Loch Laggan proglacial lake drainage proposed by Macpherson (1978). The evidence also has a bearing on the controversy over the age of outwash fan deposits in upper Glen Roy, and this problem is re-examined here. Since no Late Devensian Lateglacial deposits are found anywhere in the region, whereas early Flandrian (Holocene) successions are found in several basins, the evidence as a whole is interpreted as indicating that the outwash deposits at the Roy–Turret confluence are of Loch Lomond Stadial age.
Xenoliths in the lamprophyre dykes of Lomondside: constraints on the nature of the crust beneath the southern Dalradian
Authors: Dempster T. J. , Bluck B. J. 
Published: January 2010

Synopsis
Xenoliths within a late-Caledonian lamprophyre dyke intruded into Dalradian metasediments reveal the presence at depth of Dalradian rocks of relatively high regional metamorphic grade and probable Highland Border Complex rocks. The xenolith suite is largely composed of fragments of cognate cumulate rocks together with metamorphosed country rocks both associated with a deep magma chamber. The latter formed close to the Highland Boundary Fault, which dips to the north beneath a thickened Dalradian pile. Pyrope-rich garnets within the xcnocryst assemblage may indicate that the lamprophyre magma originated in high pressure rocks within the mantle.
Geophysical evidence for a concealed Caledonian intrusive body at Sandhead, Wigtownshire
Authors: Kimbell G. S. , Stone P. 
Published: January 2010

Synopsis
A marked magnetic anomaly at Sandhead, 11 km SSE o f Stranraer on the Rhins of Galloway, has been modelled in terms of an intrusive body which rises to within 50 m of the ground surface. Two culminations are apparent but both remain concealed beneath a cover of hornfelsed Ordovician and Silurian grey-wackes. The intrusion seems most likely to be a late Caledonian diorite. The controlling influence on its location and shape was possibly a late phase of dextral shear on the Cairngarroch (Orlock Bridge) Fault.
Geochemistry, weathering and diagenesis of the Diabaig Formation (Torridon Group) in NW Scotland
Authors: Rodd J. A. , Stewart A. D. 
Published: January 2010

Synopsis
The late Proterozoic Diabaig Formation consists of alluvial red breccias and sandstones, and lacustrine grey shales, which accumulated in the lower parts of palaeovalleys eroded in gneiss. The sediments are significantly depleted in Ca and Na with respect to the local gneisses which provided 80% of the sediment. Geochemical mass balance calculations, taken together with the mineralogy, show that these losses occurred mainly during breakdown of plagioclase and amphibole during sediment transport and reworking. Mobilisation of Ca and Na during diagenesis was quantitatively insignificant, despite clear evidence for albitization of detrital plagioclasc. There is no evidence of primary carbonates or evaporites in the shales. The Ca and Na removed from the sediments was lost to a hydraulically open, regionally extensive lake.
Porphyroblast–fabric relationships: an example from the Appin Group in the Glen Roy area
Authors: Phillips E. R. , Key R. M. 
Published: January 2010

Synopsis
The Neoproterozoic Grampian and Appin groups exposed in the Glen Roy area were deformed during an initial progressive tectono–thermal event of the Grampian orogeny. Prograde regional metamorphism to amphibolite facies accompanied deformation with the thermal peak coinciding with the second phase of folding (F2) and the imposition of an S2 crenulation to transposition fabric. In the pelitic to semipelitic schists of the Lochaber Subgroup (Appin Group), metamorphism resulted in the development of the assemblage: quartz + muscovite + biotite ± garnet, plagioclase (An 13 to 22%), staurolite and opaques. The complexity of porphyroblast–fabric relationships recorded from the schists varies systematically across the area and can be directly related to the intensity of S2. Six progressive stages of S2 crenulation cleavage development are recognized, preserved within multitextured, syn-kinematic garnet porphyroblasts. These stages show a progression from a planar S1 fabric to differentiated S2 crenulation cleavage, through to the development of a differentiated S2 transposition fabric. Porphyroblast–fabric relationships are further complicated by the localized reactivation of S1 in response to movement along the Grampian–Appin lithostratigraphic boundary during F2 folding. Biotite porphyroblasts developed early during the imposition of S2 and were subsequently deformed during D2 to form lenticular mica-fish. Staurolite (rare) nucleation and growth, representing peak metamorphism recorded by these schists, post–dated S2 development.