Some 40 brachiopod species are known from the localities of Kilbucho and Wallace’s Cast in the Kirkcolm Formation in the Northern Belt of the Southern Uplands of Scotland. The fauna is diverse despite the relatively small numbers of brachiopod specimens (c. 180) available for study. Much of the fauna was transported downslope and is locally preserved in obtrution deposits. It represents a broad census of outer shelf and upper slope palaeocommunities around this part of the Laurentian margin during the early Katian, and is dominated by relatively small plectambonitoid brachiopods. When compared with other circum-Iapetus assemblages, the brachiopods from the Southern Uplands compare most closely with those from the Bardahessiagh Formation, Pomeroy, Northern Ireland, rather than with adjacent, well-known faunas from the Girvan district, SW Scotland. These new data suggest that this part of the Southern Uplands was located in closer proximity to Pomeroy than Girvan, and located in deep-water environments similar to those in the upper parts of the Bardahessiagh Formation.

Zavitokichnus fusiformis n. igen. et n. isp. occurs in Lower Cretaceous (Valanginian to Hauterivian) limestones of the Fatric Superunit in the Western Carpathians. Typical cross sections of this more or less spiral trace fossil are sometimes U–O–C–S-shaped. In cross-section the trace fossil passes from a simple linear form, and spreads to a wider rolled-up or rolled-out form and then it returns to a linear trace. Spreite-like lamellae are distinguishable on several cross-section examples. The trace fossil was produced by a deposit feeder and it might be classified as a fodinichnion. Z. fusiformis co-occurs with trace fossil associations of Zoophycos, Chondrites, Planolites, Hormosiroidea and Palaeophycus in carbonate sediments of a deep-seated ramp along the margin of the Fatric intrashelf basin.

The Sixth Hutton Symposium on the Origin of Granites and Related Rocks was held on July 2–6, 2007 at the University of Stellenbosch, South Africa, founded on granite, nestled at the feet of towering mountains and fringed by the rolling winelands of the Western Cape. This Special Issue opens with Master’s historical account of how the Cape granites influenced 18th and early 19th century thinking on the origins of these rocks. The fascinating fact is that the granites of the Western Cape were apparently the first intrusive granites recognised outside Britain. The balance of the volume contains a collection of research papers derived from the meeting and illustrates some of the important directions in which granite research may be evolving. One of the characteristics of the papers and talks presented at the meeting was that there seemed to be some shift in interest, away from the crust as a source of granitic magmas and towards mantle rocks that have been metasomatised by subduction-zone fluids or melts. Nevertheless, the crust still holds pride of place as the cradle of granite genesis.

The morphology of the amphibamid temnospondyl amphibian Platyrhinops lyelli from the Middle Pennsylvanian of Linton, Ohio is reassessed from previously described and undescribed specimens. Newly reported or newly significant features include the presence of bicuspid marginal teeth, anteriorly widened frontals, elongate choanae, a broad rhomboidal sphenethmoid and a pair of flattened blade-like ceratohyals. One specimen shows an unusual distribution of tooth sizes along the premaxillaries. No derived characters can be found to justify reference of the species lyelli to the genus Amphibamus as represented by its type species A. grandiceps, but Platyrhinops does belong to the ‘Amphibamus branch’ of the Amphibamidae.

Conodont faunal dynamics and high-resolution biostratigraphy in the lithologically and faunally anomalous ‘Täljsten’ succession, which spans the Darriwilian Lenodus variabilis–Yangtzeplacognathus crassus Zone boundary, were investigated in a 2·5 m-thick section on Mt Kinnekulle that includes an interval yielding fossil meteorites and extraterrestrial chromite. The previous interpretation that this interval reflects a regression is consistent with the occurrence and abundance patterns of some conodont taxa. The disappearance of e.g., Periodon, suggests that the regression began prior to the deposition of the grey ‘Täljsten’. The transition from red to grey limestone coincides with a conspicuous faunal re-arrangement. The lower half of the ‘Täljsten’ reflects a gradual shallowing favourable for some taxa, such as Lenodus, and the immigration of Microzarkodina cf. ozarkodella and Histiodella holodentata. In the middle of the ‘Täljsten’ interval, coinciding with the appearance of abundant cystoids, conditions became less hospitable for conodonts, resulting in a low diversity and low abundance fauna, which occurs to the top of the interval. The overlying red limestone, apparently deposited during a deepening event, marks a return to pre-‘Täljsten’ conditions with a re-organised fauna. The close correlation between the lithologic shifts and conodont faunal changes demonstrates the usefulness of conodonts as environmental indicators.

