An early study of part of the Zagros mountains of south-western Iran put forward evidence for extensive overthrusting and nappe formation. A simplified interpretation of the stratigraphy now obviates the necessity for such tectonic complications.

The north-eastern limit of Zagros folding is marked by a long narrow belt of structural deformity and stratigraphic discontinuity known as the Crush Zone, which includes basic intrusive rocks contemporaneous with the late Tertiary foldings.

It is suggested that the Crush Zone is closely related to the Zagros orogeny, and geophysical evidence is used to speculate on a possible explanation. The general concept of the Crush Zone could prove to be of more widespread application.

The morphology, origin, and orientation patterns of distinctive types of sedimentary deformation structure are considered. The structures described are laminar folds, load marks and pouches, and convolute and corrugated lamination. A set of criteria obtained from detailed field analysis of the structures is put forward to indicate minor lateral translations of mobilised sediment.

Laminar folds occur in a laminated mudstone/siltstone lithology and are the result of predominantly lateral movements in response to an unstable palaeoslope. Laminar folds are metadepositional or postdepositional in origin. Orientation patterns are characteristically unimodal. Load marks and pouches are preserved in a banded siltstone/sandstone-mudstone lithology, and result from sediment movements which are either vertical, or vertical with some lateral translation. They are syndepositional or metadepositional in origin. Orientation patterns are predominantly unimodal but bimodal and random patterns are also present. Convolute and corrugated laminations are found in thin siltstone/sandstone beds and have developed through sediment movements which were almost exclusively vertical. The convolutions and corrugations are metadepositional in origin. The majority of orientation patterns are unimodal but there is an increase in the number of random patterns.

The positioning of deformation units which show internal lateral translation in a broader stratigraphical and geographical context, suggests there may be a regional palaeoslope control on the lateral movement of mobilised sediment.

The Blue Ridge thrust sheet is one of the principal thrust masses of metamorphic rocks in the southern Appalachians. A broad zone of sheared and retrogressively metamorphosed rocks near the sole of the thrust sheet around the Grandfather Mountain window displays numerous small tight or isoclinal folds having axes subparallel to an intense penetrative cataclastic a lineation and axial planes parallel to foliation in the thrust sheet. These folds seem to have formed by tightening, flattening, and passive rotation of earlier more open folds originally formed perpendicular to the direction of transport. The style and orientation of these folds closely resemble those of analogous structures in thrust masses of crystalline rocks in the Caledonian orogenic belt in Scotland and Norway, suggesting that the structures of both regions may have similar origins.

Naturally occurring linear features recognisable on aerial photographs may be related to bedrock tectonics. The identification and analysis of such linear elements, “megajoints”, reveals much information about the style and dimensions of subsurface geologic structures. Various terminologies, as applicable to air photo linears, are brought together and analysis is carried out in four test applications of Permyakov's original methods, the calculation of three-dimensional parameters from two-dimensional data. Some comparison is made with other techniques. Much of this linear vector analysis is carried out manually but possibilities exist for mechanical analysis and synthesis using certain up-to-date techniques. The methods described are applicable to many fields of academic and practical geology at or above the reconnaissance level.

The regional metamorphism of the Pakhals in the Yellandlapad area is synchronous with folding and is superimposed in the east by dislocation metamorphism due to overthrust. The development of ottrelite is contemporaneous with the overthrust. It is suggested that the conditions of growth of ottrelite may be distinctive from those of chloritoid.

New exposures of Upper Llandovery and Cambrian strata are described from the southern Malvern Hills. The rocks occur in a small faulted outlier between Midsummer and Hollybush Hills, within the main Pre-Cambrian outcrop. The Cambrian is represented by a thin succession of Malvern Quartzite and Hollybush Sandstone and is overlain by an Upper Llandovery limestone with a basal conglomerate containing rounded pebbles of Hollybush Sandstone. The new exposures weaken the case for a major post-Llandoverian fault at the western boundary of the local Pre-Cambrian outcrop, but provide further evidence of an important phase of pre-Llandoverian tectonism in the Malvern area.

Faunas of brachiopods, graptolites and conodonts from the Llandoverian limestone allow a correlation with the C5 substage of the shelly sequence, the griestoniensis graptolite zone and a position near the boundary of the celloni and amorphognathoides conodont zones.

Previous records are revised, and new identifications of reptiles are presented, based on a study of specimensin older collections. Amphibious marine forms of Alpine Trias and Muschelkalk affinities are recognized from the Midlands, albeit on tantalizingly incomplete material. Such evidence as the reptiles provide indicates an early to mid-Ladinian age for the upper part of the Building Stones, the boundary between Anisian and Ladinian here being taken to lie within the Middle Muschelkalk.

The field of composition and the geochemical trend of the lower portion of the stratiform Stillwater igneous complex correlate well with the field and trend for alpine-type ultrabasic masses in the nearby gneissic basement of the Beartooth Mountains. This is consistent with a derivation of some alpine-type masses by the tectonic disruption and metamorphism of stratiform complexes.

Core material from carbonate cemented sandstones of Eocene age from the Maracaibo Basin, Venezuela, exhibits evidence of post-burial sideritisation of calcite. the process being identical in its essentials with dolomitisation. and resulting in a marked increase in porosity and permeability of the cemented sandstones. As a result of this increase, sub-surface waters have been able to leach out much of the sideritc cement, and subsequent mechanical compaction of the sandstones has produced a characteristic “bead”-like arrangement of remnant sideritc granules around the sand grains. The whole process can be reconstructed from thin-sections, and these are used to illustrate the text.