A well-preserved stratigraphic record of the organic carbon isotopic composition across the Precambrian–Cambrian transition has been obtained from a sequence of entirely detrital rocks underlying the Lublin Slope, East European Platform, Poland. The observed δ13C pattern for organic carbon is comparable to isotope data determined for coeval carbonate platform sequences elsewhere. These results underline the truly global nature of these secular variations within the carbon cycle during the terminal Proterozoic and early Cambrian, largely independent of host lithology and facies. The direct combination of micropalaeontological and geochemical results from sedimentary organic matter allows a detailed interpretation of the isotope record as probably caused by secular changes in the net balance of burial and erosion rates of repositories of organic carbon. Furthermore, these variations appear to be directly correlatable with changes in the diversity and abundance of the biota and radiation/extinction events.

Stratigraphic, petrographic and geochemical evidence indicate that the volcano-sedimentary rocks of the Late Devonian Piskahegan Group, located in the northern Appalachians of southwestern New Brunswick, represent the eroded remnants of a large epicontinental caldera complex. This complex – the Mount Pleasant Caldera – is one of few recognizable pre-Cenozoic calderas and is divisible into Exocaldera, Intracaldera and Late Caldera-Fill sequences. The Intracaldera Sequence comprises four formations that crop out in a triangular-shaped area and includes: thick ash flow tuffs, thick sedimentary breccias that dip inward, and stocks of intermediate to felsic composition that intrude the volcanic pile or are localized along caldera-margin faults. The Exocaldera Sequence contains ash flow tuffs, mafic lavas, alluvial redbeds and porphyritic felsic lavas that comprise five formations. The Late Caldera-Fill Sequence contains rocks that are similar to those of the outflow facies and comprises two formations and two minor intrusive units. Geochemical and mineralogical data support the stratigraphic subdivision and indicate that the basaltic rocks are mantle-derived and have intraplate chemical affinities. The andesites were probably derived from basaltic magma by fractional crystallization and assimilation of crustal material. The various felsic units are related by episodes of fractional crystallization in a high-level, zoned magma chamber. Fractionation was repeatedly interrupted by eruption of material from the roof zone such that seven stages of caldera development have been identified. The genesis of the caldera is related to a period of lithospheric thinning that followed the Acadian Orogeny in the northern Appalachians.

The oldest rocks in the Penbegˇli-Tut inlier of southeastern Turkey belong to the Meryemuşagˇi Formation (base not seen); they are mostly clastic rocks of ?late Precambrian age, overlain with angular unconformity by unfossiliferous quartzites (270 m est.) of the Zabuk Formation. The latter unit is succeeded conformably by the Koruk Formation (Lower?/Middle Cambrian), comprising almost 200 m of dolomite and grey and red nodular limestone, and the Sosink Formation (Middle Cambrian), about 600 m of silty mudstone and sandstone with a few thin limestone beds, overlain unconformably by Cretaceous carbonates. The closest comparison is with the Derik-Mardin area, 220 km to the east, where the section is more complete. The upper Koruk Formation contains trilobites of the Pardailhania and Solenopleuropsis biozones; trilobites from the Sosink Formation indicate the Solenopleuropsis Biozone, a post-Solenopleuropsis interval, and a level with Holasaphus mesopotamicus, known only from the Derik area. Acritarchs from the highest Koruk Formation and the whole of the Sosink belong to the lower part of microflora A2, described from the Middle Cambrian of eastern Newfoundland.

Minor Pliocene dacites from Crommyonia mark the western end of the South Aegean volcanic arc. They form small lava domes and flows generally associated with extensional faults. An older group (3.6–4 Ma) occurs in the west and a younger group (2.3–2.8 Ma) in the east. Volcanic rocks of similar age are found at Aegina, Poros and Milos in the western part of the South Aegean arc, whereas volcanism in the eastern part of the arc is of Quaternary age. The two groups of rocks at Crommyonia are chemically distinct. Both groups contain multiple generations of plagioclase. Both have εNd (−8.0 to −10.6) that is much more negative than any other rocks in the South Aegean arc and model ages that are similar to those for many Miocene extensional granites of the Cyclades. The model ages are interpreted to reflect a mid-Proterozoic mantle event recognized elsewhere in the Hellenides. The Crommyonia dacitic magmas represent the first stages of melting of deep lithosphere as a result of both subduction-related hydrous fluids and extensional decompression. Plagioclase compositions suggest important magma evolution in a base-of-crust magma chamber, where the strong crustal Nd isotope signature was acquired. With time, asthenospheric sources that upwelled as a result of extension played an increasingly important role in determining the isotopic characteristics of the arc volcanism.

The Kruuse Fjord Gabbro Complex is a composite intrusion of layered gabbro and troctolite with subordinate ultramafic rocks and minor trondhjemitic bodies. It was emplaced into Archaean continental crust of East Greenland during early Tertiary rifting of Greenland from Eurasia. The work to date has identified an outer gabbro series and an inner troctolite series, and these are separated by a narrow zone of trondhjemitic intrusions. In the southeast, the partially crystallized cumulates of the gabbro series were intruded by a lenticular, ultramafic pluton 800 m in thickness. Volumetrically minor, syenite–trachyandesite net-veined dykes and later, diabase dykes cross-cut the plutonic rocks. Structural and topographic features suggest that the layered rocks were affected by synmagmatic subsidence and deformation but not by monoclinal coastal flexure.