The Cape Granites are a granitic suite intruded into Neoproterozoic greywackes and slates, and unconformably overlain by early Palaeozoic Table Mountain Group orthoquartzites. They were first recognised at Paarl in 1776 by Francis Masson, and by William Anderson and William Hamilton in 1778. Studies of the Cape Granites were central to some of the early debates between the Wernerian Neptunists (Robert Jameson and his former pupils) and the Huttonian Plutonists (John Playfair, Basil Hall, Charles Darwin), in the first decades of the 19th Century, since it is at the foot of Table Mountain that the first intrusive granites outside of Scotland were described by Hall in 1812. The Neptunists believed that all rocks, including granite and basalt, were precipitated from the primordial oceans, whereas the Plutonists believed in the intrusive origin of some igneous rocks, such as granite. In this paper, some of the early descriptions and debates concerning the Cape Granites are reviewed, and the history of the development of ideas on granites (as well as on contact metamorphism and sea level changes) at the Cape in the late 18th Century and early to mid 19th Century, during the emerging years of the discipline of geology, is presented for the first time.

Foraminiferal, algal and problematica assemblages from the Mississippian (late Viséan and early Serpukhovian) Lower Limestone Formation have been studied in order to validate lithostratigraphical correlations of limestones within the central and western parts of the Midland Valley of Scotland. Analysis of more than 100 outcrops allows recognition of four calcareous microfossil assemblages, which span the late Brigantian and early Pendleian, and enables a detailed correlation to be made within the Central Coalfield (north Lanarkshire) and with the thinner sequences to the west (north Ayrshire), to the south (Douglas area, south Lanarkshire), and to the east (Bathgate area, West Lothian). The age of the Lower Limestone Formation is modified because the upper part of this formation is now assigned to the Pendleian (due to the first occurrences of new foraminiferans and the co-occurrence with the Namurian goniatites), and some individual limestone horizons within the formation are repositioned, or their precise correlation with other limestones is established. A refined stratigraphical framework is proposed for the above noted areas, and a correlation between them and the Pennine region in northern England is proposed, passing through the Archerbeck Borehole sequence in the Scottish Borders.

A specific type of granitoid, referred to as sanukitoid (Shirey & Hanson 1984), was emplaced mainly across the Archaean–Proterozoic transition. The major and trace element composition of sanukitoids is intermediate between typical Archaean TTG and modern arc granitoids. However, among sanukitoids, two groups can be distinguished on the basis of the Ti content of the less differentiated rocks of the suite: high- and low-Ti sanukitoids. Melting experiments and petrogenetic modelling show that they may have formed by either (1) melting of mantle peridotite previously metasomatised by felsic melts of TTG composition, or (2) by reaction between TTG melts and mantle peridotite (assimilation). Rocks of the sanukitoid suite were emplaced at the Archaean–Proterozoic boundary, possibly marking the time when TTG-dominated granitoid magmatism changed to a more modern-style, arc-dominated magmatism. Consequently, the intermediate character of sanukitoids is not only compositional but chronological. The succession of granitoid magmatism with time is integrated in a plate tectonic model where it is linked to the thermal evolution of subduction zones, reflecting the progressive cooling of Earth: (1) the Archaean Earth’s heat production was high enough to allow the production of large amounts of TTG granitoids formed by partial melting of recycled basaltic crust (‘slab melting’); (2) at the end of the Archaean, due to the progressive cooling of the Earth, the extent of slab melting was reduced, resulting in lower melt:rock ratios. In such conditions the slab melts can be strongly contaminated by assimilation of mantle peridotite, thus giving rise to low-Ti sanukitoids. It is also possible that the slab melts were totally consumed in reactions with mantle peridotite, subsequent melting of this ‘melt-metasomatised mantle’ producing the high-Ti sanukitoid magmas; (3) after 2·5 Ga, Earth heat production was too low to allow slab melting, except in relatively rare geodynamic circumstances, and most modern arc magmas are produced by melting of the mantle wedge peridotite metasomatised by fluids from dehydration of the subducted slab. Of course, such changes did not take place exactly at the same time all over the world. The Archaean mechanisms coexisted with new processes over a relatively long time period, even if they were subordinate to the more modern processes.

