The Lower Palaeozoic Bonney Pluton is a regionally extensive coarse-grained, variably megacrystic, monzodioritic to granitic body that crops out over 1000 km2 in South Victoria Land. It intruded upper amphibolite facies Koettlitz Group metasediments and interlayered orthogneisses. Magmatic fabrics are developed in the centre of the pluton by flow alignment of K-feldspars before the majority of phases had crystallized, whereas solid-state fabrics developed in the pluton margins by ductile–plastic deformation. Structures developed in the host-rocks vary around this elongate northwest–southeast-trending pluton. Upright, tight northwest–southeast-trending macroscopic folds are developed at the sides of the pluton, with axis-parallel stretching lineations and boudinage indicating strong northwest–southeast extension. Broad warps of tight macroscopic folds, and mesoscopic refolded folds, sheath folds and complicated interference patterns characterize areas at the ends of the pluton. Emplacement of the pluton involved radial expansion in a regional northeast–southwest compression, and growth predominantly in the northwest–southeast direction. Superposition of the radial expansion and regional compression resulted in an inhomogeneous strain field at a regional scale, with coaxial strain at the sides of the pluton and non-coaxial strain at the ends. Upright folds developed at the pluton's sides, and became tighter with continued coaxial deformation. Non-coaxial structures developed at the ends of the pluton and were pushed aside by the growing pluton into areas of coaxial deformation, resulting in complex folding, re-folding and sheath folds. Metamorphism of the host-rocks and migmatite development was more intense at the sides of the pluton than near the ends, possibly due to different P-T-t paths of host-rocks around syntectonic plutons.

The emplacement of the Older Ryoke granitoids took place in the Mid-Cretaceous Period in the outermost side of the Inner Zone of southwest Japan, which was located at the eastern margin of the Eurasian Continent before the opening of the Japan Sea. The Ryoke Belt constitutes a long segment of the Cretaceous to Palaeogene felsic magmatic belt of Pacific Asia. The Older Ryoke granitoids represent its initial magmatism, related to the subduction of an oceanic plate underneath the Eurasian plate in that time. Their magmas were generated in the lower to middle crust beneath the Ryoke Belt in the subduction regime. They were emplaced during the Ryoke regional metamorphism and converted to orthogneisses.

General agreement exists that the position of the base of the Cambrian (Precambrian–Cambrian boundary) should coincide with a biostratigraphic marker that can be widely traced and is linked to the evolution of the small shelly fauna. On the Siberian platform the presence of distinct facies during the Vendian–Cambrian interval has made biostratigraphic correlation based on palaeontological data highly contentious. A solution to this problem appears to exist with the recognition of an almost uninterrupted profile in the Aldan–Uchur watershed where key sections expose the eastern and transitional facial region. On this basis we present a general biostratigraphic scheme for the Vendian–Cambrian across the southern Siberian platform that connects separate facies. Further correlation with key sections in northern Siberia leads to the recognition of three biostratigraphic zones for the Vendian–Cambrian interval. These are: Anabarites trisulcatus Zone; Purella antiqua Zone; Aldanocyathus sunnaginicus Zone. The abundance of Chinese-type small shelly fossils in the region of the eastern facies suggest correlation of the A. sunnaginicus Zone with the Siphogonuchites–Paragloborilus Zone of China, and the P. antiqua Zone with the Circotheca–Anabarites–Protohertzina Zone. In places, at the base of the Circotheca–Anabarites–Protohertzina Zone in China, analogies to the A. trisulcatus Zone can be identified. It is proposed that in Siberia the base of the A. sunnaginicus Zone (= base of Tommotian Stage) be taken as the base of the Cambrian. This would correspond with Marker B of the Meishucunian in China

Many seismic reflections from within sedimentary successions are thought to be generated along stratal surfaces because those surfaces are laterally continuous and have marked acoustic impedance contrasts. As stratal surfaces are isochronous, those reflections are then also taken as being chronostratigraphically significant. In contrast, seismic reflections are thought not to be generated along the boundaries of lithostratigraphic units because those boundaries are discontinuous and gradational. Nevertheless, synthetic seismic analysis shows that seismic reflections should in many circumstances be expected to follow lithostratigraphic unit boundaries, not stratal surfaces. As these lithostratigraphic unit boundaries will generally be diachronous, seismic reflections from within sedimentary successions should evidently not be treated as necessarily having chronostratigraphic significance.

Previously undescribed collections of ammonites from the Corsicana Formation (Maastrichtian), the highest unit of the Cretaceous present in northeast Texas, U.S.A., include Eubaculites carinatus (Morton, 1834), Nostoceras (Nostoceras) major sp. nov., Glyptoxoceras sp., and Jeletzkytes sp. nov., which are new records for the unit. Other ammonites are Sphenodiscus lobatus (Tuomey, 1854), S. pleurisepta (Conrad, 1857), Trachyscaphites yorkensis (Stephenson, 1941), Discoscaphites conradi (Morton, 1834) and Baculites columna (Morton, 1834). Elements of the fauna are present in the Escondido Formation in Trans-Pecos Texas and northern Mexico, the Prairie Bluff Chalk in Alabama and Mississippi, the Owl Creek Formation in Mississippi, Tennessee and Missouri, and the Severn Formation in Maryland. In the U.S. Western Interior they occur in the Hoploscaphites nicolleti Zone, in the Fox Hills Formation.