The gabbro series is composed of a marginal gabbro unit, about 20 m wide, bordering more than a 2 km thickness of layered olivine and magnetite gabbro cumulates. The marginal gabbro is interpreted to be chilled magma. The layered cumulates are the product of repeated injections of magma that fractionated in an open-system magma chamber. Anorthositic and troctolitic layers in the lower part of the sequence may represent inputs of magma and suggest that the order of cumulus mineral crystallization was (1) plagioclase (An39–85), (2) olivine (Fo46–82), (3) augite (Wo28–47En39–58Fs8–18 ) and (4) magnetite. The disappearance of cumulus magnetite and a reversal in mineral compositions at 1.5 km from the base of the succession suggests a major input of magma occurred at this height. In the troctolite series, the composition of cumulus minerals, mineral crystallization sequence and style of emplacement are similar to those in the gabbro series. The ultramafic pluton is composed of coarse-grained wehrlite, olivine melagabbro and troctolite that were formed by at least three injections of magma. The typical mineral crystallization sequence was (1) cumulus chromite and olivine (Fo84–88); (2) poikilitic chrome diopside (Wo29–51En43–63Fs3–13 ); and (3) intercumulus plagioclase (An75–90), phlogopite, apatite and localized disseminated sulphides containing Au and platinum-group elements.

Comparison of crystallization sequences and the major and trace element compositions of clinopyroxene suggests that the gabbroic and troctolitic rocks formed from a magma represented by the chilled marginal gabbro, a tholeiitic basalt magma similar to E-MORB, whereas the ultramafic rocks formed from a magma that was relatively enriched in incompatible trace elements and volatiles. The association of these two magma types is an example of bimodal mafic–ultramafic magmatism in a rifting environment.

The Tokat Complex is a strongly deformed tectono-sedimentary mixture of low-grade metamorphic rocks with abundant recrystallized limestone and relatively rare serpentinite and radiolarian chert in blocks of variable size. Samples from the radiolarian chert blocks, found in highly crushed zones, each of which corresponds to a thrust sheet within an imbricate thrust zone, have yielded a Tithonian fossil assemblage. They are interpreted as tectonic inclusions emplaced within the Tokat Complex after its main post-early Permian–pre-Liassic metamorphism, and were derived from the rifting and opening of a Neotethyan ocean. The presence of Tithonian blocks within low-grade metamorphic rocks of the Tokat Complex shows that Tethys ocean was in existence in this region by latest Jurassic time. We also suggest that the presence of ophiolitic slices imbricated with the Pontide basement, Tokat Complex, explains the swarm of North Anatolian Fault Zone (NAFZ) splays in this region where the NAFZ likely followed a major pre-existing crustal weakness.

Compositional zoning and dissolution in cement is a direct response to the fluctuation of pore water chemistry, the variation of which during burial can be controlled by many factors, including the interaction between pore water and rock-forming minerals and the mixing of fluids from different origins. This paper suggests that tectonic activity can, by altering the hydraulic gradient, also influence pore water chemistry and lead to dissolution of cement, made clear by zoning within siderite crystals. Three different stages of siderite cement have been described from the Tirrawarra Sandstone in the Moorari and Fly Lake fields of the southern Cooper Basin, here referred to as S1 (early), S2 (middle), and S3 (late). Ragged dissolution surfaces separate the main phases, occurring after precipitation of S1 and S2 with incipient dissolution suggested within S2. Back-scattered electron (BSE) images and electron microprobe analyses clearly differentiate each main phase of siderite. S1 is a homogeneous, iron-rich siderite whereas S2 displays patchy compositional zoning associated with several minor dissolution stages, and S3 commences with even compositional banding and grades into a thick homogeneous phase in the terms of composition.

Isotope analyses and fluid inclusion studies indicate that S1 formed at a temperature around 30 °C, S2 precipitated at a minimum temperature of 68 °C, and S3 formed around 102 °C. The heterogeneous, pitted and zoned S2 is thought to have formed during a time of active tectonism in the Cooper Basin, whereas the evenly banded nature of S3 suggests that it precipitated during a quiet tectonic period when pore waters largely remained relatively constant. It appears that siderite cements in the Tirrawarra Sandstone record tectonic activity in the form of irregular growth and dissolution highlighted by compositional zoning with stages of strong dissolution recording particularly active times when pore waters changed composition dramatically. Some zoning could be related in part to tectonic pulses. The temperature recorded by each of the siderite stages allows their precipitation to be tied to a burial history curve, and by making some simple assumptions about that history, the timing of cementation can be estimated. This can be an additional tool for calibrating the thermal history of an area.

Gondwanan Neoproterozoic tectonothermal events (Pan-African and Brasiliano) are represented in northern mainland of Nova Scotia by volcanic and sedimentary rocks assigned to the Jeffers and Georgeville groups and by gabbroic to granitoid plutons. These rocks comprise part of Avalonia, an exotic terrane in the Appalachian orogen that was deposited in an arc-related environment along the periphery of Gondwana prior to accretion to Laurentia. Lavas sampled in the basal units of the Jeffers and Georgeville groups yielded slightly discordant U–Pb zircon and monazite data that fall on chords with upper intercept ages of 628 Ma and 617.7±1.6 Ma, respectively. Syntectonic to late syntectonic plutons intruded into these groups yielded U–Pb zircon ages of 606.6±1.6 Ma and 603+9−5 Ma. The former intrusion also yielded a concordant titanite age of 607±3 Ma. When combined with previously published ages, these data indicate that the back-arc deposition recorded in these groups lasted 10–15 million years (628–613 Ma) and was closely followed by c. 613–595 Ma metamorphism, intrusion and heterogeneous strike-slip related deformation. Assuming no significant shuffling of fault blocks, the relative locations of the Cobequid–Antigonish back-arc basin and the southern Cape Breton Island volcanic arc are consistent with their genesis above a north-west-dipping subduction zone. The age range of arc-related magmatism in Nova Scotia is similar to that of Avalonian rocks in southeastern Newfoundland and Britain, lending support to hypotheses of Neoproterozoic linkages.