Two regional-scale, recumbent folds control the structure of the Beinn Udlaidh area, Tyndrum, Perthshire. They reached their maximum development during D2, following the regional metamorphic peak, and are part of a stack of larger SE-facing recumbent folds formed during the ∼470 Ma Grampian Orogeny. The rocks belong to the Neoproterozoic–Lower Ordovician Dalradian Supergroup, and preserve a sedimentary transition between the Grampian Group and the overlying Appin Group. The latter occupies the core of the S-facing, recumbent Beinn Udlaidh Syncline (D2) which, with the underlying complementary Glen Lochy Anticline, is gently folded by a regional-scale structure, the Orchy Dome. The recumbent folds postdate an early fabric (S1), which is generally obliterated by the D2 imprint, but preserved as inclusion trails in regional metamorphic garnets, that are highly oblique to, and wrapped by, S2. It is concluded that the Dalradian rocks described here from below the Iltay Boundary Slide are in structural continuity with those of the Tay Nappe above, and that the Slide represents a structurally-modified disconformity between the Leven Schist (Appin Group) and the overlying Ben Lui Schist (Argyll Group). The Orchy Dome probably influenced the spatial distribution of minor intrusions and explosion vents of the lamprophyre suite.

A detailed account of the morphology and ontogeny of the late Middle Cambrian crustacean †Henningsmoenicaris scutula is presented. Ten successive ontogenetic stages could be recognised in the material collected from various localities in Sweden. Morphogenetic changes include the development of a pair of stalked lateral eyes and the increase in the number and size of appendages and their setal armature. Notably, early stages lack ‘proximal endites’ on all post-antennular appendages; such a spine-bearing endite has previously been thought to appear simultaneously on these limbs. In †H. scutula a single functional endite appears on the third limb in an advanced stage; an additional endite appears on the second limb and, subsequently, further endites appear on more posterior limbs. Furthermore, a single specimen of †Sandtorpia vestrogothiensis gen. et sp. nov. is described. Based on this new information and data of other ‘Orsten’ taxa, particularly those assigned already to the early evolutionary lineage of Crustacea, a small-scale computer-based phylogenetic analysis was performed. This resolved the basal branchings of Crustacea s. l. as follows: †Oelandocarididae (=†Oelandocaris oelandica+†H. scutula+†S. vestrogothiensis)+(†Cambropachycopidae (=†Goticaris longispinosa+†Cambropachycope clarksoni)+ (†Martinssonia elongata+Labrophora (=†Phosphatocopina+Eucrustacea))). Plotting ontogenetic data on the phylogram and comparing the ground pattern at every node led to the detection of three peramorphic heterochronic events in the evolutionary lineage towards Eucrustacea.

In geochemical diagrams, granitoids define ‘trends’ that reflect increasing differentiation or melting degree. The position of an individual sample in such a trend, whilst linked to the temperature of equilibration, is difficult to interpret. On the other hand, the positions of the trends within the geochemical space (and not the position of a sample within a trend) carry important genetic information, as they reflect the nature of the source (degree of enrichment) and the depth of melting. This paper discusses the interpretation of geochemical trends, to extract information relating to the sources of granitoid magmas and the depth of melting.

%Applying this approach to mid-Archaean granitoids from both the Barberton granite–greenstone terrane (South Africa) and the Pilbara Craton (Australia) reveals two features. The first is the diversity of the group generally referred to as ‘TTGs’ (tonalites, trondhjemites and granodiorites). These appear to be composed of at least three distinct sub-series, one resulting from deep melting of relatively depleted sources, the second from shallower melting of depleted sources, and the third from shallow melting of enriched sources. The second feature is the contrast between the (spatial as well as temporal) distributions and associations of the granites in both cratons.