During the Eifelian and early Givetian, isolated mud mounds were established in a shallow basin, predominantly characterized by calcareous mudstone deposition, in the eastern Anti-Atlas of Morocco. The shapes, lithologies and faunas of these mounds stand in marked contrast with those of nearby contemporaneous, more widespread stromatoporoid/coral biostromes and small carbonate platforms adjacent to shallow shelves. With one exception, the mounds are totally exhumed, perfectly exposing their original morphologies. The smaller mounds are asymmetrical, with steeper northeastern and eastern (35–75°) than southwestern and western flanks (30–50°). The largest mound is almost circular and symmetrical, with scattered stromatoporoids, tabulate and rugose corals that do not form a rigid framework. Frame-builders are much rarer or absent in the smaller mounds. The nature and geographical distribution of the mounds reflects a bathymetric gradient, indicating that they formed on low-angle ramps which sloped gently into a shallow basin. A large reef mound was constructed at moderate depth, while small mud mounds accumulated in deeper water. Decrease of frame-builders and increase in pelagic organisms in the latter document the transition to a pelagic platform with reduced sedimentation at a short distance from the deepest mound.

The late Precambrian–early Palaeozoic Monian Supergroup of the Mona Complex is a thick sequence of flysch-type sediments and metavolcanic rocks which were deposited during the late Precambrian–early Palaeozoic and deformed during the late Precambrian and Caledonian (Ordovician/Silurian) orogenies. The Monian Supergroup includes tectonically emplaced, geographically separated outcrops of metabasalt/andesite, gabbro and serpentinized ultramafic rocks all of ophiolite affinity. The major units of the Mona Complex are separated by important faults/fault zones which may represent terrane boundaries. New chemical analyses, together with existing ones, show that the metabasalts and meta-andesites from the older New Harbour Group of north Anglesey have characteristics of suprasubduction zone arc eruptives whereas the metabasalts from the younger Gwna Group of south Anglesey and Lleyn have MORB geochemistry. It is suggested that these volcanic rocks were produced during the late Precambrian–early Palaeozoic development of the lapetus Ocean and emplaced as separate terranes during its closure.

Twenty-five Ordovician K-bentonite samples ranging in age from Llanvirn to Ashgill and representing both sides of the lapetus suture were analysed by INAA and XRF and compared on magmatic and tectonic discrimination diagrams. The proportional distribution of Nb, Y, Ti, Zr, Hf, Ta, Th and REE indicates that source volcanics were erupted in a setting that changed from subduction-related in the Llanvirn/Llandeilo to marginal basin extensional volcanism in the Caradoc/Ashgill. Welsh K-bentonites appear to be derived from volcanoes within the Welsh Basin, but K-bentonites from the Southern Uplands to not have characteristics consistent with a fore-arc setting, further suggesting a source related to ensialic marginal basin extensional volcanism.

Detailed mapping of the Precambrian rocks of the Llangynog Inlier, made possible by a series of new exposures, has allowed the establishment for the first time of the 1100 m thick succession within the Precambrian rocks of the area. All boundaries of the Precambrian rocks with younger strata in the area are either faults or unconformities. Some 350–400 m of rhyolitic lavas form the oldest rocks seen in the area; they are extensively silicified and devitrified and show little of their original texture, although flow-banding is visible in some outcrops and the presence of perlitic and snowflake textures imply that originally they were glassy in part. These lavas are succeeded by a varied succession dominated by volcaniclastic siltstones showing evidence of shallow water deposition and containing medusoids and trace fossils of Ediacaran age. Interbedded in the sediments are basaltic lavas, autobreccias and rare hyaloclastites displaying textural features characteristic of submarine eruption, and rhyolitic pumiceous and shardic ash-flow tuffs. The name Coomb Volcanic Formation is proposed for this succession, within which are recognized two members, a lower Castell Cogan Rhyolite Member succeeded by the Coed Cochion Volcaniclastic Member. In association are varied intrusions, comprising both dolerites and dacites. A palaeoenvironmental model, built on evidence of petrography, palaeontology and sedimentology is that of shallow water to emergent volcanic islands.

Investigations into the micromorphology of the Pwll Du Red Beds in Gower, South Wales, have revealed pedo-features in the form of compound void coatings. Overlying marine deposits dated to the Ipswichian (Oxygen Isotope Substage 5e), the Red Beds are interpreted as the product of sedimentation and pedogenesis during Early Devensian time.

The groundmass of andesitic dykes at Sezaki, southwest Japan, has trachytic texture and contains microscopic shear zones. The shear zones comprise a conjugate pair formed by flattening of the solidifying dyke rock, probably caused by the magma pressure of the still molten part of the dyke. This pressure shortened the solidifying rock perpendicular to the dyke margins and caused it to extrude parallel to the magma flow direction. The groundmass shears indicate that locally the magma flowed 60° upward in the dykes. It is concluded that while groundmass shears are a useful indicator of flow direction in dykes, phenocryst alignment in dykes is strongly influenced by magma-pressure flattening and thus may be a poor indicator of flow direction