Lower Permian volcanism was the first magmatic activity to occur after the collision events in the Mongolian orogenic zone, east China. The Permian volcanic rocks are therefore a key to understanding the dynamics of the unified continental lithosphere. The volcanic rocks consist of basic and intermediate rocks. The intermediate rocks with high initial 87Sr/86Sr ratios (0.7051 to 0.7052) and low εNd values (−0.73 to −3.57) generally overlie the basic rocks in the field. The basic rocks have relatively low initial 87Sr/86Sr ratios (0.7034 to 0.7051) and high εNd values (2.72 to −0.10). Two parallel Rb–Sr isochrons give almost the same age, about 270 Ma. One consists of the basic rocks giving an initial isochron 87Sr/86Sr ratio of 0.7035. The other consists of the intermediate rocks and one sample of basalt, which give an initial isochron 87Sr/86Sr value of 0.7051. The strong correlations between SiO2 and other major elements suggest that fractional crystallization played an important role in the magmatic processes. However, fractional crystallization cannot explain the geochemistry of most incompatible trace elements and Sr–Nd isotope characteristics. The positive correlation between Th/Nb and (La/Sm)N ratios demonstrates the direct relation between the enrichment of the light rare earth elements and the contamination of continental sediments. The high contents of large ion lithosphere elements (LILE) in the Permian volcanic rocks may suggest an additional ‘crust + fluid’ component, especially in the intermediate rocks, which are highly enriched in Ba (> 400 ppm) relative to the basic rocks (> 200 ppm). We propose that the subduction slab dropped into depleted mantle and released fluid, which induced the mantle metasomatism and LILE enrichment. The metasomatized mantle partially melted and formed the ‘primary’ magma. This primary magma assimilated with the Proterozoic biotite–quartz schist during its rise, and finally formed the Permian volcanic rocks. Magma assimilated with the Proterozoic biotite–quartz schist in small amounts could have produced the basic rocks, while assimilation of larger amounts of magma (because of longer assimilation time) would generate intermediate rocks.

Late Cretaceous–Early Eocene Tethyan evolution of western Turkey is characterized by ophiolite obduction, high-pressure/low-temperature metamorphism, subduction, arc magmatism and continent–continent collision. The imprints of these events in the Upper Cretaceous–Lower Eocene sedimentary record of western Anatolia are studied in thirty-eight well-described stratigraphic sections. During the Late Cretaceous period, western Turkey consisted of two continents, the Pontides in the north and the Anatolide-Taurides in the south. These continental masses were separated by the İzmir-Ankara Neo-Tethyan ocean. During the convergence the Pontides formed the upper plate, the Anatolide-Taurides the lower plate. The arc magmatism in the Pontides along the Black Sea coast is biostratigraphically tightly constrained in time between the late Turonian and latest Campanian. Ophiolite obduction over the passive margin of the Anatolide-Tauride Block started in the Santonian soon after the inception of subduction in the Turonian. As a result, large areas of the Anatolide-Tauride Block subsided and became a region of pelagic carbonate sedimentation during the Campanian. The leading margin of the Anatolide-Tauride Block was buried deeply and was deformed and metamorphosed to blueschist facies during Campanian times. The Campanian arc volcanic rocks in the Pontides are conformably overlain by shaley limestone of Maastrichtian–Palaeocene age. However, Maastrichtian sedimentary sequences north of the Tethyan suture are of fore-arc type suggesting that although arc magmatism ceased by the end of the Campanian age, continent–continent collision was delayed until Palaeocene time, when there was a change from marine to continental sedimentation in the fore-arc basins. The interval between the end of the arc magmatism and continent–continent collision may have been related to a northward jump of the subduction zone at the end of Campanian time, or to continued obduction during the Maastrichtian.

Throughout the 1300 km long East Greenland Caledonides, the western exposed marginal thrusts overlie foreland rocks of latest Neoproterozoic–Early Palaeozoic age, mainly exposed in tectonic windows. In the western, 100–130 km wide, marginal thrust belt, the thrust planes outlining the windows appear to follow long flats developed in Lower Palaeozoic carbonates. East of the marginal thrust belt, thrust inclinations steepen, and by implication the remaining part of the Caledonian orogen extending eastwards to the present Atlantic Ocean coast is allochthonous and thick-skinned. The contrast between the restricted Neoproterozoic–Lower Palaeozoic foreland succession and the very thick and almost continuous sedimentation of the allochthonous Neoproterozoic Eleonore Bay Supergroup–Tillite Group–Cambro-Ordovician sequence of the fjord zone of East Greenland confirms the presence of distinct N–S trending facies belts on the northwestern passive margin of Iapetus. Comparisons with the Caledonides of Northwest Scotland, which may originally have lain as little as 500 km south of the East Greenland Caledonides, provide further clues to the understanding of Neoproterozoic–Early Palaeozoic basin geometry on this sector of the developing Iapetus margin. The areas of the Laurentian margin represented in the foreland windows of East Greenland were inboard of Neoproterozoic rifting but, with respect to the Torridonian basins of Northwest Scotland, the Eleonore Bay Supergroup succession must have been laid down further outboard. Similarly the Lower Palaeozoic developments of the foreland of Northwest Scotland are thicker than the equivalent foreland sequences of East Greenland, but much thinner than the allochthonous East Greenland Cambro-Ordovician succession.