The Dalradian Supergroup contains three distinct glacigenic units, formerly termed ‘Boulder Beds’, which are correlated with widespread Neoproterozoic glaciations. The oldest and thickest unit, the Port Askaig Formation, marks the Appin–Argyll group boundary of the Dalradian Supergroup and has been correlated with the Middle Cryogenian (Sturtian) glaciation. The Auchnahyle Formation, a diamictite-bearing sequence near Tomintoul in NE Scotland, exhibits strong lithological similarities to the Port Askaig Formation. Both these glacigenic ‘Boulder Bed’ units contain abundant dolomite clasts in their lower parts and more granitic material at higher levels. Both metadiamictite units are overlain by thick shallow-marine quartzite units. C isotope data from Appin Group carbonate strata below the Auchnahyle Formation support this correlation. U–Pb laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) detrital zircon data from the Auchnahyle Formation metadiamictite differ slightly from the Port Askaig Formation, but are similar to detrital zircon spectra obtained from the Macduff Formation, a diamictite unit in the younger Southern Highland Group of the Dalradian Supergroup; both apparently reflect derivation from local basement rocks. No detritus younger than 0·9 Ga is observed, so the data do not constrain significantly the depositional age of the glacial strata. A thin tholeiitic pillow basalt unit in the lower part of the Auchnahyle Formation is geochemically distinct from pre-tectonic metadolerite sills and from basic metavolcanic rocks up-section. A Sturtian (c. 720–700 Ma) age for the Auchnahyle Formation metadiamictite would imply that this basaltic volcanism represents the oldest recorded volcanic activity in the Dalradian Supergroup and is inferred to represent an early, local phase of proto-Iapetan rifting within the Rodinian supercontinent.

Many continental flood basalt provinces contain rhyolites with ‘A-type’ compositions and many studies have concluded that these higher silica rocks are crustal melts from metapelitic or tonalitic country rock. However, although many of the low-Ti continental flood basalt sequences exhibit a marked a silica gap from ∼55–65 wt. SiO2, many incompatible element ratios, and the calculated eruption temperatures (950–1100°C) are strikingly similar between the rhyolites and associated basalts. Using experimental evidence, derivation of the low-Ti rhyolites from a basaltic parent is shown to be a viable alternative to local crustal melting. Comparison of liquid compositions from experimental melting of both crustal and mantle-derived (basaltic) source materials allows the two to be distinguished on the basis of Al2O3 and FeO content. The basalt experiments are reversible, such that the same melts can be produced by melting or crystallisation. The effect of increased water content in the source is also detectable in the liquid composition. The majority of rhyolites from continental flood basalt provinces fall along the experimental trend for basalt melting/ crystallisation at relatively low water content. The onset of the silica gap in the rhyolites is accompanied by an abrupt decrease in TiO2 and FeO*, marking the start of Fe–Ti oxide crystallisation. Differentiation from 55–65 wt. SiO2 requires ∼30 fractional crystallisation in which magnetite is an important phase, sometimes accompanied by limited crustal contamination. The rapid increase in silica occurs over a small temperature interval and for relatively small changes in the amount of fractional crystallisation, thus intermediate compositions are less likely to be sampled. It is argued that the presence of a silica gap is not diagnostic of a crustal melting origin for either A-type granites or rhyolites in continental flood basalt provinces. The volume of these rhyolites erupted over the Phanerozoic is significant and models for crustal growth should take this substantial contribution from the mantle into account.