The presence of alluvial fan deposits in the lower Neoproterozoic Torridon Group in northwest Scotland illuminates Torridonian basin development at the eastern Laurentian margin. The 450 m thick Cape Wrath Member of the Applecross Formation consists of alluvial fan conglomerate and arkose succeeded by more distal, braidplain feldspathic sandstone. Palaeocurrent data comprising >2650 measurements on trough cross-bedding are of low variability and show overall eastward flow. The projection upcurrent of regionally divergent flow directions for the lower part of the member indicates a fan of c. 50 km radius with its apex 30 km to the west near a basement (pre-Caledonian) normal fault with downthrow to the east beneath the north Minch Basin. Extensional tectonics controlled deposition of the Applecross Formation. Regional uplift, causing erosion of a youthful topography on the Lewisian Gneiss, was followed by the development of the Applecross extensional basin in two main stages. Uplift of a western source area by movement on basin-bounding normal faults occurred first in the north and caused pediplanation and alluvial fan deposition in the Cape Wrath area, with subsequent uplift of the source area for the main body of the Applecross Formation occurring further to the west and south along the line of the Minch Fault. The bulk of the Applecross Formation was derived from a weathered terrain of felsic crystalline and related supracrustal rocks reaching from the Outer Hebrides region westward for up to c. 250 km onto what are now the continental margins of the North Atlantic. The tectonic events may mark an early phase in the crustal extension that led ultimately to the opening of the Iapetus ocean.

The Kula volcanic province lies in an area of active normal faulting in western Turkey. In this study, we show that the interaction of the basalts with the local drainage, and in particular the Gediz river, can be used to determine the history of fault movements downstream. The lava flows have been studied previously, and some of them dated. We use these results and combine them with new field observations of lavas that flowed into the river valley to measure the rate of down-cutting of the river and hence the rate of uplift of the footwall block due to movement of the graben-bounding fault. We show that there has been, in general, an acceleration of fault movement with time during the last 2 Ma. This increased activity of the graben-bounding fault is matched by an intensification of volcanic activity. An inferred four-fold increase in fault movement rate over the last 0.2 Ma has been matched by a similar increase in volume of volcanic activity.

The Slieve League Peninsula of northwest Ireland lies on the western limb of a major orogenic strike-swing in which regional foliation trends have deviated from the northeast–southwest trends typical of much of Scotland, to west–east orientations. Across-strike coastal exposures on the western tip of the peninsula through Neoproterozoic Dalradian metasediments enable a detailed examination and analysis of the structural evolution of a Caledonian orogenic root zone which has been previously correlated with the Loch Awe Syncline of southwest Scotland. Minor structural development may be evaluated in terms of regional strain profiles and overprinting relationships. Over much of the area, a composite, steep northeast–southwest-trending S2–S3 foliation containing a gently southwest-plunging quartz mineral elongation lineation is the dominant fabric at outcrop, and is associated with MP2 almandine–amphibolite facies metamorphism. F2 folds are isoclinal with curvilinear hinges and similar geometry. They typically plunge steeply towards the southwest and display variable (dextral) or north-directed vergence, whilst minor F3 fold hinges plunge moderately towards the southwest and typically verge (sinistrally) towards the south. Major, composite D1–D3 tectonic slides are developed in the Argyll Group. Structural and stratigraphic relationships indicate that D1 induced large-scale reversals in younging across tectonic slides, resulting in reversals in subsequent F2 and F3 facing patterns. Tectonic sliding is associated with an intensification of strain demonstrated by increasingly intrafolial and curvilinear folding, together with extensional crenulations, sheared quartz pods and metre-scale asymmetric boudinage of metadolerites, all of which indicate dextral (D2) and sinistral (D3) shear. After unfolding subsequent folds (F4), this corresponds to top-to-the-north (D2) and top-to-the-south (D3) translations. D4 results in regionally northwest-verging structures, with minor crenulations and the S4 cleavage transecting fold hinges in an anticlockwise sense, suggesting a dextral component of deformation. The detailed kinematic data indicate that the overall geometry of this western, deep-level arm of the root zone is not a product of the classic mushrooming fountain of nappes model, but rather major interference between consistent northerly directed D2 thrusting and a later phase of southeast-directed (D3) retrocharriage (‘back-folding’) which intensifies towards the south.

The range of Treptichnus pedum, the index trace fossil for the Treptichnus pedum Zone, extends some 4 m below the Global Standard Stratotype-section and Point for the base of the Cambrian Period at Fortune Head on the Burin Peninsula in southeastern Newfoundland. The identification of zigzag traces of Treptichnus isp., even further below the GSSP than T. pedum in the Fortune Head section, and in other terminal Proterozoic successions around the globe, supports the concept of a gradational onset of three-dimensional burrowing across the Proterozoic–Cambrian boundary. Although T. pedum remains a reasonable indicator for the base of the Cambrian Period, greater precision in the stratotype section can be achieved by a detailed re-evaluation of the stratigraphic ranges and the morphological variation of ichnotaxa included in the T. pedum Zone.