The authors revise the occurrences of burrow networks with striated walls having dominantly transverse to oblique striae, which have been assigned to the ichnogenera Spongeliomorpha Saporta, 1887, and Steinichnus Bromley & Asgaard, 1979. The taxonomic status of the ichnogenus Steinichnus Bromley & Asgaard, 1979 is examined and it is suggested that this ichnogenus is a subjective junior synonym of Spongeliomorpha Saporta, 1887. Spongeliomorpha is best reserved for an unlined network of burrows having distinct surface ridges or grooves of different orientation and massive filling. The diagnosis of Spongeliomorpha is emended accordingly and the proposed ichnospecies revised for consistency with the diagnostic features of the ichnogenus. Spongeliomorpha milfordensis Metz, 1993a is considered a subjective junior synonym of Spongeliomorpha carlsbergi (Bromley & Asgaard, 1979) after a visual comparison and statistical analysis of the angle of striation with respect to the burrow midline in the type material. Nevertheless, the use of statistical techniques is not advocated for distinction of ichnotaxa, but may support observations. Spongeliomorpha carlsbergi is considered as an indicator of nonmarine settings and was probably produced by burrowing insects. Proposed ichnospecies of Spongeliomorpha that fit the emended diagnosis include S. sudolica (Zaręczny, 1878); S. iberica Saporta, 1887; S. sicula D’Alessandro & Bromley, 1995; S. chevronensis Muñiz & Mayoral, 2001; and Spongeliomorpha isp. nov. aff. sicula Lewy & Goldring, 2006.

Dispersed spore assemblages have been recovered from the Am Binnein Sandstones from the upper part of the ‘Lower Old Red Sandstone’ sequence on the island of Arran, Scotland. The spore assemblages belong with the Emphanisporites annulatus–Camarozonotriletes sextantii (AS) Spore Assemblage Biozone (SAB), indicating an Early Devonian, Emsian (but not earliest Emsian or latest Emsian) age. This is the first reliable age constraint for the ‘Lower Old Red Sandstone’ of Arran, and enables correlation with the more extensive sequence developed on the mainland in the Midland Valley of Scotland. The Am Binnein Sandstones are confirmed as correlatives of the Strathmore Group.

Partial melting of metapelitic rocks beneath the mafic–ultramafic Rustenburg Layered Suite of the Bushveld Complex in the vicinity of the periclinal Schwerin Fold resulted in a structurally controlled distribution of granitic leucosomes in the upper metamorphic aureole. In the core of the pericline, subvertical structures facilitated the rise of buoyant leucosome through the aureole towards the contact with the Bushveld Complex, with leucosomes accumulating in en-echelon tension gashes. In a subhorizontal syn-metamorphic shear zone to the southeast of the pericline, leucosomes accumulated in subhorizontal dilational structural sites. The kinematics of this shear zone are consistent with slumping of material off the southeastern limb of the rising Schwerin pericline. The syndeformational timing of leucosome emplacement supports a syn-intrusive, density-driven origin for the Schwerin Fold. Modelling of the cooling of the Rustenburg Layered Suite and heating of the floor rocks using a multiple intrusion model indicates that temperatures above the solidus were maintained for >600,000 years up to 300 m from the contact, in agreement with rheological modelling of floor-rock diapirs that indicate growth rates on the order of 8 mm/year for the Schwerin Fold.

Trace element inversion modelling of Grenvillean anorthosite massifs and associated rocks yield NMORB-normalised trace element profiles enriched in highly incompatible elements; commonly with negative Nb and Th anomalies. Model melts can be divided into subtypes that cannot be linked through fractional crystallisation processes. Most model melts are depleted in the heavy rare-earth elements and can be explained by partial melting of arc basaltic sources (5–60 melting ) with garnet-bearing residues. Some of the model melts have flat NMORB-normalised profiles (for rare-earth elements), have high compatible element contents, and might have been derived from mantle fertilised by arc magmatism, followed by low-pressure fractional crystallisation. Intermediate Ce/Yb types may represent mixtures of these end-members, or less probably, variations in the crustal source composition and residual assemblage. The active tectonic context now favoured for the Grenville Province appears to be inconsistent with plume or thermal insulation models. The heat source for crustal and mantle melting could record either post-orogenic thermal relaxation of a tectonically-thickened arc crust, or basaltic underplating caused by delamination of a mantle root or subduction slab beneath this arc crust. In this context, pre-Proterozoic anorthosites may be lacking, because prior to ca. 2·5 Ga, the crust may have been too weak to be thickened tectonically. The absence of post-Proterozoic anorthosites may be due to the secular decrease in radiogenic heating and cooling of the mantle and crust.